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diff --git a/Master/texmf-dist/doc/luatex/base/luatexref-t.tex b/Master/texmf-dist/doc/luatex/base/luatexref-t.tex deleted file mode 100644 index a44af108036..00000000000 --- a/Master/texmf-dist/doc/luatex/base/luatexref-t.tex +++ /dev/null @@ -1,10872 +0,0 @@ -% engine=luatex language=uk -% $Id$ - -% TODO: fix layout of function legend descriptions -% check numbers -% check \luatex command - -%\nopdfcompression -%\loggingall -\environment luatexref-env -\logo[DFONT] {dfont} -\logo[CFF] {cff} -\logo[CMAP] {CMap} -\logo[PATGEN] {patgen} -\logo[MP] {MetaPost} -\logo[METAPOST]{MetaPost} -\logo[MPLIB] {MPlib} -\logo[COCO] {coco} -\logo[SUNOS] {SunOS} -\logo[BSD] {bsd} -\logo[SYSV] {sysv} -\logo[DPI] {dpi} - -\setvariables - [document] - [beta=0.80.0] - -\starttext - -\dontcomplain \nonknuthmode - -\setups[titlepage] - -\title{Contents} - -\placecontent[criterium=text,level=subsection] - -\chapter{Introduction} - -\startframedtext[framecolor=red,foregroundcolor=red,width=\hsize,style=\tfa] - -This book will eventually become the reference manual of \LUATEX. At the moment, -it simply reports the behavior of the executable matching the snapshot or beta -release date in the title page. - -\blank - -Features may come and go. The current version of \LUATEX\ is not meant for -production and users cannot depend on stability, nor on functionality staying the -same. - -\blank - -Nothing is considered stable just yet. This manual therefore simply reflects the -current state of the executable. {\bs Absolutely nothing\/} on the following -pages is set in stone. When the need arises, anything can (and will) be changed. - -\stopframedtext - -\blank[2*line] - -\LUATEX\ consists of a number of interrelated but (still) distinguishable parts: - -\startitemize[packed] -\item \PDFTEX\ version 1.40.9, converted to C (with patches from later releases). -\item The direction model and some other bits from \ALEPH\ RC4 converted to C. -\item \LUA\ 5.2.1 -\item dedicated \LUA\ libraries -\item various \TEX\ extensions -\item parts of \FONTFORGE\ 2008.11.17 -\item the \METAPOST\ library -\item newly written compiled source code to glue it all together -\stopitemize - -Neither \ALEPH's I/O translation processes, nor tcx files, nor \ENCTEX\ can be -used, these encoding|-|related functions are superseded by a \LUA|-|based -solution (reader callbacks). Also, some experimental \PDFTEX\ features are -removed. These can be implemented in \LUA\ instead. - -\chapter{Basic \TEX\ enhancements} - -\section{Introduction} - -From day one, \LUATEX\ has offered extra functionality when compared to the -superset of \PDFTEX\ and \ALEPH. That has not been limited to the possibility to -execute \LUA\ code via \type {\directlua}, but \LUATEX\ also adds functionality -via new \TEX-side primitives. - -However, starting with beta \type {0.39.0}, most of that functionality is hidden -by default. When \LUATEX\ 0.40.0 starts up in \quote {iniluatex} mode (\type -{luatex -ini}), it defines only the primitive commands known by \TEX82 and the -one extra command \type {\directlua}. - -As is fitting, a \LUA\ function has to be called to add the extra primitives to -the user environment. The simplest method to get access to all of the new -primitive commands is by adding this line to the format generation file: - -\starttyping -\directlua { tex.enableprimitives('',tex.extraprimitives()) } -\stoptyping - -But be aware that the curly braces may not have the proper \type{\catcode} -assigned to them at this early time (giving a 'Missing number' error), so it may -be needed to put these assignments - -\starttyping -\catcode `\{=1 -\catcode `\}=2 -\stoptyping - -before the above line. More fine-grained primitives control is possible, you can -look up the details in \in{section}[luaprimitives]. For simplicity's sake, this -manual assumes that you have executed the \type {\directlua} command as given -above. - -The startup behavior documented above is considered stable in the sense that -there will not be backward-incompatible changes any more. - -\section{Version information} - -There are three new primitives to test the version of \LUATEX: - -\starttabulate[|l|p|p|] -\NC \bf primitive \NC \bf explanation \NC \bf value \NC \NR -\NC \tex{luatexbanner} \NC the banner as reported on the command line \NC \luatexbanner \NC \NR -\NC \tex{luatexversion} \NC a combination of major and minor number \NC \the\luatexversion \NC \NR -\NC \tex{luatexrevision} \NC the revision number, the current value is \NC \luatexrevision \NC \NR -\stoptabulate - -The official \LUATEX\ version is defined as follows: - -\startitemize -\startitem - The major version is the integer result of \tex {luatexversion} divided by - 100. The primitive is an \quote {internal variable}, so you may need to prefix - its use with \type {\the} depending on the context. -\stopitem -\startitem - The minor version is the two-digit result of \tex {luatexversion} modulo 100. -\stopitem -\startitem - The revision is the given by \tex {luatexrevision}. This primitive expands to - a positive integer. -\stopitem -\startitem - The full version number consists of the major version, minor version and - revision, separated by dots. -\stopitem -\stopitemize - -\section{\UNICODE\ text support} - -Text input and output is now considered to be \UNICODE\ text, so input characters -can use the full range of \UNICODE\ ($2^{20}+2^{16}-1 = \hbox{0x10FFFF}$). - -Later chapters will talk of characters and glyphs. Although these are not -interchangeable, they are closely related. During typesetting, a character is -always converted to a suitable graphic representation of that character in a -specific font. However, while processing a list of to|-|be|-|typeset nodes, its -contents may still be seen as a character. Inside \LUATEX\ there is not yet a -clear separation between the two concepts. Until this is implemented, please do -not be too harsh on us if we make errors in the usage of the terms. - -A few primitives are affected by this, all in a similar fashion: each of them has -to accommodate for a larger range of acceptable numbers. For instance, \tex -{char} now accepts values between~0 and $1{,}114{,}111$. This should not be a -problem for well|-|behaved input files, but it could create incompatibilities for -input that would have generated an error when processed by older \TEX|-|based -engines. The affected commands with an altered initial (left of the equals sign) -or secondary (right of the equals sign) value are: \tex {char}, \tex {lccode}, -\tex {uccode}, \tex {catcode}, \tex {sfcode}, \tex {efcode}, \tex {lpcode}, \tex -{rpcode}, \tex {chardef}. - -As far as the core engine is concerned, all input and output to text files is -\UTF-8 encoded. Input files can be pre|-|processed using the \luatex {reader} -callback. This will be explained in a later chapter. - -Output in byte|-|sized chunks can be achieved by using characters just outside of -the valid \UNICODE\ range, starting at the value $1{,}114{,}112$ (0x110000). When -the time comes to print a character $c>=1{,}114{,}112$, \LUATEX\ will actually -print the single byte corresponding to $c$ minus 1{,}114{,}112. - -Output to the terminal uses \type {^^} notation for the lower control range -($c<32$), with the exception of \type {^^I}, \type {^^J} and \type {^^M}. These -are considered \quote {safe} and therefore printed as-is. - -Normalization of the \UNICODE\ input can be handled by a macro package during -callback processing (this will be explained in \in{section}[iocallback]). - -\section{Extended tables} - -All traditional \TEX\ and \ETEX\ registers can be 16-bit numbers as in \ALEPH. -The affected commands are: - -\startcolumns[n=4] -\starttyping -\count -\dimen -\skip -\muskip -\marks -\toks -\countdef -\dimendef -\skipdef -\muskipdef -\toksdef -\box -\unhbox -\unvbox -\copy -\unhcopy -\unvcopy -\wd -\ht -\dp -\setbox -\vsplit -\stoptyping -\stopcolumns - -The glyph properties (like \type {\efcode}) introduced in \PDFTEX\ that deal with -font expansion (hz) and character protruding are also 16-bit. Because font memory -management has been rewritten, these character properties are no longer shared -among fonts instances that originate from the same metric file. - -The behavior documented in the above section is considered stable in the sense -that there will not be backward-incompatible changes any more. - -\section{Attribute registers} - -Attributes are a completely new concept in \LUATEX. Syntactically, they behave a -lot like counters: attributes obey \TEX's nesting stack and can be used after -\tex {the} etc.\ just like the normal \tex {count} registers. - -\startsyntax -\attribute <16-bit number> <optional equals> <32-bit number>!crlf -\attributedef <csname> <optional equals> <16-bit number> -\stopsyntax - -Conceptually, an attribute is either \quote {set} or \quote {unset}. Unset -attributes have a special negative value to indicate that they are unset, that -value is the lowest legal value: \type {-"7FFFFFFF} in hexadecimal, a.k.a. -$-2147483647$ in decimal. It follows that the value \type {-"7FFFFFFF} cannot be -used as a legal attribute value, but you {\it can\/} assign \type {-"7FFFFFFF} to -\quote {unset} an attribute. All attributes start out in this \quote {unset} -state in \INITEX\ (prior to 0.37, there could not be valid negative attribute -values, and the \quote {unset} value was $-1$). - -Attributes can be used as extra counter values, but their usefulness comes mostly -from the fact that the numbers and values of all \quote {set} attributes are -attached to all nodes created in their scope. These can then be queried from any -\LUA\ code that deals with node processing. Further information about how to use -attributes for node list processing from \LUA\ is given in~\in {chapter}[nodes]. - -The behavior documented in the above subsection is considered stable in the sense -that there will not be backward-incompatible changes any more. - -\subsection{Box attributes} - -Nodes typically receive the list of attributes that is in effect when they are -created. This moment can be quite asynchronous. For example: in paragraph -building, the individual line boxes are created after the \tex {par} command has -been processed, so they will receive the list of attributes that is in effect -then, not the attributes that were in effect in, say, the first or third line of -the paragraph. - -Similar situations happen in \LUATEX\ regularly. A few of the more obvious -problematic cases are dealt with: the attributes for nodes that are created -during hyphenation, kerning and ligaturing borrow their attributes from their -surrounding glyphs, and it is possible to influence box attributes directly. - -When you assemble a box in a register, the attributes of the nodes contained in -the box are unchanged when such a box is placed, unboxed, or copied. In this -respect attributes act the same as characters that have been converted to -references to glyphs in fonts. For instance, when you use attributes to implement -color support, each node carries information about its eventual color. In that -case, unless you implement mechanisms that deal with it, applying a color to -already boxed material will have no effect. Keep in mind that this -incompatibility is mostly due to the fact that separate specials and literals are -a more unnatural approach to colors than attributes. - -It is possible to fine-tune the list of attributes that are applied to a \type -{hbox}, \type {vbox} or \type {vtop} by the use of the keyword \type {attr}. An -example: - -\starttyping -\attribute2=5 -\setbox0=\hbox {Hello} -\setbox2=\hbox attr1=12 attr2=-"7FFFFFFF{Hello} -\stoptyping - -This will set the attribute list of box~2 to $1=12$, and the attributes of box~0 -will be $2=5$. As you can see, assigning the maximum negative value causes an -attribute to be ignored. - -The \type {attr} keyword(s) should come before a \type {to} or \type {spread}, if -that is also specified. - -\section{\LUA\ related primitives} - -In order to merge \LUA\ code with \TEX\ input, a few new primitives are needed. - -\subsection{\tex{directlua}} - -The primitive \tex {directlua} is used to execute \LUA\ code immediately. The -syntax is - -\startsyntax -\directlua <general text>!crlf -\directlua name <general text> <general text>!crlf -\directlua <16-bit number> <general text> -\stopsyntax - -The last \syntax {<general text>} is expanded fully, and then fed into the \LUA\ -interpreter. After reading and expansion has been applied to the \syntax -{<general text>}, the resulting token list is converted to a string as if it was -displayed using \type {\the\toks}. On the \LUA\ side, each \type {\directlua} -block is treated as a separate chunk. In such a chunk you can use the \type -{local} directive to keep your variables from interfering with those used by the -macro package. - -The conversion to and from a token list means that you normally can not use \LUA\ -line comments (starting with \type {--}) within the argument. As there typically -will be only one \quote {line} the first line comment will run on until the end -of the input. You will either need to use \TEX|-|style line comments (starting -with \%), or change the \TEX\ category codes locally. Another possibility is to -say: - -\starttyping -\begingroup -\endlinechar=10 -\directlua ... -\endgroup -\stoptyping - -Then \LUA\ line comments can be used, since \TEX\ does not replace line endings -with spaces. - -The \syntax {name <general text>} specifies the name of the \LUA\ chunk, mainly -shown in the stack backtrace of error messages created by \LUA\ code. The \syntax -{<general text>} is expanded fully, thus macros can be used to generate the chunk -name, i.e. - -\starttyping -\directlua name{\jobname:\the\inputlineno} ... -\stoptyping - -to include the name of the input file as well as the input line into the chunk -name. - -Likewise, the \syntax {<16-bit number>} designates a name of a \LUA\ chunk, but -in this case the name will be taken from the \type {lua.name} array (see the -documentation of the \type {lua} table further in this manual). This syntax is -new in version 0.36.0. - -The chunk name should not start with a \type {@}, or it will be displayed as a -file name (this is a quirk in the current \LUA\ implementation). - -The \tex {directlua} command is expandable. Since it passes \LUA\ code to the -\LUA\ interpreter its expansion from the \TEX\ viewpoint is usually empty. -However, there are some \LUA\ functions that produce material to be read by \TEX, -the so called print functions. The most simple use of these is \type -{tex.print(<string> s)}. The characters of the string \type {s} will be placed on -the \TEX\ input buffer, that is, \quote {before \TeX's eyes} to be read by \TEX\ -immediately. For example: - -\startbuffer -\count10=20 -a\directlua{tex.print(tex.count[10]+5)}b -\stopbuffer - -\typebuffer - -expands to - -\getbuffer - -Here is another example: - -\startbuffer -$\pi = \directlua{tex.print(math.pi)}$ -\stopbuffer - -\typebuffer - -will result in - -\getbuffer - -Note that the expansion of \tex {directlua} is a sequence of characters, not of -tokens, contrary to all \TEX\ commands. So formally speaking its expansion is -null, but it places material on a pseudo-file to be immediately read by \TEX, as -\ETEX's \tex {scantokens}. - -For a description of print functions look at \in{section~}[sec:luaprint]. - -Because the \syntax {<general text>} is a chunk, the normal \LUA\ error handling -is triggered if there is a problem in the included code. The \LUA\ error messages -should be clear enough, but the contextual information is still pretty bad. -Often, you will only see the line number of the right brace at the end of the -code. - -While on the subject of errors: some of the things you can do inside \LUA\ code -can break up \LUATEX\ pretty bad. If you are not careful while working with the -node list interface, you may even end up with assertion errors from within the -\TEX\ portion of the executable. - -The behavior documented in the above subsection is considered stable in the sense -that there will not be backward-incompatible changes any more. - -\subsection{\tex{luafunction}} - -The \type {\directlua} commands involves tokenization of its argument (after -picking up an optional name or number specification). The tokenlist is then -converted into a string and given to \LUA\ to turn into a function that is -called. The overhead is rather small but when you use this primitive hundreds or -thousands of times, it can become noticeable. For this reason there is a variant -call available: \type {\luafunction}. This command is used as follows: - -\starttyping -\directlua { - local t = lua.get_functions_table() - t[1] = function() tex.print("!") end - t[2] = function() tex.print("?") end -} - -\luafunction1 -\luafunction2 -\stoptyping - -Of course the functions can also be defined in a separate file. There is no limit -on the number of functions apart from normal \LUA\ limitations. Of course there -is the limitation of no arguments but that would involve parsing and thereby give -no gain. The function, when called in fact gets one argument, being the index, so -in: - -\starttyping -\directlua { - local t = lua.get_functions_table() - t[8] = function(slot) tex.print(slot) end -} -\stoptyping - -the number \type {8} gets typeset. - -\subsection{\tex{latelua}} - -\tex{latelua} stores \LUA\ code in a whatsit that will be processed -at the time of shipping out. Its intended use is a cross between -\tex{pdfliteral} and \tex{write}. -Within the \LUA\ code you can print \PDF\ -statements directly to the \PDF\ file via \type{pdf.print}, -or you can write to other output streams via \type{texio.write} -or simply using lua's I/O routines. - -\startsyntax -\latelua <general text>!crlf -\latelua name <general text> <general text>!crlf -\latelua <16-bit number> <general text> -\stopsyntax - -Expansion of macros etcetera in the final \type{<general text>} is delayed -until just before the whatsit is executed (like in \tex{write}). With -regard to PDF output stream \tex{latelua} behaves as \tex{pdfliteral page}. - -The \syntax{name <general text>} and \syntax{<16-bit number>} behave -in the same way as they do for \type{\directlua} - -\subsection{\tex{luaescapestring}} - -This primitive converts a \TEX\ token sequence so that it can be -safely used as the contents of a \LUA\ string: embedded backslashes, -double and single quotes, and newlines and carriage returns are -escaped. This is done by prepending an extra token consisting of a -backslash with category code~12, and for the line endings, -converting them to \type{n} and \type{r} respectively. The token -sequence is fully expanded. - -\startsyntax -\luaescapestring <general text> -\stopsyntax - -Most often, this command is not actually the best way to deal with the -differences between the \TEX\ and \LUA. In very short bits of \LUA\ -code it is often not needed, and for longer stretches of \LUA\ code it -is easier to keep the code in a separate file and load it using \LUA's -\type{dofile}: - -\starttyping -\directlua { dofile('mysetups.lua')} -\stoptyping - - -\section{New \ETEX\ primitives} - -\subsection{\tex{clearmarks}} - -This primitive clears a mark class completely, resetting all three -connected mark texts to empty. - -\startsyntax -\clearmarks <16-bit number> -\stopsyntax - -\subsection{\tex{noligs} and \tex{nokerns}} - -These primitives prohibit ligature and kerning insertion at the time -when the initial node list is built by \LUATEX's main control loop. -They are part of a temporary trick and will be removed in the near -future. For now, you need to enable these primitives when you want to -do node list processing of \quote{characters}, where \TEX's normal -processing would get in the way. - -\startsyntax -\noligs <integer>!crlf -\nokerns <integer> -\stopsyntax - -These primitives can now be implemented by overloading the ligature -building and kerning functions, i.e.\ by assigning dummy functions -to their associated callbacks. - -\subsection{\tex{formatname}} - -\tex{formatname}'s syntax is identical to \tex{jobname}. - -In \INITEX, the expansion is empty. Otherwise, the expansion is the -value that \tex{jobname} had during the \INITEX\ run that dumped the -currently loaded format. - -\subsection{\tex{scantextokens}} - -The syntax of \tex{scantextokens} is identical to \tex{scantokens}. -This primitive is a slightly adapted version of \ETEX's \tex{scantokens}. The -differences are: - -\startitemize -\item The last (and usually only) line does not have a - \tex{endlinechar} appended -\item \tex{scantextokens} never raises an EOF error, - and it does not execute \tex{everyeof} tokens. -\item The \quote{\unknown\ while end of file \unknown} error tests are not executed, allowing - the expansion to end on a different grouping level or while a - conditional is still incomplete. -\stopitemize - -\subsection {Verbose versions of single-character aligments commands (0.45)} - -\LUATEX\ defines two new primitives that have the same function as -\type{#} and \type{&} in aligments: - -\starttabulate[|l|l|l|l|] -\NC \bf primitive \NC \bf explanation \NC\NR -\NC \tex{alignmark} \NC Duplicates the functionality of \char`\#~% - inside alignment preambles\NC\NR -\NC \tex{aligntab} \NC Duplicates the functionality of \char`\&~% - inside alignments (and preambles)\NC\NR -\stoptabulate - - -\subsection{Catcode tables} - -Catcode tables are a new feature that allows you to switch to a -predefined catcode regime in a single statement. You can have a -practically unlimited number of different tables. - -The subsystem is backward compatible: if you never use the following -commands, your document will not notice any difference in behavior -compared to traditional \TEX. - -The contents of each catcode table is independent from any other -catcode tables, and their contents is stored and retrieved from the -format file. - -\subsubsection{\tex{catcodetable}} - -\startsyntax -\catcodetable <15-bit number> -\stopsyntax - -The primitive \tex{catcodetable} switches to a different catcode table. -Such a table has to be previously created using one of the two -primitives below, or it has to be zero. Table zero is initialized by -\INITEX. - -\subsubsection{\tex{initcatcodetable}} - -\startsyntax -\initcatcodetable <15-bit number> -\stopsyntax - -The primitive \tex{initcatcodetable} creates a new table with catcodes -identical to those defined by \INITEX: - -\starttabulate[|l|l|l|l|l|] -\NC~0\NC \tt\letterbackslash \NC \NC \tt escape \NC\NR -\NC~5\NC \tt\letterhat\letterhat M \NC return \NC \tt car{\_}ret \NC (this name may change) \NC\NR -\NC~9\NC \tt\letterhat\letterhat @ \NC null \NC \tt ignore \NC\NR -\NC10\NC \tt <space> \NC space \NC \tt spacer \NC\NR -\NC11\NC {\tt a} -- {\tt z} \NC \NC \tt letter \NC\NR -\NC11\NC {\tt A} -- {\tt Z} \NC \NC \tt letter \NC\NR -\NC12\NC everything else \NC \NC \tt other \NC\NR -\NC14\NC \tt\letterpercent \NC \NC \tt comment \NC\NR -\NC15\NC \tt\letterhat\letterhat ? \NC delete \NC \tt invalid{\_}char \NC\NR -\stoptabulate - -The new catcode table is allocated globally: it will not go away after -the current group has ended. If the supplied number is identical to -the currently active table, an error is raised. - -\subsubsection{\tex{savecatcodetable}} - -\startsyntax -\savecatcodetable <15-bit number> -\stopsyntax - -\tex{savecatcodetable} copies the current set of catcodes to a -new table with the requested number. The definitions in this new table -are all treated as if they were made in the outermost level. - -The new table is allocated globally: it will not go away after the -current group has ended. If the supplied number is the currently -active table, an error is raised. - -\subsection{\tex{suppressfontnotfounderror} (0.11)} - -\startsyntax -\suppressfontnotfounderror = 1 -\stopsyntax - -If this new integer parameter is non|-|zero, then \LUATEX\ will not -complain about font metrics that are not found. Instead it will -silently skip the font assignment, making the requested csname for the -font \tex{ifx} equal to \tex{nullfont}, so that it can be tested -against that without bothering the user. - -\subsection{\tex{suppresslongerror} (0.36)} - -\startsyntax -\suppresslongerror = 1 -\stopsyntax - -If this new integer parameter is non|-|zero, then \LUATEX\ will not -complain about \type{\par} commands encountered in contexts where -that is normally prohibited (most prominently in the arguments -of non-long macros). - -\subsection{\tex{suppressifcsnameerror} (0.36)} - -\startsyntax -\suppressifcsnameerror = 1 -\stopsyntax - -If this new integer parameter is non|-|zero, then \LUATEX\ will not -complain about non-expandable commands appearing in the middle of a -\type{\ifcsname} expansion. Instead, it will keep getting expanded -tokens from the input until it encounters an \type{\endcsname} -command. Use with care! This command is experimental: if the input -expansion is unbalanced wrt. \type{\csname} \ldots \type{\endcsname} -pairs, the \LUATEX\ process may hang indefinitely. - - -\subsection{\tex{suppressoutererror} (0.36)} - -\startsyntax -\suppressoutererror = 1 -\stopsyntax - -If this new integer parameter is non|-|zero, then \LUATEX\ will not -complain about \type{\outer} commands encountered in contexts where -that is normally prohibited. - -The addition of this command coincides with a change in the -\LUATEX\ engine: ever since the snapshot of 20060915, \type{\outer} -was simply ignored. That behavior has now reverted back to be -\TEX82-compatible by default. - - - -\subsection{\tex{suppressmathparerror} (0.80)} - -The following setting will permit \par tokens in a math formula: - -\startsyntax -\suppressmathparerror = 1 -\stopsyntax - -So, the next code is valid then: - -\starttyping -$ x + 1 = - -a $ -\stoptyping - - -\subsection{\tex{outputbox} (0.37)} - -\startsyntax -\outputbox = 65535 -\stopsyntax - -This new integer parameter allows you to alter the number of the box -that will be used to store the page sent to the output routine. Its default -value is 255, and the acceptable range is from 0 to 65535. - - -\subsection{Font syntax} - -\LUATEX\ will accept a braced argument as a font name: - -\starttyping -\font\myfont = {cmr10} -\stoptyping - -This allows for embedded spaces, without the need for double quotes. -Macro expansion takes place inside the argument. - -\subsection{File syntax (0.45)} - -\LUATEX\ will accept a braced argument as a file name: - -\starttyping -\input {plain} -\openin 0 {plain} -\stoptyping - -This allows for embedded spaces, without the need for double quotes. -Macro expansion takes place inside the argument. - -\subsection{Images and Forms} - -\LUATEX\ accepts optional dimension parameters for \type{\pdfrefximage} -and \type{\pdfrefxform} in the same format as for \type{\pdfximage}. -With images, these dimensions are then used -instead of the ones given to \type{\pdfximage}; -but the original dimensions are not overwritten, -so that a \type{\pdfrefximage} without dimensions still provides -the image with dimensions defined by \type{\pdfximage}. -These optional parameters are not implemented for \type{\pdfxform}. - -\starttyping -\pdfrefximage width 20mm height 10mm depth 5mm \pdflastximage -\pdfrefxform width 20mm height 10mm depth 5mm \pdflastxform -\stoptyping - -\section{Debugging} - -If \tex{tracingonline} is larger than~2, the node list display will -also print the node number of the nodes. - -\section{Global leaders} - -There is a new experimental primitive: \type{\gleaders} (a \LUATEX\ -extension, added in 0.43). This type of leaders is anchored to the -origin of the box to be shipped out. So they are like normal -\type{\leaders} in that they align nicely, except that the alignment -is based on the {\it largest\/} enclosing box instead of the -{\it smallest\/}. - - -\section{Expandable character codes (0.75)} - -The new expandable command \tex{Uchar} reads a number between~0 and -$1{,}114{,}111$ and expands to the associated Unicode character. - - -\chapter {\LUA\ general} - -\section[init]{Initialization} - -\subsection{\LUATEX\ as a \LUA\ interpreter} - -There are some situations that make \LUATEX\ behave like a standalone \LUA\ -interpreter: - -\startitemize[packed] -\item if a \type{--luaonly} option is given on the commandline, or -\item if the executable is named \type{texlua} (or \type{luatexlua}), or -\item if the only non|-|option argument (file) on the commandline has the extension - \type{lua} or \type{luc}. -\stopitemize - -In this mode, it will set \LUA's \type{arg[0]} to the found script -name, pushing preceding options in negative values and the rest of the -commandline in the positive values, just like the \LUA\ -interpreter. - -\LUATEX\ will exit immediately after executing the specified \LUA\ -script and is, in effect, a somewhat bulky standalone \LUA\ -interpreter with a bunch of extra preloaded libraries. - -\subsection{\LUATEX\ as a \LUA\ byte compiler} - -There are two situations that make \LUATEX\ behave like the \LUA\ -byte compiler: - -\startitemize[packed] -\item if a \type{--luaconly} option is given on the commandline, or -\item if the executable is named \type{texluac} -\stopitemize - -In this mode, \LUATEX\ is exactly like \type{luac} from the standalone -\LUA\ distribution, except that it does not have the \type{-l} switch, -and that it accepts (but ignores) the \type{--luaconly} switch. - -\subsection{Other commandline processing} - -When the \LUATEX\ executable starts, it looks for the \type{--lua} -commandline option. If there is no \type{--lua} option, the -commandline is interpreted in a similar fashion as in traditional -\PDFTEX\ and \ALEPH. - -The following command-line switches are understood. - -\starttabulate[|lT|p|] -\NC --fmt=FORMAT \NC load the format file FORMAT \NC\NR -\NC --lua=FILE \NC load and execute a \LUA\ initialization script\NC\NR -\NC --safer \NC disable easily exploitable \LUA\ commands \NC\NR -\NC --nosocket \NC disable the \LUA\ socket library \NC\NR -\NC --help \NC display help and exit \NC\NR -\NC --ini \NC be iniluatex, for dumping formats \NC\NR -\NC --interaction=STRING \NC set interaction mode (STRING=batchmode/nonstopmode/\crlf - scrollmode/errorstopmode) \NC \NR -\NC --halt-on-error \NC stop processing at the first error\NC \NR -\NC --kpathsea-debug=NUMBER \NC set path searching debugging flags according to - the bits of NUMBER \NC \NR -\NC --progname=STRING \NC set the program name to STRING \NC \NR -\NC --version \NC display version and exit \NC\NR -\NC --credits \NC display credits and exit \NC\NR -\NC --recorder \NC enable filename recorder \NC \NR -\NC --etex \NC ignored\NC \NR -\NC --output-comment=STRING \NC use STRING for DVI file comment instead of date - (no effect for PDF)\NC \NR -\NC --output-directory=DIR \NC use DIR as the directory to write files to \NC \NR -\NC --draftmode \NC switch on draft mode (generates no output PDF)\NC \NR -\NC --output-format=FORMAT \NC use FORMAT for job output; FORMAT is 'dvi' or 'pdf' \NC \NR -\NC --[no-]shell-escape \NC disable/enable \type{\write18{SHELL COMMAND}} \NC \NR -\NC --enable-write18 \NC enable \type{\write18{SHELL COMMAND}} \NC \NR -\NC --disable-write18 \NC disable \type{\write18{SHELL COMMAND}} \NC \NR -\NC --shell-restricted \NC restrict \type{\write18} to a list of commands - given in texmf.cnf \NC \NR -\NC --debug-format \NC enable format debugging \NC \NR -\NC --[no-]file-line-error \NC disable/enable file:line:error style messages \NC \NR -\NC --[no-]file-line-error-style \NC aliases of --[no-]file-line-error \NC \NR -\NC --jobname=STRING \NC set the job name to STRING \NC \NR -\NC --[no-]parse-first-line \NC disable/enable parsing of the first line of the - input file \NC \NR -\NC --translate-file= \NC ignored \NC \NR -\NC --default-translate-file= \NC ignored \NC \NR -\NC --8bit \NC ignored \NC \NR -\NC --[no-]mktex=FMT \NC disable/enable mktexFMT generation (FMT=tex/tfm)\NC \NR -\NC --synctex=NUMBER \NC enable synctex \NC \NR -\stoptabulate - -A note on the creation of the various temporary files and the \type{\jobname}. -The value to use for \type{\jobname} is decided as follows: - -\startitemize -\item If \type{--jobname} is given on the command line, its argument - will be the value for \tex{jobname}, without any changes. The - argument will not be used for actual input so it need not exist. - The \type{--jobname} switch only controls the \tex{jobname} setting. -\item Otherwise, \tex{jobname} will be the name of the first file that - is read from the file system, with any path components and the last - extension (the part following the last \type{.}) stripped off. -\item An exception to the previous point: if the command - line goes into interactive mode (by starting with a command) and - there are no files input via \type{\everyjob} either, then the - \tex{jobname} is set to \type{texput} as a last resort. -\stopitemize - -The file names for output files that are generated automatically are -created by attaching the proper extension (\type{.log}, \type{.pdf}, -etc.) to the found \tex{jobname}. These files are created in the -directory pointed to by \type{--output-directory}, or in the current -directory, if that switch is not present. - -\blank - -Without the \type{--lua} option, command line processing works like it does in -any other web2c-based typesetting engine, except that \LUATEX\ has a few extra -switches. - - -If the \type{--lua} option is present, \LUATEX\ will enter an alternative mode -of commandline processing in comparison to the standard web2c -programs. - -In this mode, a small series of actions is taken in order. First, -it will parse the commandline as usual, but it will only interpret -a small subset of the options immediately: \type{--safer}, \type{--nosocket}, -\type{--[no-]shell-escape}, \type{--enable-write18}, \type{--disable-write18}, -\type{--shell-restricted}, \type{--help}, \type{--version}, and \type{--credits}. - -Now it searches for the requested \LUA\ initialization script. If it -cannot be found using the actual name given on the commandline, a -second attempt is made by prepending the value of the environment -variable \type{LUATEXDIR}, if that variable is defined in the environment. - -Then it checks the various safety switches. You can use those to disable -some \LUA\ commands that can easily be abused by a malicious document. At -the moment, \type{--safer} \type{nil}s the following functions: - -\starttabulate[|l|l|] -\NC \bf library \NC \bf functions \NC \NR -\NC \tt os \NC \tt execute exec setenv rename remove tmpdir \NC \NR -\NC \tt io \NC \tt popen output tmpfile \NC \NR -\NC \tt lfs \NC \tt rmdir mkdir chdir lock touch \NC \NR -\stoptabulate - -Furthermore, it disables loading of compiled \LUA\ libraries (support -for these was added in 0.46.0), and it makes \lua{io.open()} fail on -files that are opened for anything besides reading. - -\type{--nosocket} makes the socket library unavailable, so that -\LUA\ cannot use networking. - -The switches \type{--[no-]shell-escape}, \type{--[enable|disable]-write18}, and -\type{--shell-restricted} have the same -effects as in \PDFTEX, and additionally make -\type{io.popen()}, \type{os.execute}, \type{os.exec} and \type{os.spawn} -adhere to the requested option. - -Next the initialization script is loaded and executed. From within the -script, the entire commandline is available in the \LUA\ table -\lua{arg}, beginning with \lua {arg[0]}, containing the name of the executable. - -Commandline processing happens very early on. So early, in fact, that -none of \TEX's initializations have taken place yet. For that reason, -the tables that deal with typesetting, like \luatex{tex}, \luatex{token}, -\luatex{node} and \luatex{pdf}, are off|-|limits during the execution -of the startup file (they are nilled). Special care is taken that \luatex{texio.write} and -\luatex{texio.write_nl} function properly, so that you can at least -report your actions to the log file when (and if) it eventually -becomes opened (note that \TEX\ does not even know its \tex{jobname} -yet at this point). See \in{chapter}[libraries] for more information -about the \LUATEX-specific \LUA\ extension tables. - - -Everything you do in the \LUA\ initialization script will remain -visible during the rest of the run, with the exception of the -aforementioned \luatex{tex}, \luatex{token}, \luatex{node} and -\luatex{pdf} tables: those will be initialized -to their documented state after the execution of the script. You -should not store anything in variables or within tables with these -four global names, as they will be overwritten completely. - -We recommend you use the startup file only for your own -\TEX|-|independent initializations (if you need any), to parse the -commandline, set values in the \luatex{texconfig} table, and register -the callbacks you need. - -\LUATEX\ allows some of the commandline options to be overridden -by reading values from the \luatex{texconfig} table at the end of -script execution (see the description of the \luatex{texconfig} table -later on in this document for more details on which ones exactly). - -Unless the \luatex{texconfig} table tells \LUATEX\ not to initialize -\KPATHSEA\ at all (set \luatex{texconfig.kpse_init} to \type{false} for that), -\LUATEX\ acts on some more commandline options after the -initialization script is finished: -in order to initialize the built|-|in \KPATHSEA\ library properly, -\LUATEX\ needs to know the correct program name to use, and for that it -needs to check \type{--progname}, or \type{--ini} and \type{--fmt}, if -\type{--progname} is missing. - - -\section{\LUA\ changes} - -{\bf NOTE:} \LUATEX\ 0.74.0 is the first version with Lua 5.2, and -this is used without any patches to the core, which has some side -effects. In particular, Lua's \type{tonumber()} may return values in -scientific notation, thereby confusing the \TEX\ end of things when it -is used as the right-hand side of an assignment to a \type{\dimen} -or \type{\count}. - -{\bf NOTE:} Also in \LUATEX\ 0.74.0 (this is a change in Lua 5.2), -loading dynamic Lua libraries will fail if there are two Lua libraries -loaded at the same time (which will typically happen on Win32, because -there is one Lua 5.2 inside luatex, and another will likely be linked -to the \type{dll} file of the module itself). We plan to fix that later -by switching \LUATEX\ itself to using de DLL version of Lua 5.2 inside -\LUATEX\ instead of including a static version in the binary. - -Starting from version 0.45, \LUATEX\ is able to use the kpathsea -library to find \type{require()}d modules. For this purpose, -\type{package.searchers[2]} is replaced by a different loader function, -that decides at runtime whether to use kpathsea or the built-in core -lua function. It uses \KPATHSEA\ when that is already initialized at -that point in time, otherwise it reverts to using the normal -\type{package.path} loader. - -Initialization of \KPATHSEA\ can happen either implicitly (when -\LUATEX\ starts up and the startup script has not set -\type{texconfig.kpse_init} to false), or explicitly by calling the -\LUA\ function \type{kpse.set_program_name()}. - -Starting from version 0.46.0 \LUATEX\ is -also able to use dynamically loadable \LUA\ libraries, unless -\type{--safer} was given as an option on the command line. - -For this purpose, \type{package.searchers[3]} is replaced by a different -loader function, that decides at runtime whether to use kpathsea or -the build-in core lua function. As in the previous paragraph, it uses -\KPATHSEA\ when that is already initialized at that point in time, -otherwise it reverts to using the normal \type{package.cpath} loader. - -This functionality required an extension to kpathsea: - -\startnarrower -There is a new kpathsea file format: \type{kpse_clua_format} that -searches for files with extension \type{.dll} and \type{.so}. The -\type{texmf.cnf} setting for this variable is \type{CLUAINPUTS}, and -by default it has this value: - -\starttyping -CLUAINPUTS=.:$SELFAUTOLOC/lib/{$progname,$engine,}/lua// -\stoptyping %$ - -This path is imperfect (it requires a TDS subtree below the binaries -directory), but the architecture has to be in the path somewhere, and -the currently simplest way to do that is to search below the binaries -directory only. - -One level up (a \type{lib} directory parallel to \type{bin}) would -have been nicer, but that is not doable because \TEXLIVE\ uses a -\type{bin/<arch>} structure. -\stopnarrower - -In keeping with the other \TEX-like programs in \TEXLIVE, the two -\LUA\ functions -\type{os.execute} and \type{io.popen} (as well as the two new functions \type{os.exec} -and \type{os.spawn} that are explained below) take the value of \type{shell_escape} -and/or \type{shell_escape_commands} in account. Whenever \LUATEX\ is run with the -assumed intention to typeset a document (and by that I mean that it is called as -\type{luatex}, as opposed to \type{texlua}, and that the commandline option -\type{--luaonly} was not given), it will only run the four functions above if the -matching texmf.cnf variable(s) or their \type{texconfig} (see~\in{section}[texconfig]) -counterparts allow execution of the requested system command. In \quote{script -interpreter} runs of \LUATEX, these settings have no effect, and all four functions -function as normal. This change is new in 0.37.0. - - - -The \lua{f:read("*line")} and \lua{f:lines()} functions from the io library have -been adjusted so that they are line|-|ending neutral: any of \type{LF}, \type -{CR} or \type{CR+LF} are acceptable line endings. - -\lua{luafilesystem} has been extended: there are two extra boolean functions -(\luatex{lfs.isdir(filename)} and \luatex{lfs.isfile(filename)}) and -one extra string field in its attributes table -(\type{permissions}). There is an additional function (added in 0.51) -\type{lfs.shortname()} which takes a file name and returns its short -name on WIN32 platforms. On other platforms, it just returns the given -argument. The file name is not tested for existence. Finally, for -non-WIN32 platforms only, there is the new function -\type{lfs.readlink()} (added in 0.51) that takes an existing symbolic -link as argument and returns its content. It returns an error on -WIN32. - -The \lua{string} library has an extra function: -\luatex{string.explode(s[,m])}. This function returns an array containing -the string argument \type{s} split into sub-strings based on the value -of the string argument \type{m}. The second argument is a string that -is either empty (this splits the string into characters), a single -character (this splits on each occurrence of that character, possibly -introducing empty strings), or a single character followed by the plus -sign \type{+} (this special version does not create empty -sub-strings). The default value for \type{m} is \quote{\type{ +}} (multiple -spaces). - -Note: \type{m} is not hidden by surrounding braces (as it would be if -this function was written in \TEX\ macros). - -The \lua{string} library also has six extra iterators that return strings -piecemeal: - -\startitemize -\item \luatex{string.utfvalues(s)} (returns an integer value in the -\UNICODE\ range) -\item \luatex{string.utfcharacters(s)} (returns a string with a single -\UTF-8 token in it) -\item \luatex{string.characters(s)} (a string containing one byte) -\item \luatex{string.characterpairs(s)} (two strings each containing one byte) will -produce an empty second string if the string length was odd. -\item \luatex{string.bytes(s)} (a single byte value) -\item \luatex{string.bytepairs(s)} (two byte values) Will produce nil instead of a -number as its second return value if the string length was odd. -\stopitemize - -The \luatex{string.characterpairs()} and \luatex{string.bytepairs()} -are useful especially in the conversion of UTF-16 encoded data into UTF-8. - - -Starting with \LUATEX\ 0.74, there is also a two-argument form of -\type{string.dump()}. The second argument is a boolean which, if true, -strips the symbols from the dumped data. This matches an extension -made in \type{luajit}. - -Note: The \lua{string} library functions \luatex{len}, \luatex{lower}, -\luatex{sub} etc. are not \UNICODE|-|aware. For strings in the UTF-8 -encoding, i.e., strings containing characters above code point 127, the -corresponding functions from the \lua{slnunicode} library can be used, -e.g., \luatex{unicode.utf8.len}, \luatex{unicode.utf8.lower} etc. The -exceptions are \luatex{unicode.utf8.find}, that always returns byte -positions in a string, and \luatex{unicode.utf8.match} and -\luatex{unicode.utf8.gmatch}. While the latter two functions in general -{\it are} \UNICODE|-|aware, they fall-back to non|-|\UNICODE|-|aware -behavior when using the empty capture \lua{()} (other captures work as -expected). For the interpretation of character classes in -\luatex{unicode.utf8} functions refer to the library sources at -\hyphenatedurl{http://luaforge.net/projects/sln}. The \lua{slnunicode} -library will be replaced by an internal \UNICODE\ library in a future -\LUATEX\ version. -\blank - -The \lua{os} library has a few extra functions and variables: - -\startitemize -\item \luatex{os.selfdir} is a variable that holds the directory path -of the actual executable. For example: {\tt \directlua{tex.sprint(os.selfdir)}} -(present since 0.27.0). - -\item \luatex{os.exec(commandline)} is a variation on \lua{os.execute}. - - The \type{commandline} can be either a single string or a single table. - - If the argument is a table: \LUATEX\ first checks if there is a value at - integer index zero. If there is, this is the command to be executed. Otherwise, - it will use the value at integer index one. (if neither are present, nothing - at all happens). - - The set of consecutive values starting at integer 1 in the table are - the arguments that are passed on to the command (the value at index 1 - becomes \type{arg[0]}). The command is searched for in the execution path, - so there is normally no need to pass on a fully qualified pathname. - - If the argument is a string, then it is automatically converted into - a table by splitting on whitespace. In this case, it is impossible - for the command and first argument to differ from each other. - - In the string argument format, whitespace can be protected by putting (part - of) an argument inside single or double quotes. One layer of quotes is - interpreted by \LUATEX, and all occurrences of \tex{"}, \tex{'} or - \type{\\} within the quoted text are un-escaped. In the table format, there - is no string handling taking place. - - This function normally does not return control back to the \LUA\ script: the - command will replace the current process. However, it will return the two values - \type{nil} and \type {'error'} if there was a problem while attempting to execute the command. - - On Windows, the current process is actually kept in memory until after the - execution of the command has finished. This prevents crashes in situations - where \TEXLUA\ scripts are run inside integrated \TEX\ environments. - - The original reason for this command is that it cleans out the current - process before starting the new one, making it especially useful for - use in \TEXLUA. - -\item \luatex{os.spawn(commandline)} is a returning version of \lua{os.exec}, - with otherwise identical calling conventions. - - If the command ran ok, then the return value is the exit status of the - command. Otherwise, it will return the two values \type{nil} and \type {'error'}. - -\item \luatex{os.setenv('key','value')} - This sets a variable in the environment. Passing \lua{nil} instead of a - value string will remove the variable. - -\item \luatex{os.env} - This is a hash table containing a dump of the variables and values - in the process environment at the start of the run. It is writeable, - but the actual environment is {\em not\/} updated automatically. - -\item \luatex{os.gettimeofday()} -Returns the current \quote {\UNIX\ time}, but as a float. This function is -not available on the \SUNOS\ platforms, so do not use this function -for portable documents. - -\item \luatex{os.times()} -Returns the current process times according to \ the \UNIX\ C library function -\quote {times}. This function is not available on the \MSWINDOWS\ -and \SUNOS\ platforms, so do not use this function for portable -documents. - -\item \luatex{os.tmpdir()} This will create a directory in the \quote {current -directory} with the name \type{luatex.XXXXXX} where the \type {X}-es are -replaced by a unique string. The function also returns this string, -so you can \type{lfs.chdir()} into it, or \type{nil} if it failed to -create the directory. The user is responsible for cleaning up at -the end of the run, it does not happen automatically. - -\item \luatex{os.type} -This is a string that gives a global indication of the class of operating -system. The possible values are currently \type{windows}, \type{unix}, and -\type{msdos} (you are unlikely to find this value \quote {in the wild}). - -\item \luatex{os.name} -This is a string that gives a more precise indication of the operating -system. These possible values are not yet fixed, and for \type{os.type} values -\type{windows} and \type{msdos}, the \type{os.name} values are simply -\type{windows} and \type{msdos} - -The list for the type \type{unix} is more precise: \type{linux}, -\type{freebsd}, \type{kfreebsd} (since 0.51), \type{cygwin} (since -0.53), \type{openbsd}, \type{solaris}, \type{sunos} (pre-solaris), -\type{hpux}, \type{irix}, \type{macosx}, \type{gnu} (hurd), \type{bsd} (unknown, but \BSD|-|like), -\type{sysv} (unknown, but \SYSV|-|like), \type{generic} (unknown). - -(\type{os.version} is planned as a future extension) - -\item \luatex{os.uname()} -This function returns a table with specific operating system -information acquired at runtime. The keys in the returned table are -all string valued, and their names are: \type{sysname}, \type{machine}, -\type{release}, \type{version}, and \type{nodename}. - - -\stopitemize - -In stock \LUA, many things depend on the current locale. In \LUATEX, we can't do -that, because it makes documents unportable. While \LUATEX\ is running if -forces the following locale settings: - -\starttyping -LC_CTYPE=C -LC_COLLATE=C -LC_NUMERIC=C -\stoptyping - -\section {\LUA\ modules} - -{\bf NOTE}: Starting with \LUATEX\ 0.74, the implied use of the -built-in Lua modules in this section is deprecated. If you want to use -one of these libraries, please start your source file with a -proper \type{require} line. In the near future, \LUATEX\ will switch -to loading these modules on demand. - -Some modules that are normally external to \LUA\ are statically linked -in with \LUATEX, because they offer useful functionality: - -\startitemize -\item \lua{slnunicode}, from the \type {Selene} libraries, \hyphenatedurl{http://luaforge.net/projects/sln}. (version 1.1) - -This library has been slightly extended so that the \type{unicode.utf8.*} -functions also accept the first 256 values of plane~18. This is the range \LUATEX\ -uses for raw binary output, as explained above. - -\item \lua{luazip}, from the kepler project, \hyphenatedurl{http://www.keplerproject.org/luazip/}. - (version 1.2.1, but patched for compilation with \LUA\ 5.2) -\item \lua{luafilesystem}, also from the kepler project, \hyphenatedurl{http://www.keplerproject.org/luafilesystem/}. - (version 1.5.0) -\item \lua{lpeg}, by Roberto Ierusalimschy, \hyphenatedurl{http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html}. (version 0.10.2) - -Note: \lua{lpeg} is not \UNICODE|-|aware, but interprets strings on a -byte|-|per|-|byte basis. This mainly means that \luatex{lpeg.S} cannot be -used with characters above code point 127, since those characters are -encoded using two bytes, and thus \luatex{lpeg.S} will look for one -of those two bytes when matching, not the combination of the two. - -The same is true for \luatex{lpeg.R}, although the latter will display -an error message if used with characters above code point 127: I.\,e.\ -\luatex{lpeg.R('aä')} results in the message \type{bad argument #1 to -'R' (range must have two characters)}, since to \lua{lpeg}, \type{ä} -is two 'characters' (bytes), so \type{aä} totals three. - -\item \lua{lzlib}, by Tiago Dionizio, \hyphenatedurl{http://luaforge.net/projects/lzlib/}. (version 0.2) -\item \lua{md5}, by Roberto Ierusalimschy \hyphenatedurl{http://www.inf.puc-rio.br/~roberto/md5/md5-5/md5.html}. - -\item \lua{luasocket}, by Diego Nehab -\hyphenatedurl{http://w3.impa.br/~diego/software/luasocket/} -(version 2.0.2). - -Note: the \type{.lua} support modules from \type{luasocket} are also -preloaded inside the executable, there are no external file dependencies. -\stopitemize - - -\chapter[libraries]{\LUATEX\ \LUA\ Libraries} - -{\bf NOTE}: Starting with \LUATEX\ 0.74, the implied use of the -built-in Lua modules \type{epdf}, \type{fontloader}, \type{mplib}, -and \type{pdfscanner} is deprecated. If you want to use these, please -start your source file with a proper \type{require} line. In the near -future, \LUATEX\ will switch to loading these modules on demand. - - -The interfacing between \TEX\ and \LUA\ is facilitated by a set of -library modules. The \LUA\ libraries in this chapter are all defined and -initialized by the \LUATEX\ executable. Together, they allow \LUA\ -scripts to query and change a number of \TEX's internal variables, run -various internal \TEX\ functions, and set up \LUATEX's hooks to execute -\LUA\ code. - -The following sections are in alphabetical order. - -\section{The \luatex{callback} library} - -This library has functions that register, find and list callbacks. - -A quick note on what callbacks are (thanks, Paul!): - -Callbacks are entry points to \LUATEX's internal operations, which can be -interspersed with additional \LUA\ code, and even replaced altogether. -In the first case, \TEX\ is simply augmented with new operations -(for instance, a manipulation of the nodes resulting from the paragraph -builder); in the second case, its hard-coded behavior (for instance, the -paragraph builder itself) is ignored and processing relies on user code only. - -More precisely, the code to be inserted at a given callback is a function -(an anonymous function or the name of a function variable); % Is this line useful? -it will receive the arguments associated with the callback, if any, and must -frequently return some other arguments for \TEX\ to resume its operations. - -The first task is registering a callback: - -\startfunctioncall -id, error = callback.register (<string> callback_name, <function> func) -id, error = callback.register (<string> callback_name, nil) -id, error = callback.register (<string> callback_name, false) -\stopfunctioncall - -where the \syntax{callback_name} is a predefined callback name, see -below. The function returns the internal \type{id} of the callback -or \type{nil}, if the callback could not be registered. In the latter -case, \type{error} contains an error message, otherwise it is -\type{nil}. - -\LUATEX\ internalizes the callback function in such a way that -it does not matter if you redefine a function accidentally. - -Callback assignments are always global. You can use the special value -\type {nil} instead of a function for clearing the callback. - -For some minor speed gain, you can assign the boolean \type{false} to -the non-file related callbacks, doing so will prevent \LUATEX\ from -executing whatever it would execute by default (when no callback -function is registered at all). Be warned: this may cause all sorts of -grief unless you know {\it exactly} what you are doing! This functionality -is present since version 0.38. - -Currently, callbacks are not dumped into the format file. - -\startfunctioncall -<table> info = callback.list() -\stopfunctioncall - -The keys in the table are the known callback names, the value is a -boolean where \type{true} means that the callback is currently set -(active). - -\startfunctioncall -<function> f = callback.find (callback_name) -\stopfunctioncall - -If the callback is not set, \luatex{callback.find} returns \type{nil}. - -\subsection{File discovery callbacks} - -The behavior documented in this subsection is considered stable in the -sense that there will not be backward-incompatible changes any more. - -\subsubsection{\luatex{find_read_file} and \luatex{find_write_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<number> id_number, <string> asked_name) -\stopfunctioncall - -Arguments: - -\startitemize - -\sym{id_number} - -This number is zero for the log or \tex{input} files. For \TEX's \tex{read} or -\tex{write} the number is incremented by one, so \tex{read0} becomes~1. - -\sym{asked_name} - -This is the user|-|supplied filename, as found by \tex{input}, \tex{openin} -or \tex{openout}. - -\stopitemize - -Return value: - -\startitemize - -\sym{actual_name} - -This is the filename used. For the very first file that is read in by -\TEX, you have to make sure you return an \type{actual_name} that has -an extension and that is suitable for use as \type{jobname}. If you -don't, you will have to manually fix the name of the log file and -output file after \LUATEX\ is finished, and an eventual format -filename will become mangled. That is because these file names depend -on the jobname. - -You have to return \type{nil} if the file cannot be found. - -\stopitemize - -\subsubsection{\luatex{find_font_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<string> asked_name) -\stopfunctioncall - -The \type{asked_name} is an \OTF\ or \TFM\ font metrics file. - -Return \type{nil} if the file cannot be found. - -\subsubsection{\luatex{find_output_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<string> asked_name) -\stopfunctioncall - -The \type{asked_name} is the \PDF\ or \DVI\ file for writing. - -\subsubsection{\luatex{find_format_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<string> asked_name) -\stopfunctioncall - -The \type{asked_name} is a format file for reading (the format file -for writing is always opened in the current directory). - -\subsubsection{\luatex{find_vf_file}} - -Like \luatex{find_font_file}, but for virtual fonts. This applies to -both \ALEPH's \OVF\ files and traditional Knuthian \VF\ files. - -\subsubsection{\luatex{find_map_file}} - -Like \luatex{find_font_file}, but for map files. - -\subsubsection{\luatex{find_enc_file}} - -Like \luatex{find_font_file}, but for enc files. - -\subsubsection{\luatex{find_sfd_file}} - -Like \luatex{find_font_file}, but for subfont definition files. - -\subsubsection{\luatex{find_pk_file}} - -Like \luatex{find_font_file}, but for pk bitmap files. The argument -\type{asked_name} is a bit special in this case. Its form is - -\starttyping -<base res>dpi/<fontname>.<actual res>pk -\stoptyping - -So you may be asked for \type{600dpi/manfnt.720pk}. It is up to you -to find a \quote{reasonable} bitmap file to go with that specification. - -\subsubsection{\luatex{find_data_file}} - -Like \luatex{find_font_file}, but for embedded files (\tex{pdfobj file '...'}). - -\subsubsection{\luatex{find_opentype_file}} - -Like \luatex{find_font_file}, but for \OPENTYPE\ font files. - -\subsubsection{\luatex{find_truetype_file} and \luatex{find_type1_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<string> asked_name) -\stopfunctioncall - -The \type{asked_name} is a font file. This callback is called while -\LUATEX\ is building its internal list of needed font files, so the -actual timing may surprise you. Your return value is later fed back -into the matching \luatex{read_file} callback. - -Strangely enough, \luatex{find_type1_file} is also used for \OPENTYPE\ -(\OTF) fonts. - -\subsubsection{\luatex{find_image_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<string> actual_name = function (<string> asked_name) -\stopfunctioncall - -The \type{asked_name} is an image file. Your return value is used to -open a file from the harddisk, so make sure you return something that -is considered the name of a valid file by your operating system. - -\subsection[iocallback]{File reading callbacks} - -The behavior documented in this subsection is considered stable in the -sense that there will not be backward-incompatible changes any more. - -\subsubsection{\luatex{open_read_file}} - -Your callback function should have the following conventions: - -\startfunctioncall -<table> env = function (<string> file_name) -\stopfunctioncall - -Argument: - -\startitemize - -\sym{file_name} - -The filename returned by a previous \luatex{find_read_file} or the return -value of \luatex{kpse.find_file()} if there was no such callback defined. - -\stopitemize - -Return value: - -\startitemize - -\sym{env} - -This is a table containing at least one required and one optional -callback function for this file. The required field is -\luatex{reader} and the associated function will be called once -for each new line to be read, the optional one is \luatex{close} -that will be called once when \LUATEX\ is done with the file. - -\LUATEX\ never looks at the rest of the table, so you can use it to -store your private per|-|file data. Both the callback functions will -receive the table as their only argument. - -\stopitemize - -\subsubsubsection{\luatex{reader}} - -\LUATEX\ will run this function whenever it needs a new input line -from the file. - -\startfunctioncall -function(<table> env) - return <string> line -end -\stopfunctioncall - -Your function should return either a string or \type{nil}. The value \type{nil} -signals that the end of file has occurred, and will make \TEX\ call -the optional \luatex{close} function next. - -\subsubsubsection{\luatex{close}} - -\LUATEX\ will run this optional function when it decides to close the file. - -\startfunctioncall -function(<table> env) -end -\stopfunctioncall - -Your function should not return any value. - -\subsubsection{General file readers} - -There is a set of callbacks for the loading of binary data -files. These all use the same interface: - -\startfunctioncall -function(<string> name) - return <boolean> success, <string> data, <number> data_size -end -\stopfunctioncall - -The \type{name} will normally be a full path name as it is returned by -either one of the file discovery callbacks or the internal version of -\luatex{kpse.find_file()}. - -\startitemize - -\sym{success} - -Return \type{false} when a fatal error occurred (e.\,g.\ when the file cannot be -found, after all). - -\sym{data} - -The bytes comprising the file. - -\sym{data_size} - -The length of the \type{data}, in bytes. - -\stopitemize - -Return an empty string and zero if the file was found but there was a -reading problem. - -The list of functions is as follows: - -\starttabulate[|l|p|] -\NC \luatex{read_font_file} \NC ofm or tfm files \NC\NR -\NC \luatex{read_vf_file} \NC virtual fonts \NC\NR -\NC \luatex{read_map_file} \NC map files \NC\NR -\NC \luatex{read_enc_file} \NC encoding files \NC\NR -\NC \luatex{read_sfd_file} \NC subfont definition files \NC\NR -\NC \luatex{read_pk_file} \NC pk bitmap files \NC\NR -\NC \luatex{read_data_file} \NC embedded files (\tex{pdfobj file ...}) \NC\NR -\NC \luatex{read_truetype_file} \NC \TRUETYPE\ font files \NC\NR -\NC \luatex{read_type1_file} \NC \TYPEONE\ font files \NC\NR -\NC \luatex{read_opentype_file} \NC \OPENTYPE\ font files \NC\NR -\stoptabulate - -\subsection{Data processing callbacks} - -\subsubsection{\luatex{process_input_buffer}} - - -This callback allows you to change the contents of the line input -buffer just before \LUATEX\ actually starts looking at it. - -\startfunctioncall -function(<string> buffer) - return <string> adjusted_buffer -end -\stopfunctioncall - -If you return \type{nil}, \LUATEX\ will pretend like your callback -never happened. You can gain a small amount of processing time from -that. - -This callback does not replace any internal code. - -\subsubsection{\luatex{process_output_buffer} (0.43)} - -This callback allows you to change the contents of the line output -buffer just before \LUATEX\ actually starts writing it to a file as the -result of a \tex{write} command. It is only called for output to an -actual file (that is, excluding the log, the terminal, and \tex{write18} -calls). - -\startfunctioncall -function(<string> buffer) - return <string> adjusted_buffer -end -\stopfunctioncall - -If you return \type{nil}, \LUATEX\ will pretend like your callback -never happened. You can gain a small amount of processing time from -that. - -This callback does not replace any internal code. - - -\subsubsection{\luatex{process_jobname} (0.71)} - -This callback allows you to change the jobname given by \type{\jobname} -in \TEX\ and \type{tex.jobname} in Lua. It does not affect the internal -job name or the name of the output or log files. - -\startfunctioncall -function(<string> jobname) - return <string> adjusted_jobname -end -\stopfunctioncall - -The only argument is the actual job name; you should not use -\type{tex.jobname} inside this function or infinite recursion may occur. -If you return \type{nil}, \LUATEX\ will pretend your callback never -happened. - -This callback does not replace any internal code. - - -\subsubsection{\luatex{token_filter}} - -This callback allows you to replace the way \LUATEX\ fetches -lexical tokens. - -\startfunctioncall -function() - return <table> token -end -\stopfunctioncall - -The calling convention for this callback is a bit more complicated than -for most other callbacks. The function should either return a \LUA\ -table representing a valid to|-|be|-|processed token or tokenlist, or -something else like \type{nil} or an empty table. - -If your \LUA\ function does not return a table representing a valid -token, it will be immediately called again, until it eventually does -return a useful token or tokenlist (or until you reset the callback -value to nil). See the description of \luatex{token} for some -handy functions to be used in conjunction with this callback. - -If your function returns a single usable token, then that token will -be processed by \LUATEX\ immediately. If the function returns a token -list (a table consisting of a list of consecutive token tables), then -that list will be pushed to the input stack at a completely new token -list level, with its token type set to \quote{inserted}. In either case, -the returned token(s) will not be fed back into the callback function. - -Setting this callback to \type{false} has no effect (because otherwise -nothing would happen, forever). - -\subsection{Node list processing callbacks} - -The description of nodes and node lists is in~\in{chapter}[nodes]. - -\subsubsection{\luatex{buildpage_filter}} - -This callback is called whenever \LUATEX\ is ready to move stuff to -the main vertical list. You can use this callback to do specialized -manipulation of the page building stage like imposition or column -balancing. - -\startfunctioncall -function(<string> extrainfo) -end -\stopfunctioncall - -The string \type{extrainfo} gives some additional information about -what \TEX's state is with respect to the \quote{current page}. The possible -values are: - -\starttabulate[|lT|p|] -\NC \ssbf value \NC \bf explanation \NC\NR -\NC alignment \NC a (partial) alignment is being added \NC\NR -\NC after_output \NC an output routine has just finished \NC\NR -\NC box \NC a typeset box is being added \NC\NR -%\NC pre_box \NC interline material is being added \NC\NR -%\NC adjust \NC \tex{vadjust} material is being added \NC\NR -\NC new_graf \NC the beginning of a new paragraph \NC\NR -\NC vmode_par \NC \tex{par} was found in vertical mode \NC\NR -\NC hmode_par \NC \tex{par} was found in horizontal mode \NC\NR -\NC insert \NC an insert is added \NC\NR -\NC penalty \NC a penalty (in vertical mode) \NC\NR -\NC before_display \NC immediately before a display starts \NC\NR -\NC after_display \NC a display is finished \NC\NR -\NC end \NC \LUATEX\ is terminating (it's all over)\NC\NR -\stoptabulate - -This callback does not replace any internal code. - - -\subsubsection{\luatex{pre_linebreak_filter}} - -This callback is called just before \LUATEX\ starts converting a list -of nodes into a stack of \tex{hbox}es, after the addition of -\type{\parfillskip}. - -\startfunctioncall -function(<node> head, <string> groupcode) - return true | false | <node> newhead -end -\stopfunctioncall - -The string called \type {groupcode} identifies the nodelist's context -within \TEX's processing. The range of possibilities is given in the -table below, but not all of those can actually appear in -\luatex {pre_linebreak_filter}, some are for the -\luatex {hpack_filter} and \luatex {vpack_filter} callbacks that -will be explained in the next two paragraphs. - -\starttabulate[|lT|p|] -\NC \ssbf value \NC \bf explanation \NC\NR -\NC <empty> \NC main vertical list \NC\NR -\NC hbox \NC \tex{hbox} in horizontal mode \NC\NR -\NC adjusted_hbox\NC \tex{hbox} in vertical mode \NC\NR -\NC vbox \NC \tex{vbox} \NC\NR -\NC vtop \NC \tex{vtop} \NC\NR -\NC align \NC \tex{halign} or \tex{valign} \NC\NR -\NC disc \NC discretionaries \NC\NR -\NC insert \NC packaging an insert \NC\NR -\NC vcenter \NC \tex{vcenter} \NC\NR -\NC local_box \NC \tex{localleftbox} or \tex{localrightbox} \NC\NR -\NC split_off \NC top of a \tex{vsplit} \NC\NR -\NC split_keep \NC remainder of a \tex{vsplit} \NC\NR -\NC align_set \NC alignment cell \NC\NR -\NC fin_row \NC alignment row \NC\NR -\stoptabulate - -As for all the callbacks that deal with nodes, the return value can be one of three things: - -\startitemize -\item boolean \type{true} signals succesful processing -\item \type{<node>} signals that the \quote{head} node should be replaced by the returned node -\item boolean \type{false} signals that the \quote{head} node list should be ignored and -flushed from memory -\stopitemize - - -This callback does not replace any internal code. - - -\subsubsection{\luatex{linebreak_filter}} - -This callback replaces \LUATEX's line breaking algorithm. - -\startfunctioncall -function(<node> head, <boolean> is_display) - return <node> newhead -end -\stopfunctioncall - -The returned node is the head of the list that will be added to the -main vertical list, the boolean argument is true if this paragraph is -interrupted by a following math display. - -If you return something that is not a \type{<node>}, \LUATEX\ will -apply the internal linebreak algorithm on the list that starts at -\type{<head>}. Otherwise, the \type{<node>} you return is supposed -to be the head of a list of nodes that are all allowed in vertical -mode, and at least one of those has to represent a hbox. Failure to do -so will result in a fatal error. - -Setting this callback to \type{false} is possible, but dangerous, -because it is possible you will end up in an unfixable -\quote{deadcycles loop}. - -\subsubsection{\luatex{post_linebreak_filter}} - -This callback is called just after \LUATEX\ has converted a list -of nodes into a stack of \tex{hbox}es. - -\startfunctioncall -function(<node> head, <string> groupcode) - return true | false | <node> newhead -end -\stopfunctioncall - -This callback does not replace any internal code. - -\subsubsection{\luatex{hpack_filter}} - -This callback is called when \TEX\ is ready to start boxing some -horizontal mode material. Math items and line boxes are ignored -at the moment. - -\startfunctioncall -function(<node> head, <string> groupcode, <number> size, - <string> packtype [, <string> direction]) - return true | false | <node> newhead -end -\stopfunctioncall - -The \type{packtype} is either \type{additional} or \type{exactly}. If -\type{additional}, then the \type{size} is a \tex{hbox spread ...} -argument. If \type{exactly}, then the \type{size} is a \tex{hbox to ...}. -In both cases, the number is in scaled points. - -The \type{direction} is either one of the three-letter direction specifier -strings, or \type{nil} (added in 0.45). - - -This callback does not replace any internal code. - -\subsubsection{\luatex{vpack_filter}} - -This callback is called when \TEX\ is ready to start boxing some -vertical mode material. Math displays are ignored at the moment. - -This function is very similar to the \luatex{hpack_filter}. Besides -the fact that it is called at different moments, there is an extra -variable that matches \TEX's \tex{maxdepth} setting. - -\startfunctioncall -function(<node> head, <string> groupcode, <number> size, <string> - packtype, <number> maxdepth [, <string> direction]) - return true | false | <node> newhead -end -\stopfunctioncall - -This callback does not replace any internal code. - -\subsubsection{\luatex{pre_output_filter}} - -This callback is called when \TEX\ is ready to start boxing the -box 255 for \tex{output}. - -\startfunctioncall -function(<node> head, <string> groupcode, <number> size, <string> packtype, - <number> maxdepth [, <string> direction]) - return true | false | <node> newhead -end -\stopfunctioncall - -This callback does not replace any internal code. - -\subsubsection{\luatex{hyphenate}} - -\startfunctioncall -function(<node> head, <node> tail) -end -\stopfunctioncall - -No return values. This callback has to insert discretionary nodes in -the node list it receives. - -Setting this callback to \type{false} will prevent the internal -discretionary insertion pass. - -\subsubsection{\luatex{ligaturing}} - -\startfunctioncall -function(<node> head, <node> tail) -end -\stopfunctioncall - -No return values. This callback has to apply ligaturing to the node -list it receives. - -You don't have to worry about return values because the \type{head} -node that is passed on to the callback is guaranteed not to be a -glyph_node (if need be, a temporary node will be prepended), and -therefore it cannot be affected by the mutations that take place. -After the callback, the internal value of the \quote {tail of the list} -will be recalculated. - -The \type{next} of \type{head} is guaranteed to be non-nil. - -The \type{next} of \type{tail} is guaranteed to be nil, and therefore the -second callback argument can often be ignored. It is provided for -orthogonality, and because it can sometimes be handy when special -processing has to take place. - -Setting this callback to \type{false} will prevent the internal -ligature creation pass. - -\subsubsection{\luatex{kerning}} - -\startfunctioncall -function(<node> head, <node> tail) -end -\stopfunctioncall - -No return values. This callback has to apply kerning between the nodes -in the node list it receives. See \type{ligaturing} for calling -conventions. - -Setting this callback to \type{false} will prevent the internal -kern insertion pass. - -\subsubsection{\luatex{mlist_to_hlist}} - -This callback replaces \LUATEX's math list to node list conversion algorithm. - -\startfunctioncall -function(<node> head, <string> display_type, <boolean> need_penalties) - return <node> newhead -end -\stopfunctioncall - -The returned node is the head of the list that will be added to the vertical or -horizontal list, the string argument is either \quote{text} or \quote{display} -depending on the current math mode, the boolean argument is \type{true} if penalties -have to be inserted in this list, \type{false} otherwise. - -Setting this callback to \type{false} is bad, it will almost -certainly result in an endless loop. - -\subsection{Information reporting callbacks} - -\subsubsection{\luatex{pre_dump} (0.61)} - -\startfunctioncall -function() -end -\stopfunctioncall - -This function is called just before dumping to a format file starts. -It does not replace any code and there are neither arguments nor return values. - -\subsubsection{\luatex{start_run}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback replaces the code that prints \LUATEX's banner. Note that for -successful use, this callback has to be set in the lua initialization script, -otherwise it will be seen only after the run has already started. - -\subsubsection{\luatex{stop_run}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback replaces the code that prints \LUATEX's statistics and \quote{output written -to} messages. - -\subsubsection{\luatex{start_page_number}} - -\startfunctioncall -function() -end -\stopfunctioncall - -Replaces the code that prints the \type{[} and the page number at the -begin of \tex{shipout}. This callback will also override the -printing of box information that normally takes place when -\tex{tracingoutput} is positive. - -\subsubsection{\luatex{stop_page_number}} - -\startfunctioncall -function() -end -\stopfunctioncall - -Replaces the code that prints the \type{]} at the end of \tex{shipout}. - -\subsubsection{\luatex{show_error_hook}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback is run from inside the \TEX\ error function, and the idea -is to allow you to do some extra reporting on top of what \TEX\ already -does (none of the normal actions are removed). You may find some of -the values in the \luatex{status} table useful. - -This callback does not replace any internal code. - -\iffalse % this has been retracted for the moment -\startitemize - -\sym{message} - -is the formal error message \TEX\ has given to the user. -(the line after the '!'). - -\sym{indicator} - -is either a filename (when it is a string) or a location indicator (a -number) that can mean lots of different things like a token list id -or a \tex{read} number. - -\sym{lineno} - -is the current line number. -\stopitemize - -This is an investigative item for 'testing the water' only. -The final goal is the total replacement of \TEX's error handling -routines, but that needs lots of adjustments in the web source because -\TEX\ deals with errors in a somewhat haphazard fashion. This is why the -exact definition of \type{indicator} is not given here. -\fi - - -\subsubsection{\luatex{show_error_message}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback replaces the code that prints the error message. The usual -interaction after the message is not affected. - -\subsubsection{\luatex{show_lua_error_hook}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback replaces the code that prints the extra lua error message. - - -\subsubsection{\luatex{start_file}} - -\startfunctioncall -function(category,filename) -end -\stopfunctioncall - -This callback replaces the code that prints \LUATEX's when a file is opened -like \type {(filename} for regular files. The category is a number: - -\starttabulate[|||] -\NC 1 \NC a normal data file, like a \TEX\ source \NC \NR -\NC 2 \NC a font map coupling font names to resources \NC \NR -\NC 3 \NC an image file (\type {png}, \type {pdf}, etc) \NC \NR -\NC 4 \NC an embedded font subset \NC \NR -\NC 5 \NC a fully embedded font \NC \NR -\stoptabulate - -\subsubsection{\luatex{stop_file}} - -\startfunctioncall -function(category) -end -\stopfunctioncall - -This callback replaces the code that prints \LUATEX's when a file is closed -like the \type{)} for regular files. - -\subsection{PDF-related callbacks} - -\subsubsection{\luatex{finish_pdffile}} - -\startfunctioncall -function() -end -\stopfunctioncall - -This callback is called when all document pages are already written to the \PDF\ -file and \LUATEX\ is about to finalize the output document structure. Its intended -use is final update of \PDF\ dictionaries such as \type{/Catalog} or -\type{/Info}. The callback does not replace any code. There are neither -arguments nor return values. - - -\subsubsection{\luatex{finish_pdfpage}} - - -\startfunctioncall -function(shippingout) -end -\stopfunctioncall - -This callback is called after the pdf page stream has been assembled and before the -page object gets finalized. This callback is available in \LUATEX\ 0.78.4 and later. - - -\subsection{Font-related callbacks} - -\subsubsection{\luatex{define_font}} - -\startfunctioncall -function(<string> name, <number> size, <number> id) - return <table> font -end -\stopfunctioncall - -The string \type{name} is the filename part of the font -specification, as given by the user. - -The number \type{size} is a bit special: - -\startitemize[packed] -\item if it is positive, it specifies an \quote{at size} in scaled points. -\item if it is negative, its absolute value represents a \quote{scaled} -setting relative to the designsize of the font. -\stopitemize - -The \type{id} is the internal number assigned to the font. - -The internal structure of the \type{font} table that is to be -returned is explained in \in{chapter}[fonts]. That table is saved -internally, so you can put extra fields in the table for your -later \LUA\ code to use. - -Setting this callback to \type{false} is pointless as it will prevent -font loading completely but will nevertheless generate errors. - -\section{The \luatex{epdf} library} - -The \type{epdf} library provides Lua bindings to many \PDF\ access functions -that are defined by the poppler pdf viewer library (written in C$+{}+$ -by Kristian H\o gsberg, based on xpdf by Derek Noonburg). -Within \LUATEX\ (and \PDFTEX), -xpdf functionality is being used since long time to embed \PDF\ files. -The \type{epdf} library shall allow to scrutinize an external \PDF\ file. -It gives access to its document structure, -e.\,g., catalog, cross-reference table, individual pages, objects, -annotations, info, and metadata. The \LUATEX\ team is evaluating -the possibility of reducing the binding to a basic low level \PDF\ -primitives and delegate the complete set of functions -to an external shared object module. - - -The \type{epdf} library is still in alpha state: -\PDF\ access is currently read|-|only -(it's not yet possible to alter a \PDF\ file or to assemble it from scratch), -and many function bindings are still missing. - -For a start, -a \PDF\ file is opened by \type{epdf.open()} with file name, e.\,g.: - -\starttyping -doc = epdf.open("foo.pdf") -\stoptyping - -This normally returns a \type{PDFDoc} userdata variable; -but if the file could not be opened successfully, -instead of a fatal error just the value \type{nil} is returned. - -All Lua functions in the \type{epdf} library are named after the -poppler functions listed in the poppler header files for the various classes, -e.\,g., files \type{PDFDoc.h}, \type{Dict.h}, and \type{Array.h}. -These files can be found in the poppler subdirectory within the \LUATEX\ sources. -Which functions are already implemented in the \type{epdf} library -can be found in the \LUATEX\ source file \type{lepdflib.cc}. -For using the \type{epdf} library, -knowledge of the \PDF\ file architecture is indispensable. - -There are many different userdata types defined -by the \type{epdf} library, currently these are -\type{AnnotBorderStyle}, -\type{AnnotBorder}, -\type{Annots}, -\type{Annot}, -\type{Array}, -\type{Attribute}, -\type{Catalog}, -\type{Dict}, -\type{EmbFile}, -\type{GString}, -\type{LinkDest}, -\type{Links}, -\type{Link}, -\type{ObjectStream}, -\type{Object}, -\type{PDFDoc}, -\type{PDFRectangle}, -\type{Page}, -\type{Ref}, -\type{Stream}, -\type{StructElement}, -\type{StructTreeRoot} -\type{TextSpan}, -\type{XRefEntry} -and -\type{XRef} - - -All these userdata names and the Lua access functions closely resemble -the classes naming from the poppler header files, -including the choice of mixed upper and lower case letters. -The Lua function calls use object-oriented syntax, e.\,g., -the following calls return the \type{Page} object for page~1: - -\starttyping -pageref = doc:getCatalog():getPageRef(1) -pageobj = doc:getXRef():fetch(pageref.num, pageref.gen) -\stoptyping - -But writing such chained calls is risky, -as an intermediate function may return \type{nil} on error; -therefore between function calls there should be Lua type checks -(e.\,g., against \type{nil}) done. -If a non-object item is requested -(e.\,g., a \type{Dict} item by calling \type{page:getPieceInfo()}, -cf.~\type{Page.h}) but not available, -the Lua functions return \type{nil} (without error). -If a function should return an \type{Object}, but it's not existing, -a \type{Null} object is returned instead -(also without error; this is in|-|line with poppler behavior). - -All library objects have a \type{__gc} metamethod for garbage collection. -The \type{__tostring} metamethod gives the type name for each object. - -All object constructors: - -\startfunctioncall -<PDFDoc> = epdf.open(<string> PDF filename) -<Annot> = epdf.Annot(<XRef>, <Dict>, <Catalog>, <Ref>) -<Annots> = epdf.Annots(<XRef>, <Catalog>, <Object>) -<Array> = epdf.Array(<XRef>) -<Attribute> = epdf.Attribute(<Type>,<Object>)| epdf.Attribute(<string>, <int>, <Object>) -<Dict> = epdf.Dict(<XRef>) -<Object> = epdf.Object() -<PDFRectangle> = epdf.PDFRectangle() -\stopfunctioncall - -The functions \type{StructElement_Type}, -\type{Attribute_Type} and -\type{AttributeOwner_Type} return a hash table \type{{<string>,<integer>}}. - - - -\type{Annot} methods: - -\startfunctioncall -<boolean> = <Annot>:isOK() -<Object> = <Annot>:getAppearance() -<AnnotBorder> = <Annot>:getBorder() -<boolean> = <Annot>:match(<Ref>) -\stopfunctioncall - -\type{AnnotBorderStyle} methods: - -\startfunctioncall -<number> = <AnnotBorderStyle>:getWidth() -\stopfunctioncall - -\type{Annots} methods: - -\startfunctioncall -<integer> = <Annots>:getNumAnnots() -<Annot> = <Annots>:getAnnot(<integer>) -\stopfunctioncall - -\type{Array} methods: - -\startfunctioncall - <Array>:incRef() - <Array>:decRef() -<integer> = <Array>:getLength() - <Array>:add(<Object>) -<Object> = <Array>:get(<integer>) -<Object> = <Array>:getNF(<integer>) -<string> = <Array>:getString(<integer>) -\stopfunctioncall - - -\type{Attribute} methods: - -\startfunctioncall -<boolean> = <Attribute>:isOk() -<integer> = <Attribute>:getType() -<integer> = <Attribute>:getOwner() -<string> = <Attribute>:getTypeName() -<string> = <Attribute>:getOwnerName() -<Object> = <Attribute>:getValue() -<Object> = <Attribute>:getDefaultValue -<string> = <Attribute>:getName() -<integer> = <Attribute>:getRevision() - <Attribute>:setRevision(<unsigned integer>) -<boolean> = <Attribute>:istHidden() - <Attribute>:setHidden(<boolean>) -<string> = <Attribute>:getFormattedValue() -<string> = <Attribute>:setFormattedValue(<string>) -\stopfunctioncall - - - -\type{Catalog} methods: - -\startfunctioncall -<boolean> = <Catalog>:isOK() -<integer> = <Catalog>:getNumPages() -<Page> = <Catalog>:getPage(<integer>) -<Ref> = <Catalog>:getPageRef(<integer>) -<string> = <Catalog>:getBaseURI() -<string> = <Catalog>:readMetadata() -<Object> = <Catalog>:getStructTreeRoot() -<integer> = <Catalog>:findPage(<integer> object number, <integer> object generation) -<LinkDest> = <Catalog>:findDest(<string> name) -<Object> = <Catalog>:getDests() -<integer> = <Catalog>:numEmbeddedFiles() -<EmbFile> = <Catalog>:embeddedFile(<integer>) -<integer> = <Catalog>:numJS() -<string> = <Catalog>:getJS(<integer>) -<Object> = <Catalog>:getOutline() -<Object> = <Catalog>:getAcroForm() -\stopfunctioncall - -\type{EmbFile} methods: - -\startfunctioncall -<string> = <EmbFile>:name() -<string> = <EmbFile>:description() -<integer> = <EmbFile>:size() -<string> = <EmbFile>:modDate() -<string> = <EmbFile>:createDate() -<string> = <EmbFile>:checksum() -<string> = <EmbFile>:mimeType() -<Object> = <EmbFile>:streamObject() -<boolean> = <EmbFile>:isOk() -\stopfunctioncall - -\type{Dict} methods: - -\startfunctioncall - <Dict>:incRef() - <Dict>:decRef() -<integer> = <Dict>:getLength() - <Dict>:add(<string>, <Object>) - <Dict>:set(<string>, <Object>) - <Dict>:remove(<string>) -<boolean> = <Dict>:is(<string>) -<Object> = <Dict>:lookup(<string>) -<Object> = <Dict>:lookupNF(<string>) -<integer> = <Dict>:lookupInt(<string>, <string>) -<string> = <Dict>:getKey(<integer>) -<Object> = <Dict>:getVal(<integer>) -<Object> = <Dict>:getValNF(<integer>) -<boolean> = <Dict>:hasKey(<string>) -\stopfunctioncall - -\type{Link} methods: - -\startfunctioncall -<boolean> = <Link>:isOK() -<boolean> = <Link>:inRect(<number>, <number>) -\stopfunctioncall - -\type{LinkDest} methods: - -\startfunctioncall -<boolean> = <LinkDest>:isOK() -<integer> = <LinkDest>:getKind() -<string> = <LinkDest>:getKindName() -<boolean> = <LinkDest>:isPageRef() -<integer> = <LinkDest>:getPageNum() -<Ref> = <LinkDest>:getPageRef() -<number> = <LinkDest>:getLeft() -<number> = <LinkDest>:getBottom() -<number> = <LinkDest>:getRight() -<number> = <LinkDest>:getTop() -<number> = <LinkDest>:getZoom() -<boolean> = <LinkDest>:getChangeLeft() -<boolean> = <LinkDest>:getChangeTop() -<boolean> = <LinkDest>:getChangeZoom() -\stopfunctioncall - -\type{Links} methods: - -\startfunctioncall -<integer> = <Links>:getNumLinks() -<Link> = <Links>:getLink(<integer>) -\stopfunctioncall - -\type{Object} methods: - -\startfunctioncall - <Object>:initBool(<boolean>) - <Object>:initInt(<integer>) - <Object>:initReal(<number>) - <Object>:initString(<string>) - <Object>:initName(<string>) - <Object>:initNull() - <Object>:initArray(<XRef>) - <Object>:initDict(<XRef>) - <Object>:initStream(<Stream>) - <Object>:initRef(<integer> object number, <integer> object generation) - <Object>:initCmd(<string>) - <Object>:initError() - <Object>:initEOF() -<Object> = <Object>:fetch(<XRef>) -<integer> = <Object>:getType() -<string> = <Object>:getTypeName() -<boolean> = <Object>:isBool() -<boolean> = <Object>:isInt() -<boolean> = <Object>:isReal() -<boolean> = <Object>:isNum() -<boolean> = <Object>:isString() -<boolean> = <Object>:isName() -<boolean> = <Object>:isNull() -<boolean> = <Object>:isArray() -<boolean> = <Object>:isDict() -<boolean> = <Object>:isStream() -<boolean> = <Object>:isRef() -<boolean> = <Object>:isCmd() -<boolean> = <Object>:isError() -<boolean> = <Object>:isEOF() -<boolean> = <Object>:isNone() -<boolean> = <Object>:getBool() -<integer> = <Object>:getInt() -<number> = <Object>:getReal() -<number> = <Object>:getNum() -<string> = <Object>:getString() -<string> = <Object>:getName() -<Array> = <Object>:getArray() -<Dict> = <Object>:getDict() -<Stream> = <Object>:getStream() -<Ref> = <Object>:getRef() -<integer> = <Object>:getRefNum() -<integer> = <Object>:getRefGen() -<string> = <Object>:getCmd() -<integer> = <Object>:arrayGetLength() - = <Object>:arrayAdd(<Object>) -<Object> = <Object>:arrayGet(<integer>) -<Object> = <Object>:arrayGetNF(<integer>) -<integer> = <Object>:dictGetLength(<integer>) - = <Object>:dictAdd(<string>, <Object>) - = <Object>:dictSet(<string>, <Object>) -<Object> = <Object>:dictLookup(<string>) -<Object> = <Object>:dictLookupNF(<string>) -<string> = <Object>:dictgetKey(<integer>) -<Object> = <Object>:dictgetVal(<integer>) -<Object> = <Object>:dictgetValNF(<integer>) -<boolean> = <Object>:streamIs(<string>) - = <Object>:streamReset() -<integer> = <Object>:streamGetChar() -<integer> = <Object>:streamLookChar() -<integer> = <Object>:streamGetPos() - = <Object>:streamSetPos(<integer>) -<Dict> = <Object>:streamGetDict() -\stopfunctioncall - -\type{Page} methods: - -\startfunctioncall -<boolean> = <Page>:isOk() -<integer> = <Page>:getNum() -<PDFRectangle> = <Page>:getMediaBox() -<PDFRectangle> = <Page>:getCropBox() -<boolean> = <Page>:isCropped() -<number> = <Page>:getMediaWidth() -<number> = <Page>:getMediaHeight() -<number> = <Page>:getCropWidth() -<number> = <Page>:getCropHeight() -<PDFRectangle> = <Page>:getBleedBox() -<PDFRectangle> = <Page>:getTrimBox() -<PDFRectangle> = <Page>:getArtBox() -<integer> = <Page>:getRotate() -<string> = <Page>:getLastModified() -<Dict> = <Page>:getBoxColorInfo() -<Dict> = <Page>:getGroup() -<Stream> = <Page>:getMetadata() -<Dict> = <Page>:getPieceInfo() -<Dict> = <Page>:getSeparationInfo() -<Dict> = <Page>:getResourceDict() -<Object> = <Page>:getAnnots() -<Links> = <Page>:getLinks(<Catalog>) -<Object> = <Page>:getContents() -\stopfunctioncall - -\type{PDFDoc} methods: - -\startfunctioncall -<boolean> = <PDFDoc>:isOk() -<integer> = <PDFDoc>:getErrorCode() -<string> = <PDFDoc>:getErrorCodeName() -<string> = <PDFDoc>:getFileName() -<XRef> = <PDFDoc>:getXRef() -<Catalog> = <PDFDoc>:getCatalog() -<number> = <PDFDoc>:getPageMediaWidth() -<number> = <PDFDoc>:getPageMediaHeight() -<number> = <PDFDoc>:getPageCropWidth() -<number> = <PDFDoc>:getPageCropHeight() -<integer> = <PDFDoc>:getNumPages() -<string> = <PDFDoc>:readMetadata() -<Object> = <PDFDoc>:getStructTreeRoot() -<integer> = <PDFDoc>:findPage(<integer> object number, <integer> object generation) -<Links> = <PDFDoc>:getLinks(<integer>) -<LinkDest> = <PDFDoc>:findDest(<string>) -<boolean> = <PDFDoc>:isEncrypted() -<boolean> = <PDFDoc>:okToPrint() -<boolean> = <PDFDoc>:okToChange() -<boolean> = <PDFDoc>:okToCopy() -<boolean> = <PDFDoc>:okToAddNotes() -<boolean> = <PDFDoc>:isLinearized() -<Object> = <PDFDoc>:getDocInfo() -<Object> = <PDFDoc>:getDocInfoNF() -<integer> = <PDFDoc>:getPDFMajorVersion() -<integer> = <PDFDoc>:getPDFMinorVersion() -\stopfunctioncall - -\type{PDFRectangle} methods: - -\startfunctioncall -<boolean> = <PDFRectangle>:isValid() -\stopfunctioncall - -%\type{Ref} methods: -% -%\startfunctioncall -%\stopfunctioncall - -\type{Stream} methods: - -\startfunctioncall -<integer> = <Stream>:getKind() -<string> = <Stream>:getKindName() - = <Stream>:reset() - = <Stream>:close() -<integer> = <Stream>:getChar() -<integer> = <Stream>:lookChar() -<integer> = <Stream>:getRawChar() -<integer> = <Stream>:getUnfilteredChar() - = <Stream>:unfilteredReset() -<integer> = <Stream>:getPos() -<boolean> = <Stream>:isBinary() -<Stream> = <Stream>:getUndecodedStream() -<Dict> = <Stream>:getDict() -\stopfunctioncall - -\type{StructElement} methods: - -\startfunctioncall -<string> = <StructElement>:getTypeName() -<integer> = <StructElement>:getType() -<boolean> = <StructElement>:isOk() -<boolean> = <StructElement>:isBlock() -<boolean> = <StructElement>:isInline() -<boolean> = <StructElement>:isGrouping() -<boolean> = <StructElement>:isContent() -<boolean> = <StructElement>:isObjectRef() -<integer> = <StructElement>:getMCID() -<Ref> = <StructElement>:getObjectRef() -<Ref> = <StructElement>:getParentRef() -<boolean> = <StructElement>:hasPageRef() -<Ref> = <StructElement>:getPageRef() -<StructTreeRoot> = <StructElement>:getStructTreeRoot() -<string> = <StructElement>:getID() -<string> = <StructElement>:getLanguage() -<integer> = <StructElement>:getRevision() - <StructElement>:setRevision(<unsigned integer>) -<string> = <StructElement>:getTitle() -<string> = <StructElement>:getExpandedAbbr() -<integer> = <StructElement>:getNumChildren() -<StructElement> = <StructElement>:getChild() - = <StructElement>:appendChild<StructElement>) -<integer> = <StructElement>:getNumAttributes() -<Attribute> = <StructElement>:geAttribute(<integer>) -<string> = <StructElement>:appendAttribute(<Attribute>) -<Attribute> = <StructElement>:findAttribute(<Attribute::Type>,boolean,Attribute::Owner) -<string> = <StructElement>:getAltText() -<string> = <StructElement>:getActualText() -<string> = <StructElement>:getText(<boolean>) -<table> = <StructElement>:getTextSpans() -\stopfunctioncall - - -\type{StructTreeRoot} methods: - -\startfunctioncall -<StructElement> = <StructTreeRoot>:findParentElement -<PDFDoc> = <StructTreeRoot>:getDoc -<Dict> = <StructTreeRoot>:getRoleMap -<Dict> = <StructTreeRoot>:getClassMap -<integer> = <StructTreeRoot>:getNumChildren -<StructElement> = <StructTreeRoot>:getChild - <StructTreeRoot>:appendChild -<StructElement> = <StructTreeRoot>:findParentElement -\stopfunctioncall - - -\type{TextSpan} han only one method: - -\startfunctioncall -<string> = <TestSpan>:getText() -\stopfunctioncall - - - - -\type{XRef} methods: - -\startfunctioncall -<boolean> = <XRef>:isOk() -<integer> = <XRef>:getErrorCode() -<boolean> = <XRef>:isEncrypted() -<boolean> = <XRef>:okToPrint() -<boolean> = <XRef>:okToPrintHighRes() -<boolean> = <XRef>:okToChange() -<boolean> = <XRef>:okToCopy() -<boolean> = <XRef>:okToAddNotes() -<boolean> = <XRef>:okToFillForm() -<boolean> = <XRef>:okToAccessibility() -<boolean> = <XRef>:okToAssemble() -<Object> = <XRef>:getCatalog() -<Object> = <XRef>:fetch(<integer> object number, <integer> object generation) -<Object> = <XRef>:getDocInfo() -<Object> = <XRef>:getDocInfoNF() -<integer> = <XRef>:getNumObjects() -<integer> = <XRef>:getRootNum() -<integer> = <XRef>:getRootGen() -<integer> = <XRef>:getSize() -<Object> = <XRef>:getTrailerDict() -\stopfunctioncall - -%*********************************************************************** - -\section{The \luatex{font} library} - -The font library provides the interface into the internals of the font -system, and also it contains helper functions to load traditional -\TEX\ font metrics formats. Other font loading functionality is -provided by the \luatex{fontloader} library that will be discussed in -the next section. - -\subsection{Loading a \TFM\ file} - -The behavior documented in this subsection is considered stable in the -sense that there will not be backward-incompatible changes any more. - -\startfunctioncall -<table> fnt = font.read_tfm(<string> name, <number> s) -\stopfunctioncall - -The number is a bit special: - -\startitemize -\item if it is positive, it specifies an \quote{at size} in scaled points. -\item if it is negative, its absolute value represents a \quote{scaled} -setting relative to the designsize of the font. -\stopitemize - -The internal structure of the metrics font table that is returned is -explained in \in{chapter}[fonts]. - -\subsection{Loading a \VF\ file} - -The behavior documented in this subsection is considered stable in the -sense that there will not be backward-incompatible changes any more. - -\startfunctioncall -<table> vf_fnt = font.read_vf(<string> name, <number> s) -\stopfunctioncall - -The meaning of the number \type{s} and the format of the returned -table are similar to the ones in the \luatex{read_tfm()} function. - -\subsection{The fonts array} - -The whole table of \TEX\ fonts is accessible from \LUA\ using a virtual array. - -\starttyping -font.fonts[n] = { ... } -<table> f = font.fonts[n] -\stoptyping - -See \in{chapter}[fonts] for the structure of the tables. Because this -is a virtual array, you cannot call \type{pairs} on it, but see below -for the \type{font.each} iterator. - -The two metatable functions implementing the virtual array are: - -\startfunctioncall -<table> f = font.getfont(<number> n) -font.setfont(<number> n, <table> f) -\stopfunctioncall - -Note that at the moment, each access to the \type{font.fonts} or call -to \type{font.getfont} creates a lua table for the whole font. This -process can be quite slow. In a later version of \LUATEX, this -interface will change (it will start using userdata objects instead of -actual tables). - -Also note the following: assignments can only be made to fonts that -have already been defined in \TEX, but have not been accessed {\it at -all\/} since that definition. This limits the usability of the write -access to \type{font.fonts} quite a lot, a less stringent ruleset will -likely be implemented later. - -\subsection{Checking a font's status} - -You can test for the status of a font by calling this function: - -\startfunctioncall -<boolean> f = font.frozen(<number> n) -\stopfunctioncall - -The return value is one of \type{true} (unassignable), \type{false} (can be changed) -or \type{nil} (not a valid font at all). - -\subsection{Defining a font directly} - -You can define your own font into \luatex{font.fonts} by calling this function: - -\startfunctioncall -<number> i = font.define(<table> f) -\stopfunctioncall - -The return value is the internal id number of the defined font (the -index into \luatex{font.fonts}). If the font creation fails, an error is -raised. The table is a font structure, as explained in -\in{chapter}[fonts]. - -\subsection{Projected next font id} - -\startfunctioncall -<number> i = font.nextid() -\stopfunctioncall - -This returns the font id number that would be returned by a -\type{font.define} call if it was executed at this spot in the code -flow. This is useful for virtual fonts that need to reference -themselves. - -\subsection{Font id (0.47)} - -\startfunctioncall -<number> i = font.id(<string> csname) -\stopfunctioncall - -This returns the font id associated with \type{csname} string, or $-1$ -if \type{csname} is not defined; new in 0.47. - -\subsection{Currently active font} - -\startfunctioncall -<number> i = font.current() -font.current(<number> i) -\stopfunctioncall - -This gets or sets the currently used font number. - -\subsection{Maximum font id} - -\startfunctioncall -<number> i = font.max() -\stopfunctioncall - -This is the largest used index in \type{font.fonts}. - -\subsection{Iterating over all fonts} - -\startfunctioncall -for i,v in font.each() do - ... -end -\stopfunctioncall - -This is an iterator over each of the defined \TEX\ fonts. The first -returned value is the index in \type{font.fonts}, the second the font -itself, as a \LUA\ table. The indices are listed incrementally, but they -do not always form an array of consecutive numbers: in some cases -there can be holes in the sequence. - -\section{The \luatex{fontloader} library (0.36)} - -\subsection{Getting quick information on a font} - -\startfunctioncall -<table> info = fontloader.info(<string> filename) -\stopfunctioncall - -This function returns either \type{nil}, or a \type{table}, or an -array of small tables (in the case of a TrueType collection). The -returned table(s) will contain some fairly interesting information -items from the font(s) defined by the file: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC fontname \NC string \NC the \POSTSCRIPT\ name of the font\NC\NR -\NC fullname \NC string \NC the formal name of the font\NC\NR -\NC familyname \NC string \NC the family name this font belongs to\NC\NR -\NC weight \NC string \NC a string indicating the color value of the font\NC\NR -\NC version \NC string \NC the internal font version\NC\NR -\NC italicangle \NC float \NC the slant angle\NC\NR -\NC units_per_em \NC number \NC (since 0.78.2) 1000 for \POSTSCRIPT-based fonts, usually 2048 for \TRUETYPE\NC\NR -\NC pfminfo \NC table \NC (since 0.78.2) (see \in{section}[fontloaderpfminfotable])\NC\NR -\stoptabulate - -Getting information through this function is (sometimes much) more -efficient than loading the font properly, and is therefore handy when -you want to create a dictionary of available fonts based on a -directory contents. - -\subsection{Loading an \OPENTYPE\ or \TRUETYPE\ file} - -If you want to use an \OPENTYPE\ font, you have to get the metric -information from somewhere. Using the \type{fontloader} library, the -simplest way to get that information is thus: - -\starttyping -function load_font (filename) - local metrics = nil - local font = fontloader.open(filename) - if font then - metrics = fontloader.to_table(font) - fontloader.close(font) - end - return metrics -end - -myfont = load_font('/opt/tex/texmf/fonts/data/arial.ttf') -\stoptyping - -The main function call is - -\startfunctioncall -<userdata> f, <table> w = fontloader.open(<string> filename) -<userdata> f, <table> w = fontloader.open(<string> filename, <string> fontname) -\stopfunctioncall - -The first return value is a userdata representation of the font. The -second return value is a table containing any warnings and errors -reported by fontloader while opening the font. In normal typesetting, -you would probably ignore the second argument, but it can be useful -for debugging purposes. - -For \TRUETYPE\ collections (when filename ends in 'ttc') and \DFONT\ -collections, you have to use a second string argument to specify which -font you want from the collection. Use the \type{fontname} -strings that are returned by \type{fontloader.info} for that. - -To turn the font into a table, \type{fontloader.to_table} is used on -the font returned by \type{fontloader.open}. - -\startfunctioncall -<table> f = fontloader.to_table(<userdata> font) -\stopfunctioncall - -This table cannot be used directly by \LUATEX\ and should be turned -into another one as described in~\in{chapter}[fonts]. -Do not forget to store the \type{fontname} value in the \type{psname} -field of the metrics table to be returned to \LUATEX, otherwise the -font inclusion backend will not be able to find the correct font in -the collection. - -See \in{section}[fontloadertables] for details on the userdata object -returned by \type{fontloader.open()} and the layout of the -\type{metrics} table returned by \type{fontloader.to_table()}. - -The font file is parsed and partially interpreted by the font -loading routines from \FONTFORGE. The file format can be \OPENTYPE, -\TRUETYPE, \TRUETYPE\ Collection, \CFF, or \TYPEONE. - -There are a few advantages to this approach compared to reading the -actual font file ourselves: - -\startitemize - -\item The font is automatically re|-|encoded, so that the \type{metrics} - table for \TRUETYPE\ and \OPENTYPE\ fonts is using \UNICODE\ for - the character indices. - -\item Many features are pre|-|processed into a format that is easier to handle - than just the bare tables would be. - -\item \POSTSCRIPT|-|based \OPENTYPE\ fonts do not store the character height and - depth in the font file, so the character boundingbox has to be - calculated in some way. - -\item In the future, it may be interesting to allow \LUA\ scripts access to - the font program itself, perhaps even creating or changing the font. - -\stopitemize - -A loaded font is discarded with: - -\startfunctioncall -fontloader.close(<userdata> font) -\stopfunctioncall - -\subsection{Applying a \quote{feature file}} - -You can apply a \quote{feature file} to a loaded font: - -\startfunctioncall -<table> errors = fontloader.apply_featurefile(<userdata> font, <string> filename) -\stopfunctioncall - -A \quote{feature file} is a textual representation of the features in an -\OPENTYPE\ font. See\crlf -\hyphenatedurl {http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html}\crlf -and\crlf -\hyphenatedurl {http://fontforge.sourceforge.net/featurefile.html}\crlf -for a more detailed description of feature files. - -If the function fails, the return value is a table containing any -errors reported by fontloader while applying the feature file. On -success, \type{nil} is returned. (the return value is new in 0.65) - - - -\subsection{Applying an \quote{\AFM\ file}} - -You can apply an \quote{\AFM\ file} to a loaded font: - -\startfunctioncall -<table> errors = fontloader.apply_afmfile(<userdata> font, <string> filename) -\stopfunctioncall - -An \AFM\ file is a textual representation of (some of) the meta information -in a \TYPEONE\ font. See \hyphenatedurl{ftp://ftp.math.utah.edu/u/ma/hohn/linux/postscript/5004.AFM_Spec.pdf} -for more information about afm files. - -Note: If you \type{fontloader.open()} a \TYPEONE\ file named \type{font.pfb}, -the library will automatically search for and apply \type{font.afm} -if it exists in the same directory as the file \type{font.pfb}. In that case, -there is no need for an explicit call to \type{apply_afmfile()}. - -If the function fails, the return value is a table containing any -errors reported by fontloader while applying the AFM file. On -success, \type{nil} is returned. (the return value is new in 0.65) - -\subsection[fontloadertables]{Fontloader font tables} - -As mentioned earlier, the return value of \type{fontloader.open()} is -a userdata object. In \LUATEX\ versions before 0.63, the only way to -have access to the actual metrics was to call -\type{fontloader.to_table()} on this object, returning the table -structure that is explained in the following subsections. - -However, it turns out that the result from -\type{fontloader.to_table()} sometimes needs very large amounts of memory -(depending on the font's complexity and size) so starting with \LUATEX\ 0.63, -it is possible to access the userdata object directly. - -In the \LUATEX\ 0.63.0, the following is implemented: - -\startitemize -\item all top-level keys that would be returned by \type{to_table()} - can also be accessed directly. -\item the top-level key \quote{glyphs} returns a {\it virtual\/} array that - allows indices from \type{0} to ($\type{f.glyphmax}-1$). -\item the items in that virtual array (the actual glyphs) are themselves also - userdata objects, and each has accessors for all of the keys - explained in the section \quote{Glyph items} below. -\item the top-level key \quote{subfonts} returns an {\it actual} array of - userdata objects, one for each of the subfonts (or nil, if there are no subfonts). -\stopitemize - - -A short example may be helpful. This code generates a printout of all -the glyph names in the font \type{PunkNova.kern.otf}: - -\starttyping -local f = fontloader.open('PunkNova.kern.otf') -print (f.fontname) -local i = 0 -while (i < f.glyphmax) do - local g = f.glyphs[i] - if g then - print(g.name) - end - i = i + 1 -end -fontloader.close(f) -\stoptyping - -In this case, the \LUATEX\ memory requirement stays below 100MB on the -test computer, while the internal stucture generated by -\type{to_table()} needs more than 2GB of memory (the font itself is -6.9MB in disk size). - -In \LUATEX\ 0.63 only the top-level font, the subfont table entries, -and the glyphs are virtual objects, everything else still produces -normal lua values and tables. In future versions, more return values -may be replaced by userdata objects (as much as needed to keep the -memory requirements in check). - -If you want to know the valid fields in a font or glyph -structure, call the \type{fields} function on an object of a -particular type (either glyph or font for now, more will be -implemented later): - -\startfunctioncall -<table> fields = fontloader.fields(<userdata> font) -<table> fields = fontloader.fields(<userdata> font_glyph) -\stopfunctioncall - -For instance: - -\startfunctioncall -local fields = fontloader.fields(f) -local fields = fontloader.fields(f.glyphs[0]) -\stopfunctioncall - - -\subsubsection{Table types} - -\subsubsubsection{Top-level} - -The top|-|level keys in the returned table are (the explanations in -this part of the documentation are not yet finished): - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC table_version \NC number \NC indicates the metrics version (currently~0.3)\NC\NR -\NC fontname \NC string \NC \POSTSCRIPT\ font name\NC\NR -\NC fullname \NC string \NC official (human-oriented) font name\NC\NR -\NC familyname \NC string \NC family name\NC\NR -\NC weight \NC string \NC weight indicator\NC\NR -\NC copyright \NC string \NC copyright information\NC\NR -\NC filename \NC string \NC the file name\NC\NR -\NC version \NC string \NC font version\NC\NR -\NC italicangle \NC float \NC slant angle\NC\NR -\NC units_per_em \NC number \NC 1000 for \POSTSCRIPT-based fonts, usually 2048 for \TRUETYPE\NC\NR -\NC ascent \NC number \NC height of ascender in \type{units_per_em}\NC\NR -\NC descent \NC number \NC depth of descender in \type{units_per_em}\NC\NR -\NC upos \NC float \NC \NC\NR -\NC uwidth \NC float \NC \NC\NR -\NC uniqueid \NC number \NC \NC\NR -\NC glyphcnt \NC number \NC number of included glyphs\NC\NR -\NC glyphs \NC array \NC \NC\NR -\NC glyphmax \NC number \NC maximum used index the glyphs array\NC\NR -\NC hasvmetrics \NC number \NC \NC\NR -\NC onlybitmaps \NC number \NC \NC\NR -\NC serifcheck \NC number \NC \NC\NR -\NC isserif \NC number \NC \NC\NR -\NC issans \NC number \NC \NC\NR -\NC encodingchanged \NC number \NC \NC\NR -\NC strokedfont \NC number \NC \NC\NR -\NC use_typo_metrics \NC number \NC \NC\NR -\NC weight_width_slope_only \NC number \NC \NC\NR -\NC head_optimized_for_cleartype \NC number \NC \NC\NR -\NC uni_interp \NC enum \NC \type {unset}, \type {none}, \type {adobe}, - \type {greek}, \type {japanese}, \type {trad_chinese}, - \type {simp_chinese}, \type {korean}, \type {ams}\NC\NR -\NC origname \NC string \NC the file name, as supplied by the user\NC\NR -\NC map \NC table \NC \NC\NR -\NC private \NC table \NC \NC\NR -\NC xuid \NC string \NC \NC\NR -\NC pfminfo \NC table \NC \NC\NR -\NC names \NC table \NC \NC\NR -\NC cidinfo \NC table \NC \NC\NR -\NC subfonts \NC array \NC \NC\NR -\NC commments \NC string \NC \NC\NR -\NC fontlog \NC string \NC \NC\NR -\NC cvt_names \NC string \NC \NC\NR -\NC anchor_classes \NC table \NC \NC\NR -\NC ttf_tables \NC table \NC \NC\NR -\NC ttf_tab_saved \NC table \NC \NC\NR -\NC kerns \NC table \NC \NC\NR -\NC vkerns \NC table \NC \NC\NR -\NC texdata \NC table \NC \NC\NR -\NC lookups \NC table \NC \NC\NR -\NC gpos \NC table \NC \NC\NR -\NC gsub \NC table \NC \NC\NR -\NC mm \NC table \NC \NC\NR -\NC chosenname \NC string \NC \NC\NR -\NC macstyle \NC number \NC \NC\NR -\NC fondname \NC string \NC \NC\NR -%\NC design_size \NC number \NC \NC\NR -\NC fontstyle_id \NC number \NC \NC\NR -\NC fontstyle_name \NC table \NC \NC\NR -%\NC design_range_bottom \NC number \NC \NC\NR -%\NC design_range_top \NC number \NC \NC\NR -\NC strokewidth \NC float \NC \NC\NR -\NC mark_classes \NC table \NC \NC\NR -\NC creationtime \NC number \NC \NC\NR -\NC modificationtime \NC number \NC \NC\NR -\NC os2_version \NC number \NC \NC\NR -\NC sfd_version \NC number \NC \NC\NR -\NC math \NC table \NC \NC\NR -\NC validation_state \NC table \NC \NC\NR -\NC horiz_base \NC table \NC \NC\NR -\NC vert_base \NC table \NC \NC\NR -\NC extrema_bound \NC number \NC \NC\NR -\stoptabulate - -\subsubsubsection{Glyph items} - -The \type{glyphs} is an array containing the per|-|character -information (quite a few of these are only present if nonzero). - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC name \NC string \NC the glyph name\NC\NR -\NC unicode \NC number \NC unicode code point, or -1\NC\NR -\NC boundingbox \NC array \NC array of four numbers, see note below\NC\NR -\NC width \NC number \NC only for horizontal fonts\NC\NR -\NC vwidth \NC number \NC only for vertical fonts\NC\NR -\NC tsidebearing \NC number \NC only for vertical ttf/otf fonts, and only if nonzero (0.79.0)\NC\NR -\NC lsidebearing \NC number \NC only if nonzero and not equal to boundingbox[1]\NC\NR -\NC class \NC string \NC one of "none", "base", "ligature", "mark", "component" - (if not present, the glyph class is \quote{automatic})\NC\NR -\NC kerns \NC array \NC only for horizontal fonts, if set\NC\NR -\NC vkerns \NC array \NC only for vertical fonts, if set\NC\NR -\NC dependents \NC array \NC linear array of glyph name strings, only if nonempty\NC\NR -\NC lookups \NC table \NC only if nonempty\NC\NR -\NC ligatures \NC table \NC only if nonempty\NC\NR -\NC anchors \NC table \NC only if set\NC\NR -\NC comment \NC string \NC only if set\NC\NR -\NC tex_height \NC number \NC only if set\NC\NR -\NC tex_depth \NC number \NC only if set\NC\NR -\NC italic_correction \NC number \NC only if set\NC\NR -\NC top_accent \NC number \NC only if set\NC\NR -\NC is_extended_shape \NC number \NC only if this character is part of a math extension list\NC\NR -\NC altuni \NC table \NC alternate \UNICODE\ items \NC\NR -\NC vert_variants \NC table \NC \NC \NR -\NC horiz_variants \NC table \NC \NC \NR -\NC mathkern \NC table \NC \NC \NR -\stoptabulate - -On \type{boundingbox}: The boundingbox information for \TRUETYPE\ fonts and \TRUETYPE-based \OTF\ fonts is read -directly from the font file. \POSTSCRIPT-based fonts do not have this information, so the boundingbox of -traditional \POSTSCRIPT\ fonts is generated by interpreting the actual bezier curves to find the exact -boundingbox. This can be a slow process, so starting from \LUATEX\ 0.45, the boundingboxes of \POSTSCRIPT-based -\OTF\ fonts (and raw \CFF\ fonts) are calculated using an approximation of the glyph shape based on the actual -glyph points only, instead of taking the whole curve into account. This means that glyphs that have missing -points at extrema will have a too-tight boundingbox, but the processing is so much faster that in our opinion -the tradeoff is worth it. - - -The \type{kerns} and \type{vkerns} are linear arrays of small hashes: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC char \NC string \NC \NC\NR -\NC off \NC number \NC \NC\NR -\NC lookup \NC string \NC \NC\NR -\stoptabulate - -The \type{lookups} is a hash, based on lookup subtable names, with -the value of each key inside that a linear array of small hashes: - -% TODO: fix this description -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC type \NC enum \NC \type {position}, \type {pair}, \type {substitution}, \type {alternate}, - \type {multiple}, \type {ligature}, \type {lcaret}, \type {kerning}, \type {vkerning}, \type {anchors}, - \type {contextpos}, \type {contextsub}, \type {chainpos}, \type {chainsub}, - \type {reversesub}, \type {max}, \type {kernback}, \type {vkernback} \NC\NR -\NC specification \NC table \NC extra data \NC\NR -\stoptabulate - -For the first seven values of \type{type}, there can be additional -sub|-|information, stored in the sub-table \type{specification}: - -\starttabulate[|lT|l|p|] -\NC \ssbf value \NC \bf type \NC \bf explanation \NC\NR -\NC position \NC table \NC a table of the \type {offset_specs} type\NC\NR -\NC pair \NC table \NC one string: \type {paired}, and an array of one or - two \type {offset_specs} tables: \type{offsets}\NC\NR -\NC substitution \NC table \NC one string: \type {variant}\NC\NR -\NC alternate \NC table \NC one string: \type {components}\NC\NR -\NC multiple \NC table \NC one string: \type {components}\NC\NR -\NC ligature \NC table \NC two strings: \type {components}, \type {char}\NC\NR -\NC lcaret \NC array \NC linear array of numbers\NC\NR -\stoptabulate - -Tables for \type{offset_specs} contain up to four number|-|valued -fields: \type{x} (a horizontal offset), \type{y} (a vertical offset), -\type{h} (an advance width correction) and \type{v} (an advance height -correction). - -The \type{ligatures} is a linear array of small hashes: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC lig \NC table \NC uses the same substructure as a single item in the \type{lookups} table explained above\NC\NR -\NC char \NC string \NC \NC\NR -\NC components \NC array \NC linear array of named components\NC\NR -\NC ccnt \NC number \NC \NC\NR -\stoptabulate - -The \type{anchor} table is indexed by a string signifying the -anchor type, which is one of - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC mark \NC table \NC placement mark\NC\NR -\NC basechar \NC table \NC mark for attaching combining items to a base char\NC\NR -\NC baselig \NC table \NC mark for attaching combining items to a ligature\NC\NR -\NC basemark \NC table \NC generic mark for attaching combining items to connect to\NC\NR -\NC centry \NC table \NC cursive entry point\NC\NR -\NC cexit \NC table \NC cursive exit point\NC\NR -\stoptabulate - -The content of these is a short array of defined anchors, with the -entry keys being the anchor names. For all except \type{baselig}, the -value is a single table with this definition: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC x \NC number \NC x location\NC\NR -\NC y \NC number \NC y location\NC\NR -\NC ttf_pt_index \NC number \NC truetype point index, only if given\NC\NR -\stoptabulate - -For \type{baselig}, the value is a small array of such anchor sets -sets, one for each constituent item of the ligature. - -For clarification, an anchor table could for example look like this : - -\starttyping -['anchor'] = { - ['basemark'] = { - ['Anchor-7'] = { ['x']=170, ['y']=1080 } - }, - ['mark'] ={ - ['Anchor-1'] = { ['x']=160, ['y']=810 }, - ['Anchor-4'] = { ['x']=160, ['y']=800 } - }, - ['baselig'] = { - [1] = { ['Anchor-2'] = { ['x']=160, ['y']=650 } }, - [2] = { ['Anchor-2'] = { ['x']=460, ['y']=640 } } - } - } -\stoptyping -Note: The \type {baselig} table can be sparse! - - -\subsubsubsection{map table} - -The top|-|level map is a list of encoding mappings. Each of those is a table itself. - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC enccount \NC number \NC \NC\NR -\NC encmax \NC number \NC \NC\NR -\NC backmax \NC number \NC \NC\NR -\NC remap \NC table \NC \NC\NR -\NC map \NC array \NC non|-|linear array of mappings\NC\NR -\NC backmap \NC array \NC non|-|linear array of backward mappings\NC\NR -\NC enc \NC table \NC \NC\NR -\stoptabulate - -The \type{remap} table is very small: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC firstenc \NC number \NC \NC\NR -\NC lastenc \NC number \NC \NC\NR -\NC infont \NC number \NC \NC\NR -\stoptabulate - -The \type{enc} table is a bit more verbose: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC enc_name \NC string \NC \NC\NR -\NC char_cnt \NC number \NC \NC\NR -\NC char_max \NC number \NC \NC\NR -\NC unicode \NC array \NC of \UNICODE\ position numbers\NC\NR -\NC psnames \NC array \NC of \POSTSCRIPT\ glyph names\NC\NR -\NC builtin \NC number \NC \NC\NR -\NC hidden \NC number \NC \NC\NR -\NC only_1byte \NC number \NC \NC\NR -\NC has_1byte \NC number \NC \NC\NR -\NC has_2byte \NC number \NC \NC\NR -\NC is_unicodebmp \NC number \NC only if nonzero\NC\NR -\NC is_unicodefull \NC number \NC only if nonzero\NC\NR -\NC is_custom \NC number \NC only if nonzero\NC\NR -\NC is_original \NC number \NC only if nonzero\NC\NR -\NC is_compact \NC number \NC only if nonzero\NC\NR -\NC is_japanese \NC number \NC only if nonzero\NC\NR -\NC is_korean \NC number \NC only if nonzero\NC\NR -\NC is_tradchinese \NC number \NC only if nonzero [name?]\NC\NR -\NC is_simplechinese \NC number \NC only if nonzero\NC\NR -\NC low_page \NC number \NC \NC\NR -\NC high_page \NC number \NC \NC\NR -\NC iconv_name \NC string \NC \NC\NR -\NC iso_2022_escape \NC string \NC \NC\NR -\stoptabulate - -\subsubsubsection{private table} - -This is the font's private \POSTSCRIPT\ dictionary, if any. Keys and -values are both strings. - -\subsubsubsection{cidinfo table} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC registry \NC string \NC \NC\NR -\NC ordering \NC string \NC \NC\NR -\NC supplement \NC number \NC \NC\NR -\NC version \NC number \NC \NC\NR -\stoptabulate - -\subsubsubsection[fontloaderpfminfotable]{pfminfo table} - -The \type{pfminfo} table contains most of the OS/2 information: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC pfmset \NC number \NC \NC\NR -\NC winascent_add \NC number \NC \NC\NR -\NC windescent_add \NC number \NC \NC\NR -\NC hheadascent_add \NC number \NC \NC\NR -\NC hheaddescent_add \NC number \NC \NC\NR -\NC typoascent_add \NC number \NC \NC\NR -\NC typodescent_add \NC number \NC \NC\NR -\NC subsuper_set \NC number \NC \NC\NR -\NC panose_set \NC number \NC \NC\NR -\NC hheadset \NC number \NC \NC\NR -\NC vheadset \NC number \NC \NC\NR -\NC pfmfamily \NC number \NC \NC\NR -\NC weight \NC number \NC \NC\NR -\NC width \NC number \NC \NC\NR -\NC avgwidth \NC number \NC \NC\NR -\NC firstchar \NC number \NC \NC\NR -\NC lastchar \NC number \NC \NC\NR -\NC fstype \NC number \NC \NC\NR -\NC linegap \NC number \NC \NC\NR -\NC vlinegap \NC number \NC \NC\NR -\NC hhead_ascent \NC number \NC \NC\NR -\NC hhead_descent \NC number \NC \NC\NR -\NC os2_typoascent \NC number \NC \NC\NR -\NC os2_typodescent \NC number \NC \NC\NR -\NC os2_typolinegap \NC number \NC \NC\NR -\NC os2_winascent \NC number \NC \NC\NR -\NC os2_windescent \NC number \NC \NC\NR -\NC os2_subxsize \NC number \NC \NC\NR -\NC os2_subysize \NC number \NC \NC\NR -\NC os2_subxoff \NC number \NC \NC\NR -\NC os2_subyoff \NC number \NC \NC\NR -\NC os2_supxsize \NC number \NC \NC\NR -\NC os2_supysize \NC number \NC \NC\NR -\NC os2_supxoff \NC number \NC \NC\NR -\NC os2_supyoff \NC number \NC \NC\NR -\NC os2_strikeysize \NC number \NC \NC\NR -\NC os2_strikeypos \NC number \NC \NC\NR -\NC os2_family_class \NC number \NC \NC\NR -\NC os2_xheight \NC number \NC \NC\NR -\NC os2_capheight \NC number \NC \NC\NR -\NC os2_defaultchar \NC number \NC \NC\NR -\NC os2_breakchar \NC number \NC \NC\NR -\NC os2_vendor \NC string \NC \NC\NR -\NC codepages \NC table \NC A two-number array of encoded code pages\NC\NR -\NC unicoderages \NC table \NC A four-number array of encoded unicode ranges\NC\NR -\NC panose \NC table \NC \NC\NR -\stoptabulate - -The \type{panose} subtable has exactly 10 string keys: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC familytype \NC string \NC Values as in the \OPENTYPE\ font specification: - \type {Any}, \type {No Fit}, \type {Text and Display}, \type {Script}, - \type {Decorative}, \type {Pictorial} \NC\NR -\NC serifstyle \NC string \NC See the \OPENTYPE\ font specification for values\NC\NR -\NC weight \NC string \NC id. \NC\NR -\NC proportion \NC string \NC id. \NC\NR -\NC contrast \NC string \NC id. \NC\NR -\NC strokevariation \NC string \NC id. \NC\NR -\NC armstyle \NC string \NC id. \NC\NR -\NC letterform \NC string \NC id. \NC\NR -\NC midline \NC string \NC id. \NC\NR -\NC xheight \NC string \NC id. \NC\NR -\stoptabulate - -\subsubsubsection[fontloadernamestable]{names table} - -Each item has two top|-|level keys: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC lang \NC string \NC language for this entry \NC\NR -\NC names \NC table \NC \NC\NR -\stoptabulate - -The \type{names} keys are the actual \TRUETYPE\ name strings. The -possible keys are: - -\starttabulate[|lT|p|] -\NC \ssbf key \NC \bf explanation \NC\NR -\NC copyright \NC \NC\NR -\NC family \NC \NC\NR -\NC subfamily \NC \NC\NR -\NC uniqueid \NC \NC\NR -\NC fullname \NC \NC\NR -\NC version \NC \NC\NR -\NC postscriptname \NC \NC\NR -\NC trademark \NC \NC\NR -\NC manufacturer \NC \NC\NR -\NC designer \NC \NC\NR -\NC descriptor \NC \NC\NR -\NC venderurl \NC \NC\NR -\NC designerurl \NC \NC\NR -\NC license \NC \NC\NR -\NC licenseurl \NC \NC\NR -\NC idontknow \NC \NC\NR -\NC preffamilyname \NC \NC\NR -\NC prefmodifiers \NC \NC\NR -\NC compatfull \NC \NC\NR -\NC sampletext \NC \NC\NR -\NC cidfindfontname \NC \NC\NR -\NC wwsfamily \NC \NC\NR -\NC wwssubfamily \NC \NC\NR -\stoptabulate - -\subsubsubsection{anchor_classes table} - -The anchor_classes classes: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC name \NC string \NC a descriptive id of this anchor class\NC\NR -\NC lookup \NC string \NC \NC\NR -\NC type \NC string \NC one of \type {mark}, \type {mkmk}, \type {curs}, \type {mklg} \NC\NR -\stoptabulate - -% type is actually a lookup subtype, not a feature name. Officially, these strings -% should be gpos_mark2mark etc. - -\subsubsubsection{gpos table} - -Th gpos table has one array entry for each lookup. (The \type {gpos_} prefix is somewhat redundant.) - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC type \NC string \NC one of - \type {gpos_single}, \type {gpos_pair}, \type {gpos_cursive}, - \type {gpos_mark2base},\crlf \type {gpos_mark2ligature}, \type {gpos_mark2mark}, \type {gpos_context},\crlf - \type {gpos_contextchain} -\NC\NR -\NC flags \NC table \NC \NC\NR -\NC name \NC string \NC \NC\NR -\NC features \NC array \NC \NC\NR -\NC subtables \NC array \NC \NC\NR -\stoptabulate - -The flags table has a true value for each of the lookup flags that is -actually set: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC r2l \NC boolean \NC \NC\NR -\NC ignorebaseglyphs \NC boolean \NC \NC\NR -\NC ignoreligatures \NC boolean \NC \NC\NR -\NC ignorecombiningmarks \NC boolean \NC \NC\NR -\NC mark_class \NC string \NC (new in 0.44)\NC\NR -\stoptabulate - - -The features subtable items of gpos have: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC tag \NC string \NC \NC\NR -\NC scripts \NC table \NC \NC\NR -\stoptabulate - -The scripts table within features has: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC script \NC string \NC \NC\NR -\NC langs \NC array of strings \NC \NC\NR -\stoptabulate - - -The subtables table has: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC name \NC string \NC \NC\NR -\NC suffix \NC string \NC (only if used)\NC\NR % used by gpos_single to get a default -\NC anchor_classes \NC number \NC (only if used)\NC\NR -\NC vertical_kerning \NC number \NC (only if used)\NC\NR -\NC kernclass \NC table \NC (only if used)\NC\NR -\stoptabulate - - -The kernclass with subtables table has: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC firsts \NC array of strings \NC \NC\NR -\NC seconds \NC array of strings \NC \NC\NR -\NC lookup \NC string or array \NC associated lookup(s) \NC \NR -\NC offsets \NC array of numbers \NC \NC\NR -\stoptabulate - -\subsubsubsection{gsub table} - -This has identical layout to the \type{gpos} table, except for the -type: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC type \NC string \NC one of \type {gsub_single}, \type {gsub_multiple}, \type {gsub_alternate}, - \type {gsub_ligature},\crlf \type {gsub_context}, \type {gsub_contextchain}, \type {gsub_reversecontextchain} -\NC\NR -\stoptabulate - - - -\subsubsubsection{ttf_tables and ttf_tab_saved tables} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC tag \NC string \NC \NC\NR -\NC len \NC number \NC \NC\NR -\NC maxlen \NC number \NC \NC\NR -\NC data \NC number \NC \NC\NR -\stoptabulate - -\subsubsubsection{mm table} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC axes \NC table \NC array of axis names \NC \NR -\NC instance_count \NC number \NC \NC \NR -\NC positions \NC table \NC array of instance positions - (\#axes * instances )\NC \NR -\NC defweights \NC table \NC array of default weights for instances \NC \NR -\NC cdv \NC string \NC \NC \NR -\NC ndv \NC string \NC \NC \NR -\NC axismaps \NC table \NC \NC \NR -\stoptabulate - -The \type{axismaps}: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC blends \NC table \NC an array of blend points \NC \NR -\NC designs \NC table \NC an array of design values \NC \NR -\NC min \NC number \NC \NC \NR -\NC def \NC number \NC \NC \NR -\NC max \NC number \NC \NC \NR -\stoptabulate - - -\subsubsubsection{mark_classes table (0.44)} - -The keys in this table are mark class names, and the values -are a space-separated string of glyph names in this class. - -Note: This table is indeed new in 0.44. The manual said it existed -before then, but in practise it was missing due to a bug. - -\subsubsubsection{math table} - -\starttabulate[|lT|p|] -\NC ScriptPercentScaleDown \NC \NC \NR -\NC ScriptScriptPercentScaleDown \NC \NC \NR -\NC DelimitedSubFormulaMinHeight \NC \NC \NR -\NC DisplayOperatorMinHeight \NC \NC \NR -\NC MathLeading \NC \NC \NR -\NC AxisHeight \NC \NC \NR -\NC AccentBaseHeight \NC \NC \NR -\NC FlattenedAccentBaseHeight \NC \NC \NR -\NC SubscriptShiftDown \NC \NC \NR -\NC SubscriptTopMax \NC \NC \NR -\NC SubscriptBaselineDropMin \NC \NC \NR -\NC SuperscriptShiftUp \NC \NC \NR -\NC SuperscriptShiftUpCramped \NC \NC \NR -\NC SuperscriptBottomMin \NC \NC \NR -\NC SuperscriptBaselineDropMax \NC \NC \NR -\NC SubSuperscriptGapMin \NC \NC \NR -\NC SuperscriptBottomMaxWithSubscript \NC \NC \NR -\NC SpaceAfterScript \NC \NC \NR -\NC UpperLimitGapMin \NC \NC \NR -\NC UpperLimitBaselineRiseMin \NC \NC \NR -\NC LowerLimitGapMin \NC \NC \NR -\NC LowerLimitBaselineDropMin \NC \NC \NR -\NC StackTopShiftUp \NC \NC \NR -\NC StackTopDisplayStyleShiftUp \NC \NC \NR -\NC StackBottomShiftDown \NC \NC \NR -\NC StackBottomDisplayStyleShiftDown \NC \NC \NR -\NC StackGapMin \NC \NC \NR -\NC StackDisplayStyleGapMin \NC \NC \NR -\NC StretchStackTopShiftUp \NC \NC \NR -\NC StretchStackBottomShiftDown \NC \NC \NR -\NC StretchStackGapAboveMin \NC \NC \NR -\NC StretchStackGapBelowMin \NC \NC \NR -\NC FractionNumeratorShiftUp \NC \NC \NR -\NC FractionNumeratorDisplayStyleShiftUp \NC \NC \NR -\NC FractionDenominatorShiftDown \NC \NC \NR -\NC FractionDenominatorDisplayStyleShiftDown \NC \NC \NR -\NC FractionNumeratorGapMin \NC \NC \NR -\NC FractionNumeratorDisplayStyleGapMin \NC \NC \NR -\NC FractionRuleThickness \NC \NC \NR -\NC FractionDenominatorGapMin \NC \NC \NR -\NC FractionDenominatorDisplayStyleGapMin \NC \NC \NR -\NC SkewedFractionHorizontalGap \NC \NC \NR -\NC SkewedFractionVerticalGap \NC \NC \NR -\NC OverbarVerticalGap \NC \NC \NR -\NC OverbarRuleThickness \NC \NC \NR -\NC OverbarExtraAscender \NC \NC \NR -\NC UnderbarVerticalGap \NC \NC \NR -\NC UnderbarRuleThickness \NC \NC \NR -\NC UnderbarExtraDescender \NC \NC \NR -\NC RadicalVerticalGap \NC \NC \NR -\NC RadicalDisplayStyleVerticalGap \NC \NC \NR -\NC RadicalRuleThickness \NC \NC \NR -\NC RadicalExtraAscender \NC \NC \NR -\NC RadicalKernBeforeDegree \NC \NC \NR -\NC RadicalKernAfterDegree \NC \NC \NR -\NC RadicalDegreeBottomRaisePercent \NC \NC \NR -\NC MinConnectorOverlap \NC \NC \NR -\NC FractionDelimiterSize \NC (new in 0.47.0)\NC \NR -\NC FractionDelimiterDisplayStyleSize \NC (new in 0.47.0)\NC \NR -\stoptabulate - -\subsubsubsection{validation_state table} - -\starttabulate[|lT|p|] -\NC \ssbf key \NC \bf explanation \NC\NR -\NC bad_ps_fontname \NC \NC \NR -\NC bad_glyph_table \NC \NC \NR -\NC bad_cff_table \NC \NC \NR -\NC bad_metrics_table \NC \NC \NR -\NC bad_cmap_table \NC \NC \NR -\NC bad_bitmaps_table \NC \NC \NR -\NC bad_gx_table \NC \NC \NR -\NC bad_ot_table \NC \NC \NR -\NC bad_os2_version \NC \NC \NR -\NC bad_sfnt_header \NC \NC \NR -\stoptabulate - -\subsubsubsection{horiz_base and vert_base table} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC tags \NC table \NC an array of script list tags\NC \NR -\NC scripts \NC table \NC \NC \NR -\stoptabulate - - -The \type{scripts} subtable: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC baseline \NC table \NC \NC \NR -\NC default_baseline \NC number \NC \NC \NR -\NC lang \NC table \NC \NC \NR -\stoptabulate - - -The \type{lang} subtable: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC tag \NC string \NC a script tag \NC \NR -\NC ascent \NC number \NC \NC \NR -\NC descent \NC number \NC \NC \NR -\NC features \NC table \NC \NC \NR -\stoptabulate - -The \type{features} points to an array of tables with the same layout -except that in those nested tables, the tag represents a language. - -\subsubsubsection{altuni table} - -An array of alternate \UNICODE\ values. Inside that array -are hashes with: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC unicode \NC number \NC this glyph is also used for this unicode\NC \NR -\NC variant \NC number \NC the alternative is driven by this unicode selector\NC \NR -\stoptabulate - -\subsubsubsection{vert_variants and horiz_variants table} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC variants \NC string \NC \NC \NR -\NC italic_correction \NC number \NC \NC \NR -\NC parts \NC table \NC \NC \NR -\stoptabulate - -The \type{parts} table is an array of smaller tables: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC component \NC string \NC \NC \NR -\NC extender \NC number \NC \NC \NR -\NC start \NC number \NC \NC \NR -\NC end \NC number \NC \NC \NR -\NC advance \NC number \NC \NC \NR -\stoptabulate - - -\subsubsubsection{mathkern table} - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC top_right \NC table \NC \NC \NR -\NC bottom_right \NC table \NC \NC \NR -\NC top_left \NC table \NC \NC \NR -\NC bottom_left \NC table \NC \NC \NR -\stoptabulate - -Each of the subtables is an array of small hashes with two keys: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC height \NC number \NC \NC \NR -\NC kern \NC number \NC \NC \NR -\stoptabulate - -\subsubsubsection{kerns table} - -Substructure is identical to the per|-|glyph subtable. - -\subsubsubsection{vkerns table} - -Substructure is identical to the per|-|glyph subtable. - -\subsubsubsection{texdata table} - - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC type \NC string \NC \type {unset}, \type {text}, \type {math}, \type {mathext}\NC\NR -\NC params \NC array \NC 22 font numeric parameters\NC\NR -\stoptabulate - -\subsubsubsection{lookups table} - -Top|-|level \type{lookups} is quite different from the ones at -character level. The keys in this hash are strings, the values the -actual lookups, represented as dictionary tables. - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC type \NC string \NC \NC\NR -\NC format \NC enum \NC one of \type {glyphs}, \type {class}, \type {coverage}, \type {reversecoverage} \NC\NR -\NC tag \NC string \NC \NC\NR -\NC current_class \NC array \NC \NC\NR -\NC before_class \NC array \NC \NC\NR -\NC after_class \NC array \NC \NC\NR -\NC rules \NC array \NC an array of rule items\NC\NR -\stoptabulate - -Rule items have one common item and one specialized item: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC lookups \NC array \NC a linear array of lookup names\NC\NR -\NC glyphs \NC array \NC only if the parent's format is \type{glyphs}\NC\NR -\NC class \NC array \NC only if the parent's format is \type{class}\NC\NR -\NC coverage \NC array \NC only if the parent's format is \type{coverage}\NC\NR -\NC reversecoverage \NC array \NC only if the parent's format is \type{reversecoverage}\NC\NR -\stoptabulate - -A glyph table is: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC names \NC string \NC \NC\NR -\NC back \NC string \NC \NC\NR -\NC fore \NC string \NC \NC\NR -\stoptabulate - -A class table is: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC current \NC array \NC of numbers \NC\NR -\NC before \NC array \NC of numbers \NC\NR -\NC after \NC array \NC of numbers \NC\NR -\stoptabulate - -coverage: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC current \NC array \NC of strings \NC\NR -\NC before \NC array \NC of strings\NC\NR -\NC after \NC array \NC of strings \NC\NR -\stoptabulate - -reversecoverage: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC current \NC array \NC of strings \NC\NR -\NC before \NC array \NC of strings\NC\NR -\NC after \NC array \NC of strings \NC\NR -\NC replacements \NC string \NC \NC\NR -\stoptabulate - -%*********************************************************************** - -\section{The \luatex{img} library} - -The \type{img} library can be used as an alternative to -\tex{pdfximage} and \tex{pdfrefximage}, and the associated \quote {satellite} -commands like \tex{pdfximagebbox}. -Image objects can also be used within virtual fonts -via the \type{image} command listed in~\in{section}[virtualfonts]. - -\subsection{\luatex{img.new}} - -\startfunctioncall -<image> var = img.new() -<image> var = img.new(<table> image_spec) -\stopfunctioncall - -This function creates a userdata object of type \quote {image}. The -\type{image_spec} argument is optional. If it is given, it must be -a table, and that table must contain a \type{filename} key. A number of -other keys can also be useful, these are explained below. - -You can either say - -\starttyping -a = img.new() -\stoptyping - -followed by - -\starttyping -a.filename = "foo.png" -\stoptyping - -or you can put the file name (and some or all of the other keys) -into a table directly, like so: - -\starttyping -a = img.new({filename='foo.pdf', page=1}) -\stoptyping - -The generated \type{<image>} userdata object allows access to a set of -user|-|specified values as well as a set of values that are normally -filled in and updated automatically by \LUATEX\ itself. Some of those -are derived from the actual image file, others are updated to reflect -the \PDF\ output status of the object. - -There is one required user-specified field: the file name -(\type{filename}). It can optionally be augmented by the requested -image dimensions (\type{width}, \type{depth}, \type{height}), -user-specified image attributes (\type{attr}), the requested \PDF\ page -identifier (\type{page}), the requested boundingbox (\type{pagebox}) -for \PDF\ inclusion, the requested color space object (\type{colorspace}). - -The function \type{img.new} does not access the actual image file, it -just creates the \type{<image>} userdata object and initializes some -memory structures. The \type{<image>} object and its internal -structures are automatically garbage collected. - -Once the image is scanned, all the values in the \type{<image>} -except \type{width}, \type{height} and \type{depth}, become frozen, -and you cannot change them any more. - -\subsection{\luatex{img.keys}} - -\startfunctioncall -<table> keys = img.keys() -\stopfunctioncall - -This function returns a list of all the possible \type{image_spec} -keys, both user-supplied and automatic ones. - -% hahe: i need to add r/w ro column... -\starttabulate[|l|l|p|] -\NC \bf field name\NC \bf type \NC description \NC \NR -\NC attr \NC string \NC the image attributes for \LUATEX \NC \NR -\NC bbox \NC table \NC table with 4 boundingbox dimensions - \type{llx}, \type{lly}, \type{urx}, - and \type{ury} overruling the \type{pagebox} - entry\NC \NR -\NC colordepth \NC number \NC the number of bits used by the color space\NC \NR -\NC colorspace \NC number \NC the color space object number \NC \NR -\NC depth \NC number \NC the image depth for \LUATEX\ - (in scaled points)\NC \NR -\NC filename \NC string \NC the image file name \NC \NR -\NC filepath \NC string \NC the full (expanded) file name of the image\NC \NR -\NC height \NC number \NC the image height for \LUATEX\ - (in scaled points)\NC \NR -\NC imagetype \NC string \NC one of \type{pdf}, \type{png}, \type{jpg}, \type{jp2}, - \type{jbig2}, or \type{nil} \NC \NR -\NC index \NC number \NC the \PDF\ image name suffix \NC \NR -\NC objnum \NC number \NC the \PDF\ image object number \NC \NR -\NC page \NC ?? \NC the identifier for the requested image page - (type is number or string, - default is the number 1)\NC \NR -\NC pagebox \NC string \NC the requested bounding box, one of - \type {none}, \type {media}, \type {crop}, - \type {bleed}, \type {trim}, \type {art} \NC \NR -\NC pages \NC number \NC the total number of available pages \NC \NR -\NC rotation \NC number \NC the image rotation from included \PDF\ file, - in multiples of 90~deg. \NC \NR -\NC stream \NC string \NC the raw stream data for an \type{/Xobject} - \type{/Form} object\NC \NR -\NC transform \NC number \NC the image transform, integer number 0..7\NC \NR -\NC width \NC number \NC the image width for \LUATEX\ - (in scaled points)\NC \NR -\NC xres \NC number \NC the horizontal natural image resolution - (in \DPI) \NC \NR -\NC xsize \NC number \NC the natural image width \NC \NR -\NC yres \NC number \NC the vertical natural image resolution - (in \DPI) \NC \NR -\NC ysize \NC number \NC the natural image height \NC \NR -\stoptabulate - -A running (undefined) dimension in \type{width}, \type{height}, or \type{depth} is -represented as \type{nil} in \LUA, so if you want to load an image at -its \quote {natural} size, you do not have to specify any of those three fields. - -The \type{stream} parameter allows to fabricate an \type{/XObject} \type{/Form} -object from a string giving the stream contents, -e.\,g., for a filled rectangle: - -\startfunctioncall -a.stream = "0 0 20 10 re f" -\stopfunctioncall - -When writing the image, an \type{/Xobject} \type{/Form} object is created, -like with embedded \PDF\ file writing. The object is written out only once. -The \type{stream} key requires that also the \type{bbox} table is given. -The \type{stream} key conflicts with the \type{filename} key. -The \type{transform} key works as usual also with \type{stream}. - -The \type{bbox} key needs a table with four boundingbox values, e.\,g.: - -\startfunctioncall -a.bbox = {"30bp", 0, "225bp", "200bp"} -\stopfunctioncall - -This replaces and overrules any given \type{pagebox} value; -with given \type{bbox} the box dimensions coming with an embedded \PDF\ file -are ignored. -The \type{xsize} and \type{ysize} dimensions are set accordingly, -when the image is scaled. -The \type{bbox} parameter is ignored for non-\PDF\ images. - -The \type{transform} allows to mirror and rotate the image in steps of 90~deg. -The default value~0 gives an unmirrored, unrotated image. -Values 1|--|3 give counterclockwise rotation by 90, 180, or 270~degrees, -whereas with values 4|--|7 the image is first mirrored -and then rotated counterclockwise by 90, 180, or 270~degrees. -The \type{transform} operation gives the same visual result -as if you would externally preprocess the image by a graphics tool -and then use it by \LUATEX. -If a \PDF\ file to be embedded already contains a \type{/Rotate} specification, -the rotation result is the combination of the \type{/Rotate} rotation -followed by the \type{transform} operation. - -\subsection{\luatex{img.scan}} - -\startfunctioncall -<image> var = img.scan(<image> var) -<image> var = img.scan(<table> image_spec) -\stopfunctioncall - -When you say \type{img.scan(a)} for a new image, the file is scanned, -and variables such as \type{xsize}, \type{ysize}, image \type{type}, number of -\type{pages}, and the resolution are extracted. Each of the \type{width}, -\type{height}, \type{depth} fields are set up according to the image dimensions, -if they were not given an explicit value already. -An image file will never be scanned more than once for a given image variable. -With all subsequent \type{img.scan(a)} calls only the dimensions are again -set up (if they have been changed by the user in the meantime). - -For ease of use, you can do right-away a - -\starttyping -<image> a = img.scan ({ filename = "foo.png" }) -\stoptyping - -without a prior \type{img.new}. - -Nothing is written yet at this point, so you can do \type{a=img.scan}, -retrieve the available info like image width and height, and then -throw away \type{a} again by saying \type{a=nil}. In that case no -image object will be reserved in the PDF, and the used memory will be -cleaned up automatically. - -\subsection{\luatex{img.copy}} - -\startfunctioncall -<image> var = img.copy(<image> var) -<image> var = img.copy(<table> image_spec) -\stopfunctioncall - -If you say \type{a = b}, then both variables point to the same -\type{<image>} object. if you want to write out an image with -different sizes, you can do a \type{b=img.copy(a)}. - -Afterwards, \type{a} and \type{b} still reference the same actual -image dictionary, but the dimensions for \type{b} can now be changed -from their initial values that were just copies from \type{a}. - -% Hartmut, I don't know if this makes sense. An example of what -% can, and what cannot be changed would be helpful. -% -- will think about it... - -\subsection{\luatex{img.write}} - -\startfunctioncall -<image> var = img.write(<image> var) -<image> var = img.write(<table> image_spec) -\stopfunctioncall - -By \type{img.write(a)} a \PDF\ object number is allocated, -and a whatsit node of subtype \type{pdf_refximage} is generated -and put into the output list. -By this the image \type{a} is placed into the page stream, -and the image file is written out into an image stream object -after the shipping of the current page is finished. - -Again you can do a terse call like - -\starttyping -img.write ({ filename = "foo.png" }) -\stoptyping - -The \type{<image>} variable is returned in case you want it for later -processing. - -\subsection{\luatex{img.immediatewrite}} - -\startfunctioncall -<image> var = img.immediatewrite(<image> var) -<image> var = img.immediatewrite(<table> image_spec) -\stopfunctioncall - -By \type{img.immediatewrite(a)} a \PDF\ object number is -allocated, and the image file for image \type{a} is written out -immediately into the \PDF\ file as an image stream object (like -with \tex{immediate}\tex{pdfximage}). The object number of the image -stream dictionary is then available by the \type{objnum} key. No -\type{pdf_refximage} whatsit node is generated. You will need an -\luatex{img.write(a)} or \luatex{img.node(a)} call to let the -image appear on the page, or reference it by another trick; else -you will have a dangling image object in the \PDF\ file. - -Also here you can do a terse call like - -\starttyping -a = img.immediatewrite ({ filename = "foo.png" }) -\stoptyping - -The \type{<image>} variable is returned and you will most likely need it. - -\subsection{\luatex{img.node}} - -\startfunctioncall -<node> n = img.node(<image> var) -<node> n = img.node(<table> image_spec) -\stopfunctioncall - -This function allocates a \PDF\ object number and returns a -whatsit node of subtype \type{pdf_refximage}, filled with the -image parameters \type{width}, \type{height}, \type{depth}, and -\type{objnum}. Also here you can do a terse call like: - -\starttyping -n = img.node ({ filename = "foo.png" }) -\stoptyping - -This example outputs an image: - -\starttyping -node.write(img.node{filename="foo.png"}) -\stoptyping - -\subsection{\luatex{img.types}} - -\startfunctioncall -<table> types = img.types() -\stopfunctioncall - -This function returns a list with the supported image file type names, -currently these are \type{pdf}, \type{png}, \type{jpg}, \type{jp2} (JPEG~2000), -and \type{jbig2}. - -\subsection{\luatex{img.boxes}} - -\startfunctioncall -<table> boxes = img.boxes() -\stopfunctioncall - -This function returns a list with the supported \PDF\ page box names, -currently these are \type {media}, \type {crop}, \type {bleed}, \type {trim}, and \type {art} -(all in lowercase letters). - -%*********************************************************************** - -\section{The \luatex{kpse} library} - -This library provides two separate, but nearly identical interfaces to -the \KPATHSEA\ file search functionality: there is a \quote{normal} -procedural interface that shares its kpathsea instance with \LUATEX\ -itself, and an object oriented interface that is completely on its -own. The object oriented interface and \type{kpse.new} have been added -in \LUATEX\ 0.37. - -\subsection{\luatex{kpse.set_program_name} and \luatex{kpse.new}} - -Before the search library can be used at all, its database has to be -initialized. There are three possibilities, two of which belong to the -procedural interface. - -First, when \LUATEX\ is used to typeset documents, this initialization -happens automatically and the \KPATHSEA\ executable and program names -are set to \type{luatex} (that is, unless explicitly prohibited by the -user's startup script. See~\in{section}[init] for more details). - -Second, in \TEXLUA\ mode, the initialization has to be done explicitly -via the \luatex{kpse.set_program_name} function, which sets the -\KPATHSEA\ executable (and optionally program) name. - -\startfunctioncall -kpse.set_program_name(<string> name) -kpse.set_program_name(<string> name, <string> progname) -\stopfunctioncall - -The second argument controls the use of the \quote{dotted} values in the -\type{texmf.cnf} configuration file, and defaults to the first argument. - -Third, if you prefer the object oriented interface, you have to call a -different function. It has the same arguments, but it returns a -userdata variable. - -\startfunctioncall -local kpathsea = kpse.new(<string> name) -local kpathsea = kpse.new(<string> name, <string> progname) -\stopfunctioncall - -Apart from these two functions, the calling conventions of the -interfaces are identical. Depending on the chosen interface, you -either call \type{kpse.find_file()} or \type{kpathsea:find_file()}, -with identical arguments and return vales. - -\subsection{\luatex{find_file}} - -The most often used function in the library is find_file: - -\startfunctioncall -<string> f = kpse.find_file(<string> filename) -<string> f = kpse.find_file(<string> filename, <string> ftype) -<string> f = kpse.find_file(<string> filename, <boolean> mustexist) -<string> f = kpse.find_file(<string> filename, <string> ftype, <boolean> mustexist) -<string> f = kpse.find_file(<string> filename, <string> ftype, <number> dpi) -\stopfunctioncall - -Arguments: -\startitemize[intro] - -\sym{filename} - -the name of the file you want to find, with or without extension. - -\sym{ftype} - -maps to the \type {-format} argument of \KPSEWHICH. The supported - \type{ftype} values are the same as the ones supported by the -standalone \type{kpsewhich} program: - -\startsimplecolumns -\starttyping -'gf' -'pk' -'bitmap font' -'tfm' -'afm' -'base' -'bib' -'bst' -'cnf' -'ls-R' -'fmt' -'map' -'mem' -'mf' -'mfpool' -'mft' -'mp' -'mppool' -'MetaPost support' -'ocp' -'ofm' -'opl' -'otp' -'ovf' -'ovp' -'graphic/figure' -'tex' -'TeX system documentation' -'texpool' -'TeX system sources' -'PostScript header' -'Troff fonts' -'type1 fonts' -'vf' -'dvips config' -'ist' -'truetype fonts' -'type42 fonts' -'web2c files' -'other text files' -'other binary files' -'misc fonts' -'web' -'cweb' -'enc files' -'cmap files' -'subfont definition files' -'opentype fonts' -'pdftex config' -'lig files' -'texmfscripts' -'lua', -'font feature files', -'cid maps', -'mlbib', -'mlbst', -'clua', -\stoptyping -\stopsimplecolumns - -The default type is \type{tex}. Note: this is different from -\KPSEWHICH, which tries to deduce the file type itself from -looking at the supplied extension. The last four types: -'font feature files', 'cid maps', 'mlbib', 'mlbst' were new -additions in \LUATEX\ 0.40.2. - - -\sym{mustexist} - -is similar to \KPSEWHICH's \type{-must-exist}, and the default is \type{false}. -If you specify \type{true} (or a non|-|zero integer), then the \KPSE\ library -will search the disk as well as the \type {ls-R} databases. - -\sym{dpi} - -This is used for the size argument of the formats \type{pk}, \type{gf}, and \type{bitmap font}. -\stopitemize - -\subsection{\luatex{lookup}} - -A more powerful (but slower) generic method for finding files is also -available (since 0.51). It returns a string for each found file. - -\startfunctioncall -<string> f, ... = kpse.lookup(<string> filename, <table> options) -\stopfunctioncall - -The options match commandline arguments from \type{kpsewhich}: - -\starttabulate[|l|l|p|] -\NC \ssbf key \NC \ssbf type \NC \ssbf description \NC \NR -\NC debug \NC number \NC set debugging flags for this lookup\NC \NR -\NC format \NC string \NC use specific file type (see list above)\NC \NR -\NC dpi \NC number \NC use this resolution for this lookup; default 600\NC \NR -\NC path \NC string \NC search in the given path\NC \NR -\NC all \NC boolean \NC output all matches, not just the first\NC \NR -\NC mustexist \NC boolean \NC (0.65 and higher) search the disk as well as ls-R if necessary\NC \NR -\NC must-exist\NC boolean \NC (0.64 and lower) search the disk as well as ls-R if necessary\NC \NR -\NC mktexpk \NC boolean \NC disable/enable mktexpk generation for this lookup\NC \NR -\NC mktextex \NC boolean \NC disable/enable mktextex generation for this lookup\NC \NR -\NC mktexmf \NC boolean \NC disable/enable mktexmf generation for this lookup\NC \NR -\NC mktextfm \NC boolean \NC disable/enable mktextfm generation for this lookup\NC \NR -\NC subdir \NC string - or table \NC only output matches whose directory part - ends with the given string(s) \NC \NR -\stoptabulate - -\subsection{\luatex{init_prog}} - -Extra initialization for programs that need to generate bitmap fonts. - -\startfunctioncall -kpse.init_prog(<string> prefix, <number> base_dpi, <string> mfmode) -kpse.init_prog(<string> prefix, <number> base_dpi, <string> mfmode, <string> fallback) -\stopfunctioncall - - -\subsection{\luatex{readable_file}} - -Test if an (absolute) file name is a readable file. - -\startfunctioncall -<string> f = kpse.readable_file(<string> name) -\stopfunctioncall - -The return value is the actual absolute filename you should use, -because the disk name is not always the same as the requested name, -due to aliases and system|-|specific handling under e.\,g.\ \MSDOS. - -Returns \lua {nil} if the file does not exist or is not readable. - -\subsection{\luatex{expand_path}} - -Like kpsewhich's \type {-expand-path}: - -\startfunctioncall -<string> r = kpse.expand_path(<string> s) -\stopfunctioncall - -\subsection{\luatex{expand_var}} - -Like kpsewhich's \type{-expand-var}: - -\startfunctioncall -<string> r = kpse.expand_var(<string> s) -\stopfunctioncall - -\subsection{\luatex{expand_braces}} - -Like kpsewhich's \type{-expand-braces}: - -\startfunctioncall -<string> r = kpse.expand_braces(<string> s) -\stopfunctioncall - -\subsection{\luatex{show_path}} - -Like kpsewhich's \type{-show-path}: - -\startfunctioncall -<string> r = kpse.show_path(<string> ftype) -\stopfunctioncall - - -\subsection{\luatex{var_value}} - -Like kpsewhich's \type{-var-value}: - -\startfunctioncall -<string> r = kpse.var_value(<string> s) -\stopfunctioncall - -\subsection{\luatex{version}} - -Returns the kpathsea version string (new in 0.51) - -\startfunctioncall -<string> r = kpse.version() -\stopfunctioncall - - -\section{The \luatex{lang} library} - -This library provides the interface to \LUATEX's structure -representing a language, and the associated functions. - -\startfunctioncall -<language> l = lang.new() -<language> l = lang.new(<number> id) -\stopfunctioncall - -This function creates a new userdata object. An object of type -\type{<language>} is the first argument to most of the other functions -in the \luatex{lang} library. These functions can also be used as if -they were object methods, using the colon syntax. - -Without an argument, the next available internal id number will be -assigned to this object. With argument, an object will be created that -links to the internal language with that id number. - -\startfunctioncall -<number> n = lang.id(<language> l) -\stopfunctioncall - -returns the internal \tex{language} id number this object refers to. - -\startfunctioncall -<string> n = lang.hyphenation(<language> l) -lang.hyphenation(<language> l, <string> n) -\stopfunctioncall - -Either returns the current hyphenation exceptions for this language, -or adds new ones. The syntax of the string is explained in~\in{section}[patternsexceptions]. - -\startfunctioncall -lang.clear_hyphenation(<language> l) -\stopfunctioncall - -Clears the exception dictionary for this language. - -\startfunctioncall -<string> n = lang.clean(<string> o) -\stopfunctioncall - -Creates a hyphenation key from the supplied hyphenation value. The -syntax of the argument string is explained in~\in{section}[patternsexceptions]. -This function is useful if -you want to do something else based on the words in a dictionary file, -like spell-checking. - -\startfunctioncall -<string> n = lang.patterns(<language> l) -lang.patterns(<language> l, <string> n) -\stopfunctioncall - -Adds additional patterns for this language object, or returns the -current set. The syntax of this string is explained in~\in{section}[patternsexceptions]. - -\startfunctioncall -lang.clear_patterns(<language> l) -\stopfunctioncall - -Clears the pattern dictionary for this language. - -\startfunctioncall -<number> n = lang.prehyphenchar(<language> l) -lang.prehyphenchar(<language> l, <number> n) -\stopfunctioncall - -Gets or sets the \quote{pre|-|break} hyphen character for implicit -hyphenation in this language (initially the hyphen, decimal 45). - -\startfunctioncall -<number> n = lang.posthyphenchar(<language> l) -lang.posthyphenchar(<language> l, <number> n) -\stopfunctioncall - -Gets or sets the \quote{post|-|break} hyphen character for implicit -hyphenation in this language (initially null, decimal~0, indicating -emptiness). - - -\startfunctioncall -<number> n = lang.preexhyphenchar(<language> l) -lang.preexhyphenchar(<language> l, <number> n) -\stopfunctioncall - -Gets or sets the \quote{pre|-|break} hyphen character for explicit -hyphenation in this language (initially null, decimal~0, indicating -emptiness). - -\startfunctioncall -<number> n = lang.postexhyphenchar(<language> l) -lang.postexhyphenchar(<language> l, <number> n) -\stopfunctioncall - -Gets or sets the \quote{post|-|break} hyphen character for explicit -hyphenation in this language (initially null, decimal~0, indicating -emptiness). - -\startfunctioncall -<boolean> success = lang.hyphenate(<node> head) -<boolean> success = lang.hyphenate(<node> head, <node> tail) -\stopfunctioncall - -Inserts hyphenation points (discretionary nodes) in a node list. If -\type{tail} is given as argument, processing stops on that node. -Currently, \type{success} is always true if \type{head} (and \type{tail}, if -specified) are proper nodes, regardless of possible other errors. - -Hyphenation works only on \quote{characters}, a special subtype of all -the glyph nodes with the node subtype having the value \type{1}. Glyph -modes with different subtypes are not processed. See -\in{section~}[charsandglyphs] for more details. - - -\section{The \luatex{lua} library} - -This library contains one read|-|only item: - -\starttyping -<string> s = lua.version -\stoptyping - -This returns the \LUA\ version identifier string. The value is -currently \directlua {tex.print(lua.version)}. - -\subsection{\LUA\ bytecode registers} - -\LUA\ registers can be used to communicate \LUA\ functions across \LUA\ -chunks. The accepted values for assignments are functions and -\type{nil}. Likewise, the retrieved value is either a function or \type{nil}. - -\starttyping -lua.bytecode[<number> n] = <function> f -lua.bytecode[<number> n]() -\stoptyping - -The contents of the \luatex{lua.bytecode} array is stored inside the format -file as actual \LUA\ bytecode, so it can also be used to preload \LUA\ code. - -Note: The function must not contain any upvalues. Currently, functions -containing upvalues can be stored (and their upvalues are set to -\type{nil}), but this is an artifact of the current \LUA\ -implementation and thus subject to change. - -The associated function calls are - -\startfunctioncall -<function> f = lua.getbytecode(<number> n) -lua.setbytecode(<number> n, <function> f) -\stopfunctioncall - -Note: Since a \LUA\ file loaded using \luatex{loadfile(filename)} is -essentially an anonymous function, a complete file can be stored in a -bytecode register like this: - -\startfunctioncall -lua.bytecode[n] = loadfile(filename) -\stopfunctioncall - -Now all definitions (functions, variables) contained in the file can be -created by executing this bytecode register: - -\startfunctioncall -lua.bytecode[n]() -\stopfunctioncall - -Note that the path of the file is stored in the \LUA\ bytecode to be -used in stack backtraces and therefore dumped into the format file if -the above code is used in \INITEX. If it contains private information, i.e. -the user name, this information is then contained in the format file as -well. This should be kept in mind when preloading files into a bytecode -register in \INITEX. - -\subsection{\LUA\ chunk name registers} - -There is an array of 65536 (0--65535) potential chunk names for use with -the \type{\directlua} and \type{\latelua} primitives. - -\startfunctioncall -lua.name[<number> n] = <string> s -<string> s = lua.name[<number> n] -\stopfunctioncall - -If you want to unset a lua name, you can assign \type{nil} to it. - - -\section{The \luatex{mplib} library} - -The \MP\ library interface registers itself in the table \type{mplib}. It -is based on \MPLIB\ version \ctxlua{tex.sprint(mplib.version())}. - -\subsection{\luatex{mplib.new}} - -To create a new \METAPOST\ instance, call - -\startfunctioncall -<mpinstance> mp = mplib.new({...}) -\stopfunctioncall - -This creates the \type{mp} instance object. The argument hash can have a number of -different fields, as follows: - -\starttabulate[|lT|l|p|p|] -\NC \ssbf name \NC \bf type \NC \bf description \NC \bf default \NC\NR -\NC error_line \NC number \NC error line width \NC 79 \NC\NR -\NC print_line \NC number \NC line length in ps output \NC 100\NC\NR -\NC random_seed \NC number \NC the initial random seed \NC variable\NC\NR -\NC interaction \NC string \NC the interaction mode, one of -\type {batch}, \type {nonstop}, \type {scroll}, \type {errorstop} \NC \type {errorstop}\NC\NR -\NC job_name \NC string \NC \type {--jobname} \NC \type {mpout} \NC\NR -\NC find_file \NC function \NC a function to find files \NC only local files\NC\NR -\stoptabulate - -The \type{find_file} function should be of this form: - -\starttyping -<string> found = finder (<string> name, <string> mode, <string> type) -\stoptyping - -with: - -\starttabulate[|lT|l|p|] -\NC \bf name \NC \bf the requested file \NC \NR -\NC mode \NC the file mode: \type {r} or \type {w} \NC \NR -\NC type \NC the kind of file, one of: \type {mp}, \type {tfm}, \type {map}, \type {pfb}, \type {enc} \NC \NR -\stoptabulate - -Return either the full pathname of the found file, or \type{nil} if -the file cannot be found. - -Note that the new version of \MPLIB\ no longer uses binary mem files, -so the way to preload a set of macros is simply to start off with -an \type{input} command in the first \type{mp:execute()} call. - - -\subsection{\luatex{mp:statistics}} - -You can request statistics with: - -\startfunctioncall -<table> stats = mp:statistics() -\stopfunctioncall - -This function returns the vital statistics for an \MPLIB\ instance. There are four -fields, giving the maximum number of used items in each of four -allocated object classes: - -\starttabulate[|lT|l|p|] -\NC main_memory \NC number \NC memory size \NC\NR -\NC hash_size \NC number \NC hash size\NC\NR -\NC param_size \NC number \NC simultaneous macro parameters\NC\NR -\NC max_in_open \NC number \NC input file nesting levels\NC\NR -\stoptabulate - -Note that in the new version of \MPLIB, this is informational only. The -objects are all allocated dynamically, so there is no chance of running -out of space unless the available system memory is exhausted. - -\subsection{\luatex{mp:execute}} - -You can ask the \METAPOST\ interpreter to run a chunk of code by calling - -\startfunctioncall -<table> rettable = mp:execute('metapost language chunk') -\stopfunctioncall - -for various bits of \METAPOST\ language input. Be sure to check the -\type{rettable.status} (see below) because when a fatal \METAPOST\ -error occurs the \MPLIB\ instance will become unusable thereafter. - -Generally speaking, it is best to keep your chunks small, but beware -that all chunks have to obey proper syntax, like each of them is a -small file. For instance, you cannot split a single statement over -multiple chunks. - -In contrast with the normal standalone \type{mpost} command, there is -{\em no\/} implied \quote{input} at the start of the first chunk. - -\subsection{\luatex{mp:finish}} - -\startfunctioncall -<table> rettable = mp:finish() -\stopfunctioncall - -If for some reason you want to stop using an \MPLIB\ instance while -processing is not yet actually done, you can call \type{mp:finish}. -Eventually, used memory will be freed and open files will be closed by -the \LUA\ garbage collector, but an explicit \type{mp:finish} is the -only way to capture the final part of the output streams. - -\subsection{Result table} - -The return value of \type{mp:execute} and \type{mp:finish} is a table -with a few possible keys (only \type {status} is always guaranteed to be present). - -\starttabulate[|l|l|p|] -\NC log \NC string \NC output to the \quote {log} stream \NC \NR -\NC term \NC string \NC output to the \quote {term} stream \NC \NR -\NC error \NC string \NC output to the \quote {error} stream (only used for \quote {out of memory})\NC \NR -\NC status \NC number \NC the return value: 0=good, 1=warning, 2=errors, 3=fatal error \NC \NR -\NC fig \NC table \NC an array of generated figures (if any)\NC \NR -\stoptabulate - -When \type{status} equals~3, you should stop using this \MPLIB\ instance -immediately, it is no longer capable of processing input. - -If it is present, each of the entries in the \type{fig} array is a -userdata representing a figure object, and each of those has a number of -object methods you can call: - -\starttabulate[|l|l|p|] -\NC boundingbox \NC function \NC returns the bounding box, as an array of 4 values\NC \NR -\NC postscript \NC function \NC returns a string that is the ps output of the \type{fig}. - this function accepts two optional integer arguments for - specifying the values of \type{prologues} (first argument) - and \type{procset} (second argument)\NC \NR -\NC svg \NC function \NC returns a string that is the svg output of the \type{fig}. - This function accepts an optional integer argument for - specifying the value of \type{prologues}\NC \NR -\NC objects \NC function \NC returns the actual array of graphic objects in this \type{fig} \NC \NR -\NC copy_objects \NC function \NC returns a deep copy of the array of graphic objects in this \type{fig} \NC \NR -\NC filename \NC function \NC the filename this \type{fig}'s \POSTSCRIPT\ output - would have written to in standalone mode\NC \NR -\NC width \NC function \NC the \type{charwd} value \NC \NR -\NC height \NC function \NC the \type{charht} value \NC \NR -\NC depth \NC function \NC the \type{chardp} value \NC \NR -\NC italcorr \NC function \NC the \type{charit} value \NC \NR -\NC charcode \NC function \NC the (rounded) \type{charcode} value \NC \NR -\stoptabulate - -{\bf NOTE:} you can call \type{fig:objects()} only once for any one \type{fig} object! - -When the boundingbox represents a \quote {negated rectangle}, i.e.\ when the first set -of coordinates is larger than the second set, the picture is empty. - -Graphical objects come in various types that each has a different list of -accessible values. The types are: \type{fill}, \type{outline}, \type{text}, -\type{start_clip}, \type{stop_clip}, \type{start_bounds}, \type{stop_bounds}, \type{special}. - -There is helper function (\type{mplib.fields(obj)}) to get the list of -accessible values for a particular object, but you can just as easily -use the tables given below. - -All graphical objects have a field \type{type} that gives the object -type as a string value; it is not explicit mentioned in the following tables. -In the following, \type{number}s are \POSTSCRIPT\ points represented as -a floating point number, unless stated otherwise. Field values that -are of type \type{table} are explained in the next section. - -\subsubsection{fill} - -\starttabulate[|l|l|p|] -\NC path \NC table \NC the list of knots \NC \NR -\NC htap \NC table \NC the list of knots for the reversed trajectory \NC \NR -\NC pen \NC table \NC knots of the pen \NC \NR -\NC color \NC table \NC the object's color \NC \NR -\NC linejoin \NC number \NC line join style (bare number)\NC \NR -\NC miterlimit \NC number \NC miterlimit\NC \NR -\NC prescript \NC string \NC the prescript text \NC \NR -\NC postscript \NC string \NC the postscript text \NC \NR -\stoptabulate - -The entries \type{htap} and \type{pen} are optional. - -There is helper function (\type{mplib.pen_info(obj)}) that returns -a table containing a bunch of vital characteristics of the used pen -(all values are floats): - -\starttabulate[|l|l|p|] -\NC width \NC number \NC width of the pen\NC \NR -\NC sx \NC number \NC $x$ scale \NC \NR -\NC rx \NC number \NC $xy$ multiplier \NC \NR -\NC ry \NC number \NC $yx$ multiplier \NC \NR -\NC sy \NC number \NC $y$ scale \NC \NR -\NC tx \NC number \NC $x$ offset \NC \NR -\NC ty \NC number \NC $y$ offset \NC \NR -\stoptabulate - -\subsubsection{outline} - -\starttabulate[|l|l|p|] -\NC path \NC table \NC the list of knots \NC \NR -\NC pen \NC table \NC knots of the pen \NC \NR -\NC color \NC table \NC the object's color \NC \NR -\NC linejoin \NC number \NC line join style (bare number)\NC \NR -\NC miterlimit \NC number \NC miterlimit \NC \NR -\NC linecap \NC number \NC line cap style (bare number)\NC \NR -\NC dash \NC table \NC representation of a dash list\NC \NR -\NC prescript \NC string \NC the prescript text \NC \NR -\NC postscript \NC string \NC the postscript text \NC \NR -\stoptabulate - -The entry \type{dash} is optional. - -\subsubsection{text} - -\starttabulate[|l|l|p|] -\NC text \NC string \NC the text \NC \NR -\NC font \NC string \NC font tfm name \NC \NR -\NC dsize \NC number \NC font size\NC \NR -\NC color \NC table \NC the object's color \NC \NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC transform \NC table \NC a text transformation \NC \NR -\NC prescript \NC string \NC the prescript text \NC \NR -\NC postscript \NC string \NC the postscript text \NC \NR -\stoptabulate - -\subsubsection{special} - -\starttabulate[|l|l|p|] -\NC prescript \NC string \NC special text \NC \NR -\stoptabulate - -\subsubsection{start_bounds, start_clip} - -\starttabulate[|l|l|p|] -\NC path \NC table \NC the list of knots \NC \NR -\stoptabulate - -\subsubsection{stop_bounds, stop_clip} - -Here are no fields available. - -\subsection{Subsidiary table formats} - -\subsubsection{Paths and pens} - -Paths and pens (that are really just a special type of paths as far as -\MPLIB\ is concerned) are represented by an array where each entry -is a table that represents a knot. - -\starttabulate[|lT|l|p|] -\NC left_type \NC string \NC when present: 'endpoint', but usually absent \NC \NR -\NC right_type \NC string \NC like \type{left_type}\NC \NR -\NC x_coord \NC number \NC X coordinate of this knot\NC \NR -\NC y_coord \NC number \NC Y coordinate of this knot\NC \NR -\NC left_x \NC number \NC X coordinate of the precontrol point of this knot\NC \NR -\NC left_y \NC number \NC Y coordinate of the precontrol point of this knot\NC \NR -\NC right_x \NC number \NC X coordinate of the postcontrol point of this knot\NC \NR -\NC right_y \NC number \NC Y coordinate of the postcontrol point of this knot\NC \NR -\stoptabulate - -There is one special case: pens that are (possibly transformed) -ellipses have an extra string-valued key \type{type} with value -\type{elliptical} besides the array part containing the knot list. - -\subsubsection{Colors} - -A color is an integer array with 0, 1, 3 or 4 values: - -\starttabulate[|l|l|p|] -\NC 0 \NC marking only \NC no values \NC\NR -\NC 1 \NC greyscale \NC one value in the range $(0,1)$, \quote {black} is $0$ \NC\NR -\NC 3 \NC \RGB \NC three values in the range $(0,1)$, \quote {black} is $0,0,0$ \NC\NR -\NC 4 \NC \CMYK \NC four values in the range $(0,1)$, \quote {black} is $0,0,0,1$ \NC\NR -\stoptabulate - -If the color model of the internal object was \type{uninitialized}, then -it was initialized to the values representing \quote {black} in the colorspace -\type{defaultcolormodel} that was in effect at the time of the \type{shipout}. - -\subsubsection{Transforms} - -Each transform is a six-item array. - -\starttabulate[|l|l|p|] -\NC 1 \NC number \NC represents x \NC\NR -\NC 2 \NC number \NC represents y \NC\NR -\NC 3 \NC number \NC represents xx \NC\NR -\NC 4 \NC number \NC represents yx \NC\NR -\NC 5 \NC number \NC represents xy \NC\NR -\NC 6 \NC number \NC represents yy \NC\NR -\stoptabulate - -Note that the translation (index 1 and 2) comes first. This differs -from the ordering in \POSTSCRIPT, where the translation comes last. - -\subsubsection{Dashes} - -Each \type{dash} is two-item hash, using the same model as \POSTSCRIPT\ -for the representation of the dashlist. \type{dashes} is an array of -\quote {on} and \quote {off}, values, and \type{offset} is the phase of the pattern. - -\starttabulate[|l|l|p|] -\NC dashes \NC hash \NC an array of on-off numbers \NC\NR -\NC offset \NC number \NC the starting offset value \NC\NR -\stoptabulate - -\subsection{Character size information} - -These functions find the size of a glyph in a defined font. The -\type{fontname} is the same name as the argument to \type{infont}; -the \type{char} is a glyph id in the range 0 to 255; the returned -\type{w} is in AFM units. - -\subsubsection{\luatex{mp:char_width}} - -\startfunctioncall -<number> w = mp:char_width(<string> fontname, <number> char) -\stopfunctioncall - -\subsubsection{\luatex{mp:char_height}} - -\startfunctioncall -<number> w = mp:char_height(<string> fontname, <number> char) -\stopfunctioncall - -\subsubsection{\luatex{mp:char_depth}} - -\startfunctioncall -<number> w = mp:char_depth(<string> fontname, <number> char) -\stopfunctioncall - -\section{The \luatex{node} library} - -The \luatex{node} library contains functions that facilitate dealing -with (lists of) nodes and their values. They allow you to create, alter, -copy, delete, and insert \LUATEX\ node objects, the core -objects within the typesetter. - -\LUATEX\ nodes are represented in \LUA\ as userdata with -the metadata type \luatex{luatex.node}. The various parts within -a node can be accessed using named fields. - -Each node has at least the three fields \type{next}, \type{id}, and -\type{subtype}: - -\startitemize[intro] - -\item The \type{next} field returns the userdata -object for the next node in a linked list of nodes, or -\type{nil}, if there is no next node. - -\item The \type{id} indicates \TEX's \quote{node type}. The field \type{id} -has a numeric value for efficiency reasons, but some of the library -functions also accept a string value instead of \type{id}. - -\item The \type{subtype} is another number. It often gives further information -about a node of a particular \type{id}, but it is most important when dealing -with \quote{whatsits}, because they are differentiated solely based on their -\type{subtype}. -\stopitemize - -The other available fields depend on the \type{id} (and for \quote{whatsits}, the -\type{subtype}) of the node. Further details on the various fields and their -meanings are given in~\in{chapter}[nodes]. - -Support for \type{unset} (alignment) nodes is partial: -they can be queried and modified from \LUA\ code, but not created. - -Nodes can be compared to each other, but: you are actually comparing -indices into the node memory. This means that equality tests can only -be trusted under very limited conditions. It will not work correctly -in any situation where one of the two nodes has been freed and|/|or -reallocated: in that case, there will be false positives. - -At the moment, memory management of nodes should still be done -explicitly by the user. Nodes are not \quote{seen} by the \LUA\ -garbage collector, so you have to call the node freeing functions -yourself when you are no longer in need of a node (list). Nodes form -linked lists without reference counting, so you have to be careful -that when control returns back to \LUATEX\ itself, you have not -deleted nodes that are still referenced from a \type{next} pointer -elsewhere, and that you did not create nodes that are referenced more -than once. - -There are statistics available with regards to the allocated node memory, -which can be handy for tracing. - -\subsection{Node handling functions} - -\subsubsection{\luatex{node.is_node}} - -\startfunctioncall -<boolean> t = node.is_node(<any> item) -\stopfunctioncall - -This function returns true if the argument is a userdata object of -type \type{<node>}. - -\subsubsection{\luatex{node.types}} - -\startfunctioncall -<table> t = node.types() -\stopfunctioncall - -This function returns an array that maps node id numbers to node type -strings, providing an overview of the possible top|-|level \type{id} -types. - -\subsubsection{\luatex{node.whatsits}} - -\startfunctioncall -<table> t = node.whatsits() -\stopfunctioncall - -\TEX's \quote{whatsits} all have the same \type{id}. The various subtypes -are defined by their \type{subtype} fields. The function is much like -\luatex{node.types}, except that it provides an array of \type{subtype} -mappings. - -\subsubsection{\luatex{node.id}} - -\startfunctioncall -<number> id = node.id(<string> type) -\stopfunctioncall - -This converts a single type name to its internal numeric -representation. - -\subsubsection{\luatex{node.subtype}} - -\startfunctioncall -<number> subtype = node.subtype(<string> type) -\stopfunctioncall - -This converts a single whatsit name to its internal numeric -representation (\type{subtype}). - -\subsubsection{\luatex{node.type}} - -\startfunctioncall -<string> type = node.type(<any> n) -\stopfunctioncall - -In the argument is a number, then this function converts an internal -numeric representation to an external string representation. -Otherwise, it will return the string \type{node} if the object -represents a node (this is new in 0.65), and \type{nil} otherwise. - -\subsubsection{\luatex{node.fields}} - -\startfunctioncall -<table> t = node.fields(<number> id) -<table> t = node.fields(<number> id, <number> subtype) -\stopfunctioncall - -This function returns an array of valid field names for a particular -type of node. If you want to get the valid fields for a -\quote{whatsit}, you have to supply the second argument also. In other -cases, any given second argument will be silently ignored. - -This function accepts string \type{id} and \type{subtype} values as -well. - -\subsubsection{\luatex{node.has_field}} - -\startfunctioncall -<boolean> t = node.has_field(<node> n, <string> field) -\stopfunctioncall - -This function returns a boolean that is only true if \type{n} is -actually a node, and it has the field. - -\subsubsection{\luatex{node.new}} - -\startfunctioncall -<node> n = node.new(<number> id) -<node> n = node.new(<number> id, <number> subtype) -\stopfunctioncall - -Creates a new node. All of the new node's fields are initialized to -either zero or \type{nil} except for \type{id} and \type{subtype} (if -supplied). If you want to create a new whatsit, then the second -argument is required, otherwise it need not be present. As with all -node functions, this function creates a node on the \TEX\ level. - -This function accepts string \type{id} and \type{subtype} values as -well. - -\subsubsection{\luatex{node.free}} - -\startfunctioncall -node.free(<node> n) -\stopfunctioncall - -Removes the node \type{n} from \TEX's memory. Be careful: no checks -are done on whether this node is still pointed to from a register or some -\type{next} field: it is up to you to make sure that the internal data -structures remain correct. - -\subsubsection{\luatex{node.flush_list}} - -\startfunctioncall -node.flush_list(<node> n) -\stopfunctioncall - -Removes the node list \type{n} and the complete node list following -\type{n} from \TEX's memory. Be careful: no checks are done on whether -any of these nodes is still pointed to from a register or some -\type{next} field: it is up to you to make sure that the internal data -structures remain correct. - -\subsubsection{\luatex{node.copy}} - -\startfunctioncall -<node> m = node.copy(<node> n) -\stopfunctioncall - -Creates a deep copy of node \type{n}, including all nested lists as in -the case of a hlist or vlist node. Only the \type{next} field is not -copied. - -\subsubsection{\luatex{node.copy_list}} - -\startfunctioncall -<node> m = node.copy_list(<node> n) -<node> m = node.copy_list(<node> n, <node> m) -\stopfunctioncall - -Creates a deep copy of the node list that starts at \type{n}. If -\type{m} is also given, the copy stops just before node \type{m}. - -Note that you cannot copy attribute lists this way, specialized functions for -dealing with attribute lists will be provided later but are not there yet. -However, there is normally no need to copy attribute lists as when you do -assignments to the \type{attr} field or make changes to specific attributes, the -needed copying and freeing takes place automatically. - -\subsubsection{\luatex{node.next} (0.65)} - -\startfunctioncall -<node> m = node.next(<node> n) -\stopfunctioncall - -Returns the node following this node, or \type{nil} if there is no -such node. - -\subsubsection{\luatex{node.prev} (0.65)} - -\startfunctioncall -<node> m = node.prev(<node> n) -\stopfunctioncall - -Returns the node preceding this node, or \type{nil} if there is no -such node. - - -\subsubsection{\luatex{node.current_attr} (0.66)} - -\startfunctioncall -<node> m = node.current_attr() -\stopfunctioncall - -Returns the currently active list of attributes, if there is one. - -The intended usage of \type{current_attr} is as follows: - -\starttyping -local x1 = node.new("glyph") -x1.attr = node.current_attr() -local x2 = node.new("glyph") -x2.attr = node.current_attr() -\stoptyping - -or: - -\starttyping -local x1 = node.new("glyph") -local x2 = node.new("glyph") -local ca = node.current_attr() -x1.attr = ca -x2.attr = ca -\stoptyping - -The attribute lists are ref counted and the assignment takes care -of incrementing the refcount. You cannot expect the value \type {ca} -to be valid any more when you assign attributes (using \type -{tex.setattribute}) or when control has been passed back to \TEX. - - -Note: this function is somewhat experimental, and it returns the {\it - actual} attribute list, not a copy thereof. -Therefore, changing any of the attributes in the list will change -these values for all nodes that have the current attribute list -assigned to them. - - -\subsubsection{\luatex{node.hpack}} - -\startfunctioncall -<node> h, <number> b = node.hpack(<node> n) -<node> h, <number> b = node.hpack(<node> n, <number> w, <string> info) -<node> h, <number> b = node.hpack(<node> n, <number> w, <string> info, <string> dir) -\stopfunctioncall - -This function creates a new hlist by packaging the list that begins at node -\type{n} into a horizontal box. With only a single argument, this box -is created using the natural width of its components. In the three -argument form, \type{info} must be either \type{additional} or -\type{exactly}, and \type{w} is the additional (\tex{hbox spread}) -or exact (\tex{hbox to}) width to be used. - -Direction support added in \LUATEX\ 0.45. - -The second return value is the badness of the generated box, -this extension was added in 0.51. - -Caveat: at this moment, there can be unexpected side|-|effects to this -function, like updating some of the \tex{marks} and \tex{inserts}. -Also note that the content of \type{h} is the original node list -\type{n}: if you call \type{node.free(h)} you will also free the -node list itself, unless you explicitly set the \type{list} field -to \type{nil} beforehand. And in a similar way, calling -\type{node.free(n)} will invalidate \type{h} as well! - -\subsubsection{\luatex{node.vpack} (since 0.36)} - -\startfunctioncall -<node> h, <number> b = node.vpack(<node> n) -<node> h, <number> b = node.vpack(<node> n, <number> w, <string> info) -<node> h, <number> b = node.vpack(<node> n, <number> w, <string> info, <string> dir) -\stopfunctioncall - -This function creates a new vlist by packaging the list that begins at node -\type{n} into a vertical box. With only a single argument, this box -is created using the natural height of its components. In the three -argument form, \type{info} must be either \type{additional} or -\type{exactly}, and \type{w} is the additional (\tex{vbox spread}) or exact (\tex{vbox to}) height to be used. - -Direction support added in \LUATEX\ 0.45. - -The second return value is the badness of the generated box, -this extension was added in 0.51. - -See the description of \type{node.hpack()} for a few memory allocation -caveats. - -\subsubsection{\luatex{node.dimensions} (0.43)} - -\startfunctioncall -<number> w, <number> h, <number> d = node.dimensions(<node> n) -<number> w, <number> h, <number> d = node.dimensions(<node> n, <string> dir) -<number> w, <number> h, <number> d = node.dimensions(<node> n, <node> t) -<number> w, <number> h, <number> d = node.dimensions(<node> n, <node> t, <string> dir) -\stopfunctioncall - -This function calculates the natural in-line dimensions of the node -list starting at node \type{n} and terminating just before node \type{t} -(or the end of the list, if there is no second argument). The return values are scaled -points. An alternative format that starts with glue parameters as the -first three arguments is also possible: - -\startfunctioncall -<number> w, <number> h, <number> d = - node.dimensions(<number> glue_set, <number> glue_sign, - <number> glue_order, <node> n) -<number> w, <number> h, <number> d = - node.dimensions(<number> glue_set, <number> glue_sign, - <number> glue_order, <node> n, <string> dir) -<number> w, <number> h, <number> d = - node.dimensions(<number> glue_set, <number> glue_sign, - <number> glue_order, <node> n, <node> t) -<number> w, <number> h, <number> d = - node.dimensions(<number> glue_set, <number> glue_sign, - <number> glue_order, <node> n, <node> t, <string> dir) -\stopfunctioncall - -This calling method takes glue settings into account and is especially -useful for finding the actual width of a sublist of nodes that are -already boxed, for example in code like this, which prints the -width of the space inbetween the \type{a} and \type{b} as it would -be if \type{\box0} was used as-is: - -\starttyping -\setbox0 = \hbox to 20pt {a b} - -\directlua{print (node.dimensions(tex.box[0].glue_set, - tex.box[0].glue_sign, - tex.box[0].glue_order, - tex.box[0].head.next, - node.tail(tex.box[0].head))) } -\stoptyping - -Direction support added in \LUATEX\ 0.45. - -\subsubsection{\luatex{node.mlist_to_hlist}} - -\startfunctioncall -<node> h = node.mlist_to_hlist(<node> n, - <string> display_type, <boolean> penalties) -\stopfunctioncall - -This runs the internal mlist to hlist conversion, converting the math list in -\type{n} into the horizontal list \type{h}. The interface is exactly the same as -for the callback \type{mlist_to_hlist}. - -\subsubsection{\luatex{node.slide}} - -\startfunctioncall -<node> m = node.slide(<node> n) -\stopfunctioncall - -Returns the last node of the node list that starts at \type{n}. As a -side|-|effect, it also creates a reverse chain of \type{prev} pointers -between nodes. - -\subsubsection{\luatex{node.tail}} - -\startfunctioncall -<node> m = node.tail(<node> n) -\stopfunctioncall - -Returns the last node of the node list that starts at \type{n}. - - -\subsubsection{\luatex{node.length}} - -\startfunctioncall -<number> i = node.length(<node> n) -<number> i = node.length(<node> n, <node> m) -\stopfunctioncall - -Returns the number of nodes contained in the node list that starts at -\type{n}. If \type{m} is also supplied it stops at \type{m} instead of -at the end of the list. The node \type{m} is not counted. - -\subsubsection{\luatex{node.count}} - -\startfunctioncall -<number> i = node.count(<number> id, <node> n) -<number> i = node.count(<number> id, <node> n, <node> m) -\stopfunctioncall - -Returns the number of nodes contained in the node list that starts at -\type{n} that have a matching \type{id} field. -If \type{m} is also supplied, counting stops at \type{m} instead of at -the end of the list. The node \type{m} is not counted. - -This function also accept string \type{id}'s. - -\subsubsection{\luatex{node.traverse}} - -\startfunctioncall -<node> t = node.traverse(<node> n) -\stopfunctioncall - -This is a lua iterator that loops over the node list that starts at \type{n}. -Typical input code like this - -\starttyping -for n in node.traverse(head) do - ... -end -\stoptyping - -is functionally equivalent to: - -\starttyping -do - local n - local function f (head,var) - local t - if var == nil then - t = head - else - t = var.next - end - return t - end - while true do - n = f (head, n) - if n == nil then break end - ... - end -end -\stoptyping - -It should be clear from the definition of the function \type{f} that -even though it is possible to add or remove nodes from the node list while -traversing, you have to take great care to make sure all the \type{next} -(and \type{prev}) pointers remain valid. - -If the above is unclear to you, see the section \quote{For Statement} -in the Lua Reference Manual. - -\subsubsection{\luatex{node.traverse_id}} - -\startfunctioncall -<node> t = node.traverse_id(<number> id, <node> n) -\stopfunctioncall - -This is an iterator that loops over all the nodes in the list that -starts at \type{n} that have a matching \type{id} field. - -See the previous section for details. The change is in the local -function \type{f}, which now does an extra while loop checking -against the upvalue \type{id}: - -\starttyping - local function f (head,var) - local t - if var == nil then - t = head - else - t = var.next - end - while not t.id == id do - t = t.next - end - return t - end -\stoptyping - -\subsubsection{\luatex{node.end_of_math} (0.76)} - -\startfunctioncall -<node> t = node.end_of_math(<node> start) -\stopfunctioncall - -Looks for and returns the next \type{math_node} following the \type{start}. -If the given node is a math endnode this helper return that node, else it follows the list and return the next math endnote. If no such node is found nil is returned. - -\subsubsection{\luatex{node.remove}} - -\startfunctioncall -<node> head, current = node.remove(<node> head, <node> current) -\stopfunctioncall - -This function removes the node \type{current} from the list following -\type{head}. It is your responsibility to make sure it is really part -of that list. The return values are the new \type{head} and -\type{current} nodes. The returned \type{current} is the node -following the \type{current} in the calling argument, and is only -passed back as a convenience (or \type{nil}, if there is no such node). The -returned \type{head} is more important, because if the function is -called with \type{current} equal to \type{head}, it will be changed. - -\subsubsection{\luatex{node.insert_before}} - -\startfunctioncall -<node> head, new = node.insert_before(<node> head, <node> current, <node> new) -\stopfunctioncall - -This function inserts the node \type{new} before \type{current} into -the list following \type{head}. It is your responsibility to make sure -that \type{current} is really part of that list. The return values are -the (potentially mutated) \type{head} and the node \type{new}, set up to -be part of the list (with correct \type{next} field). If \type{head} -is initially \type{nil}, it will become \type{new}. - -\subsubsection{\luatex{node.insert_after}} - -\startfunctioncall -<node> head, new = node.insert_after(<node> head, <node> current, <node> new) -\stopfunctioncall - -This function inserts the node \type{new} after \type{current} into -the list following \type{head}. It is your responsibility to make sure -that \type{current} is really part of that list. The return values are -the \type{head} and the node \type{new}, set up to be part of the list -(with correct \type{next} field). If \type{head} is initially -\type{nil}, it will become \type{new}. - -\subsubsection{\luatex{node.first_glyph} (0.65)} - -\startfunctioncall -<node> n = node.first_glyph(<node> n) -<node> n = node.first_glyph(<node> n, <node> m) -\stopfunctioncall - -Returns the first node in the list starting at \type{n} that is a -glyph node with a subtype indicating it is a glyph, or \type{nil}. -If \type{m} is given, processing stops at (but including) that node, -otherwise processing stops at the end of the list. - -Note: this function used to be called \type{first_character}. It has -been renamed in \LUATEX\ 0.65, and the old name is deprecated now. - -\subsubsection{\luatex{node.ligaturing}} - -\startfunctioncall -<node> h, <node> t, <boolean> success = node.ligaturing(<node> n) -<node> h, <node> t, <boolean> success = node.ligaturing(<node> n, <node> m) -\stopfunctioncall - -Apply \TEX-style ligaturing to the specified nodelist. The tail node -\type{m} is optional. The two returned nodes \type{h} and \type{t} are -the new head and tail (both \type{n} and \type{m} can change into -a new ligature). - -\subsubsection{\luatex{node.kerning}} - -\startfunctioncall -<node> h, <node> t, <boolean> success = node.kerning(<node> n) -<node> h, <node> t, <boolean> success = node.kerning(<node> n, <node> m) -\stopfunctioncall - -Apply \TEX|-|style kerning to the specified nodelist. The tail node -\type{m} is optional. The two returned nodes \type{h} and \type{t} are -the head and tail (either one of these can be an inserted kern node, -because special kernings with word boundaries are possible). - -\subsubsection{\luatex{node.unprotect_glyphs}} - -\startfunctioncall -node.unprotect_glyphs(<node> n) -\stopfunctioncall - -Subtracts 256 from all glyph node subtypes. This and the next -function are helpers to convert from \type{characters} to -\type{glyphs} during node processing. - -\subsubsection{\luatex{node.protect_glyphs}} - -\startfunctioncall -node.protect_glyphs(<node> n) -\stopfunctioncall - -Adds 256 to all glyph node subtypes in the node list starting at -\type{n}, except that if the value is 1, it adds only 255. The special -handling of 1 means that \type{characters} will become \type{glyphs} -after subtraction of 256. - -\subsubsection{\luatex{node.last_node}} - -\startfunctioncall -<node> n = node.last_node() -\stopfunctioncall - -This function pops the last node from \TEX's \quote{current list}. -It returns that node, or \type{nil} if the current list is empty. - -\subsubsection{\luatex{node.write}} - -\startfunctioncall -node.write(<node> n) -\stopfunctioncall - -This is an experimental function that will append a node list to -\TEX's \quote {current list} (the node list is not deep-copied -any more since version 0.38). There is no error checking yet! - -\subsubsection{\luatex{node.protrusion_skippable} (0.60.1)} -\startfunctioncall -<boolean> skippable = node.protrusion_skippable(<node> n) -\stopfunctioncall - -Returns \type{true} if, for the purpose of line boundary discovery -when character protrusion is active, this node can be skipped. - -\subsection{Attribute handling} - -Attributes appear as linked list of userdata objects in the -\type{attr} field of individual nodes. They can be handled -individually, but it is much safer and more efficient to use the -dedicated functions associated with them. - -\subsubsection{\luatex{node.has_attribute}} - -\startfunctioncall -<number> v = node.has_attribute(<node> n, <number> id) -<number> v = node.has_attribute(<node> n, <number> id, <number> val) -\stopfunctioncall - -Tests if a node has the attribute with number \type{id} set. If -\type{val} is also supplied, also tests if the value matches \type{val}. -It returns the value, or, if no match is found, \type{nil}. - -\subsubsection{\luatex{node.set_attribute}} - -\startfunctioncall -node.set_attribute(<node> n, <number> id, <number> val) -\stopfunctioncall - -Sets the attribute with number \type{id} to the value -\type{val}. Duplicate assignments are ignored. {\em [needs explanation]} - -\subsubsection{\luatex{node.unset_attribute}} - -\startfunctioncall -<number> v = node.unset_attribute(<node> n, <number> id) -<number> v = node.unset_attribute(<node> n, <number> id, <number> val) -\stopfunctioncall - -Unsets the attribute with number \type{id}. If \type{val} is also supplied, -it will only perform this operation if the value matches \type{val}. -Missing attributes or attribute|-|value pairs are ignored. - -If the attribute was actually deleted, returns its old -value. Otherwise, returns \type{nil}. - -\section{The \luatex{pdf} library} - -This contains variables and functions that are related to the \PDF\ backend. - -%*********************************************************************** - -\subsection{\luatex{pdf.mapfile}, \luatex{pdf.mapline} (new in 0.53.0)} - -\startfunctioncall -pdf.mapfile(<string> map file) -pdf.mapfile(<string> map line) -\stopfunctioncall - -These two functions can be used to replace primitives \type{\pdfmapfile} -and \type{\pdfmapline} from \PDFTEX. They expect a string as only parameter -and have no return value. - -The also functions replace the former variables -\luatex{pdf.pdfmapfile} and \luatex{pdf.pdfmapline}. - -%*********************************************************************** -\subsection{\luatex{pdf.catalog}, \luatex{pdf.info}, - \luatex{pdf.names}, \luatex{pdf.trailer} (new in 0.53.0)} - -These variables offer a read|-|write interface to the corresponding -\PDFTEX\ token lists. The value types are strings and they are -written out to the \PDF\ file directly after the \PDFTEX\ token registers. - -The preferred interface is now \luatex {pdf.setcatalog}, \luatex {pdf.setinfo} -\luatex {pdf.setnames} and \luatex {pdf.settrailer} for setting these properties -and \luatex {pdf.getcatalog}, \luatex {pdf.getinfo} \luatex {pdf.getnames} and -\luatex {pdf.gettrailer} for querying them, - -The corresponding \quote {\type{pdf}} parameter names \luatex {pdf.pdfcatalog}, -\luatex {pdf.pdfinfo}, \luatex {pdf.pdfnames}, and \luatex {pdf.pdftrailer} are -removed in 0.79.0. - -%*********************************************************************** -\subsection{\luatex{pdf.<set/get>pageattributes}, \luatex{pdf.<set/get>pageresources}, - \luatex{pdf.<set/get>pagesattributes}} - -These variables offer a read|-|write interface to related -token lists. The value types are strings. The variables have no -interaction with the corresponding \PDFTEX\ token registers -\tex{pdfpageattr}, \tex{pdfpageresources}, and \tex{pdfpagesattr}. -They are written out to the \PDF\ file directly after -the \PDFTEX\ token registers. - -The preferred interface is now \luatex {pdf.setpageattributes}, \luatex -{pdf.setpagesattributes} and \luatex {pdf.setpageresources} for setting these -properties and \luatex {pdf.getpageattributes}, \luatex {pdf.getpageattributes} and -\luatex {pdf.getpageresources} for querying them. - -%*********************************************************************** - -\subsection{\luatex{pdf.h}, \luatex{pdf.v}} - - -These are the \type{h} and \type{v} values that define the current location -on the output page, measured from its lower left corner. The values can be queried -using scaled points as units. - -\starttyping -local h = pdf.h -local v = pdf.v -\stoptyping - -\subsection{\luatex{pdf.getpos}, \luatex{pdf.gethpos}, \luatex{pdf.getvpos}} - -These are the function variants of \type {pdf.h} and \type {pdf.v}. Sometimes -using a function is preferred over a key so this saves wrapping. Also, these -functions are faster then the key based access, as \type {h} and \type {v} -keys are not real variables but looked up using a metatable call. The -\type {getpos} function returns two values, the other return one. - -\starttyping -local h, v = pdf.getpos() -\stoptyping - -\subsection{\luatex{pdf.hasmatrix}, \luatex{pdf.getmatrix}} - -The current matrix transformation is available via the \type {getmatrix} command, -which returns 6 values: \type {sx}, \type {rx}, \type {ry}, \type {sy}, \type {tx}, -and \type {ty}. The \type {hasmatrix} function returns \type {true} when a matrix is -applied. - -\starttyping -if pdf.hasmatrix() then - local sx, rx, ry, sy, tx, ty = pdf.getmatrix() - -- do something useful or not -end -\stoptyping - - - -\subsection{\luatex{pdf.print}} - -A print function to write stuff to the \PDF\ document -that can be used from within a \tex{latelua} argument. -This function is not to be used inside \tex{directlua} -unless you know {\it exactly} what you are doing. - -\startfunctioncall -pdf.print(<string> s) -pdf.print(<string> type, <string> s) -\stopfunctioncall - -The optional parameter can be used to mimic the behavior of -\tex{pdfliteral}: the \type{type} is \type{direct} or \type{page}. - -\subsection{\luatex{pdf.immediateobj}} - -This function creates a \PDF\ object -and immediately writes it to the \PDF\ file. -It is modelled after \PDFTEX's \tex{immediate}\tex{pdfobj} primitives. -All function variants return the object number -of the newly generated object. - -\startfunctioncall -<number> n = pdf.immediateobj(<string> objtext) -<number> n = pdf.immediateobj("file", <string> filename) -<number> n = pdf.immediateobj("stream", <string> streamtext, <string> attrtext) -<number> n = pdf.immediateobj("streamfile", <string> filename, <string> attrtext) -\stopfunctioncall - -The first version puts the \type{objtext} raw into an object. -Only the object wrapper is automatically generated, -but any internal structure (like \type{<< >>} dictionary markers) -needs to provided by the user. -The second version with keyword \type{"file"} as 1st argument -puts the contents of the file with name \type{filename} raw into the object. -The third version with keyword \type{"stream"} creates a stream object -and puts the \type{streamtext} raw into the stream. -The stream length is automatically calculated. -The optional \type{attrtext} goes into the dictionary of that object. -The fourth version with keyword \type{"streamfile"} does the same as the 3rd one, -it just reads the stream data raw from a file. - -An optional first argument can be given to make the function use a -previously reserved \PDF\ object. - -\startfunctioncall -<number> n = pdf.immediateobj(<integer> n, <string> objtext) -<number> n = pdf.immediateobj(<integer> n, "file", <string> filename) -<number> n = pdf.immediateobj(<integer> n, "stream", <string> streamtext, <string> attrtext) -<number> n = pdf.immediateobj(<integer> n, "streamfile", <string> filename, <string> attrtext) -\stopfunctioncall - -%*********************************************************************** - -\subsection{\luatex{pdf.obj}} - -This function creates a \PDF\ object, -which is written to the \PDF\ file only when referenced, -e.\,g., by \luatex{pdf.refobj()}. - -All function variants return the object number of the newly generated -object, and there are two separate calling modes. - -The first mode is modelled after \PDFTEX's \tex{pdfobj} primitive. - -\startfunctioncall -<number> n = pdf.obj(<string> objtext) -<number> n = pdf.obj("file", <string> filename) -<number> n = pdf.obj("stream", <string> streamtext, <string> attrtext) -<number> n = pdf.obj("streamfile", <string> filename, <string> attrtext) -\stopfunctioncall - -An optional first argument can be given to make the function use a -previously reserved \PDF\ object. - -\startfunctioncall -<number> n = pdf.obj(<integer> n, <string> objtext) -<number> n = pdf.obj(<integer> n, "file", <string> filename) -<number> n = pdf.obj(<integer> n, "stream", <string> streamtext, <string> attrtext) -<number> n = pdf.obj(<integer> n, "streamfile", <string> filename, <string> attrtext) -\stopfunctioncall - -The second mode accepts a single argument table with key--value pairs. - -\startfunctioncall -<number> n = pdf.obj{ type = <string>, - immmediate = <boolean>, - objnum = <number>, - attr = <string>, - compresslevel = <number>, - objcompression = <boolean>, - file = <string>, - string = <string>} -\stopfunctioncall - -The \type{type} field can have the values \type{raw} and -\type{stream}, this field is required, the others are optional -(within constraints). - -Note: this mode makes \type{pdf.obj} look more flexible than it -actually is: the constraints from the separate parameter version -still apply, so for example you can't have both \type{string} and -\type{file} at the same time. - -%*********************************************************************** - -\subsection{\luatex{pdf.refobj}} - -This function, -the \LUA\ version of the \tex{pdfrefobj} primitive, -references an object by its object number, -so that the object will be written out. - -\startfunctioncall -pdf.refobj(<integer> n) -\stopfunctioncall - -This function works in both the \tex{directlua} and \tex{latelua} environment. -Inside \tex{directlua} a new whatsit node -\quote{pdf_refobj} is created, which will be marked for flushing during -page output and the object is then written directly after the page, -when also the resources objects are written out. -Inside \tex{latelua} the object will be marked for flushing. - -This function has no return values. - -%*********************************************************************** - -\subsection{\luatex{pdf.reserveobj}} - -This function creates an empty \PDF\ object and returns its number. - -\startfunctioncall -<number> n = pdf.reserveobj() -<number> n = pdf.reserveobj("annot") -\stopfunctioncall - -\subsection{\luatex{pdf.registerannot} (new in 0.47.0)} - -This function adds an object number to the \type{/Annots} array for the -current page without doing anything else. This function can only be -used from within \type{\latelua}. - -\startfunctioncall -pdf.registerannot (<number> objnum) -\stopfunctioncall - -\section{The \luatex{pdfscanner} library (new in 0.72.0)} - -The \luatex{pdfscanner} library allows interpretation of PDF content streams -and \type{/ToUnicode} (cmap) streams. You can get those streams from the -\luatex{epdf} library, as explained in an earlier section. There is only -a single top|-|level function in this library: - -\startfunctioncall -pdfscanner.scan (<Object> stream, <table> operatortable, <table> info) -\stopfunctioncall - -The first argument, \type{stream}, should be either a PDF stream -object, or a PDF array of PDF stream objects (those options comprise -the possible return values of \type{<Page>:getContents()} -and \type{<Object>:getStream()} in the \type{epdf} library). - -The second argument, \type{operatortable}, should be a Lua table where -the keys are PDF operator name strings and the values are Lua -functions (defined by you) that are used to process those -operators. The functions are called whenever the scanner finds one -of these PDF operators in the content stream(s). The functions are -called with two arguments: the \type{scanner} object itself, and -the \type{info} table that was passed are the third argument -to \type{pdfscanner.scan}. - -Internally, \type{pdfscanner.scan} loops over the PDF operators in the -stream(s), collecting operands on an internal stack until it finds a -PDF operator. If that PDF operator's name exists -in \type{operatortable}, then the associated function is -executed. After the function has run (or when there is no function to -execute) the internal operand stack is cleared in preparation for the -next operator, and processing continues. - -The \type{scanner} argument to the processing functions is needed -because it offers various methods to get the actual operands from the -internal operand stack. The most important of those functions is -\type{} - -A simple example of processing a PDF's document stream -could look like this: - -\starttyping -function Do (scanner, info) - local val = scanner:pop() - local name = val[2] -- val[1] == 'name' - print (info.space ..'Use XObject '.. name) - local resources = info.resources - local xobject = resources:lookup("XObject"):getDict():lookup(name) - if (xobject and xobject:isStream()) then - local dict = xobject:getStream():getDict() - if dict then - local name = dict:lookup('Subtype') - if name:getName() == 'Form' then - local newinfo = { space = info.space .. " " , - resources = dict:lookup('Resources'):getDict() } - pdfscanner.scan(xobject, operatortable, newinfo) - end - end - end -end -operatortable = {Do = Do} - -doc = epdf.open(arg[1]) -pagenum = 1 -while pagenum <= doc:getNumPages() do - local page = doc:getCatalog():getPage(pagenum) - local info = { space = " " , resources = page:getResourceDict()} - print ('Page ' .. pagenum) - pdfscanner.scan(page:getContents(), operatortable, info) - pagenum = pagenum + 1 -end -\stoptyping - -This example iterates over all the actual content in the PDF, and -prints out the found XObject names. While the code demonstrates quite -some of the \type{epdf} functions, let's focus on the type -\type{pdfscanner} specific code instead. - -From the bottom up, the line - -\starttyping - pdfscanner.scan(page:getContents(), operatortable, info) -\stoptyping - -runs the scanner with the PDF page's top-level content. - -The third argument, \type{info}, contains two entries: \type{space} is -used to indent the printed output, and \type{resources} is needed so -that embedded \type{XForms} can find their own content. - -The second argument, \type{operatortable} defines a processing function -for a single PDF operator, \type{Do}. - -The function \type{Do} prints the name of the current XObject, and -then starts a new scanner for that object's content stream, under the -condition that the XObject is in fact a \type{/Form}. That nested -scanner is called with new \type{info} argument with an -updated \type{space} value so that the indentation of the output nicely -nests, and with an new \type{resources} field to help the next -iteration down to properly process any other, embedded XObjects. - -Of course, this is not a very useful example in practise, but for the -purpose of demonstrating \type{pdfscanner}, it is just long enough. -It makes use of only one \type{scanner} method: \type{scanner:pop()}. -That function pops the top operand of the internal stack, and returns -a lua table where the object at index one is a string representing -the type of the operand, and object two is its value. - -The list of possible operand types and associated lua value types is: - -\starttabulate[|lT|p|] -\NC integer \NC <number> \NC \NR -\NC real \NC <number> \NC \NR -\NC boolean \NC <boolean> \NC \NR -\NC name \NC <string> \NC \NR -\NC operator \NC <string> \NC \NR -\NC string \NC <string> \NC \NR -\NC array \NC <table> \NC \NR -\NC dict \NC <table> \NC \NR -\stoptabulate - -In case of \type{integer} or \type{real}, the value is always -a Lua (floating point) number. - -In case of \type{name}, the leading slash is always stripped. - -In case of \type{string}, please bear in mind that PDF actually -supports different types of strings (with different encodings) in -different parts of the PDF document, so may need to reencode some of -the results; \type{pdfscanner} always outputs the byte stream without -reencoding anything. \type{pdfscanner} does not differentiate between -literal strings and hexidecimal strings (the hexadecimal values are -decoded), and it treats the stream data for inline images as a string -that is the single operand for \type{EI}. - -In case of \type{array}, the table content is a list of \type{pop} -return values. - -In case of \type{dict}, the table keys are PDF name strings -and the values are \type{pop} return values. - -\blank - -There are few more methods defined that you can ask \type{scanner}: - -\starttabulate[|lT|p|] -\NC pop \NC as explained above\NC \NR -\NC popNumber \NC return only the value of a \type{real} or \type{integer}\NC \NR -\NC popName \NC return only the value of a \type{name} \NC \NR -\NC popString \NC return only the value of a \type{string} \NC \NR -\NC popArray \NC return only the value of a \type{array} \NC \NR -\NC popDict \NC return only the value of a \type{dict} \NC \NR -\NC popBool \NC return only the value of a \type{boolean} \NC \NR -\NC done \NC abort further processing of this \type{scan()} call\NC \NR -\stoptabulate - -The \type{popXXX} are convenience functions, and come in handy when -you know the type of the operands beforehand (which you usually do, in -PDF). For example, the \type{Do} function could have used \type{local -name = scanner:popName()} instead, because the single operand -to the \type{Do} operator is always a PDF name object. - -The \type{done} function allows you to abort processing of a stream -once you have learned everything you want to learn. This comes in handy -while parsing \type{/ToUnicode}, because there usually is trailing -garbage that you are not interested in. Without \type{done}, processing -only end at the end of the stream, possibly wasting CPU cycles. - -\section{The \luatex{status} library} - -This contains a number of run|-|time configuration items that -you may find useful in message reporting, as well as an iterator -function that gets all of the names and values as a table. - -\startfunctioncall -<table> info = status.list() -\stopfunctioncall - -The keys in the table are the known items, the value is the -current value. Almost all of the values in \type{status} are -fetched through a metatable at run|-|time whenever they are -accessed, so you cannot use \type{pairs} on \type{status}, but you -{\it can\/} use \type{pairs} on \type{info}, of course. If you do -not need the full list, you can also ask for a single item by -using its name as an index into \type{status}. - -The current list is: - -\starttabulate[|lT|p|] -\NC \ssbf key \NC \bf explanation \NC\NR -\NC pdf_gone\NC written \PDF\ bytes \NC \NR -\NC pdf_ptr\NC not yet written \PDF\ bytes \NC \NR -\NC dvi_gone\NC written \DVI\ bytes \NC \NR -\NC dvi_ptr\NC not yet written \DVI\ bytes \NC \NR -\NC total_pages\NC number of written pages \NC \NR -\NC output_file_name\NC name of the \PDF\ or \DVI\ file \NC \NR -\NC log_name\NC name of the log file \NC \NR -\NC banner\NC terminal display banner \NC \NR -\NC var_used\NC variable (one|-|word) memory in use \NC \NR -\NC dyn_used\NC token (multi|-|word) memory in use \NC \NR -\NC str_ptr\NC number of strings \NC \NR -\NC init_str_ptr\NC number of \INITEX\ strings \NC \NR -\NC max_strings\NC maximum allowed strings \NC \NR -\NC pool_ptr\NC string pool index \NC \NR -\NC init_pool_ptr\NC \INITEX\ string pool index \NC \NR -\NC pool_size\NC current size allocated for string characters \NC \NR -\NC node_mem_usage\NC a string giving insight into currently used nodes\NC\NR -\NC var_mem_max\NC number of allocated words for nodes\NC \NR -\NC fix_mem_max\NC number of allocated words for tokens\NC \NR -\NC fix_mem_end\NC maximum number of used tokens\NC \NR -\NC cs_count\NC number of control sequences \NC \NR -\NC hash_size\NC size of hash \NC \NR -\NC hash_extra\NC extra allowed hash \NC \NR -\NC font_ptr\NC number of active fonts \NC \NR -\NC max_in_stack\NC max used input stack entries \NC \NR -\NC max_nest_stack\NC max used nesting stack entries \NC \NR -\NC max_param_stack\NC max used parameter stack entries \NC \NR -\NC max_buf_stack\NC max used buffer position \NC \NR -\NC max_save_stack\NC max used save stack entries \NC \NR -\NC stack_size\NC input stack size \NC \NR -\NC nest_size\NC nesting stack size \NC \NR -\NC param_size\NC parameter stack size \NC \NR -\NC buf_size\NC current allocated size of the line buffer \NC \NR -\NC save_size\NC save stack size \NC \NR -\NC obj_ptr\NC max \PDF\ object pointer \NC \NR -\NC obj_tab_size\NC \PDF\ object table size \NC \NR -\NC pdf_os_cntr\NC max \PDF\ object stream pointer \NC \NR -\NC pdf_os_objidx\NC \PDF\ object stream index \NC \NR -\NC pdf_dest_names_ptr\NC max \PDF\ destination pointer \NC \NR -\NC dest_names_size\NC \PDF\ destination table size \NC \NR -\NC pdf_mem_ptr\NC max \PDF\ memory used \NC \NR -\NC pdf_mem_size\NC \PDF\ memory size \NC \NR -\NC largest_used_mark\NC max referenced marks class \NC \NR -\NC filename\NC name of the current input file \NC \NR -\NC inputid\NC numeric id of the current input \NC \NR -\NC linenumber\NC location in the current input file\NC \NR -\NC lasterrorstring\NC last error string\NC \NR -\NC luabytecodes\NC number of active \LUA\ bytecode registers\NC \NR -\NC luabytecode_bytes\NC number of bytes in \LUA\ bytecode registers\NC \NR -\NC luastate_bytes\NC number of bytes in use by \LUA\ interpreters\NC \NR -\NC output_active\NC \type{true} if the \tex{output} routine is active\NC \NR -\NC callbacks\NC total number of executed callbacks so far\NC \NR -\NC indirect_callbacks\NC number of those that were themselves - a result of other callbacks (e.g. file readers)\NC \NR -\NC luatex_svn\NC the luatex repository id (added in 0.51)\NC\NR -\NC luatex_version\NC the luatex version number (added in 0.38)\NC\NR -\NC luatex_revision\NC the luatex revision string (added in 0.38)\NC\NR -\NC ini_version\NC \type{true} if this is an \INITEX\ run (added in 0.38)\NC\NR -\stoptabulate - - -\section{The \luatex{tex} library} - -The \luatex{tex} table contains a large list of virtual internal \TEX\ -parameters that are partially writable. - -The designation \quote{virtual} means that these items are not properly -defined in \LUA, but are only front\-ends that are handled by a metatable -that operates on the actual \TEX\ values. As a result, most of the \LUA\ -table operators (like \type{pairs} and \type{#}) do not work on such -items. - -At the moment, it is possible to access almost every parameter -that has these characteristics: - -\startitemize[packed] -\item You can use it after \tex{the} -\item It is a single token. -\item Some special others, see the list below -\stopitemize - -This excludes parameters that need extra arguments, like -\tex{the}\tex{scriptfont}. - -The subset comprising simple integer and dimension registers are -writable as well as readable (stuff like \tex{tracingcommands} and -\tex{parindent}). - -\subsection{Internal parameter values} - -For all the parameters in this section, it is possible to access them -directly using their names as index in the \type{tex} table, or by -using one of the functions \type{tex.get()} and \type{tex.set()}. - -The exact parameters and return values differ depending on the actual -parameter, and so does whether \type{tex.set} has any effect. For the -parameters that {\it can\/} be set, it is possible to use -\type{'global'} as the first argument to \type{tex.set}; this makes -the assignment global instead of local. - -\startfunctioncall -tex.set (<string> n, ...) -tex.set ('global', <string> n, ...) -... = tex.get (<string> n) -\stopfunctioncall - -\subsubsection{Integer parameters} - -The integer parameters accept and return \LUA\ numbers. - -Read-write: - -\startcolumns[n=2] -\starttyping -tex.adjdemerits -tex.binoppenalty -tex.brokenpenalty -tex.catcodetable -tex.clubpenalty -tex.day -tex.defaulthyphenchar -tex.defaultskewchar -tex.delimiterfactor -tex.displaywidowpenalty -tex.doublehyphendemerits -tex.endlinechar -tex.errorcontextlines -tex.escapechar -tex.exhyphenpenalty -tex.fam -tex.finalhyphendemerits -tex.floatingpenalty -tex.globaldefs -tex.hangafter -tex.hbadness -tex.holdinginserts -tex.hyphenpenalty -tex.interlinepenalty -tex.language -tex.lastlinefit -tex.lefthyphenmin -tex.linepenalty -tex.localbrokenpenalty -tex.localinterlinepenalty -tex.looseness -tex.mag -tex.maxdeadcycles -tex.month -tex.newlinechar -tex.outputpenalty -tex.pausing -tex.pdfadjustspacing -tex.pdfcompresslevel -tex.pdfdecimaldigits -tex.pdfgamma -tex.pdfgentounicode -tex.pdfimageapplygamma -tex.pdfimagegamma -tex.pdfimagehicolor -tex.pdfimageresolution -tex.pdfinclusionerrorlevel -tex.pdfminorversion -tex.pdfobjcompresslevel -tex.pdfoutput -tex.pdfpagebox -tex.pdfpkresolution -tex.pdfprotrudechars -tex.pdftracingfonts -tex.pdfuniqueresname -tex.postdisplaypenalty -tex.predisplaydirection -tex.predisplaypenalty -tex.pretolerance -tex.relpenalty -tex.righthyphenmin -tex.savinghyphcodes -tex.savingvdiscards -tex.showboxbreadth -tex.showboxdepth -tex.time -tex.tolerance -tex.tracingassigns -tex.tracingcommands -tex.tracinggroups -tex.tracingifs -tex.tracinglostchars -tex.tracingmacros -tex.tracingnesting -tex.tracingonline -tex.tracingoutput -tex.tracingpages -tex.tracingparagraphs -tex.tracingrestores -tex.tracingscantokens -tex.tracingstats -tex.uchyph -tex.vbadness -tex.widowpenalty -tex.year -\stoptyping -\stopcolumns - -Read|-|only: - -\startcolumns[n=3] -\starttyping -tex.deadcycles -tex.insertpenalties -tex.parshape -tex.prevgraf -tex.spacefactor -\stoptyping -\stopcolumns - -\subsubsection{Dimension parameters} - -The dimension parameters accept \LUA\ numbers (signifying scaled points) -or strings (with included dimension). The result is always a number in -scaled points. - -Read|-|write: - -\startcolumns[n=3] -\starttyping -tex.boxmaxdepth -tex.delimitershortfall -tex.displayindent -tex.displaywidth -tex.emergencystretch -tex.hangindent -tex.hfuzz -tex.hoffset -tex.hsize -tex.lineskiplimit -tex.mathsurround -tex.maxdepth -tex.nulldelimiterspace -tex.overfullrule -tex.pagebottomoffset -tex.pageheight -tex.pageleftoffset -tex.pagerightoffset -tex.pagetopoffset -tex.pagewidth -tex.parindent -tex.pdfdestmargin -tex.pdfeachlinedepth -tex.pdfeachlineheight -tex.pdffirstlineheight -tex.pdfhorigin -tex.pdflastlinedepth -tex.pdflinkmargin -tex.pdfpageheight -tex.pdfpagewidth -tex.pdfpxdimen -tex.pdfthreadmargin -tex.pdfvorigin -tex.predisplaysize -tex.scriptspace -tex.splitmaxdepth -tex.vfuzz -tex.voffset -tex.vsize -\stoptyping -\stopcolumns - -Read|-|only: - -\startcolumns[n=3] -\starttyping -tex.pagedepth -tex.pagefilllstretch -tex.pagefillstretch -tex.pagefilstretch -tex.pagegoal -tex.pageshrink -tex.pagestretch -tex.pagetotal -tex.prevdepth -\stoptyping -\stopcolumns - -\subsubsection{Direction parameters} - -The direction parameters are read|-|only and return a \LUA\ string. - -\startcolumns[n=3] -\starttyping -tex.bodydir -tex.mathdir -tex.pagedir -tex.pardir -tex.textdir -\stoptyping -\stopcolumns - -\subsubsection{Glue parameters} - -The glue parameters accept and return a userdata object that -represents a \type{glue_spec} node. - -\startcolumns[n=3] -\starttyping -tex.abovedisplayshortskip -tex.abovedisplayskip -tex.baselineskip -tex.belowdisplayshortskip -tex.belowdisplayskip -tex.leftskip -tex.lineskip -tex.parfillskip -tex.parskip -tex.rightskip -tex.spaceskip -tex.splittopskip -tex.tabskip -tex.topskip -tex.xspaceskip -\stoptyping -\stopcolumns - -\subsubsection{Muglue parameters} - -All muglue parameters are to be used read|-|only and return a \LUA\ string. - -\startcolumns[n=3] -\starttyping -tex.medmuskip -tex.thickmuskip -tex.thinmuskip -\stoptyping -\stopcolumns - -\subsubsection{Tokenlist parameters} - -The tokenlist parameters accept and return \LUA\ strings. \LUA\ strings are -converted to and from token lists using \tex{the}\tex{toks} style -expansion: all category codes are either space (10) or other (12). -It follows that assigning to some of these, like \quote{tex.output}, -is actually useless, but it feels bad to make exceptions in view -of a coming extension that will accept full-blown token strings. - -\startcolumns[n=3] -\starttyping -tex.errhelp -tex.everycr -tex.everydisplay -tex.everyeof -tex.everyhbox -tex.everyjob -tex.everymath -tex.everypar -tex.everyvbox -tex.output -tex.pdfpageattr -tex.pdfpageresources -tex.pdfpagesattr -tex.pdfpkmode -\stoptyping -\stopcolumns - - -\subsection{Convert commands} - -All \quote{convert} commands are read|-|only and return a \LUA\ string. -The supported commands at this moment are: - -\startcolumns[n=2] -\starttyping -tex.eTeXVersion -tex.eTeXrevision -tex.formatname -tex.jobname -tex.luatexbanner -tex.luatexrevision -tex.pdfnormaldeviate -tex.fontname(number) -tex.pdffontname(number) -tex.pdffontobjnum(number) -tex.pdffontsize(number) -tex.uniformdeviate(number) -tex.number(number) -tex.romannumeral(number) -tex.pdfpageref(number) -tex.pdfxformname(number) -tex.fontidentifier(number) -\stoptyping -\stopcolumns - -If you are wondering why this list looks haphazard; these are all the -cases of the \quote{convert} internal command that do not require an -argument, as well as the ones that require only a simple numeric -value. - -The special (lua-only) case of \type{tex.fontidentifier} returns the -\type{csname} string that matches a font id number (if there is one). - -The \PDFTEX\ related primitives will be removed from versions after 0.80. All the -version related details are available in the \type {status} table at the \LUA\ -end, for instance one can say: - -\starttyping -\let\pdftexbanner \luatexbanner -\let\pdftexversion \luatexversion -\let\pdftexrevision\luatexrevision -\stoptyping - -% or maybe in the future: -% -% \starttyping -% \def\pdftexbanner {\directlua{tex.write(status.banner)}} -% \def\pdftexversion {\directlua{tex.write(status.luatex_version}} -% \def\pdftexrevision{\directlua{tex.write(status.luatex_revision}} -% \stoptyping - -if these are really needed in a macro package. - -\subsection{Last item commands} - -All \quote{last item} commands are read|-|only and return a number. - -The supported commands at this moment are: - -\startcolumns[n=3] -\starttyping -tex.lastpenalty -tex.lastkern -tex.lastskip -tex.lastnodetype -tex.inputlineno -tex.pdflastobj -tex.pdflastxform -tex.pdflastximage -tex.pdflastximagepages -tex.pdflastannot -tex.pdflastxpos -tex.pdflastypos -tex.pdfrandomseed -tex.pdflastlink -tex.luatexversion -tex.eTeXminorversion -tex.eTeXversion -tex.currentgrouplevel -tex.currentgrouptype -tex.currentiflevel -tex.currentiftype -tex.currentifbranch -tex.pdflastximagecolordepth -\stoptyping -\stopcolumns - -\subsection{Attribute, count, dimension, skip and token registers} - -\TEX's attributes (\tex{attribute}), counters (\tex{count}), -dimensions (\tex{dimen}), skips (\tex{skip}) and token (\tex{toks}) -registers can be accessed and written to using two times five virtual -sub|-|tables of the \luatex{tex} table: - -\startcolumns[n=3] -\starttyping -tex.attribute -tex.count -tex.dimen -tex.skip -tex.toks -\stoptyping -\stopcolumns - -It is possible to use the names of relevant \tex{attributedef}, \tex{countdef}, -\tex{dimendef}, \tex{skipdef}, or \tex{toksdef} control sequences as indices -to these tables: - -\starttyping -tex.count.scratchcounter = 0 -enormous = tex.dimen['maxdimen'] -\stoptyping - -In this case, \LUATEX\ looks up the value for you on the fly. You have -to use a valid \tex{countdef} (or \tex{attributedef}, or -\tex{dimendef}, or \tex{skipdef}, or \tex{toksdef}), anything else -will generate an error (the intent is to eventually also allow -\type{<chardef tokens>} and even macros that expand into a number). - -The attribute and count registers accept and return \LUA\ numbers. - -The dimension registers accept \LUA\ numbers (in scaled points) or -strings (with an included absolute dimension; \type {em} and \type {ex} and \type {px} -are forbidden). The result is always a number in scaled points. - -The token registers accept and return \LUA\ strings. \LUA\ strings are -converted to and from token lists using \tex{the}\tex{toks} style -expansion: all category codes are either space (10) or other (12). - -The skip registers accept and return \type{glue_spec} userdata node -objects (see the description of the node interface elsewhere in this -manual). - -As an alternative to array addressing, there are also accessor -functions defined for all cases, for example, here is the set -of possibilities for \type{\skip} registers: - -\startfunctioncall -tex.setskip (<number> n, <node> s) -tex.setskip (<string> s, <node> s) -tex.setskip ('global',<number> n, <node> s) -tex.setskip ('global',<string> s, <node> s) -<node> s = tex.getskip (<number> n) -<node> s = tex.getskip (<string> s) -\stopfunctioncall - -In the function-based interface, it is possible to define values -globally by using the string \type{'global'} as the first function argument. - -\subsection{Character code registers (0.63)} - -\TEX's character code tables (\tex{lccode}, \tex{uccode}, -\tex{sfcode}, \tex{catcode}, \tex{mathcode}, \tex{delcode}) can be -accessed and written to using six virtual subtables of the \type{tex} -table - -\startcolumns[n=3] -\starttyping -tex.lccode -tex.uccode -tex.sfcode -tex.catcode -tex.mathcode -tex.delcode -\stoptyping -\stopcolumns - -The function call interfaces are roughly as above, but there are a few twists. -\type{sfcode}s are the simple ones: - -\startfunctioncall -tex.setsfcode (<number> n, <number> s) -tex.setsfcode ('global', <number> n, <number> s) -<number> s = tex.getsfcode (<number> n) -\stopfunctioncall - -The function call interface for \type{lccode} and \type{uccode} additionally allows you to set the associated sibling at the same time: - -\startfunctioncall -tex.setlccode (['global'], <number> n, <number> lc) -tex.setlccode (['global'], <number> n, <number> lc, <number> uc) -<number> lc = tex.getlccode (<number> n) -tex.setuccode (['global'], <number> n, <number> uc) -tex.setuccode (['global'], <number> n, <number> uc, <number> lc) -<number> uc = tex.getuccode (<number> n) -\stopfunctioncall - -The function call interface for \type{catcode} also allows you to -specify a category table to use on assignment or on query (default in -both cases is the current one): - -\startfunctioncall -tex.setcatcode (['global'], <number> n, <number> c) -tex.setcatcode (['global'], <number> cattable, <number> n, <number> c) -<number> lc = tex.getcatcode (<number> n) -<number> lc = tex.getcatcode (<number> cattable, <number> n) -\stopfunctioncall - - -The interfaces for \type{delcode} and \type{mathcode} use small array tables to -set and retrieve values: - -\startfunctioncall -tex.setmathcode (['global'], <number> n, <table> mval ) -<table> mval = tex.getmathcode (<number> n) -tex.setdelcode (['global'], <number> n, <table> dval ) -<table> dval = tex.getdelcode (<number> n) -\stopfunctioncall - -Where the table for \type{mathcode} is an array of 3 numbers, like this: - -\starttyping -{<number> mathclass, <number> family, <number> character} -\stoptyping - -And the table for \type{delcode} is an array with 4 numbers, like this: - -\starttyping -{<number> small_fam, <number> small_char, <number> large_fam, <number> large_char} -\stoptyping - -Normally, the third and fourth values in a delimiter code assignment -will be zero according to \tex{Udelcode} usage, but the returned table can have -values there (if the delimiter code was set using \type{\delcode}, for -example). Unset \type{delcode}'s can be recognized because -\type{dval[1]} is $-1$. - -\subsection{Box registers} - -It is possible to set and query actual boxes, using the node -interface as defined in the \luatex{node} library: - -\starttyping -tex.box -\stoptyping - -for array access, or - -\starttyping -tex.setbox(<number> n, <node> s) -tex.setbox(<string> cs, <node> s) -tex.setbox('global', <number> n, <node> s) -tex.setbox('global', <string> cs, <node> s) -<node> n = tex.getbox(<number> n) -<node> n = tex.getbox(<string> cs) -\stoptyping - -for function|-|based access. -In the function-based interface, it is possible to define values -globally by using the string \type{'global'} as the first function argument. - -Be warned that an assignment like - -\starttyping -tex.box[0] = tex.box[2] -\stoptyping - -does not copy the node list, it just duplicates a node pointer. If -\tex{box2} will be cleared by \TEX\ commands later on, the contents -of \tex{box0} becomes invalid as well. To prevent this from -happening, always use \luatex{node.copy_list()} unless you are -assigning to a temporary variable: - -\starttyping -tex.box[0] = node.copy_list(tex.box[2]) -\stoptyping - -%{\bf note: In previous versions of \LUATEX\ there were also three -%virtual tables called \type{tex.wd}, \type{tex.ht}, and \type{tex.dp} -%along with an associated function call interface. These were -%removed in version 0.63. You should switch to using \type{tex.box[].width} -%etc. instead.} -% -%If for some reason you want the functionality of these tables back, -%you can add \LUA\ code to do that for you, like this: -% -%\starttyping -%local box = tex.box -% -%local wd = { -% __index = function(t,k) local bk = box[k] return bk and bk.width or 0 end, -% __newindex = function(t,k,v) local bk = box[k] if bk then bk.width = v end end, -%} -%local ht = { -% __index = function(t,k) local bk = box[k] return bk and bk.height or 0 end, -% __newindex = function(t,k,v) local bk = box[k] if bk then bk.height = v end end, -%} -%local dp = { -% __index = function(t,k) local bk = box[k] return bk and bk.depth or 0 end, -% __newindex = function(t,k,v) local bk = box[k] if bk then bk.depth = v end end, -%} -% -%tex.wd = { } setmetatable(tex.wd,wd) -%tex.ht = { } setmetatable(tex.ht,ht) -%tex.dp = { } setmetatable(tex.dp,dp) -%\stoptyping - - -\subsection{Math parameters} - -It is possible to set and query the internal math parameters -using: - -\startfunctioncall -tex.setmath(<string> n, <string> t, <number> n) -tex.setmath('global', <string> n, <string> t, <number> n) -<number> n = tex.getmath(<string> n, <string> t) -\stopfunctioncall - -As before an optional first parameter \type{'global'} indicates a -global assignment. - -The first string is the parameter name minus the leading \quote{Umath}, -and the second string is the style name minus the trailing \quote{style}. - -Just to be complete, the values for the math parameter name are: - -\starttyping -quad axis operatorsize -overbarkern overbarrule overbarvgap -underbarkern underbarrule underbarvgap -radicalkern radicalrule radicalvgap -radicaldegreebefore radicaldegreeafter radicaldegreeraise -stackvgap stacknumup stackdenomdown -fractionrule fractionnumvgap fractionnumup -fractiondenomvgap fractiondenomdown fractiondelsize -limitabovevgap limitabovebgap limitabovekern -limitbelowvgap limitbelowbgap limitbelowkern -underdelimitervgap underdelimiterbgap -overdelimitervgap overdelimiterbgap -subshiftdrop supshiftdrop subshiftdown -subsupshiftdown subtopmax supshiftup -supbottommin supsubbottommax subsupvgap -spaceafterscript connectoroverlapmin -ordordspacing ordopspacing ordbinspacing ordrelspacing -ordopenspacing ordclosespacing ordpunctspacing ordinnerspacing -opordspacing opopspacing opbinspacing oprelspacing -opopenspacing opclosespacing oppunctspacing opinnerspacing -binordspacing binopspacing binbinspacing binrelspacing -binopenspacing binclosespacing binpunctspacing bininnerspacing -relordspacing relopspacing relbinspacing relrelspacing -relopenspacing relclosespacing relpunctspacing relinnerspacing -openordspacing openopspacing openbinspacing openrelspacing -openopenspacing openclosespacing openpunctspacing openinnerspacing -closeordspacing closeopspacing closebinspacing closerelspacing -closeopenspacing closeclosespacing closepunctspacing closeinnerspacing -punctordspacing punctopspacing punctbinspacing punctrelspacing -punctopenspacing punctclosespacing punctpunctspacing punctinnerspacing -innerordspacing inneropspacing innerbinspacing innerrelspacing -inneropenspacing innerclosespacing innerpunctspacing innerinnerspacing -\stoptyping - -The values for the style parameter name are: - -\starttyping -display crampeddisplay -text crampedtext -script crampedscript -scriptscript crampedscriptscript -\stoptyping - - -\subsection{Special list heads} - -The virtual table \luatex{tex.lists} contains the set of internal -registers that keep track of building page lists. - - -\starttabulate[|lT|p|] -\NC \bf field \NC \bf description \NC \NR -\NC page_ins_head \NC circular list of pending insertions \NC \NR -\NC contrib_head \NC the recent contributions \NC \NR -\NC page_head \NC the current page content\NC \NR -%\NC temp_head \NC \NC \NR -\NC hold_head \NC used for held-over items for next page\NC \NR -\NC adjust_head \NC head of the current \tex{vadjust} list \NC \NR -\NC pre_adjust_head \NC head of the current \tex{vadjust pre} list\NC \NR -% \NC align_head \NC \NC \NR -\stoptabulate - -\subsection{Semantic nest levels (0.51)} - -The virtual table \luatex{tex.nest} contains the currently active -semantic nesting state. It has two main parts: a zero-based array of -userdata for the semantic nest itself, and the numerical value -\type{tex.nest.ptr}, which gives the highest available index. Neither -the array items in \type{tex.nest[]} nor \type{tex.nest.ptr} can be -assigned to (as this would confuse the typesetting engine beyond -repair), but you can assign to the individual values inside the array -items, e.g. \type{tex.nest[tex.nest.ptr].prevdepth}. - -\type{tex.nest[tex.nest.ptr]} is the current nest state, \type{tex.nest[0]} -the outermost (main vertical list) level. - -The known fields are: - -\starttabulate[|lT|l|l|p|] -\NC \ssbf key \NC \bf type \NC \bf modes \NC \bf explanation \NC\NR -\NC mode \NC number \NC all \NC The current mode. This is a number representing the - main mode at this level:\crlf - 0 == no mode (this happens during \type{\write})\crlf - 1 == vertical,\crlf - 127 = horizontal,\crlf - 253 = display math.\crlf - $-1$ == internal vertical,\crlf - $-127$ = restricted horizontal,\crlf - $-253$ = inline math.\NC\NR -\NC modeline \NC number \NC all \NC source input line where this mode was entered in, - negative inside the output routine.\NC\NR -\NC head \NC node \NC all \NC the head of the current list\NC\NR -\NC tail \NC node \NC all \NC the tail of the current list\NC\NR -\NC prevgraf \NC number \NC vmode \NC number of lines in the previous paragraph\NC\NR -\NC prevdepth \NC number \NC vmode \NC depth of the previous paragraph (equal to \type{\pdfignoreddimen} - when it is to be ignored)\NC\NR -\NC spacefactor \NC number \NC hmode \NC the current space factor\NC\NR -\NC dirs \NC node \NC hmode \NC used for temporary storage by the line break algorithm\NC\NR -\NC noad \NC node \NC mmode \NC used for temporary storage of a pending fraction numerator, - for \type{\over} etc.\NC\NR -\NC delimptr \NC node \NC mmode \NC used for temporary storage of the previous math delimiter, - for \type{\middle}.\NC\NR -\NC mathdir \NC boolean \NC mmode \NC true when during math processing the \type{\mathdir} is not - the same as the surrounding \type{\textdir}\NC\NR -\NC mathstyle \NC number \NC mmode \NC the current \type{\mathstyle} \NC\NR -\stoptabulate - - -\subsection[sec:luaprint]{Print functions} - -The \luatex{tex} table also contains the three print functions that -are the major interface from \LUA\ scripting to \TEX. - -The arguments to these three functions are all stored in an in|-|memory -virtual file that is fed to the \TEX\ scanner as the result of the -expansion of \tex{directlua}. - -The total amount of returnable text from a \tex{directlua} command -is only limited by available system \RAM. However, each separate -printed string has to fit completely in \TEX's input buffer. - -The result of using these functions from inside callbacks is undefined -at the moment. - -\subsubsection{\luatex{tex.print}} - -\startfunctioncall -tex.print(<string> s, ...) -tex.print(<number> n, <string> s, ...) -tex.print(<table> t) -tex.print(<number> n, <table> t) -\stopfunctioncall - -Each string argument is treated by \TEX\ as a separate input line. -If there is a table argument instead of a list of strings, this has to -be a consecutive array of strings to print (the first non-string value -will stop the printing process). This syntax was added in 0.36. - -The optional parameter can be used to print the strings using the -catcode regime defined by \tex{catcodetable}~\type{n}. If \type{n} is -$-1$, the currently active catcode regime is used. If \type{n} is -$-2$, the resulting catcodes are the result of \type{\the\toks}: all -category codes are 12 (other) except for the space character, that has -category code 10 (space). Otherwise, if \type{n} is not -a valid catcode table, then it is ignored, and the currently -active catcode regime is used instead. - -The very last string of the very last \luatex{tex.print()} command in a -\tex{directlua} will not have the \tex{endlinechar} appended, all -others do. - -\subsubsection{\luatex{tex.sprint}} - -\startfunctioncall -tex.sprint(<string> s, ...) -tex.sprint(<number> n, <string> s, ...) -tex.sprint(<table> t) -tex.sprint(<number> n, <table> t) -\stopfunctioncall - -Each string argument is treated by \TEX\ as a special kind of input line -that makes it suitable for use as a partial line input mechanism: - -\startitemize[packed] -\item \TEX\ does not switch to the \quote{new line} state, so - that leading spaces are not ignored. -\item No \tex{endlinechar} is inserted. -\item Trailing spaces are not removed. - -Note that this does not prevent \TEX\ itself from eating spaces as -result of interpreting the line. For example, in - -\starttyping -before\directlua{tex.sprint("\\relax")tex.sprint(" inbetween")}after -\stoptyping - -the space before \type{inbetween} will be gobbled as a result of -the \quote{normal} scanning of \tex{relax}. -\stopitemize - -If there is a table argument instead of a list of strings, this has to -be a consecutive array of strings to print (the first non-string value -will stop the printing process). This syntax was added in 0.36. - -The optional argument sets the catcode regime, as with \type{tex.print()}. - -\subsubsection{\luatex{tex.tprint}} - -\startfunctioncall -tex.tprint({<number> n, <string> s, ...}, {...}) -\stopfunctioncall - -This function is basically a shortcut for repeated calls to -\luatex{tex.sprint(<number> n, <string> s, ...)}, once for each of -the supplied argument tables. - -\subsubsection{\luatex{tex.write}} - -\startfunctioncall -tex.write(<string> s, ...) -tex.write(<table> t) -\stopfunctioncall - -Each string argument is treated by \TEX\ as a special kind of input -line that makes it suitable for use as a quick way to dump -information: - -\startitemize -\item All catcodes on that line are either \quote{space} (for '~') or - \quote{character} (for all others). -\item There is no \tex{endlinechar} appended. -\stopitemize - -If there is a table argument instead of a list of strings, this has to -be a consecutive array of strings to print (the first non-string value -will stop the printing process). This syntax was added in 0.36. - - -\subsection{Helper functions} - -\subsubsection{\luatex{tex.round}} - -\startfunctioncall -<number> n = tex.round(<number> o) -\stopfunctioncall - -Rounds \LUA\ number \type{o}, and returns a number that is in the range -of a valid \TEX\ register value. If the number starts out of range, it -generates a \quote{number to big} error as well. - -\subsubsection{\luatex{tex.scale}} - -\startfunctioncall -<number> n = tex.scale(<number> o, <number> delta) -<table> n = tex.scale(table o, <number> delta) -\stopfunctioncall - -Multiplies the \LUA\ numbers \type{o} and \type{delta}, and returns a -rounded number that is in the range of a valid \TEX\ register value. -In the table version, it creates a copy of the table with all numeric -top||level values scaled in that manner. If the multiplied number(s) are -of range, it generates \quote{number to big} error(s) as well. - -Note: the precision of the output of this function will depend on your -computer's architecture and operating system, so use with care! An -interface to \LUATEX's internal, 100\% portable scale function will be -added at a later date. - -\subsubsection{\luatex{tex.sp} (0.51)} - -\startfunctioncall -<number> n = tex.sp(<number> o) -<number> n = tex.sp(<string> s) -\stopfunctioncall - -Converts the number \type{o} or a string \type{s} that represents -an explicit dimension into an integer number of scaled points. - -For parsing the string, the same scanning and conversion rules are used -that \LUATEX\ would use if it was scanning a dimension specifier in -its \TEX-like input language (this includes generating errors for bad -values), expect for the following: - -\startitemize[n] -\item only explicit values are allowed, control sequences are not handled -\item infinite dimension units (\type{fil...}) are forbidden -\item \type{mu} units do not generate an error (but may not be useful either) -\stopitemize - -\subsubsection{\luatex{tex.definefont}} - -\startfunctioncall -tex.definefont(<string> csname, <number> fontid) -tex.definefont(<boolean> global, <string> csname, <number> fontid) -\stopfunctioncall - -Associates \type{csname} with the internal font number \type{fontid}. -The definition is global if (and only if) \type{global} is specified -and true (the setting of \type{globaldefs} is not taken into account). - - -\subsubsection{\luatex{tex.error} (0.61)} - -\startfunctioncall -tex.error(<string> s) -tex.error(<string> s, <table> help) -\stopfunctioncall - -This creates an error somewhat like the combination of \tex{errhelp} -and \tex{errmessage} would. During this error, deletions are disabled. - -The array part of the \type{help} table has to contain strings, -one for each line of error help. - - -\subsubsection{\luatex{tex.hashtokens} (0.25)} - -\startfunctioncall -for i,v in pairs (tex.hashtokens()) do ... end -\stopfunctioncall - -Returns a name and token table pair (see~\in{section}[luatokens] about -token tables) iterator for every non-zero entry in the hash table. -This can be useful for debugging, but note that this also reports -control sequences that may be unreachable at this moment due to local -redefinitions: it is strictly a dump of the hash table. - -\subsection[luaprimitives]{Functions for dealing with primitives } - -\subsubsection{\luatex{tex.enableprimitives}} - -\startfunctioncall -tex.enableprimitives(<string> prefix, <table> primitive names) -\stopfunctioncall - -This function accepts a prefix string and an array of primitive names. - -For each combination of \quote{prefix} and \quote{name}, the -\type{tex.enableprimitives} first verifies that \quote{name} is -an actual primitive (it must be returned by one of the -\type{tex.extraprimitives()} calls explained below, or part of -\TEX82, or \type{\directlua}). If it is not, -\type{tex.enableprimitives} does nothing and skips to the next pair. - -But if it is, then it will construct a csname variable by concatenating the -\quote{prefix} and \quote{name}, unless the \quote{prefix} is already the actual -prefix of \quote{name}. In the latter case, it will discard the \quote{prefix}, -and just use \quote{name}. - -Then it will check for the existence of the constructed csname. -If the csname is currently undefined (note: that is not the same as -\type{\relax}), it will globally define the csname to have the -meaning: run code belonging to the primitive \quote{name}. If for some -reason the csname is already defined, it does nothing and tries the -next pair. - -An example: - -\starttyping - tex.enableprimitives('LuaTeX', {'formatname'}) -\stoptyping - -will define \type{\LuaTeXformatname} with the same intrinsic meaning -as the documented primitive \type{\formatname}, provided that the -control sequences \type{\LuaTeXformatname} is currently undefined. - -Second example: - -\starttyping - tex.enableprimitives('Omega',tex.extraprimitives ('omega')) -\stoptyping - -will define a whole series of csnames like \type{\Omegatextdir}, -\type{\Omegapardir}, etc., but it will stick with \type{\OmegaVersion} -instead of creating the doubly-prefixed \type{\OmegaOmegaVersion}. - -Starting with version 0.39.0 (and this is why the above two functions -are needed), \LUATEX\ in \type{--ini} mode contains only the \TEX82 -primitives and \type{\directlua}, no extra primitives {\bf at all}. - -So, if you want to have all the new functionality available using -their default names, as it is now, you will have to add - -\starttyping - \ifx\directlua\undefined \else - \directlua {tex.enableprimitives('',tex.extraprimitives ())} - \fi -\stoptyping - -near the beginning of your format generation file. Or you can choose -different prefixes for different subsets, as you see fit. - -Calling some form of \type{tex.enableprimitives()} is highly important -though, because if you do not, you will end up with a \TEX82-lookalike -that can run lua code but not do much else. The defined csnames are -(of course) saved in the format and will be available at runtime. - - -\subsubsection{\luatex{tex.extraprimitives}} - -\startfunctioncall -<table> t = tex.extraprimitives(<string> s, ...) -\stopfunctioncall - -This function returns a list of the primitives that originate -from the engine(s) given by the requested string value(s). The -possible values and their (current) return values are: - -\startluacode -function out_prim (a) - local v = tex.extraprimitives(a) - table.sort(v) - for _,n in pairs(v) do - if n == ' ' then - n = '\\normalcontrolspace' - end - tex.print(n .. '\\hskip 4pt plus 5em') - end -end -\stopluacode - -\starttabulate[|l|p|] -\NC \bf name\NC \bf values \NC \NR -\NC tex \NC \ctxlua{out_prim('tex') } \NC \NR -\NC core \NC \ctxlua{out_prim('core') } \NC \NR -\NC etex \NC \ctxlua{out_prim('etex') } \NC \NR -\NC pdftex \NC \ctxlua{out_prim('pdftex') } \NC \NR -\NC omega \NC \ctxlua{out_prim('omega') } \NC \NR -\NC aleph \NC \ctxlua{out_prim('aleph') } \NC \NR -\NC luatex \NC \ctxlua{out_prim('luatex') } \NC \NR -\NC umath \NC \ctxlua{out_prim('umath') } \NC \NR -\stoptabulate - -Note that \type{'luatex'} does not contain \type{directlua}, as that is -considered to be a core primitive, along with all the \TEX82 -primitives, so it is part of the list that is returned from \type{'core'}. - -\type{'umath'} is a subset of \type{'luatex'} that covers the Unicode math -primitives and have been added in \LUATEX\ 0.75.0 as it might be desired to -handle the prefixing of that subset differently. - -Running \type{tex.extraprimitives()} will give you the complete list -of primitives that are not defined at \LUATEX\ 0.39.0 \type{-ini} -startup. It is exactly equivalent to \type{tex.extraprimitives('etex', -'pdftex', 'omega', 'aleph', 'luatex')} - -\subsubsection{\luatex{tex.primitives}} - -\startfunctioncall -<table> t = tex.primitives() -\stopfunctioncall - -This function returns a hash table listing all primitives that \LUATEX\ -knows about. The keys in the hash are primitives names, the values are -tables representing tokens (see~\in{section }[luatokens]). The third value -is always zero. - -\subsection{Core functionality interfaces} - -\subsubsection{\luatex{tex.badness} (0.53)} - -\startfunctioncall -<number> b = tex.badness(<number> t, <number> s) -\stopfunctioncall - -This helper function is useful -during linebreak calculations. \type{t} and \type{s} are scaled values; the function -returns the badness for when total \type{t} is supposed to be made from amounts -that sum to \type{s}. The returned number is a reasonable approximation of $100(t/s)^3$; - -\subsubsection{\luatex{tex.linebreak} (0.53)} - -\startfunctioncall -local <node> nodelist, <table> info = - tex.linebreak(<node> listhead, <table> parameters) -\stopfunctioncall - -The understood parameters are as follows: - -\starttabulate[|l|l|p|] -\NC \bf name \NC \bf type \NC \bf description \NC \NR -\NC pardir \NC string \NC \NC \NR -\NC pretolerance \NC number \NC \NC \NR -\NC tracingparagraphs \NC number \NC \NC \NR -\NC tolerance \NC number \NC \NC \NR -\NC looseness \NC number \NC \NC \NR -\NC hyphenpenalty \NC number \NC \NC \NR -\NC exhyphenpenalty \NC number \NC \NC \NR -\NC pdfadjustspacing \NC number \NC \NC \NR -\NC adjdemerits \NC number \NC \NC \NR -\NC pdfprotrudechars \NC number \NC \NC \NR -\NC linepenalty \NC number \NC \NC \NR -\NC lastlinefit \NC number \NC \NC \NR -\NC doublehyphendemerits \NC number \NC \NC \NR -\NC finalhyphendemerits \NC number \NC \NC \NR -\NC hangafter \NC number \NC \NC \NR -\NC interlinepenalty \NC number or table \NC if a table, then it is an array like \type{\interlinepenalties}\NC \NR -\NC clubpenalty \NC number or table \NC if a table, then it is an array like \type{\clubpenalties}\NC \NR -\NC widowpenalty \NC number or table \NC if a table, then it is an array like \type{\widowpenalties}\NC \NR -\NC brokenpenalty \NC number \NC \NC \NR -\NC emergencystretch \NC number \NC in scaled points \NC \NR -\NC hangindent \NC number \NC in scaled points \NC \NR -\NC hsize \NC number \NC in scaled points \NC \NR -\NC leftskip \NC glue_spec node \NC \NC \NR -\NC rightskip \NC glue_spec node \NC \NC \NR -\NC pdfeachlineheight \NC number \NC in scaled points \NC \NR -\NC pdfeachlinedepth \NC number \NC in scaled points \NC \NR -\NC pdffirstlineheight \NC number \NC in scaled points \NC \NR -\NC pdflastlinedepth \NC number \NC in scaled points \NC \NR -\NC pdfignoreddimen \NC number \NC in scaled points \NC \NR -\NC parshape \NC table \NC \NC \NR -\stoptabulate - -Note that there is no interface for \type{\displaywidowpenalties}, you -have to pass the right choice for \type{widowpenalties} yourself. - -The meaning of the various keys should be fairly obvious from the -table (the names match the \TEX\ and \PDFTEX\ primitives) except for -the last 5 entries. The four \type{pdf...line...} keys are ignored if -their value equals \type{pdfignoreddimen}. - -It is your own job to make sure that \type{listhead} is a proper -paragraph list: this function does not add any nodes to it. To be -exact, if you want to replace the core line breaking, you may have to -do the following (when you are not actually working in the -\type{pre_linebreak_filter} or \type{linebreak_filter} callbacks, or when the -original list starting at listhead was generated in horizontal mode): - -\startitemize -\item add an \quote{indent box} and perhaps a \type{local_par} node at - the start (only if you need them) -\item replace any found final glue by an infinite penalty (or add such - a penalty, if the last node is not a glue) -\item add a glue node for the \type{\parfillskip} after that penalty node -\item make sure all the \type{prev} pointers are OK -\stopitemize - -The result is a node list, it still needs to be vpacked if you -want to assign it to a \tex{vbox}. - - -The returned \type{info} table contains four values that are all numbers: - -\starttabulate[|l|p|] -\NC prevdepth \NC depth of the last line in the broken paragraph \NC \NR -\NC prevgraf \NC number of lines in the broken paragraph \NC \NR -\NC looseness \NC the actual looseness value in the broken paragraph \NC \NR -\NC demerits \NC the total demerits of the chosen solution \NC \NR -\stoptabulate - -Note there are a few things you cannot interface using this function: -You cannot influence font expansion other than via -\type{pdfadjustspacing}, because the settings for that take place -elsewhere. The same is true for hbadness and hfuzz etc. All these are -in the \type{hpack()} routine, and that fetches its own variables via -globals. - -\subsubsection{\luatex{tex.shipout} (0.51)} - -\startfunctioncall -tex.shipout(<number> n) -\stopfunctioncall - -Ships out box number \type{n} to the output file, and clears the box -register. - - -\section[texconfig]{The \luatex{texconfig} table} - -This is a table that is created empty. A startup \LUA\ script could -fill this table with a number of settings that are read out by -the executable after loading and executing the startup file. - -\starttabulate[|lT|l|l|p|] -\NC \ssbf key \NC \bf type \NC \bf default \NC \bf explanation \NC\NR -\NC kpse_init \NC boolean \NC true \NC \type{false} totally disables \KPATHSEA\ initialisation, - and enables interpretation of the following numeric key--value pairs. - (only ever unset this if you implement {\it all\/} file - find callbacks!)\NC \NR -\NC shell_escape \NC string\NC \type{'f'}\NC Use \type{'y'} or \type{'t'} or \type{'1'} to enable \type{\write18} unconditionally, - \type{'p'} to enable the commands that are listed in \type{shell_escape_commands} (new in 0.37)\NC\NR -\NC shell_escape_commands \NC string\NC \NC Comma-separated list of command names that may be executed by \type{\write18} even - if \type{shell_escape} is set to \type{'p'}. Do {\it not\/} use spaces around commas, - separate any required command arguments by using a space, and use the ASCII double quote - (\type{"}) for any needed argument or path quoting (new in 0.37)\NC\NR -\NC string_vacancies \NC number\NC 75000\NC cf.\ web2c docs \NC \NR -\NC pool_free \NC number\NC 5000\NC cf.\ web2c docs \NC \NR -\NC max_strings \NC number\NC 15000\NC cf.\ web2c docs \NC \NR -\NC strings_free \NC number\NC 100\NC cf.\ web2c docs \NC \NR -\NC nest_size \NC number\NC 50\NC cf.\ web2c docs \NC \NR -\NC max_in_open \NC number\NC 15\NC cf.\ web2c docs \NC \NR -\NC param_size \NC number\NC 60\NC cf.\ web2c docs \NC \NR -\NC save_size \NC number\NC 4000\NC cf.\ web2c docs \NC \NR -\NC stack_size \NC number\NC 300\NC cf.\ web2c docs \NC \NR -\NC dvi_buf_size \NC number\NC 16384\NC cf.\ web2c docs \NC \NR -\NC error_line \NC number\NC 79\NC cf.\ web2c docs \NC \NR -\NC half_error_line \NC number\NC 50\NC cf.\ web2c docs \NC \NR -\NC max_print_line \NC number\NC 79\NC cf.\ web2c docs \NC \NR -\NC hash_extra \NC number\NC 0\NC cf.\ web2c docs \NC \NR -\NC pk_dpi \NC number\NC 72\NC cf.\ web2c docs \NC \NR -\NC trace_file_names \NC boolean \NC true \NC \type{false} disables \TEX's normal file open|-|close - feedback (the assumption is that callbacks will take care of - that) \NC \NR -\NC file_line_error \NC boolean \NC false \NC do \type{file:line} style error messages\NC \NR -\NC halt_on_error \NC boolean \NC false \NC abort run on the first encountered error\NC \NR -\NC formatname \NC string \NC \NC if no format name was given - on the commandline, this key will be tested first - instead of simply quitting\NC \NR -\NC jobname \NC string \NC \NC if no input file name was given - on the commandline, this key will be tested first - instead of simply giving up\NC \NR -\stoptabulate - -{\bf Note:} the numeric values that match web2c parameters are only used if -\type{kpse_init} is explicitly set to \type{false}. In all other cases, the normal values from -\type{texmf.cnf} are used. - -\section{The \luatex{texio} library} - -This library takes care of the low|-|level I/O interface. - -\subsection{Printing functions} - -\subsubsection{\luatex{texio.write}} - -\startfunctioncall -texio.write(<string> target, <string> s, ...) -texio.write(<string> s, ...) -\stopfunctioncall - -Without the \type{target} argument, writes all given strings to the same -location(s) \TEX\ writes messages to at this moment. If -\tex{batchmode} is in effect, it writes only to the log, -otherwise it writes to the log and the terminal. -The optional \type{target} can be one of three possibilities: -\type{term}, \type{log} or \type {term and log}. - -Note: If several strings are given, and if the first of these strings -is or might be one of the targets above, the \type{target} must be -specified explicitly to prevent \LUA\ from interpreting the first -string as the target. - -\subsubsection{\luatex{texio.write_nl}} - -\startfunctioncall -texio.write_nl(<string> target, <string> s, ...) -texio.write_nl(<string> s, ...) -\stopfunctioncall - -This function behaves like \luatex{texio.write}, but make sure that the given strings will -appear at the beginning of a new line. You can pass a single empty string -if you only want to move to the next line. - -%*********************************************************************** - -\section[luatokens]{The \luatex{token} library} - -The \luatex{token} table contains interface functions to \TEX's -handling of tokens. These functions are most useful when combined with -the \luatex{token_filter} callback, but they could be used standalone -as well. - -A token is represented in \LUA\ as a small table. For the moment, this -table consists of three numeric entries: - -\starttabulate[|l|l|p|] -\NC \bf index\NC \bf meaning \NC \bf description \NC \NR -\NC 1 \NC command code \NC this is a value between~$0$ and~$130$ (approximately)\NC \NR -\NC 2 \NC command modifier \NC this is a value between~$0$ and~$2^{21}$ \NC \NR -\NC 3 \NC control sequence id \NC for commands that are not the result of control - sequences, like letters and characters, it is zero, - otherwise, it is a number pointing into the \quote - {equivalence table} \NC \NR -\stoptabulate - -\subsection{\luatex{token.get_next}} - -\startfunctioncall -token t = token.get_next() -\stopfunctioncall - -This fetches the next input token from the current input source, -without expansion. - -\subsection{\luatex{token.is_expandable}} - -\startfunctioncall -<boolean> b = token.is_expandable(<token> t) -\stopfunctioncall - -This tests if the token \type{t} could be expanded. - -\subsection{\luatex{token.expand}} - -\startfunctioncall -token.expand(<token> t) -\stopfunctioncall - -If a token is expandable, this will expand one level of it, so that -the first token of the expansion will now be the next token to be read -by \luatex{token.get_next()}. - -\subsection{\luatex{token.is_activechar}} - -\startfunctioncall -<boolean> b = token.is_activechar(<token> t) -\stopfunctioncall - -This is a special test that is sometimes handy. Discovering whether -some control sequence is the result of an active character turned out -to be very hard otherwise. - -\subsection{\luatex{token.create}} - -\startfunctioncall -token t = token.create(<string> csname) -token t = token.create(<number> charcode) -token t = token.create(<number> charcode, <number> catcode) -\stopfunctioncall - -This is the token factory. If you feed it a string, then it is the -name of a control sequence (without leading backslash), and it will be -looked up in the equivalence table. - -If you feed it number, then this is assumed to be an input character, -and an optional second number gives its category code. This means it -is possible to overrule a character's category code, with a few -exceptions: the category codes~0 (escape), 9~(ignored), 13~(active), -14~(comment), and 15 (invalid) cannot occur inside a token. The values~0, 9, 14 -and~15 are therefore illegal as input to \luatex{token.create()}, and -active characters will be resolved immediately. - -Note: unknown string sequences and never defined active characters -will result in a token representing an \quote{undefined control sequence} -with a near|-|random name. It is {\em not} possible to define brand -new control sequences using \luatex{token.create}! - -\subsection{\luatex{token.command_name}} - -\startfunctioncall -<string> commandname = token.command_name(<token> t) -\stopfunctioncall - -This returns the name associated with the \quote{command} value of the token -in \LUATEX. There is not always a direct connection between these names and -primitives. For instance, all \tex{ifxxx} tests are grouped under -\type {if_test}, and the \quote{command modifier} defines which test is to be run. - -\subsection{\luatex{token.command_id}} - -\startfunctioncall -<number> i = token.command_id(<string> commandname) -\stopfunctioncall - -This returns a number that is the inverse operation of the previous -command, to be used as the first item in a token table. - -\subsection{\luatex{token.csname_name}} - -\startfunctioncall -<string> csname = token.csname_name(<token> t) -\stopfunctioncall - -This returns the name associated with the \quote{equivalence table} value of -the token in \LUATEX. It returns the string value of the command used -to create the current token, or an empty string if there is no -associated control sequence. - -Keep in mind that there are potentially two control sequences that -return the same csname string: single character control sequences -and active characters have the same \quote{name}. - -\subsection{\luatex{token.csname_id}} - -\startfunctioncall -<number> i = token.csname_id(<string> csname) -\stopfunctioncall - -This returns a number that is the inverse operation of the previous -command, to be used as the third item in a token table. - -\subsection{The \luatex{newtoken} libray} - -The current \type {token} library will be replaced by a new one that is more -flexible and powerful. The transition takes place in steps. In version 0.80 we -have \type {newtoken} and in version 0.85 the old lib will be replaced -completely. So if you use this new mechanism in production code you need to be -aware of incompatible updates between 0.80 and 0.90. Because the related in- and -output code will also be cleaned up and rewritten you should be aware of -incompatible logging and error reporting too. - -The old library presents tokens as triplets or numbers, the new library presents -a userdata object. The old library used a callback to intercept tokens in the -input but the new library provides a basic scanner infrastructure that can be -used to write macros that accept a wide range of arguments. This interface is on -purpose kept general and as performance is quite ok one can build additional -parsers without too much overhead. It's up to macro package writers to see how -they can benefit from this as the main principle behind \LUATEX\ is to provide -a minimal set of tools and no solutions. - -The current functions in the \type {newtoken} namespace are given in the next -table: - -\starttabulate[|lT|lT|p|] -\NC \bf function \NC \bf argument \NC \bf result \NC \NR -\HL -\NC is_token \NC token \NC checks if the given argument is a token userdatum \NC \NR -\NC get_next \NC \NC returns the next token in the input \NC \NR -\NC scan_keyword \NC string \NC returns true if the given keyword is gobbled \NC \NR -\NC scan_int \NC \NC returns a number \NC \NR -\NC scan_dimen \NC infinity, mu-units \NC returns a number representing a dimension and or two numbers being the filler and order \NC \NR -\NC scan_glue \NC mu-units \NC returns a glue spec node \NC \NR -\NC scan_toks \NC definer, expand \NC returns a table of tokens token list (this can become a linked list in later releases) \NC \NR -\NC scan_code \NC bitset \NC returns a character if its category is in the given bitset (representing catcodes) \NC \NR -\NC scan_string \NC \NC returns a string given between \type {{}}, as \type {\macro} or as sequence of characters with catcode 11 or 12 \NC \NR -\NC scan_word \NC \NC returns a sequence of characters with catcode 11 or 12 as string \NC \NR -\NC create \NC \NC returns a userdata token object of the given control sequence name (or character); this interface can change \NC \NR -\stoptabulate - -The scanners can be considered stable apart from the one scanning for a token. -This is because futures releases can return a linked list instead of a table (as -with nodes). The \type {scan_code} function takes an optional number, the \type -{keyword} function a normal \LUA\ string. The \type {infinity} boolean signals -that we also permit \type {fill} as dimension and the \type {mu-units} flags the -scanner that we expect math units. When scanning tokens we can indicate that we -are defining a macro, in which case the result will also provide information -about what arguments are expected and in the result this is separated from the -meaning by a separator token. The \type {expand} flag determines if the list will -be expanded. - -The string scanner scans for something between curly braces and expands on the way, -or when it sees a control sequence it will return its meaning. Otherwise it will -scan characters with catcode \type {letter} or \type {other}. So, given the -following definition: - -\startbuffer -\def\bar{bar} -\def\foo{foo-\bar} -\stopbuffer - -\typebuffer \getbuffer - -we get: - -\starttabulate[|l|Tl|l|] -\NC \type{\directlua{newtoken.scan_string()}{foo}} \NC \directlua{context("{\\red\\type{"..newtoken.scan_string().."}}")} {foo} \NC full expansion \NR -\NC \type{\directlua{newtoken.scan_string()}foo} \NC \directlua{context("{\\red\\type{"..newtoken.scan_string().."}}")} foo \NC letters and others \NR -\NC \type{\directlua{newtoken.scan_string()}\foo} \NC \directlua{context("{\\red\\type{"..newtoken.scan_string().."}}")}\foo \NC meaning \NR -\stoptabulate - -The \type {\foo} case only gives the meaning, but one can pass an already expanded -definition (\type {\edef}'d). In the case of the braced variant one can of course -use the \type {\detokenize} and \type {\unexpanded} primitives as there we do -expand. - -The \type {scan_word} scanner can be used to implement for instance a number scanner: - -\starttyping -function newtokens.scan_number(base) - return tonumber(newtoken.scan_word(),base) -end -\stoptyping - -This scanner accepts any valid \LUA\ number so it is a way to pick up floats -in the input. - -The creator function can be used as follows: - -\starttyping -local t = newtoken("relax") -\stoptyping - -This gives back a token object that has the properties of the \type {\relax} -primitive. The possible properties of tokens are: - -\starttabulate[|lT|p|] -\NC command \NC a number representing the internal command number \NC \NR -\NC cmdname \NC the type of the command (for instance the catcode in case of a - character or the classifier that determines the internal - treatment \NC \NR -\NC csname \NC the associated control sequence (if applicable) \NC \NR -\NC id \NC the unique id of the token \NC \NR -%NC tok \NC \NC \NR % might change -\NC active \NC a boolean indicating the active state of the token \NC \NR -\NC expandable \NC a boolean indicating if the token (macro) is expandable \NC \NR -\NC protected \NC a boolean indicating if the token (macro) is protected \NC \NR -\stoptabulate - -The numbers that represent a catcode are the same as in \TEX\ itself, so using -this information assumes that you know a bit about \TEX's internals. The other -numbers and names are used consistently but are not frozen. So, when you use them -for comparing you can best query a known primitive or character first to see the -values. - -More interesting are the scanners. You can use the \LUA\ interface as follows: - -\starttyping -\directlua { - function mymacro(n) - ... - end -} - -\def\mymacro#1{% - \directlua { - mymacro(\number\dimexpr#1) - }% -} - -\mymacro{12pt} -\mymacro{\dimen0} -\stoptyping - -But starting with version 0.80 you can also do this: - -\starttyping -\directlua { - function mymacro() - local d = newtoken.scan_dimen() - ... - end -} - -\def\mymacro{% - \directlua { - mymacro() - }% -} - -\mymacro 12pt -\mymacro \dimen0 -\stoptyping - -It is quite clear from looking at the code what the first method needs as -argument(s). For the second method you need to look at the \LUA\ code to see what -gets picked up. Instead of passing from \TEX\ to \LUA\ we let \LUA\ fetch from -the input stream. - -In the first case the input is tokenized and then turned into a string when it's -passed to \LUA\ where it gets interpreted. In the second case only a function -call gets interpreted but then the input is picked up by explicitly calling the -scanner functions. These return proper \LUA\ variables so no further conversion -has to be done. This is more efficient but in practice (given what \TEX\ has to -do) this effect should not be overestimated. For numbers and dimensions it saves a -bit but for passing strings conversion to and from tokens has to be done anyway -(although we can probably speed up the process in later versions if needed). - -When the interface is stable and has replaced the old one completely we will add -some more information here. By that time the internals have been cleaned up a bit -more so we know then what will stay and go. A positive side effect of this -transition is that we can simplify the input part because we no longer need to -intercept using callbacks. - -\chapter[math]{Math} - -The handling of mathematics in \LUATEX\ differs quite a bit from how -\TEX82 (and therefore \PDFTEX) handles math. First, \LUATEX\ adds primitives and -extends some others so that \UNICODE\ input can be used easily. Second, all -of \TEX82's internal special values (for example for operator spacing) have -been made accessible and changeable via control sequences. Third, there are -extensions that make it easier to use \OPENTYPE\ math fonts. And finally, -there are some extensions that have been proposed in the past that are now -added to the engine. - -\section{The current math style} - -Starting with \LUATEX\ 0.39.0, it is possible to discover the math -style that will be used for a formula in an expandable fashion -(while the math list is still being read). To make this possible, -\LUATEX\ adds the new primitive: \type{\mathstyle}. This is a -\quote{convert command} like e.g. \type{\romannumeral}: its value can -only be read, not set. - -\subsection{\tex{mathstyle}} - -The returned value is between 0 and 7 (in math mode), or $-1$ -(all other modes). For easy testing, the eight math style commands -have been altered so that the can be used as numeric values, so you -can write code like this: - -\starttyping -\ifnum\mathstyle=\textstyle - \message{normal text style} -\else \ifnum\mathstyle=\crampedtextstyle - \message{cramped text style} -\fi \fi -\stoptyping - -\subsection{\tex{Ustack}} - -There are a few math commands in \TEX\ where the style that will be used -is not known straight from the start. These commands (\tex{over}, -\tex{atop}, \tex{overwithdelims}, \tex{atopwithdelims}) would -therefore normally return wrong values for \type{\mathstyle}. To -fix this, \LUATEX\ introduces a special prefix command: -\type{\Ustack}: - -\starttyping -$\Ustack {a \over b}$ -\stoptyping - -The \type{\Ustack} command will scan the next brace and start a new -math group with the correct (numerator) math style. - -\section{Unicode math characters} - -Character handling is now extended up to the full \UNICODE\ range -(the \type{\U} prefix), which is compatible with \XETEX. - -The math primitives from \TEX\ are kept as they are, except for -the ones that convert from input to math commands: \type{mathcode}, -and \type{delcode}. These two now allow -for a 21-bit character argument on the left hand side of the equals sign. - -Some of the new \LUATEX\ primitives read -more than one separate value. This is shown in the tables below by a plus -sign in the second column. - -The input for such primitives would look like this: - -\starttyping -\def\overbrace {\Umathaccent 0 1 "23DE } -\stoptyping - - -Altered \TEX82 primitives: - -\starttabulate[|l|l|l|] -\NC \bf primitive \NC \bf value range (in hex) \NC\NR -\NC \tex{mathcode} \NC 0--10FFFF = 0--8000 \NC\NR -\NC \tex{delcode} \NC 0--10FFFF = 0--FFFFFF \NC\NR -\stoptabulate - -Unaltered: - -\starttabulate[|l|l|l|] -\NC \bf primitive \NC \bf value range (in hex) \NC\NR -\NC \tex{mathchardef} \NC 0--8000 \NC\NR -\NC \tex{mathchar} \NC 0--7FFF \NC\NR -\NC \tex{mathaccent} \NC 0--7FFF \NC\NR -\NC \tex{delimiter} \NC 0--7FFFFFF \NC\NR -\NC \tex{radical} \NC 0--7FFFFFF \NC\NR -\stoptabulate - -New primitives that are compatible with \XETEX: - -\starttabulate[|l|l|l|l|] -\NC \bf primitive \NC \bf value range (in hex) \NC\NR -\NC \tex{Umathchardef} \NC 0+0+0--7+FF+10FFFF$^1$ \NC\NR -\NC \tex{Umathcharnumdef}$^5$ \NC -80000000--7FFFFFFF$^3$ \NC\NR -\NC \tex{Umathcode} \NC 0--10FFFF = 0+0+0--7+FF+10FFFF$^1$ \NC\NR -\NC \tex{Udelcode} \NC 0--10FFFF = 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Umathchar} \NC 0+0+0--7+FF+10FFFF \NC\NR -\NC \tex{Umathaccent} \NC 0+0+0--7+FF+10FFFF$^{2,4}$ \NC\NR -\NC \tex{Udelimiter} \NC 0+0+0--7+FF+10FFFF$^2$ \NC\NR -\NC \tex{Uradical} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Umathcharnum} \NC -80000000--7FFFFFFF$^3$ \NC\NR -\NC \tex{Umathcodenum} \NC 0--10FFFF = -80000000--7FFFFFFF$^3$ \NC\NR -\NC \tex{Udelcodenum} \NC 0--10FFFF = -80000000--7FFFFFFF$^3$ \NC\NR -\stoptabulate - -Note 1: \type{\Umathchardef<csname>="8"0"0} and \type{\Umathchardef<number>="8"0"0} -are also accepted. - -Note 2: The new primitives that deal with delimiter-style objects do not -set up a \quote{large family}. Selecting a suitable size for display -purposes is expected to be dealt with by the font via the -\tex{Umathoperatorsize} parameter (more information a following section). - -Note 3: For these three primitives, all information is packed into a single -signed integer. For the first two (\tex{Umathcharnum} and -\tex{Umathcodenum}), the lowest 21 bits are the character code, the 3 -bits above that represent the math class, and the family data is kept in -the topmost bits (This means that the values for math families 128--255 are -actually negative). For \tex{Udelcodenum} there is no math class; the -math family information is stored in the bits directly on top of the -character code. Using these three commands is not as natural as using the -two- and three-value commands, so unless you know exactly what you are -doing and absolutely require the speedup resulting from the faster input -scanning, it is better to use the verbose commands instead. - -Note 4: As of \LUATEX\ 0.65, \tex{Umathaccent} accepts optional -keywords to control various details regarding math accents. See -\in{section}[mathacc] below for details. - -Note 5: \tex{Umathcharnumdef} was added in release 0.72. - - -New primitives that exist in \LUATEX\ only (all of these will be explained -in following sections): - - -\starttabulate[|l|l|l|l|] -\NC \bf primitive \NC \bf value range (in hex) \NC\NR -\NC \tex{Uroot} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Uoverdelimiter} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Uunderdelimiter} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Udelimiterover} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\NC \tex{Udelimiterunder} \NC 0+0--FF+10FFFF$^2$ \NC\NR -\stoptabulate - -\section{Cramped math styles} - -\LUATEX\ has four new primitives to set the cramped math styles -directly: - -\starttyping -\crampeddisplaystyle -\crampedtextstyle -\crampedscriptstyle -\crampedscriptscriptstyle -\stoptyping - -These additional commands are not all that valuable on their own, but -they come in handy as arguments to the math parameter settings that -will be added shortly. - -\section{Math parameter settings} - -In \LUATEX, the font dimension parameters that \TEX\ used in math -typesetting are now accessible via primitive commands. In fact, -refactoring of the math engine has resulted in many more parameters -than were accessible before. - -\starttabulate -\NC \bf primitive name \NC \bf description \NC \NR -\NC \type{\Umathquad} \NC the width of 18mu's\NC \NR -\NC \type{\Umathaxis} \NC height of the vertical center axis of - the math formula above the baseline\NC \NR -\NC \type{\Umathoperatorsize} \NC minimum size of large operators in display mode \NC \NR -\NC \type{\Umathoverbarkern} \NC vertical clearance above the rule \NC \NR -\NC \type{\Umathoverbarrule} \NC the width of the rule \NC \NR -\NC \type{\Umathoverbarvgap} \NC vertical clearance below the rule \NC \NR -\NC \type{\Umathunderbarkern} \NC vertical clearance below the rule \NC \NR -\NC \type{\Umathunderbarrule} \NC the width of the rule \NC \NR -\NC \type{\Umathunderbarvgap} \NC vertical clearance above the rule \NC \NR -\NC \type{\Umathradicalkern} \NC vertical clearance above the rule \NC \NR -\NC \type{\Umathradicalrule} \NC the width of the rule \NC \NR -\NC \type{\Umathradicalvgap} \NC vertical clearance below the rule \NC \NR -\NC \type{\Umathradicaldegreebefore}\NC the forward kern that takes place before placement of - the radical degree \NC \NR -\NC \type{\Umathradicaldegreeafter} \NC the backward kern that takes place after placement of - the radical degree \NC \NR -\NC \type{\Umathradicaldegreeraise} \NC this is the percentage of the total height and depth of - the radical sign that the degree is raised by. It is - expressed in \type{percents}, so 60\% is expressed as the - integer $60$.\NC \NR -\NC \type{\Umathstackvgap} \NC vertical clearance between the two - elements in a \type{\atop} stack \NC \NR -\NC \type{\Umathstacknumup} \NC numerator shift upward in \type{\atop} stack \NC \NR -\NC \type{\Umathstackdenomdown} \NC denominator shift downward in \type{\atop} stack\NC \NR -\NC \type{\Umathfractionrule} \NC the width of the rule in a \type{\over}\NC \NR -\NC \type{\Umathfractionnumvgap} \NC vertical clearance between the numerator and the rule\NC \NR -\NC \type{\Umathfractionnumup} \NC numerator shift upward in \type{\over} \NC \NR -\NC \type{\Umathfractiondenomvgap} \NC vertical clearance between the denominator and the rule\NC \NR -\NC \type{\Umathfractiondenomdown} \NC denominator shift downward in \type{\over} \NC \NR -\NC \type{\Umathfractiondelsize} \NC minimum delimiter size for \type{\...withdelims}\NC \NR -\NC \type{\Umathlimitabovevgap} \NC vertical clearance for limits above operators\NC \NR -\NC \type{\Umathlimitabovebgap} \NC vertical baseline clearance for limits above operators\NC \NR -\NC \type{\Umathlimitabovekern} \NC space reserved at the top of the limit\NC \NR -\NC \type{\Umathlimitbelowvgap} \NC vertical clearance for limits below operators\NC \NR -\NC \type{\Umathlimitbelowbgap} \NC vertical baseline clearance for limits below operators\NC \NR -\NC \type{\Umathlimitbelowkern} \NC space reserved at the bottom of the limit\NC \NR -\NC \type{\Umathoverdelimitervgap} \NC vertical clearance for limits above delimiters\NC \NR -\NC \type{\Umathoverdelimiterbgap} \NC vertical baseline clearance for limits above delimiters\NC \NR -\NC \type{\Umathunderdelimitervgap} \NC vertical clearance for limits below delimiters\NC \NR -\NC \type{\Umathunderdelimiterbgap} \NC vertical baseline clearance for limits below delimiters\NC \NR -\NC \type{\Umathsubshiftdrop} \NC subscript drop for boxes and subformulas\NC \NR -\NC \type{\Umathsubshiftdown} \NC subscript drop for characters\NC \NR -\NC \type{\Umathsupshiftdrop} \NC superscript drop (raise, actually) for boxes and subformulas\NC \NR -\NC \type{\Umathsupshiftup} \NC superscript raise for characters\NC \NR -\NC \type{\Umathsubsupshiftdown} \NC subscript drop in the presence of a superscript\NC \NR -\NC \type{\Umathsubtopmax} \NC the top of standalone subscripts cannot be higher than this above the baseline\NC \NR -\NC \type{\Umathsupbottommin} \NC the bottom of standalone superscripts cannot be less than this above the baseline\NC \NR -\NC \type{\Umathsupsubbottommax} \NC the bottom of the superscript of a combined super- and subscript - be at least as high as this above the baseline\NC \NR -\NC \type{\Umathsubsupvgap} \NC vertical clearance between super- and subscript\NC \NR -\NC \type{\Umathspaceafterscript} \NC additional space added after a super- or subscript\NC \NR -\NC \type{\Umathconnectoroverlapmin}\NC minimum overlap between parts in an extensible recipe\NC \NR -\stoptabulate - -Each of the parameters in this section can be set by a command like this: - -\starttyping -\Umathquad\displaystyle=1em -\stoptyping - -they obey grouping, and you can use \type{\the\Umathquad\displaystyle} if needed. - -\section{Font-based Math Parameters} - -While it is nice to have these math parameters available for tweaking, it -would be tedious to have to set each of them by hand. For this reason, -\LUATEX\ initializes a bunch of these parameters whenever you assign a font -identifier to a math family based on either the traditional math font -dimensions in the font (for assignments to math family~2 and~3 using -\TFM|-|based fonts like \type{cmsy} and \type{cmex}), or based on the named -values in a potential \type{MathConstants} table when the font is loaded -via Lua. If there is a \type{MathConstants} table, this takes precedence -over font dimensions, and in that case no attention is paid to which -family is being assigned to: the \type{MathConstants} tables in the last -assigned family sets all parameters. - -In the table below, the one-letter style abbreviations and symbolic tfm -font dimension names match those using in the \TeX book. Assignments to -\tex{textfont} set the values for the cramped and uncramped display and -text styles. Use \tex{scriptfont} for the script styles, and -\tex{scriptscriptfont} for the scriptscript styles (totalling eight -parameters for three font sizes). In the \TFM\ case, assignments only happen -in family~2 and family~3 (and of course only for the parameters for which -there are font dimensions). - -Besides the parameters below, \LUATEX\ also looks at the \quote{space} -font dimension parameter. For math fonts, this should be set to zero. - -\start - -\switchtobodyfont[8pt] - -\starttabulate[|l|l|l|p|] -\NC \bf variable \NC \bf style \NC \bf default value opentype \NC \bf default value tfm \NC\NR -\NC \tex{Umathaxis} \NC -- \NC AxisHeight \NC axis_height \NC\NR -\NC \tex{Umathoperatorsize} \NC D, D' \NC DisplayOperatorMinHeight \NC $^6$ \NC\NR -\NC \tex{Umathfractiondelsize} \NC D, D' \NC FractionDelimiterDisplayStyleSize$^9$ \NC delim1 \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC FractionDelimiterSize$^9$ \NC delim2 \NC\NR -\NC \tex{Umathfractiondenomdown}\NC D, D' \NC FractionDenominatorDisplayStyleShiftDown \NC denom1 \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC FractionDenominatorShiftDown \NC denom2 \NC\NR -\NC \tex{Umathfractiondenomvgap}\NC D, D' \NC FractionDenominatorDisplayStyleGapMin \NC 3*default_rule_thickness \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC FractionDenominatorGapMin \NC default_rule_thickness \NC\NR -\NC \tex{Umathfractionnumup} \NC D, D' \NC FractionNumeratorDisplayStyleShiftUp \NC num1 \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC FractionNumeratorShiftUp \NC num2 \NC\NR -\NC \tex{Umathfractionnumvgap} \NC D, D' \NC FractionNumeratorDisplayStyleGapMin \NC 3*default_rule_thickness \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC FractionNumeratorGapMin \NC default_rule_thickness \NC\NR -\NC \tex{Umathfractionrule} \NC -- \NC FractionRuleThickness \NC default_rule_thickness \NC\NR -\NC \tex{Umathlimitabovebgap} \NC -- \NC UpperLimitBaselineRiseMin \NC big_op_spacing3 \NC\NR -\NC \tex{Umathlimitabovekern} \NC -- \NC 0$^1$ \NC big_op_spacing5 \NC\NR -\NC \tex{Umathlimitabovevgap} \NC -- \NC UpperLimitGapMin \NC big_op_spacing1 \NC\NR -\NC \tex{Umathlimitbelowbgap} \NC -- \NC LowerLimitBaselineDropMin \NC big_op_spacing4 \NC\NR -\NC \tex{Umathlimitbelowkern} \NC -- \NC 0$^1$ \NC big_op_spacing5 \NC\NR -\NC \tex{Umathlimitbelowvgap} \NC -- \NC LowerLimitGapMin \NC big_op_spacing2 \NC\NR -\NC \tex{Umathoverdelimitervgap}\NC -- \NC StretchStackGapBelowMin \NC big_op_spacing1 \NC\NR -\NC \tex{Umathoverdelimiterbgap}\NC -- \NC StretchStackTopShiftUp \NC big_op_spacing3 \NC\NR -\NC \tex{Umathunderdelimitervgap}\NC-- \NC StretchStackGapAboveMin \NC big_op_spacing2 \NC\NR -\NC \tex{Umathunderdelimiterbgap}\NC-- \NC StretchStackBottomShiftDown \NC big_op_spacing4 \NC\NR -\NC \tex{Umathoverbarkern} \NC -- \NC OverbarExtraAscender \NC default_rule_thickness \NC\NR -\NC \tex{Umathoverbarrule} \NC -- \NC OverbarRuleThickness \NC default_rule_thickness \NC\NR -\NC \tex{Umathoverbarvgap} \NC -- \NC OverbarVerticalGap \NC 3*default_rule_thickness \NC\NR -\NC \tex{Umathquad} \NC -- \NC <font_size(f)>$^1$ \NC math_quad \NC\NR -\NC \tex{Umathradicalkern} \NC -- \NC RadicalExtraAscender \NC default_rule_thickness \NC\NR -\NC \tex{Umathradicalrule} \NC -- \NC RadicalRuleThickness \NC <not set>$^2$ \NC\NR -\NC \tex{Umathradicalvgap} \NC D, D' \NC RadicalDisplayStyleVerticalGap \NC (default_rule_thickness+\crlf - (abs(math_x_height)/4))$^3$ \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC RadicalVerticalGap \NC (default_rule_thickness+\crlf - (abs(default_rule_thickness)/4))$^3$ \NC\NR -\NC \tex{Umathradicaldegreebefore}\NC -- \NC RadicalKernBeforeDegree \NC <not set>$^2$ \NC\NR -\NC \tex{Umathradicaldegreeafter}\NC -- \NC RadicalKernAfterDegree \NC <not set>$^2$ \NC\NR -\NC \tex{Umathradicaldegreeraise}\NC -- \NC RadicalDegreeBottomRaisePercent \NC <not set>$^{2,7}$ \NC\NR -\NC \tex{Umathspaceafterscript} \NC -- \NC SpaceAfterScript \NC script_space$^4$ \NC\NR -\NC \tex{Umathstackdenomdown} \NC D, D' \NC StackBottomDisplayStyleShiftDown \NC denom1 \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC StackBottomShiftDown \NC denom2 \NC\NR -\NC \tex{Umathstacknumup} \NC D, D' \NC StackTopDisplayStyleShiftUp \NC num1 \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC StackTopShiftUp \NC num3 \NC\NR -\NC \tex{Umathstackvgap} \NC D, D' \NC StackDisplayStyleGapMin \NC 7*default_rule_thickness \NC\NR -\NC " \NC T, T', S, S', SS, SS' \NC StackGapMin \NC 3*default_rule_thickness \NC\NR -\NC \tex{Umathsubshiftdown} \NC -- \NC SubscriptShiftDown \NC sub1 \NC\NR -\NC \tex{Umathsubshiftdrop} \NC -- \NC SubscriptBaselineDropMin \NC sub_drop \NC\NR -\NC \tex{Umathsubsupshiftdown} \NC -- \NC SubscriptShiftDownWithSuperscript$^8$ \NC \NC\NR -\NC \NC \NC \quad\ or SubscriptShiftDown \NC sub2 \NC\NR -\NC \tex{Umathsubtopmax} \NC -- \NC SubscriptTopMax \NC (abs(math_x_height * 4) / 5) \NC\NR -\NC \tex{Umathsubsupvgap} \NC -- \NC SubSuperscriptGapMin \NC 4*default_rule_thickness \NC\NR -\NC \tex{Umathsupbottommin} \NC -- \NC SuperscriptBottomMin \NC (abs(math_x_height) / 4) \NC\NR -\NC \tex{Umathsupshiftdrop} \NC -- \NC SuperscriptBaselineDropMax \NC sup_drop \NC\NR -\NC \tex{Umathsupshiftup} \NC D \NC SuperscriptShiftUp \NC sup1 \NC\NR -\NC " \NC T, S, SS, \NC SuperscriptShiftUp \NC sup2 \NC\NR -\NC " \NC D', T', S', SS' \NC SuperscriptShiftUpCramped \NC sup3 \NC\NR -\NC \tex{Umathsupsubbottommax} \NC -- \NC SuperscriptBottomMaxWithSubscript \NC (abs(math_x_height * 4) / 5) \NC\NR -\NC \tex{Umathunderbarkern} \NC -- \NC UnderbarExtraDescender \NC default_rule_thickness \NC\NR -\NC \tex{Umathunderbarrule} \NC -- \NC UnderbarRuleThickness \NC default_rule_thickness \NC\NR -\NC \tex{Umathunderbarvgap} \NC -- \NC UnderbarVerticalGap \NC 3*default_rule_thickness \NC\NR -\NC \tex{Umathconnectoroverlapmin}\NC -- \NC MinConnectorOverlap \NC 0$^5$ \NC\NR -\stoptabulate - -\stop - -Note 1: \OPENTYPE\ fonts set \tex{Umathlimitabovekern} and -\tex{Umathlimitbelowkern} to zero and set \tex{Umathquad} to the font size of the used font, -because these are not supported in the MATH table, - -Note 2: \TFM\ fonts do not set \tex{Umathradicalrule} because \TeX82\ uses the height of the radical -instead. When this parameter is indeed not set when \LUATEX\ has to typeset a radical, a backward -compatibility mode will kick in that assumes that an oldstyle \TeX\ font is used. Also, they do -not set \tex{Umathradicaldegreebefore}, \tex{Umathradicaldegreeafter}, and -\tex{Umathradicaldegreeraise}. These are then automatically initialized to $5/18$quad, $-10/18$quad, and 60. - -Note 3: If tfm fonts are used, then the \tex{Umathradicalvgap} is not set until the first time -\LUATEX\ has to typeset a formula because this needs parameters from both family2 and family3. -This provides a partial backward compatibility with \TEX82, but that compatibility is only partial: -once the \tex{Umathradicalvgap} is set, it will not be recalculated any more. - -Note 4: (also if tfm fonts are used) A similar situation arises wrt. \tex{Umathspaceafterscript}: it is not -set until the first time \LUATEX\ has to typeset a formula. This provides some backward compatibility with -\TEX82. But once the \tex{Umathspaceafterscript} is set, \tex{scriptspace} will never be looked at again. - -Note 5: Tfm fonts set \tex{Umathconnectoroverlapmin} to zero because -\TeX82\ always stacks extensibles without any overlap. - -Note 6: The \tex{Umathoperatorsize} is only used in \type{\displaystyle}, and is only set -in \OPENTYPE\ fonts. In \TFM\ font mode, it is artificially set to one scaled point more than the -initial attempt's size, so that always the \quote{first next} will be tried, just like in \TEX82. - -Note 7: The \tex{Umathradicaldegreeraise} is a special case because it is the only parameter that is -expressed in a percentage instead of as a number of scaled points. - -Note 8: \type{SubscriptShiftDownWithSuperscript} does not actually exist in the \quote{standard} -Opentype Math font Cambria, but it is useful enough to be added. New in version 0.38. - -Note 9: \type{FractionDelimiterDisplayStyleSize} and \type{FractionDelimiterSize} do not actually exist in the \quote{standard} -Opentype Math font Cambria, but were useful enough to be added. New in version 0.47. - - -\section{Math spacing setting} - -Besides the parameters mentioned in the previous sections, there are -also 64 new primitives to control the math spacing table (as explained in -Chapter~18 of the \TeX book). The primitive names are a simple matter -of combining two math atom types, but for completeness' sake, here is -the whole list: - -\startcolumns[n=2] -\starttyping -\Umathordordspacing -\Umathordopspacing -\Umathordbinspacing -\Umathordrelspacing -\Umathordopenspacing -\Umathordclosespacing -\Umathordpunctspacing -\Umathordinnerspacing -\Umathopordspacing -\Umathopopspacing -\Umathopbinspacing -\Umathoprelspacing -\Umathopopenspacing -\Umathopclosespacing -\Umathoppunctspacing -\Umathopinnerspacing -\Umathbinordspacing -\Umathbinopspacing -\Umathbinbinspacing -\Umathbinrelspacing -\Umathbinopenspacing -\Umathbinclosespacing -\Umathbinpunctspacing -\Umathbininnerspacing -\Umathrelordspacing -\Umathrelopspacing -\Umathrelbinspacing -\Umathrelrelspacing -\Umathrelopenspacing -\Umathrelclosespacing -\Umathrelpunctspacing -\Umathrelinnerspacing -\Umathopenordspacing -\Umathopenopspacing -\Umathopenbinspacing -\Umathopenrelspacing -\Umathopenopenspacing -\Umathopenclosespacing -\Umathopenpunctspacing -\Umathopeninnerspacing -\Umathcloseordspacing -\Umathcloseopspacing -\Umathclosebinspacing -\Umathcloserelspacing -\Umathcloseopenspacing -\Umathcloseclosespacing -\Umathclosepunctspacing -\Umathcloseinnerspacing -\Umathpunctordspacing -\Umathpunctopspacing -\Umathpunctbinspacing -\Umathpunctrelspacing -\Umathpunctopenspacing -\Umathpunctclosespacing -\Umathpunctpunctspacing -\Umathpunctinnerspacing -\Umathinnerordspacing -\Umathinneropspacing -\Umathinnerbinspacing -\Umathinnerrelspacing -\Umathinneropenspacing -\Umathinnerclosespacing -\Umathinnerpunctspacing -\Umathinnerinnerspacing -\stoptyping -\stopcolumns - -These parameters are of type \type{\muskip}, so setting a parameter -can be done like this: - -\starttyping -\Umathopordspacing\displaystyle=4mu plus 2mu -\stoptyping - -They are all initialized by initex to the values mentioned in the -table in Chapter~18 of the \TeX book. - -Note 1: for ease of use as well as for backward compatibility, \type{\thinmuskip}, -\type{\medmuskip} and \type{\thickmuskip} are treated especially. In their case a pointer to -the corresponding internal parameter is saved, not the actual \type{\muskip} value. This -means that any later changes to one of these three parameters will be taken into account. - -Note 2: Careful readers will realise that there are also primitives -for the items marked \type{*} in the \TeX book. These will not -actually be used as those combinations of atoms cannot actually -happen, but it seemed better not to break orthogonality. They are initialized to zero. - - -\section[mathacc]{Math accent handling} - -\LUATEX\ supports both top accents and bottom accents in math mode, -and math accents stretch automatically (if this is supported by the -font the accent comes from, of course). Bottom and combined accents as -well as fixed-width math accents are controlled by optional keywords -following \tex{Umathaccent}. - -The keyword \type{bottom} after \tex{Umathaccent} signals that a bottom -accent is needed, and the keyword \type{both} signals that both a top -and a bottom accent are needed (in this case two accents need to be -specified, of course). - -Then the set of three integers defining the accent is read. This set -of integers can be prefixed by the \type{fixed} keyword to indicate -that a non-stretching variant is requested (in case of both accents, -this step is repeated). - -A simple example: -\starttyping -\Umathaccent both fixed 0 0 "20D7 fixed 0 0 "20D7 {example} -\stoptyping - -If a math top accent has to be placed and the accentee is a character and has a non-zero -\type{top_accent} value, then this value will be used to place the accent instead of -the \type{\skewchar} kern used by \TEX82. - -The \type{top_accent} value represents a vertical line somewhere in the accentee. The -accent will be shifted horizontally such that its own \type{top_accent} line coincides -with the one from the accentee. If the \type{top_accent} value of the accent is zero, -then half the width of the accent followed by its italic correction is used instead. - -The vertical placement of a top accent depends on the \type{x_height} of the font of the -accentee (as explained in the \TEX book), but if value that turns out to be zero and the -font had a MathConstants table, then \type{AccentBaseHeight} is used instead. - -If a math bottom accent has to be placed, the \type{bot_accent} value is checked instead -of \type{top_accent}. Because bottom accents do not exist in \TEX82, the \type{\skewchar} -kern is ignored. - -The vertical placement of a bottom accent is straight below the accentee, no correction -takes place. - -\section{Math root extension} - -The new primitive \type{\Uroot} allows the construction of a radical -noad including a degree field. Its syntax is an extension of \type{\Uradical}: - -\starttyping -\Uradical <fam integer> <char integer> <radicand> -\Uroot <fam integer> <char integer> <degree> <radicand> -\stoptyping - -The placement of the degree is controlled by the math parameters -\type{\Umathradicaldegreebefore}, \type{\Umathradicaldegreeafter}, and -\type{\Umathradicaldegreeraise}. The degree will be typeset in \type{\scriptscriptstyle}. - - -\section{Math kerning in super- and subscripts} - -The character fields in a lua-loaded OpenType math font can have a \quote{mathkern} table. -The format of this table is the same as the \quote{mathkern} table that is returned by -the \type{fontloader} library, except that all height and kern values have to -be specified in actual scaled points. - -When a super- or subscript has to be placed next to a math item, \LUATEX\ checks -whether the super- or subscript and the nucleus are both simple character items. If -they are, and if the fonts of both character imtes are OpenType fonts (as opposed to -legacy \TEX\ fonts), then \LUATEX\ will use the OpenType MATH algorithm for deciding -on the horizontal placement of the super- or subscript. - -This works as follows: - -\startitemize -\item The vertical position of the script is calculated. -\item The default horizontal position is flat next to the base character. -\item For superscripts, the italic correction of the base character is added. -\item For a superscript, two vertical values are calculated: the bottom of the - script (after shifting up), and the top of the base. For a subscript, - the two values are the top of the (shifted down) script, and the bottom - of the base. -\item For each of these two locations: - \startitemize - \item find the mathkern value at this height for the base - (for a subscript placement, this is the bottom_right corner, - for a superscript placement the top_right corner) - \item find the mathkern value at this height for the script - (for a subscript placement, this is the top_left corner, - for a superscript placement the bottom_left corner) - \item add the found values together to get a preliminary result. - \stopitemize -\item The horizontal kern to be applied is the smallest of the two results from - previous step. -\stopitemize - -The mathkern value at a specific height is the kern value that is specified by the -next higher height and kern pair, or the highest one in the character (if there is no -value high enough in the character), or simply zero (if the character has no mathkern -pairs at all). - -\section{Scripts on horizontally extensible items like arrows} - -The new primitives \tex{Uunderdelimiter} and \tex{Uoverdelimiter} -(both from 0.35) allow the placement of a subscript or superscript on -an automatically extensible item and \tex{Udelimiterunder} and -\tex{Udelimiterover} (both from 0.37) allow the placement of -an automatically extensible item as a subscript or superscript on a -nucleus. - -The vertical placements are controlled by -\tex{Umathunderdelimiterbgap}, \tex{Umathunderdelimitervgap}, -\tex{Umathoverdelimiterbgap}, and \tex{Umathoverdelimitervgap} in a similar way as limit -placements on large operators. The superscript in \tex{Uoverdelimiter} is typeset in -a suitable scripted style, the subscript in \tex{Uunderdelimiter} is cramped as well. - -\section {Extensible delimiters} - -\LUATEX\ internally uses a structure that supports \OPENTYPE\ \quote{MathVariants} as well -as \TFM\ \quote{extensible recipes}. - - -\section{Other Math changes} - -\subsection {Verbose versions of single-character math commands} - -\LUATEX\ defines six new primitives that have the same function as -\type{^}, \type{_}, \type{$}, and \type{$$}. %$ - -\starttabulate[|l|l|l|l|] -\NC \bf primitive \NC \bf explanation \NC\NR -\NC \tex{Usuperscript} \NC Duplicates the functionality of \type{^} \NC\NR -\NC \tex{Usubscript} \NC Duplicates the functionality of \type{_} \NC\NR -\NC \tex{Ustartmath} \NC Duplicates the functionality of \type{$}, % $ - when used in non-math mode. \NC\NR -\NC \tex{Ustopmath} \NC Duplicates the functionality of \type{$}, % $ - when used in inline math mode. \NC\NR -\NC \tex{Ustartdisplaymath}\NC Duplicates the functionality of \type{$$}, % $$ - when used in non-math mode. \NC\NR -\NC \tex{Ustopdisplaymath} \NC Duplicates the functionality of \type{$$}, % $$ - when used in display math mode. \NC\NR -\stoptabulate - -All are new in version 0.38. The \tex{Ustopmath} and \tex{Ustopdisplaymath} -primitives check if the current math mode is the correct one (inline -vs. displayed), but you can freely intermix the four mathon|/|mathoff -commands with explicit dollar sign(s). - - -\subsection{Allowed math commands in non-math modes} - -The commands \type{\mathchar}, and \type{\Umathchar} and control -sequences that are the result of \type{\mathchardef} or -\type{\Umathchardef} are also acceptable in the horizontal and vertical modes. -In those cases, the \type{\textfont} from the requested math family is used. - -\section{Math todo} - -The following items are still todo. - -\startitemize -\item Pre-scripts. -\item Multi-story stacks. -\item Flattened accents for high characters (?). -\item Better control over the spacing around displays and handling of equation numbers. -\item Support for multi-line displays using \MATHML\ style alignment points. -\stopitemize - -\chapter[languages]{Languages and characters, fonts and glyphs} - -\LUATEX's internal handling of the characters and glyphs that eventually -become typeset is quite different from the way \TEX82 handles those -same objects. The easiest way to explain the difference is to focus on -unrestricted horizontal mode (i.\,e.\ paragraphs) and hyphenation first. -Later on, it will be easy to deal with the differences that occur in -horizontal and math modes. - -In \TEX82, the characters you type are converted into \type{char_node} -records when they are encountered by the main control loop. \TEX\ -attaches and processes the font information while creating those -records, so that the resulting \quote{horizontal list} contains the final -forms of ligatures and implicit kerning. This packaging is needed because -we may want to get the effective width of for instance a horizontal box. - -When it becomes necessary to hyphenate words in a paragraph, \TEX\ -converts (one word at time) the \type{char_node} records into a -string array by replacing ligatures with their components and -ignoring the kerning. Then it runs the hyphenation algorithm on this -string, and converts the hyphenated result back into a -\quote{horizontal list} that is consecutively spliced back into -the paragraph stream. Keep in mind that the paragraph may contain unboxed horizontal material, -which then already contains ligatures and kerns and the words therein -are part of the hyphenation process. - -The \type{char_node} records are somewhat misnamed, as they are glyph -positions in specific fonts, and therefore not really \quote{characters} -in the linguistic sense. There is no language information inside the -\type{char_node} records. Instead, language information is passed along -using \type{language whatsit} records inside the horizontal list. - -In \LUATEX, the situation is quite different. The characters you -type are always converted into \type{glyph_node} records with a -special subtype to identify them as being intended as linguistic -characters. \LUATEX\ stores the needed language information in those -records, but does not do any font|-|related processing at the time of -node creation. It only stores the index of the font. - -When it becomes necessary to typeset a paragraph, \LUATEX\ first -inserts all hyphenation points right into the whole node list. -Next, it processes all the font information in the whole list -(creating ligatures and adjusting kerning), and finally it adjusts -all the subtype identifiers so that the records are \quote{glyph -nodes} from now on. - -That was the broad overview. The rest of this chapter will deal with the -minutiae of the new process. - -\section[charsandglyphs]{Characters and glyphs} - -\TEX82 (including \PDFTEX) differentiated between \type{char_node}s -and \type{lig_node}s. The former are simple items that contained -nothing but a \quote{character} and a \quote{font} field, and they -lived in the same memory as tokens did. The latter also contained a -list of components, and a subtype indicating whether this ligature was -the result of a word boundary, and it was stored in the same place as -other nodes like boxes and kerns and glues. - -In \LUATEX, these two types are merged into one, somewhat larger -structure called a \type{glyph_node}. Besides having the old -character, font, and component fields, and the new special fields like -\quote{attr} (see~\in{section}[glyphnodes]), these nodes also contain: - -\startitemize - -\item A subtype, split into four main types: - - \startitemize - \item \type{character}, for characters to be hyphenated: the lowest - bit (bit 0) is set to 1. - \item \type{glyph}, for specific font glyphs: the lowest bit - (bit 0) is not set. - \item \type{ligature}, for ligatures (bit 1 is set) - \item \type{ghost}, for \quote{ghost objects} (bit 2 is set) - \stopitemize - - The latter two make further use of two extra fields (bits 3 and 4): - - \startitemize - \item \type{left}, for ligatures created from a left word boundary and - for ghosts created from \tex{leftghost} - \item \type{right}, for ligatures created from a right word boundary and - for ghosts created from \tex{rightghost} - \stopitemize - - For ligatures, both bits can be set at the same time (in case of a single|-|glyph word). - -\item \type{glyph_node}s of type \quote{character} also contain language data, - split into four items that were current when the node was created: - the \tex{setlanguage} (15 bits), \tex{lefthyphenmin} (8 bits), - \tex{righthyphenmin} (8 bits), and \tex{uchyph} (1 bit). - -\stopitemize - -Incidentally, \LUATEX\ allows 16383 separate languages, and words can -be 256 characters long. - -Because the \tex{uchyph} value is saved in the actual nodes, its -handling is subtly different from \TEX82: changes to \tex{uchyph} -become effective immediately, not at the end of the current partial -paragraph. - -Typeset boxes now always have their language information embedded in -the nodes themselves, so there is no longer a possible dependency on -the surrounding language settings. In \TEX82, a mid-paragraph -statement like \tex{unhbox0} would process the box using the current -paragraph language unless there was a \tex{setlanguage} issued inside -the box. In \LUATEX, all language variables are already frozen. - - -\section{The main control loop} - -In \LUATEX's main loop, almost all input characters that are to be -typeset are converted into \type{glyph_node} records with subtype -\quote{character}, but there are a few small exceptions. - -First, the \tex{accent} primitives creates nodes with subtype \quote{glyph} -instead of \quote{character}: one for the actual accent and one for the -accentee. The primary reason for this is that \tex{accent} in \TEX82 -is explicitly dependent on the current font encoding, so it would not -make much sense to attach a new meaning to the primitive's name, as -that would invalidate many old documents and macro packages. A -secondary reason is that in \TEX82, \tex{accent} prohibits hyphenation -of the current word. Since in \LUATEX\ hyphenation only takes place on -\quote{character} nodes, it is possible to achieve the same effect. - -This change of meaning did happen with \tex{char}, that now generates -\quote{character} nodes, consistent with its changed meaning in \XETEX. -The changed status of \tex{char} is not yet finalized, but if it stays -as it is now, a new primitive \tex{glyph} should be added to directly -insert a font glyph id. - -Second, all the results of processing in math mode eventually become -nodes with \quote{glyph} subtypes. - -Third, the \ALEPH-derived commands \tex{leftghost} and -\tex{rightghost} create nodes of a third subtype: \quote{ghost}. These nodes -are ignored completely by all further processing until the stage where -inter-glyph kerning is added. - -Fourth, automatic discretionaries are handled differently. \TEX82 -inserts an empty discretionary after sensing an input character that -matches the \tex{hyphenchar} in the current font. This test is wrong, -in our opinion: whether or not hyphenation takes place should not -depend on the current font, it is a language property. - -In \LUATEX, it works like this: if \LUATEX\ senses a string of input -characters that matches the value of the new integer parameter -\tex{exhyphenchar}, it will insert an explicit discretionary after that -series of nodes. Initex sets the \tex{exhyphenchar=`\-}. -Incidentally, this is a global parameter instead of a -language-specific one because it may be useful to change the value -depending on the document structure instead of the text language. - -Note: as of \LUATEX\ 0.63.0, the insertion of discretionaries after -a sequence of explicit hyphens happens at the same time as the other -hyphenation processing, {\it not\/} inside the main control loop. - -The only use \LUATEX\ has for \tex{hyphenchar} is at the check -whether a word should be considered for hyphenation at all. If the -\tex{hyphenchar} of the font attached to the first character node in a -word is negative, then hyphenation of that word is abandoned -immediately. {\bf This behavior is added for backward -compatibility only, and the use of \type{\hyphenchar=-1} as a means of -preventing hyphenation should not be used in new \LUATEX\ documents.} - -Fifth, \tex{setlanguage} no longer creates whatsits. The meaning of -\tex{setlanguage} is changed so that it is now an integer parameter -like all others. That integer parameter is used in \tex{glyph_node} -creation to add language information to the glyph nodes. In -conjunction, the \tex{language} primitive is extended so that it -always also updates the value of \tex{setlanguage}. - -Sixth, the \tex{noboundary} command (this command prohibits word -boundary processing where that would normally take place) now does -create whatsits. These whatsits are needed because the exact place of -the \tex{noboundary} command in the input stream has to be retained -until after the ligature and font processing stages. - -Finally, there is no longer a \type{main_loop} label in the -code. Remember that \TEX82 did quite a lot of processing while adding -\type{char_nodes} to the horizontal list? For speed reasons, it handled -that processing code outside of the \quote{main control} loop, and only the -first character of any \quote{word} was handled by that \quote{main control} loop. -In \LUATEX, there is no longer a need for that (all hard work is done -later), and the (now very small) bits of character-handling code have -been moved back inline. When \tex{tracingcommands} is on, this is -visible because the full word is reported, instead of just the initial -character. - - -\section[patternsexceptions]{Loading patterns and exceptions} - -The hyphenation algorithm in \LUATEX\ is quite different from the one -in \TEX82, although it uses essentially the same user input. - -After expansion, the argument for \tex{patterns} has to be proper -UTF-8 with individual patterns separated by spaces, no \tex{char} or -\tex{chardef-ed} commands are allowed. (The current implementation is -even more strict, and will reject all non|-|\UNICODE\ characters, but -that will be changed in the future. For now, the generated errors are -a valuable tool in discovering font-encoding specific pattern files) - -Likewise, the expanded argument for \tex{hyphenation} also has to be -proper UTF-8, but here a tiny little bit of extra syntax is provided: - -\startitemize[n] -\item three sets of arguments in curly braces (\type{{}{}{}}) - indicates a desired complex discretionary, with arguments - as in \tex{discretionary}'s command in normal document input. -\item \type{-} indicates a desired simple discretionary, cf. \tex{-} and - \type{\discretionary{-}{}{}} in normal document input. -\item Internal command names are ignored. This rule is provided - especially for \tex{discretionary}, but it also helps to deal with - \tex{relax} commands that may sneak in. -\item \type{=} indicates a (non-discretionary) hyphen in the document input. -\stopitemize - -The expanded argument is first converted back to a space-separated -string while dropping the internal command names. This string is then -converted into a dictionary by a routine that creates key||value pairs -by converting the other listed items. It is important to note that the -keys in an exception dictionary can always be generated from the -values. Here are a few examples: - -\starttabulate[|l|l|l|] -\NC \ssbf value \NC \ssbf implied key (input) \NC \ssbf effect\NC\NR -\NC \type{ta-ble} \NC table \NC \type{ta\-ble} - ($=$ \type{ta\discretionary{-}{}{}ble})\NC\NR -\NC \type{ba{k-}{}{c}ken}\NC backen \NC \type{ba\discretionary{k-}{}{c}ken}\NC\NR -\stoptabulate - -The resultant patterns and exception dictionary will be stored under -the language code that is the present value of \tex{language}. - -In the last line of the table, you see there is no \tex{discretionary} -command in the value: the command is optional in the \TEX-based input -syntax. The underlying reason for that is that it is conceivable that -a whole dictionary of words is stored as a plain text file and loaded -into \LUATEX\ using one of the functions in the \LUA\ \luatex{lang} -library. This loading method is quite a bit faster than going through -the \TEX\ language primitives, but some (most?) of that speed gain -would be lost if it had to interpret command sequences while doing so. - -Starting with \LUATEX\ 0.63.0, it is possible to specify extra hyphenation -points in compound words by using \type{{-}{}{-}} for the explicit hyphen -character (replace \type{-} by the actual explicit hyphen character if needed). -For example, this matches the word \quote{multi-word-boundaries} and allows -an extra break inbetweem \quote{boun} and \quote{daries}: - -\starttyping -\hyphenation{multi{-}{}{-}word{-}{}{-}boun-daries} -\stoptyping - -The motivation behind the \ETEX\ extension \tex{savinghyphcodes} was -that hyphenation heavily depended on font encodings. This is no longer -true in \LUATEX, and the corresponding primitive is ignored pending -complete removal. The future semantics of \tex{uppercase} and -\tex{lowercase} are still under consideration, no changes have taken -place yet. - - -\section{Applying hyphenation} - -The internal structures \LUATEX\ uses for the insertion of -discretionaries in words is very different from the ones in \TEX82, -and that means there are some noticeable differences in handling as -well. - -First and foremost, there is no \quote{compressed trie} involved in -hyphenation. The algorithm still reads \PATGEN-generated pattern -files, but \LUATEX\ uses a finite state hash to match the patterns -against the word to be hyphenated. This algorithm is based on the -\quote{libhnj} library used by OpenOffice, which in turn is inspired -by \TEX. -The memory allocation for this new implementation is completely -dynamic, so the \WEBC\ setting for \type{trie_size} is ignored. - -Differences between \LUATEX\ and \TEX82 that are a direct result of that: - -\startitemize -\item \LUATEX\ happily hyphenates the full \UNICODE\ character range. -\item Pattern and exception dictionary size is limited by the - available memory only, all allocations are done dynamically. - The trie-related settings in \type{texmf.cnf} are ignored. -\item Because there is no \quote{trie preparation} stage, language patterns - never become frozen. This means that the primitive \tex{patterns} - (and its \LUA\ counterpart \luatex{lang.patterns}) can be used at any - time, not only in initex. -\item Only the string representation of \tex{patterns} and - \tex{hyphenation} is stored in the format file. At format load time, - they are simply re-evaluated. It follows that there is no real - reason to preload languages in the format file. In fact, it is - usually not a good idea to do so. It is much smarter to load - patterns no sooner than the first time they are actually needed. -\item \LUATEX\ uses the language-specific variables -\tex{prehyphenchar} and \tex{posthyphenchar} in the creation of -implicit discretionaries, instead of \TEX82's \tex{hyphenchar}, and -the values of the language-specific variables \tex{preexhyphenchar} and -\tex{postexhyphenchar} for explicit discretionaries (instead of -\TEX82's empty discretionary). -\stopitemize - -Inserted characters and ligatures inherit their attributes from the -nearest glyph node item (usually the preceding one, but the following -one for the items inserted at the left-hand side of a word). - -Word boundaries are no longer implied by font switches, but by -language switches. One word can have two separate fonts and still be -hyphenated correctly (but it can not have two different languages, -the \tex{setlanguage} command forces a word boundary). - -All languages start out with \tex{prehyphenchar=`\-}, -\tex{posthyphenchar=0}, \tex{preexhyphenchar=0} and -\tex{postexhyphenchar=0}. -When you assign the values of one of these four parameters, you are -actually changing the settings for the current \tex{language}, this -behavior is compatible with \tex{patterns} and \tex{hyphenation}. - -\LUATEX\ also hyphenates the first word in a paragraph. - -Words can be up to 256 characters long (up from 64 in \TEX82). Longer -words generate an error right now, but eventually either the -limitation will be removed or perhaps it will become possible to -silently ignore the excess characters (this is what happens in \TEX82, -but there the behavior cannot be controlled). - -If you are using the \LUA\ function \type{lang.hyphenate}, you should be -aware that this function expects to receive a list of \quote{character} -nodes. It will not operate properly in the presence of \quote{glyph}, -\quote{ligature}, or \quote{ghost} nodes, nor does it know how to deal with -kerning. In the near future, it will be able to skip over \quote{ghost} -nodes, and we may add a less fuzzy function you can call as well. - -The hyphenation exception dictionary is maintained as key-value -hash, and that is also dynamic, so the \type{hyph_size} setting is not -used either. - -A technical paper detailing the new algorithm will be released as a -separate document. - -\section{Applying ligatures and kerning} - -After all possible hyphenation points have been inserted in the list, -\LUATEX\ will process the list to convert the \quote{character} nodes into -\quote{glyph} and \quote{ligature} nodes. This is actually done in two stages: -first all ligatures are processed, then all kerning information is -applied to the result list. But those two stages are somewhat -dependent on each other: If the used font makes it possible to do so, -the ligaturing stage adds virtual \quote{character} nodes to the word -boundaries in the list. While doing so, it removes and interprets -\type{noboundary} nodes. The kerning stage deletes those word boundary -items after it is done with them, and it does the same for \quote{ghost} -nodes. Finally, at the end of the kerning stage, all remaining -\quote{character} nodes are converted to \quote{glyph} nodes. - -This work separation is worth mentioning because, if you overrule from -\LUA\ only one of the two callbacks related to font handling, then you -have to make sure you perform the tasks normally done by \LUATEX\ -itself in order to make sure that the other, non|-|overruled, routine -continues to function properly. - -Work in this area is not yet complete, but most of the possible cases -are handled by our rewritten ligaturing engine. We are working hard to -make sure all of the possible inputs will become supported soon. - -For example, take the word \type{office}, hyphenated \type{of-fice}, -using a \quote{normal} font with all the \type{f}-\type{f} and -\type{f}-\type{i} type ligatures: - -\starttabulate[|l|l|] -\NC Initial: \NC \type{{o}{f}{f}{i}{c}{e}}\NC\NR -\NC After hyphenation: \NC \type{{o}{f}{{-},{},{}}{f}{i}{c}{e}}\NC\NR -\NC First ligature stage: \NC \type{{o}{{f-},{f},{<ff>}}{i}{c}{e}}\NC\NR -\NC Final result: \NC \type{{o}{{f-},{<fi>},{<ffi>}}{c}{e}} \NC\NR -\stoptabulate - -That's bad enough, but let us assume that there is also a hyphenation -point between the \type{f} and the \type{i}, to create -\type{of-f-ice}. Then the final result should be: - -\starttyping -{o}{{f-}, - {{f-}, - {i}, - {<fi>}}, - {{<ff>-}, - {i}, - {<ffi>}}}{c}{e} -\stoptyping - -with discretionaries in the post-break text as well as in the -replacement text of the top-level discretionary that resulted from the -first hyphenation point. - -Here is that nested solution again, in a different representation: - -\starttabulate[|l|l|l|l|] -\NC \NC pre \NC post \NC replace \NC \NR -\NC topdisc \NC \type{f-}$^1$ \NC sub1 \NC sub2 \NC \NR -\NC sub1 \NC \type{f-}$^2$ \NC \type{i}$^3$ \NC \type{<fi>}$^4$ \NC \NR -\NC sub2 \NC \type{<ff>-}$^5$\NC \type{i}$^6$ \NC \type{<ffi>}$^7$\NC \NR -\stoptabulate - -When line breaking is choosing its breakpoints, the following fields will eventually -be selected: - -\starttabulate[|l|l|l|] -\NC \type{of-f-ice} \NC \type{f-}$^1$ \NC \NR -\NC \NC \type{f-}$^2$ \NC \NR -\NC \NC \type{i}$^3$ \NC \NR -\NC \type{of-fice} \NC \type{f-}$^1$ \NC \NR -\NC \NC \type{<fi>}$^4$ \NC \NR -\NC \type{off-ice} \NC \type{<ff>-}$^5$ \NC \NR -\NC \NC \type{i}$^6$ \NC \NR -\NC \type{office} \NC \type{<ffi>}$^7$ \NC \NR -\stoptabulate - -The current solution in \LUATEX\ is not able to handle nested -discretionaries, but it is in fact smart enough to handle this -fictional \type{of-f-ice} example. It does so by combining two -sequential discretionary nodes as if they were a single object -(where the second discretionary node is treated as an extension -of the first node). - -One can observe that the \type{of-f-ice} and \type{off-ice} cases both end -with the same actual post replacement list (\type{i}), and that this -would be the case even if that \type{i} was the first item of a -potential following ligature like \type{ic}. This allows \LUATEX\ -to do away with one of the fields, and thus make the whole stuff fit -into just two discretionary nodes. - -The mapping of the seven list fields to the six fields in this -discretionary node pair is as follows: - -\starttabulate[|l|p|] -\NC \bf field \NC \bf description \NC \NR -\NC \type{disc1.pre} \NC \type{f-}$^1$ \NC \NR -\NC \type{disc1.post} \NC \type{<fi>}$^4$ \NC \NR -\NC \type{disc1.replace} \NC \type{<ffi>}$^7$ \NC \NR -\NC \type{disc2.pre} \NC \type{f-}$^2$ \NC \NR -\NC \type{disc2.post} \NC \type{i}$^{3{,}6}$\NC \NR -\NC \type{disc2.replace} \NC \type{<ff>-}$^5$\NC \NR -\stoptabulate - -What is actually generated after ligaturing has been applied is -therefore: - -\starttyping -{o}{{f-}, - {<fi>}, - {<ffi>}} - {{f-}, - {i}, - {<ff>-}}{c}{e} -\stoptyping - -The two discretionaries have different subtypes from a discretionary -appearing on its own: the first has subtype 4, and the second has -subtype 5. The need for these special subtypes stems from the fact -that not all of the fields appear in their \quote{normal} location. -The second discretionary especially looks odd, with things like the -\type{<ff>-} appearing in \type{disc2.replace}. The fact that some of -the fields have different meanings (and different processing code -internally) is what makes it necessary to have different subtypes: -this enables \LUATEX\ to distinguish this sequence of two joined -discretionary nodes from the case of two standalone discretionaries -appearing in a row. - - -\section{Breaking paragraphs into lines} - -This code is still almost unchanged, but because of the -above|-|mentioned changes with respect to discretionaries and ligatures, -line breaking will potentially be different from traditional \TEX. -The actual line breaking code is still based on the \TEX82 algorithms, -and it does not expect there to be discretionaries inside of -discretionaries. - -But that situation is now fairly common in \LUATEX, due to the changes -to the ligaturing mechanism. And also, the \LUATEX\ discretionary -nodes are implemented slightly different from the \TEX82 nodes: the -\type{no_break} text is now embedded inside the disc node, where -previously these nodes kept their place in the horizontal list (the -discretionary node contained a counter indicating how many nodes to -skip). - -The combined effect of these two differences is that \LUATEX\ does not -always use all of the potential breakpoints in a paragraph, especially -when fonts with many ligatures are used. - -% TODO: -% Check \sfcode handling -% Implement \glyph -% -% Remove \savinghyphcodes -% Allow non-UCS characters in \patterns - -\chapter[fonts]{Font structure} - -All \TEX\ fonts are represented to \LUA\ code as tables, and -internally as C~structures. All keys in the table below are saved in -the internal font structure if they are present in the table returned -by the -\luatex{define_font} callback, or if they result from the normal \TFM|/|\VF\ -reading routines if there is no \luatex{define_font} callback defined. - -The column \quote{from \VF} means that this key will be created by the -\luatex{font.read_vf()} routine, \quote{from \TFM} means that the key will be created -by the \luatex{font.read_tfm()} routine, and \quote{used} means whether or not the -\LUATEX\ engine itself will do something with the key. - -The top|-|level keys in the table are as follows: - -\starttabulate[|Tl|l|l|l|l|p|] -\NC \ssbf key \NC \bf from vf \NC \bf from tfm \NC \bf used\NC \bf value type \NC \bf description \NC\NR -\NC name \NC yes \NC yes \NC yes \NC string \NC metric (file) name\NC\NR -\NC area \NC no \NC yes \NC yes \NC string \NC (directory) location, typically empty\NC\NR -\NC used \NC no \NC yes \NC yes \NC boolean\NC used already? (initial: false)\NC \NR -\NC characters \NC yes \NC yes \NC yes \NC table \NC the defined glyphs of this font \NC \NR -\NC checksum \NC yes \NC yes \NC no \NC number \NC default: 0 \NC \NR -\NC designsize \NC no \NC yes \NC yes \NC number \NC expected size (default: 655360 == 10pt) \NC \NR -\NC direction \NC no \NC yes \NC yes \NC number \NC default: 0 (TLT) \NC \NR -\NC encodingbytes \NC no \NC no \NC yes \NC number \NC default: depends on \type {format}\NC\NR -\NC encodingname \NC no \NC no \NC yes \NC string \NC encoding name\NC\NR -\NC fonts \NC yes \NC no \NC yes \NC table \NC locally used fonts\NC \NR -\NC psname \NC no \NC no \NC yes \NC string -\NC actual (\POSTSCRIPT) name (this is the PS fontname in the -incoming font source, also used as fontname identifier in the \PDF\ output, new in 0.43)\NC\NR -\NC fullname \NC no \NC no \NC yes \NC string \NC output font name, used as a fallback in the \PDF\ output if the psname is not set\NC\NR -\NC header \NC yes \NC no \NC no \NC string \NC header comments, if any\NC \NR -\NC hyphenchar \NC no \NC no \NC yes \NC number \NC default: TeX's \tex{hyphenchar} \NC \NR -\NC parameters \NC no \NC yes \NC yes \NC hash \NC default: 7 parameters, all zero \NC \NR -\NC size \NC no \NC yes \NC yes \NC number \NC loaded (at) size. (default: same as designsize) \NC \NR -\NC skewchar \NC no \NC no \NC yes \NC number \NC default: TeX's \tex{skewchar} \NC \NR -\NC type \NC yes \NC no \NC yes \NC string \NC basic type of this font\NC \NR -\NC format \NC no \NC no \NC yes \NC string \NC disk format type\NC \NR -\NC embedding \NC no \NC no \NC yes \NC string \NC \PDF\ inclusion\NC \NR -\NC filename \NC no \NC no \NC yes \NC string \NC disk file name\NC\NR -\NC tounicode \NC no \NC yes \NC yes \NC number \NC if 1, \LUATEX\ assumes per-glyph tounicode entries are - present in the font\NC\NR -\NC stretch \NC no \NC no \NC yes \NC number \NC the \quote {stretch} value from \tex{pdffontexpand}\NC\NR -\NC shrink \NC no \NC no \NC yes \NC number \NC the \quote {shrink} value from \tex{pdffontexpand}\NC\NR -\NC step \NC no \NC no \NC yes \NC number \NC the \quote {step} value from \tex{pdffontexpand}\NC\NR -\NC auto_expand \NC no \NC no \NC yes \NC boolean\NC the \quote {autoexpand} keyword from\crlf \tex{pdffontexpand}\NC\NR -\NC expansion_factor \NC no \NC no \NC no \NC number \NC the actual expansion factor of an expanded font\NC\NR -\NC attributes \NC no \NC no \NC yes \NC string \NC the \tex{pdffontattr}\NC\NR -\NC cache \NC no \NC no \NC yes \NC string \NC this key controls caching of the lua table on the \type{tex} - end. \type{yes}: use a reference to the table that is - passed to \LUATEX\ (this is the default). \type{no}: don't store the table - reference, don't cache any lua data for this font. - \type{renew}: don't store the table reference, but - save a reference to the table that is created at the - first access to one of its fields in font.fonts. - (new in 0.40.0, before that caching was always \type{yes}). -Note: the saved reference is thread-local, so be careful when you are using coroutines: an error will be thrown if the table -has been cached in one thread, but you reference it from another thread ($\approx$ coroutine)\NC\NR -\NC nomath \NC no \NC no \NC yes \NC boolean\NC this key allows a minor speedup for text fonts. if it is - present and true, then \LUATEX\ will not check the - character enties for math-specific keys. (0.42.0)\NC\NR -\NC slant \NC no \NC no \NC yes \NC number \NC This has the same semantics as the \type{SlantFont} operator - in font map files. (0.47.0)\NC\NR -\NC extent \NC no \NC no \NC yes \NC number \NC This has the same semantics as the \type{ExtendFont} operator - in font map files. (0.50.0)\NC\NR -\stoptabulate - -The key \type{name} is always required. The keys \type{stretch}, -\type{shrink}, \type{step} and optionally \type{auto_expand} only -have meaning when used together: they can be used to replace a -post-loading \tex{pdffontexpand} command. The -\type{expansion_factor} is value that can be present inside a font -in \type{font.fonts}. It is the actual expansion factor (a value -between \type{-shrink} and \type{stretch}, with step \type{step}) -of a font that was automatically generated by the font expansion -algorithm. The key \type{attributes} can be used to replace -\tex{pdffontattr}. The key \type{used} is set by the engine when a -font is actively in use, this makes sure that the font's -definition is written to the output file (\DVI\ or \PDF). The -\TFM\ reader sets it to false. The \type{direction} is a number -signalling the \quote{normal} direction for this font. There are -sixteen possibilities: - -\starttabulate[|Tc|c|c|c|] -\NC \ssbf number \NC \bf meaning \NC \bf number \NC \bf meaning \NC\NR -\NC 0 \NC LT \NC 8 \NC TT \NC\NR -\NC 1 \NC LL \NC 9 \NC TL \NC\NR -\NC 2 \NC LB \NC 10 \NC TB \NC\NR -\NC 3 \NC LR \NC 11 \NC TR \NC\NR -\NC 4 \NC RT \NC 12 \NC BT \NC\NR -\NC 5 \NC RL \NC 13 \NC BL \NC\NR -\NC 6 \NC RB \NC 14 \NC BB \NC\NR -\NC 7 \NC RR \NC 15 \NC BR \NC\NR -\stoptabulate - -These are \OMEGA|-|style direction abbreviations: the first character -indicates the \quote{first} edge of the character glyphs (the edge that is -seen first in the writing direction), the second the \quote{top} side. - -The \type{parameters} is a hash with mixed key types. There are seven -possible string keys, as well as a number of integer indices (these -start from 8 up). The seven strings are actually used instead of the -bottom seven indices, because that gives a nicer user interface. - -The names and their internal remapping are: - -\starttabulate[|lT|c|] -\NC \ssbf name \NC \bf internal remapped number \NC\NR -\NC slant \NC 1 \NC\NR -\NC space \NC 2 \NC\NR -\NC space_stretch \NC 3 \NC\NR -\NC space_shrink \NC 4 \NC\NR -\NC x_height \NC 5 \NC\NR -\NC quad \NC 6 \NC\NR -\NC extra_space \NC 7 \NC\LR -\stoptabulate - -The keys \type{type}, \type{format}, \type{embedding}, \type{fullname} and -\type{filename} are used to embed \OPENTYPE\ fonts in the result \PDF. - -The \type{characters} table is a list of character hashes indexed by -an integer number. The number is the \quote{internal code} \TEX\ knows this -character by. - -Two very special string indexes can be used also: \type{left_boundary} is a -virtual character whose ligatures and kerns are used to handle word -boundary processing. \type{right_boundary} is similar but not actually -used for anything (yet!). - -Other index keys are ignored. - -Each character hash itself is a hash. For example, here is the -character \quote{f} (decimal 102) in the font cmr10 at 10 points: - -\starttyping -[102] = { - ['width'] = 200250, - ['height'] = 455111, - ['depth'] = 0, - ['italic'] = 50973, - ['kerns'] = { - [63] = 50973, - [93] = 50973, - [39] = 50973, - [33] = 50973, - [41] = 50973 - }, - ['ligatures'] = { - [102] = { - ['char'] = 11, - ['type'] = 0 - }, - [108] = { - ['char'] = 13, - ['type'] = 0 - }, - [105] = { - ['char'] = 12, - ['type'] = 0 - } - } -} -\stoptyping - -The following top|-|level keys can be present inside a character hash: - -\starttabulate[|lT|c|c|c|l|p|] -\NC \ssbf key \NC \bf from vf \NC \bf from tfm \NC \bf used \NC \bf value type \NC \bf description \NC\NR -\NC width \NC yes \NC yes \NC yes \NC number \NC character's width, in sp (default 0) \NC\NR -\NC height \NC no \NC yes \NC yes \NC number \NC character's height, in sp (default 0) \NC\NR -\NC depth \NC no \NC yes \NC yes \NC number \NC character's depth, in sp (default 0) \NC\NR -\NC italic \NC no \NC yes \NC yes \NC number \NC character's italic correction, in sp (default zero) \NC\NR -\NC top_accent \NC no \NC no \NC maybe \NC number \NC character's top accent alignment place, in sp (default zero) \NC\NR -\NC bot_accent \NC no \NC no \NC maybe \NC number \NC character's bottom accent alignment place, in sp (default zero) \NC\NR -\NC left_protruding \NC no \NC no \NC maybe \NC number \NC character's \tex{lpcode}\NC\NR -\NC right_protruding \NC no \NC no \NC maybe \NC number \NC character's \tex{rpcode}\NC\NR -\NC expansion_factor \NC no \NC no \NC maybe \NC number \NC character's \tex{efcode}\NC\NR -\NC tounicode \NC no \NC no \NC maybe \NC string \NC character's Unicode equivalent(s), in UTF-16BE hexadecimal format\NC\NR -\NC next \NC no \NC yes \NC yes \NC number \NC the \quote{next larger} character index \NC\NR -\NC extensible \NC no \NC yes \NC yes \NC table \NC the constituent parts of an extensible recipe \NC\NR -\NC vert_variants \NC no \NC no \NC yes \NC table \NC constituent parts of a vertical variant set\NC \NR -\NC horiz_variants\NC no \NC no \NC yes \NC table \NC constituent parts of a horizontal variant set\NC \NR -\NC kerns \NC no \NC yes \NC yes \NC table \NC kerning information \NC\NR -\NC ligatures \NC no \NC yes \NC yes \NC table \NC ligaturing information \NC\NR -\NC commands \NC yes \NC no \NC yes \NC array \NC virtual font commands \NC\NR -\NC name \NC no \NC no \NC no \NC string \NC the character (\POSTSCRIPT) name \NC\NR -\NC index \NC no \NC no \NC yes \NC number \NC the (\OPENTYPE\ or \TRUETYPE) font glyph index \NC\NR -\NC used \NC no \NC yes \NC yes \NC boolean \NC typeset already (default: false)? \NC\NR -\NC mathkern \NC no \NC no \NC yes \NC table \NC math cut-in specifications \NC\NR -\stoptabulate - -The values of \type{top_accent}, \type{bot_accent} and \type{mathkern} are used only for math -accent and superscript placement, see the \at{math chapter}[math] in this manual for details. - -The values of \type{left_protruding} and \type{right_protruding} are used only when -\tex{pdfprotrudechars} is non-zero. - -Whether or not \type{expansion_factor} is used depends on the font's global expansion -settings, as well as on the value of \tex{pdfadjustspacing}. - -The usage of \type{tounicode} is this: if this font specifies a \type{tounicode=1} at -the top level, then \LUATEX\ will construct a \type{/ToUnicode} entry for the \PDF\ -font (or font subset) based on the character-level \type{tounicode} strings, where -they are available. If a character does not have a sensible \UNICODE\ equivalent, -do not provide a string either (no empty strings). - -If the font-level \type{tounicode} is not set, then \LUATEX\ will build up -\type{/ToUnicode} based on the \TEX\ code points you used, and any character-level -\type{tounicodes} will be ignored. {\it At the moment, the string format is exactly the -format that is expected by Adobe \CMAP\ files (\UTF-16BE in hexadecimal encoding), minus -the enclosing angle brackets. This may change in the future.} Small example: the -\type{tounicode} for a \type{fi} ligature would be \type{00660069}. - -The presence of \type{extensible} will overrule \type{next}, if that is also present. -It in in turn can be overruled by \type{vert_variants}. - -The \type{extensible} table is very simple: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf description \NC\NR -\NC top \NC number \NC \quote{top} character index \NC\NR -\NC mid \NC number \NC \quote{middle} character index \NC\NR -\NC bot \NC number \NC \quote{bottom} character index \NC\NR -\NC rep \NC number \NC \quote{repeatable} character index \NC\NR -\stoptabulate - -The \type{horiz_variants} and \type{vert_variants} are arrays of components. Each of those -components is itself a hash of up to five keys: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC glyph \NC number \NC The character index (note that this is an encoding number, not a name).\NC \NR -\NC extender \NC number \NC One (1) if this part is repeatable, zero (0) otherwise.\NC \NR -\NC start \NC number \NC Maximum overlap at the starting side (in scaled points).\NC \NR -\NC end \NC number \NC Maximum overlap at the ending side (in scaled points).\NC \NR -\NC advance \NC number \NC Total advance width of this item (can be zero or missing, - then the natural size of the glyph for character \type{component} - is used).\NC \NR -\stoptabulate - -The \type{kerns} table is a hash indexed by character index (and -\quote{character index} is defined as either a non|-|negative integer or the -string value \type {right_boundary}), with the values the kerning to be -applied, in scaled points. - -The \type{ligatures} table is a hash indexed by character index (and -\quote{character index} is defined as either a non|-|negative integer or the -string value \type {right_boundary}), with the values being yet another small -hash, with two fields: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf description \NC\NR -\NC type \NC number \NC the type of this ligature command, default 0 \NC\NR -\NC char \NC number \NC the character index of the resultant ligature \NC\NR -\stoptabulate - -The \type{char} field in a ligature is required. - -The \type{type} field inside a ligature is the numerical or string value of one of the eight -possible ligature types supported by \TEX. When \TEX\ inserts a new ligature, it puts the new -glyph in the middle of the left and right glyphs. The original left and right glyphs can -optionally be retained, and when at least one of them is kept, it is also possible to move the -new \quote{insertion point} forward one or two places. The glyph that ends up to the right of the -insertion point will become the next \quote{left}. - -\starttabulate[|l|c|l|l|] -\NC \bf textual (Knuth) \NC \bf number \NC \bf string \NC result \NC\NR -\NC l + r =: n \NC 0 \NC \type{=:} \NC \|n \NC\NR -\NC l + r =:\| n \NC 1 \NC \type{=:|} \NC \|nr \NC\NR -\NC l + r \|=: n \NC 2 \NC \type{|=:} \NC \|ln \NC\NR -\NC l + r \|=:\| n \NC 3 \NC \type{|=:|} \NC \|lnr \NC\NR -\NC l + r =:\|\> n \NC 5 \NC \type{=:|>} \NC n\|r \NC\NR -\NC l + r \|=:\> n \NC 6 \NC \type{|=:>} \NC l\|n \NC\NR -\NC l + r \|=:\|\> n \NC 7 \NC \type{|=:|>} \NC l\|nr \NC\NR -\NC l + r \|=:\|\>\> n \NC 11 \NC \type{|=:|>>} \NC ln\|r \NC\NR -\stoptabulate - -The default value is~0, and can be left out. That signifies a \quote{normal} -ligature where the ligature replaces both original glyphs. In this table -the~\| indicates the final insertion point. - -The \type{commands} array is explained below. - -\section {Real fonts} - -Whether or not a \TEX\ font is a \quote{real} font that should be written to -the \PDF\ document is decided by the \type{type} value in the top|-|level -font structure. If the value is \type{real}, then this is a proper -font, and the inclusion mechanism will attempt to add the needed -font object definitions to the \PDF. - -Values for \type{type}: - -\starttabulate[|Tl|p|] -\NC \ssbf value \NC \bf description \NC\NR -\NC real \NC this is a base font \NC\NR -\NC virtual \NC this is a virtual font \NC\NR -\stoptabulate - -The actions to be taken depend on a number of different variables: - -\startitemize[packed] -\item Whether the used font fits in an 8-bit encoding scheme or not -\item The type of the disk font file -\item The level of embedding requested -\stopitemize - -A font that uses anything other than an 8-bit encoding vector has to -be written to the \PDF\ in a different way. - -The rule is: if the font table has \type {encodingbytes} set to~2, -then this is a wide font, in all other cases it isn't. The value~2 is -the default for \OPENTYPE\ and \TRUETYPE\ fonts loaded via \LUA. For -\TYPEONE\ fonts, you have to set \type {encodingbytes} to~2 -explicitly. For \PK\ bitmap fonts, wide font encoding is not -supported at all. - -If no special care is needed, \LUATEX\ currently falls back to the -mapfile|-|based solution used by \PDFTEX\ and \DVIPS. This behavior -will be removed in the future, when the existing code becomes -integrated in the new subsystem. - -But if this is a \quote{wide} font, then the new subsystem kicks in, and -some extra fields have to be present in the font structure. In this -case, \LUATEX\ does not use a map file at all. - -The extra fields are: \type{format}, \type{embedding}, \type{fullname}, -\type{cidinfo} (as explained above), \type{filename}, and the -\type{index} key in the separate characters. - -Values for \type{format} are: - -\starttabulate[|Tl|p|] -\NC \ssbf value \NC \bf description \NC\NR -\NC type1 \NC this is a \POSTSCRIPT\ \TYPEONE\ font \NC\NR -\NC type3 \NC this is a bitmapped (\PK) font \NC\NR -\NC truetype \NC this is a \TRUETYPE\ or \TRUETYPE|-|based \OPENTYPE\ font \NC\NR -\NC opentype \NC this is a \POSTSCRIPT|-|based \OPENTYPE\ font \NC\NR -\stoptabulate - -(\type{type3} fonts are provided for backward compatibility only, and do not -support the new wide encoding options.) - -Values for \type{embedding} are: - -\starttabulate[|Tl|p|] -\NC \ssbf value \NC \bf description \NC\NR -\NC no \NC don't embed the font at all \NC\NR -\NC subset \NC include and atttempt to subset the font \NC\NR -\NC full \NC include this font in its entirety \NC\NR -\stoptabulate - -It is not possible to artificially modify the transformation matrix -for the font at the moment. - -The other fields are used as follows: The \type{fullname} will be the -\POSTSCRIPT|/|\PDF\ font name. The \type{cidinfo} will be used as the -character set (the CID \type{/Ordering} and \type{/Registry} keys). The -\type{filename} points to the actual font file. If you include the -full path in the \type{filename} or if the file is in the local -directory, \LUATEX\ will run a little bit more efficient because it -will not have to re|-|run the \type{find_xxx_file} callback in that -case. - -Be careful: when mixing old and new fonts in one document, it is possible to -create \POSTSCRIPT\ name clashes that can result in printing -errors. When this happens, you have to change the \type{fullname} -of the font. - -Typeset strings are written out in a wide format using 2~bytes per -glyph, using the \type{index} key in the character information as -value. The overall effect is like having an encoding based on numbers -instead of traditional (\POSTSCRIPT) name|-|based reencoding. The way -to get the correct \type{index} numbers for \TYPEONE\ fonts is by -loading the font via \type{fontloader.open}; use the table indices as -\type{index} fields. - -This type of reencoding means that there is no longer a clear -connection between the text in your input file and the strings in the -output \PDF\ file. Dealing with this is high on the agenda. - -\section[virtualfonts]{Virtual fonts} - -You have to take the following steps if you want \LUATEX\ to treat the -returned table from \luatex{define_font} as a virtual font: - -\startitemize[packed] -\item Set the top|-|level key \type {type} to \type {virtual}. -\item Make sure there is at least one valid entry in \luatex{fonts} (see below). -\item Give a \type {commands} array to every character (see below). -\stopitemize - -The presence of the toplevel \type {type} key with the specific value -\type {virtual} will trigger handling of the rest of the special virtual -font fields in the table, but the mere existence of 'type' is enough -to prevent \LUATEX\ from looking for a virtual font on its own. - -Therefore, this also works \quote{in reverse}: if you are absolutely certain -that a font is not a virtual font, assigning the value \type{base} or -\type{real} to \type{type} will inhibit \LUATEX\ from looking for a virtual font -file, thereby saving you a disk search. - -The \luatex{fonts} is another \LUA\ array. The values are one- or two|-|key -hashes themselves, each entry indicating one of the base fonts in a -virtual font. In case your font is referring to itself, you can use the -\type {font.nextid()} function which returns the index of the next to be defined -font which is probably the currently defined one. - -An example makes this easy to understand - -\starttyping -fonts = { - { name = 'ptmr8a', size = 655360 }, - { name = 'psyr', size = 600000 }, - { id = 38 } -} -\stoptyping - -says that the first referenced font (index 1) in this virtual font is -\type{ptrmr8a} loaded at 10pt, and the second is \type{psyr} loaded -at a little over 9pt. The third one is previously defined font that -is known to \LUATEX\ as fontid \quote{38}. - -The array index numbers are used by the character command definitions -that are part of each character. - -The \luatex{commands} array is a hash where each item is another small array, with the first -entry representing a command and the extra items being the parameters to that command. The -allowed commands and their arguments are: - -\starttabulate[|Tl|l|l|p|] -\NC \ssbf command name \NC \bf arguments \NC \bf arg type \NC \bf description \NC\NR -\NC font \NC 1 \NC number \NC select a new font from the local \luatex{fonts} table\NC\NR -\NC char \NC 1 \NC number \NC typeset this character number from the current font, - and move right by the character's width\NC\NR -\NC node \NC 1 \NC node \NC output this node (list), and move right - by the width of this list\NC\NR -\NC slot \NC 2 \NC number \NC a shortcut for the combination of a font and char command\NC\NR -\NC push \NC 0 \NC \NC save current position\NC\NR -\NC nop \NC 0 \NC \NC do nothing \NC\NR -\NC pop \NC 0 \NC \NC pop position \NC\NR -\NC rule \NC 2 \NC 2 numbers \NC output a rule $ht*wd$, and move right.\NC\NR -\NC down \NC 1 \NC number \NC move down on the page\NC\NR -\NC right \NC 1 \NC number \NC move right on the page\NC\NR -\NC special \NC 1 \NC string \NC output a \tex{special} command\NC\NR -\NC lua \NC 1 \NC string \NC execute a \LUA\ script (at \tex{latelua} time)\NC\NR -\NC image \NC 1 \NC image \NC output an image (the argument can be either an \type{<image>} - variable or an \type{image_spec} table)\NC\NR -\NC comment \NC any \NC any \NC the arguments of this command are ignored\NC\NR -\stoptabulate - -Here is a rather elaborate glyph commands example: -\starttyping -... -commands = { - {'push'}, -- remember where we are - {'right', 5000}, -- move right about 0.08pt - {'font', 3}, -- select the fonts[3] entry - {'char', 97}, -- place character 97 (ASCII 'a') - {'pop'}, -- go all the way back - {'down', -200000}, -- move upwards by about 3pt - {'special', 'pdf: 1 0 0 rg'} -- switch to red color - {'rule', 500000, 20000} -- draw a bar - {'special','pdf: 0 g'} -- back to black -} -... -\stoptyping - -The default value for \type {font} is always~1 at the start of the \type{commands} array. -Therefore, if the virtual font is essentially only a re|-|encoding, then you do usually not -have create an explicit \quote{font} command in the array. - -Rules inside of \type{commands} arrays are built up using only two dimensions: -they do not have depth. For correct vertical placement, an extra \type{down} command -may be needed. - -Regardless of the amount of movement you create within the \type {commands}, -the output pointer will always move by exactly the width that was given in -the \type {width} key of the character hash. Any movements that take place -inside the \type{commands} array are ignored on the upper level. - -\subsection{Artificial fonts} - -Even in a \quote{real} font, there can be virtual characters. When \LUATEX\ encounters a \type {commands} -field inside a character when it becomes time to typeset the character, it will interpret the commands, just -like for a true virtual character. In this case, if you have created no \quote{fonts} array, then the default -(and only) \quote{base} font is taken to be the current font itself. In practice, this means that you can -create virtual duplicates of existing characters which is useful if you want to create composite characters. - -Note: this feature does {\it not\/} work the other way around. There can not be \quote{real} characters in a -virtual font! You cannot use this technique for font re-encoding either; you need a truly virtual -font for that (because characters that are already present cannot be altered). - -\subsection{Example virtual font} - -Finally, here is a plain \TEX\ input file with a virtual font demonstration: - -\startbuffer -\directlua { - callback.register('define_font', - function (name,size) - if name == 'cmr10-red' then - f = font.read_tfm('cmr10',size) - f.name = 'cmr10-red' - f.type = 'virtual' - f.fonts = {{ name = 'cmr10', size = size }} - for i,v in pairs(f.characters) do - if (string.char(i)):find('[tacohanshartmut]') then - v.commands = { - {'special','pdf: 1 0 0 rg'}, - {'char',i}, - {'special','pdf: 0 g'}, - } - else - v.commands = {{'char',i}} - end - end - else - f = font.read_tfm(name,size) - end - return f - end - ) -} - -\font\myfont = cmr10-red at 10pt \myfont This is a line of text \par -\font\myfontx= cmr10 at 10pt \myfontx Here is another line of text \par -\stopbuffer - -\typebuffer - -%\getbuffer - -\chapter[nodes]{Nodes} - -\section{\LUA\ node representation} - -\TEX's nodes are represented in \LUA\ as userdata object with a variable -set of fields. In the following syntax tables, such the type of such a -userdata object is represented as \syntax{<node>}. - - -The current return value of \luatex{node.types()} is: -\ctxlua { - local d = node.types() - tex.print('\\type{' .. d[0] .. '} (' .. 0 .. '), ') - for _,v in pairs(d) do - if _ > 0 then - tex.print('\\type{' .. v .. '} (' .. _ .. '), ') - end - end -}. - -NOTE: The \type {\lastnodetype} primitive is \ETEX\ compliant. The valid -range is still -1 .. 15 and glyph nodes have number 0 (used to be -char node) and ligature nodes are mapped to 7. That way macro -packages can use the same symbolic names as in traditional \ETEX. -Keep in mind that the internal node numbers are different and that -there are more node types than 15. - -\subsection{Auxiliary items} - -A few node|-|typed userdata objects do not occur in the \quote{normal} -list of nodes, but can be pointed to from within that list. They are -not quite the same as regular nodes, but it is easier for the library -routines to treat them as if they were. - -\subsubsection{glue_spec items} - -Skips are about the only type of data objects in traditional \TEX\ -that are not a simple value. The structure that represents the glue -components of a skip is called a \type {glue_spec}, and it has the following -accessible fields: - -\starttabulate[|lT|l|p|] -\NC \ssbf key \NC \bf type \NC \bf explanation \NC\NR -\NC width \NC number \NC \NC\NR -\NC stretch \NC number \NC \NC\NR -\NC stretch_order \NC number \NC \NC\NR -\NC shrink \NC number \NC \NC\NR -\NC shrink_order \NC number \NC \NC\NR -\NC writable \NC boolean \NC If this is true, you can't assign to this \type{glue_spec} - because it is one of the preallocated special cases. New in 0.52\NC\NR -\stoptabulate - -These objects are reference counted, so there is actually an extra -read-only field named \type {ref_count} as well. This item type will likely -disappear in the future, and the glue fields themselves will -become part of the nodes referencing glue items. - -\subsubsection{attribute{\_}list and attribute items} - -The newly introduced attribute registers are non|-|trivial, because -the value that is attached to a node is essentially a sparse array of -key|-|value pairs. - -It is generally easiest to deal with attribute lists and attributes -by using the dedicated functions in the \luatex{node} library, but -for completeness, here is the low|-|level interface. - -An \type{attribute_list} item is used as a head pointer for a list -of attribute items. It has only one user-visible field: - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC next \NC \syntax{<node>} \NC pointer to the first attribute\NC\NR -\stoptabulate - -A normal node's attribute field will point to an item of type -\type{attribute_list}, and the \type{next} field in that item will point -to the first defined \quote{attribute} item, whose \type {next} will -point to the second \quote{attribute} item, etc. - -Valid fields in \type{attribute} items: - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC next \NC \syntax{<node>} \NC pointer to the next attribute\NC\NR -\NC number \NC number \NC the attribute type id\NC\NR -\NC value \NC number \NC the attribute value\NC\NR -\stoptabulate - -As mentioned it's better to use the official helpers rather than edit -these fields directly. For instance the \type {prev} field is -used for other purposes and there is no double linked list. - - - -\subsubsection{action item} - -Valid fields: \showfields{action}\crlf -Id: \showid{action} - -These are a special kind of item that only appears inside -pdf start link objects. - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC action_type \NC number \NC \NC\NR -\NC action_id \NC number or string \NC \NC\NR -\NC named_id \NC number \NC \NC\NR -\NC file \NC string \NC \NC\NR -\NC new_window \NC number \NC \NC\NR -\NC data \NC string \NC \NC\NR -\NC ref_count \NC number \NC (read-only)\NC\NR -\stoptabulate - -\subsection{Main text nodes} - -These are the nodes that comprise actual typesetting commands. - -A few fields are present in all nodes regardless of their type, these are: - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC next \NC \syntax{<node>} \NC The next node in a list, or nil\NC\NR -\NC id \NC number \NC The node's type (\type{id}) number \NC\NR -\NC subtype \NC number \NC The node \type{subtype} identifier\NC\NR -\stoptabulate - -The \type{subtype} is sometimes just a stub entry. Not all nodes -actually use the \type{subtype}, but this way you can be sure that all -nodes accept it as a valid field name, and that is often handy in node -list traversal. In the following tables \type{next} and \type{id} are -not explicitly mentioned. - -Besides these three fields, almost all nodes also have an \type {attr} -field, and there is a also a field called \type{prev}. That last field -is always present, but only initialized on explicit request: when the -function \type{node.slide()} is called, it will set up the \type{prev} -fields to be a backwards pointer in the argument node list. - - -\subsubsection{hlist nodes} - -Valid fields: \showfields{hlist}\crlf -Id: \showid{hlist} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = unknown origin, 1 = created by -linebreaking, 2 = explicit box command. (0.46.0), -3 = paragraph indentation box, 4 = alignment column or row, 5 = alignment cell (0.62.0)\NC\NR -\NC attr \NC \syntax{<node>} \NC The head of the associated attribute list \NC\NR -\NC width \NC number \NC \NC\NR -\NC height \NC number \NC \NC\NR -\NC depth \NC number \NC \NC\NR -\NC shift \NC number \NC a displacement perpendicular to the - character progression direction \NC\NR -\NC glue_order \NC number \NC a number in the range 0--4, indicating - the glue order\NC\NR -\NC glue_set \NC number \NC the calculated glue ratio\NC\NR -\NC glue_sign \NC number \NC 0 = normal,1 = stretching,2 = shrinking \NC\NR -\NC head \NC \syntax{<node>} \NC the first node of the body of this list\NC\NR -\NC dir \NC string \NC the direction of this box. see~\in{}[dirnodes]\NC\NR -\stoptabulate - -A warning: never assign a node list to the \type{head} field -unless you are sure its internal link structure is correct, otherwise -an error may result. - -Note: the new field name \type{head} was introduced in 0.65 to replace -the old name \type{list}. Use of the name \type{list} is now -deprecated, but it will stay available until at least version 0.80. - -\subsubsection{vlist nodes} - -Valid fields: As for hlist, except that \quote{shift} is a displacement -perpendicular to the line progression direction, and \quote{subtype} only -has subtypes 0, 4, and 5. - -\subsubsection{rule nodes} - -Valid fields: \showfields{rule}\crlf -Id: \showid{rule} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC unused\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC the width of the rule; the special value $-1073741824$ - is used for \quote{running} glue dimensions\NC\NR -\NC height \NC number \NC the height of the rule (can be negative)\NC\NR -\NC depth \NC number \NC the depth of the rule (can be negative)\NC\NR -\NC dir \NC string \NC the direction of this rule. see~\in{}[dirnodes]\NC\NR -\stoptabulate - -\subsubsection{ins nodes} - -Valid fields: \showfields{ins}\crlf -Id: \showid{ins} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC the insertion class\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC cost \NC number \NC the penalty associated with this insert\NC\NR -\NC height \NC number \NC \NC\NR -\NC depth \NC number \NC \NC\NR -\NC head \NC \syntax{<node>} \NC the first node of the body of this insert\NC\NR -\NC spec \NC \syntax{<node>} \NC a pointer to the \tex{splittopskip} glue spec\NC\NR -\stoptabulate - -A warning: never assign a node list to the \type{head} field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -Note: the new field name \type{head} was introduced in 0.65 to replace -the old name \type{list}. Use of the name \type{list} is now -deprecated, but it will stay available until at least version 0.80. - - -\subsubsection{mark nodes} - -Valid fields: \showfields{mark}\crlf -Id: \showid{mark} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC unused\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC class \NC number \NC the mark class\NC\NR -\NC mark \NC table \NC a table representing a token list\NC\NR -\stoptabulate - -\subsubsection{adjust nodes} - -Valid fields: \showfields{adjust}\crlf -Id: \showid{adjust} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = normal, 1 = \quote{pre}\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC head \NC \syntax{<node>} \NC adjusted material\NC\NR -\stoptabulate - -A warning: never assign a node list to the \type{head} field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -Note: the new field name \type{head} was introduced in 0.65 to replace -the old name \type{list}. Use of the name \type{list} is now -deprecated, but it will stay available until at least version 0.80. - - -\subsubsection{disc nodes} - -Valid fields: \showfields{disc}\crlf -Id: \showid{disc} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC indicates the source of a discretionary. - 0 = the \tex{discretionary} command, - 1 = the \tex{-} command, - 2 = added automatically following a \type{-}, - 3 = added by the hyphenation algorithm (simple), - 4 = added by the hyphenation algorithm (hard, first item), - 5 = added by the hyphenation algorithm (hard, second item)\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC pre \NC \syntax{<node>} \NC pointer to the pre|-|break text\NC\NR -\NC post \NC \syntax{<node>} \NC pointer to the post|-|break text\NC\NR -\NC replace \NC \syntax{<node>} \NC pointer to the no|-|break text\NC\NR -\stoptabulate - -The subtype numbers~4 and~5 belong to the \quote{of-f-ice} explanation given elsewhere. - -A warning: never assign a node list to the pre, post or replace field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -\subsubsection{math nodes} - -Valid fields: \showfields{math}\crlf -Id: \showid{math} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = \quote{on}, 1 = \quote{off}\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC surround \NC number \NC width of the \tex{mathsurround} kern\NC\NR -\stoptabulate - -\subsubsection{glue nodes} - -Valid fields: \showfields{glue}\crlf -Id: \showid{glue} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = \tex{skip}, - 1--18 = internal glue parameters, - 100-103 = \quote{leader} subtypes \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC spec \NC \syntax{<node>} \NC pointer to a glue{\_}spec item \NC\NR -\NC leader \NC \syntax{<node>} \NC pointer to a box or rule for leaders\NC\NR -\stoptabulate - -The exact meanings of the subtypes are as follows: - -\starttabulate[|rT|l|] -\NC 1 \NC \tex{lineskip} \NC \NR -\NC 2 \NC \tex{baselineskip} \NC \NR -\NC 3 \NC \tex{parskip} \NC \NR -\NC 4 \NC \tex{abovedisplayskip} \NC \NR -\NC 5 \NC \tex{belowdisplayskip} \NC \NR -\NC 6 \NC \tex{abovedisplayshortskip} \NC \NR -\NC 7 \NC \tex{belowdisplayshortskip} \NC \NR -\NC 8 \NC \tex{leftskip} \NC \NR -\NC 9 \NC \tex{rightskip} \NC \NR -\NC 10 \NC \tex{topskip} \NC \NR -\NC 11 \NC \tex{splittopskip} \NC \NR -\NC 12 \NC \tex{tabskip} \NC \NR -\NC 13 \NC \tex{spaceskip} \NC \NR -\NC 14 \NC \tex{xspaceskip} \NC \NR -\NC 15 \NC \tex{parfillskip} \NC \NR -\NC 16 \NC \tex{thinmuskip} \NC \NR -\NC 17 \NC \tex{medmuskip} \NC \NR -\NC 18 \NC \tex{thickmuskip} \NC \NR -\NC 100 \NC \tex{leaders} \NC \NR -\NC 101 \NC \tex{cleaders} \NC \NR -\NC 102 \NC \tex{xleaders} \NC \NR -\NC 103 \NC \tex{gleaders} \NC \NR -\stoptabulate - -\subsubsection{kern nodes} - -Valid fields: \showfields{kern}\crlf -Id: \showid{kern} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = from font, - 1 = from \tex{kern} or \tex{/}, - 2 = from \tex{accent}\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC kern \NC number \NC \NC\NR -\stoptabulate - - -\subsubsection{penalty nodes} - -Valid fields: \showfields{penalty}\crlf -Id: \showid{penalty} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC not used\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC penalty \NC number \NC \NC\NR -\stoptabulate - -\subsubsection[glyphnodes]{glyph nodes} - -Valid fields: \showfields{glyph}\crlf -Id: \showid{glyph} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \ssbf type \NC \ssbf explanation \NC \NR -\NC subtype \NC number \NC bitfield \NC \NR -\NC attr \NC \syntax{<node>} \NC \NC \NR -\NC char \NC number \NC \NC \NR -\NC font \NC number \NC \NC \NR -\NC lang \NC number \NC \NC \NR -\NC left \NC number \NC \NC \NR -\NC right \NC number \NC \NC \NR -\NC uchyph \NC boolean \NC \NC \NR -\NC components \NC \syntax{<node>} \NC pointer to ligature components \NC \NR -\NC xoffset \NC number \NC \NC \NR -\NC yoffset \NC number \NC \NC \NR -\NC width \NC number \NC (new in 0.53) \NC \NR -\NC height \NC number \NC (new in 0.53) \NC \NR -\NC depth \NC number \NC (new in 0.53) \NC \NR -\NC expansion_factor \NC number \NC (new in 0.78) \NC \NR -\stoptabulate - -A warning: never assign a node list to the components field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -Valid bits for the \type{subtype} field are: - -\starttabulate[|c|l|] -\NC \ssbf bit \NC \bf meaning \NC\NR -\NC 0 \NC character \NC\NR -\NC 1 \NC ligature \NC\NR -\NC 2 \NC ghost \NC\NR -\NC 3 \NC left \NC\NR -\NC 4 \NC right \NC\NR -\stoptabulate - -See \in{section}[charsandglyphs] for a detailed description of the -\type{subtype} field. - -The \type {expansion_factor} is relatively new and the result of extensive -experiments with a more efficient implementation of expansion. Early versions of -\LUATEX\ already replaced multiple instances of fonts in the backend by scaling -but contrary to \PDFTEX\ in \LUATEX\ we now also got rid of font copies in the -frontend and replaced them by expansion factors that travel with glyph nodes. Apart -from a cleaner approach this is also a step towards a better separation between -front- and backend. - -\subsubsection{margin{\_}kern nodes} - -Valid fields: \showfields{margin_kern}\crlf -Id: \showid{margin_kern} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 0 = left side, - 1 = right side\NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC\NR -\NC glyph \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsection{Math nodes} - -These are the so||called \quote{noad}s and the nodes that are specifically -associated with math processing. Most of these nodes contain sub-nodes so -that the list of possible fields is actually quite small. First, the subnodes: - -\subsubsection{Math kernel subnodes} - -Many object fields in math mode are either simple characters in a -specific family or math lists or node lists. There are four associated -subnodes that represent these cases (in the following node -descriptions these are indicated by the word \type{<kernel>}). - -The \type{next} and \type{prev} fields for these subnodes are unused. - -\subsubsubsection{math{\_}char and math{\_}text{\_}char subnodes} - -Valid fields: \showfields{math_char}\crlf -Id: \showid{math_char} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC char \NC number \NC \NC \NR -\NC fam \NC number \NC \NC\NR -\stoptabulate - -The \type{math_char} is the simplest subnode field, it contains -the character and family for a single glyph object. The -\type{math_text_char} is a special case that you will not -normally encounter, it arises temporarily during math list conversion -(its sole function is to suppress a following italic correction). - -\subsubsubsection{sub{\_}box and sub{\_}mlist subnodes} - -Valid fields: \showfields{sub_box}\crlf -Id: \showid{sub_box} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC head \NC \syntax{<node>}\NC \NC \NR -\stoptabulate - -These two subnode types are used for subsidiary list items. For -\type{sub_box}, the \type{head} points to a \quote{normal} vbox or -hbox. For \type{sub_mlist}, the \type{head} points to a math list -that is yet to be converted. - -A warning: never assign a node list to the \type{head} field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -Note: the new field name \type{head} was introduced in 0.65 to replace -the old name \type{list}. Use of the name \type{list} is now -deprecated, but it will stay available until at least version 0.80. - -\subsubsection{Math delimiter subnode} - -There is a fifth subnode type that is used exclusively for delimiter -fields. As before, the \type{next} and \type{prev} fields are unused. - -\subsubsubsection{delim subnodes} - -Valid fields: \showfields{delim}\crlf -Id: \showid{delim} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC small_char \NC number \NC \NC \NR -\NC small_fam \NC number \NC \NC\NR -\NC large_char \NC number \NC \NC \NR -\NC large_fam \NC number \NC \NC\NR -\stoptabulate - -The fields \type{large_char} and \type{large_fam} can be zero, in that -case the font that is sed for the \type{small_fam} is expected to -provide the large version as an extension to the \type{small_char}. - -\subsubsection{Math core nodes} - -First, there are the objects (the \TEX book calls then \quote{atoms}) -that are associated with the simple math objects: Ord, Op, Bin, Rel, -Open, Close, Punct, Inner, Over, Under, Vcent. These all have -the same fields, and they are combined into a single node type with -separate subtypes for differentiation. - -\subsubsubsection{simple nodes} - -Valid fields: \showfields{noad}\crlf -Id: \showid{noad} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC see below \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC nucleus \NC \syntax{<kernel>}\NC \NC\NR -\NC sub \NC \syntax{<kernel>}\NC \NC\NR -\NC sup \NC \syntax{<kernel>}\NC \NC\NR -\stoptabulate - -Operators are a bit special because they occupy three subtypes. -\type{subtype}. - -\starttabulate[|lT|p|] -\NC \ssbf number \NC \bf node sub type \NC\NR -\NC 0 \NC Ord \NC\NR -\NC 1 \NC Op, \type{\displaylimits} \NC\NR -\NC 2 \NC Op, \type{\limits} \NC\NR -\NC 3 \NC Op, \type{\nolimits} \NC\NR -\NC 4 \NC Bin \NC\NR -\NC 5 \NC Rel \NC\NR -\NC 6 \NC Open \NC\NR -\NC 7 \NC Close \NC\NR -\NC 8 \NC Punct \NC\NR -\NC 9 \NC Inner \NC\NR -\NC 10 \NC Under \NC\NR -\NC 11 \NC Over \NC\NR -\NC 12 \NC Vcent \NC\NR -\stoptabulate - -\subsubsubsection{accent nodes} - -Valid fields: \showfields{accent}\crlf -Id: \showid{accent} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC the first bit is used for a fixed top accent flag (if the \type{accent} field is present), - the second bit for a fixed bottom accent flag (if the \type{bot_accent} field is present). - Example: the actual value \type{3} means: do not stretch either accent\NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC nucleus \NC \syntax{<kernel>}\NC \NC \NR -\NC sub \NC \syntax{<kernel>}\NC \NC\NR -\NC sup \NC \syntax{<kernel>}\NC \NC \NR -\NC accent \NC \syntax{<kernel>}\NC \NC\NR -\NC bot_accent \NC \syntax{<kernel>}\NC \NC\NR -\stoptabulate - -\subsubsubsection{style nodes} - -Valid fields: \showfields{style}\crlf -Id: \showid{style} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC style \NC string \NC contains the style \NC\NR -\stoptabulate - -There are eight possibilities for the string value: one of -\quote{display}, \quote{text}, \quote{script}, or \quote{scriptscript}. -Each of these can have a trailing \type{'} to signify -\quote{cramped} styles. - -\subsubsubsection{choice nodes} - -Valid fields: \showfields{choice}\crlf -Id: \showid{choice} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC display \NC \syntax{<node>}\NC \NC\NR -\NC text \NC \syntax{<node>}\NC \NC\NR -\NC script \NC \syntax{<node>}\NC \NC\NR -\NC scriptscript \NC \syntax{<node>}\NC \NC\NR -\stoptabulate - -A warning: never assign a node list to the display, text, script, or -scriptscript field unless you are sure its internal link structure is -correct, otherwise an error may be result. - -\subsubsubsection{radical nodes} - -Valid fields: \showfields{radical}\crlf -Id: \showid{radical} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC nucleus \NC \syntax{<kernel>}\NC \NC \NR -\NC sub \NC \syntax{<kernel>}\NC \NC\NR -\NC sup \NC \syntax{<kernel>}\NC \NC \NR -\NC left \NC \syntax{<delim>}\NC \NC \NR -\NC degree \NC \syntax{<kernel>}\NC Only set by \type{\Uroot} \NC \NR -\stoptabulate - -A warning: never assign a node list to the nucleus, sub, sup, left, or -degree field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -\subsubsubsection{fraction nodes} - -Valid fields: \showfields{fraction}\crlf -Id: \showid{fraction} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC num \NC \syntax{<kernel>}\NC \NC\NR -\NC denom \NC \syntax{<kernel>}\NC \NC \NR -\NC left \NC \syntax{<delim>}\NC \NC \NR -\NC right \NC \syntax{<delim>}\NC \NC \NR -\stoptabulate - -A warning: never assign a node list to the num, or denom field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - -\subsubsubsection{fence nodes} - -Valid fields: \showfields{fence}\crlf -Id: \showid{fence} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC subtype \NC number \NC 1 = \type{\left}, - 2 = \type{\middle}, - 3 = \type{\right} \NC\NR -\NC attr \NC \syntax{<node>}\NC \NC\NR -\NC delim \NC \syntax{<delim>}\NC \NC \NR -\stoptabulate - -\subsection{whatsit nodes} - -Whatsit nodes come in many subtypes that you can ask for by running -\luatex{node.whatsits()}: -\ctxlua {for n,name in table.sortedpairs(node.whatsits()) do - if (n<100) then - if (n>0) then tex.sprint (', ') end - tex.sprint('\\type{' .. name .. '} (' .. n .. ')') end -end } - -\subsubsection{open nodes} - -Valid fields: \showfields{whatsit,open}\crlf -Id: \showid{whatsit,open} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC stream \NC number \NC \TEX's stream id number\NC\NR -\NC name \NC string \NC file name \NC\NR -\NC ext \NC string \NC file extension \NC\NR -\NC area \NC string \NC file area (this may become obsolete) \NC\NR -\stoptabulate - -\subsubsection{write nodes} - -Valid fields: \showfields{whatsit,write}\crlf -Id: \showid{whatsit,write} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC stream \NC number \NC \TEX's stream id number\NC\NR -\NC data \NC table \NC a table representing the token list to be written\NC\NR -\stoptabulate - -\subsubsection{close nodes} - -Valid fields: \showfields{whatsit,close}\crlf -Id: \showid{whatsit,close} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC stream \NC number \NC \TEX's stream id number\NC\NR -\stoptabulate - -\subsubsection{special nodes} - -Valid fields: \showfields{whatsit,special}\crlf -Id: \showid{whatsit,special} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC data \NC string \NC the \tex{special} information\NC\NR -\stoptabulate - -\subsubsection{language nodes} - - -\LUATEX\ does not have language whatsits any more. All language -information is already present inside the glyph nodes themselves. -This whatsit subtype will be removed in the next release. - - -\subsubsection{local_par nodes} - -Valid fields: \showfields{whatsit,local_par}\crlf -Id: \showid{whatsit,local_par} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC pen_inter \NC number \NC local interline penalty (from \tex{localinterlinepenalty})\NC\NR -\NC pen_broken\NC number \NC local broken penalty (from \tex{localbrokenpenalty})\NC\NR -\NC dir \NC string \NC the direction of this par. see~\in{}[dirnodes]\NC\NR -\NC box_left \NC \syntax{<node>} \NC the \tex{localleftbox}\NC\NR -\NC box_left_width\NC number\NC width of the \tex{localleftbox}\NC\NR -\NC box_right \NC \syntax{<node>} \NC the \tex{localrightbox}\NC\NR -\NC box_right_width\NC number\NC width of the \tex{localrightbox}\NC\NR -\stoptabulate - -A warning: never assign a node list to the box_left or box_right field -unless you are sure its internal link structure is correct, otherwise -an error may be result. - - - - -\subsubsection[dirnodes]{dir nodes} - -Valid fields: \showfields{whatsit,dir}\crlf -Id: \showid{whatsit,dir} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC dir \NC string \NC the direction (but see below)\NC\NR -\NC level \NC number \NC nesting level of this direction whatsit\NC\NR -\NC dvi_ptr \NC number \NC a saved dvi buffer byte offset\NC\NR -\NC dir_h \NC number \NC a saved dvi position\NC\NR -\stoptabulate - -A note on \type{dir} strings. Direction specifiers are three-letter -combinations of \type{T}, \type{B}, \type{R}, and \type{L}. - -These are built up out of three separate items: -\startitemize -\item the first is the direction of the \quote{top} of paragraphs. -\item the second is the direction of the \quote{start} of lines. -\item the third is the direction of the \quote{top} of glyphs. -\stopitemize - -However, only four combinations are accepted: \type{TLT}, \type{TRT}, -\type{RTT}, and \type{LTL}. - -Inside actual \type{dir} whatsit nodes, the representation of -\type{dir} is not a three-letter but a four-letter combination. The -first character in this case is always either \type{+} or \type{-}, -indicating whether the value is pushed or popped from the direction -stack. - -\subsubsection{pdf_literal nodes} - -Valid fields: \showfields{whatsit,pdf_literal}\crlf -Id: \showid{whatsit,pdf_literal} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC mode \NC number \NC the \quote{mode} setting of this literal\NC\NR -\NC data \NC string \NC the \tex{pdfliteral} information\NC\NR -\stoptabulate - -Mode values: - -\starttabulate[|lT|p|] -\NC \ssbf value \NC \ssbf corresponding \tex{pdftex} keyword \NC \NR -\NC 0 \NC setorigin \NC \NR -\NC 1 \NC page \NC \NR -\NC 2 \NC direct \NC \NR -\stoptabulate - -\subsubsection{pdf_refobj nodes} - -Valid fields: \showfields{whatsit,pdf_refobj}\crlf -Id: \showid{whatsit,pdf_refobj} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC objnum \NC number \NC the referenced \PDF\ object number\NC\NR -\stoptabulate - -\subsubsection{pdf_refxform nodes} - -Valid fields: \showfields{whatsit,pdf_refxform}\crlf -Id: \showid{whatsit,pdf_refxform}. - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC objnum \NC number \NC the referenced \PDF\ object number\NC\NR -\stoptabulate - -Be aware that \type{pdf_refxform} nodes have dimensions that are used by \LUATEX. - -\subsubsection{pdf_refximage nodes} - -Valid fields: \showfields{whatsit,pdf_refximage}\crlf -Id: \showid{whatsit,pdf_refximage} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC objnum \NC number \NC the referenced \PDF\ object number\NC\NR -\stoptabulate - -Be aware that \type{pdf_refximage} nodes have dimensions that are used by \LUATEX. - -\subsubsection{pdf_annot nodes} - -Valid fields: \showfields{whatsit,pdf_annot}\crlf -Id: \showid{whatsit,pdf_annot} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC objnum \NC number \NC the referenced \PDF\ object number\NC\NR -\NC data \NC string \NC the annotation data\NC\NR -\stoptabulate - - -\subsubsection{pdf_start_link nodes} - -Valid fields: \showfields{whatsit,pdf_start_link}\crlf -Id: \showid{whatsit,pdf_start_link} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC objnum \NC number \NC the referenced \PDF\ object number\NC\NR -\NC link_attr \NC table \NC the link attribute token list\NC\NR -\NC action \NC \syntax{<node>} \NC the action to perform\NC\NR -\stoptabulate - -\subsubsection{pdf_end_link nodes} - -Valid fields: \showfields{whatsit,pdf_end_link}\crlf -Id: \showid{whatsit,pdf_end_link} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsubsection{pdf_dest nodes} - -Valid fields: \showfields{whatsit,pdf_dest}\crlf -Id: \showid{whatsit,pdf_dest} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC named_id \NC number \NC is the dest_id a string value?\NC\NR -\NC dest_id \NC number or string \NC the destination id\NC\NR -\NC dest_type \NC number\NC type of destination\NC\NR -\NC xyz_zoom \NC number\NC \NC\NR -\NC objnum \NC number \NC the \PDF\ object number\NC\NR -\stoptabulate - -\subsubsection{pdf_thread nodes} - -Valid fields: \showfields{whatsit,pdf_thread}\crlf -Id: \showid{whatsit,pdf_thread} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC named_id \NC number \NC is the tread_id a string value?\NC\NR -\NC tread_id \NC number or string \NC the thread id\NC\NR -\NC thread_attr\NC number \NC extra thread information\NC\NR -\stoptabulate - -\subsubsection{pdf_start_thread nodes} - -Valid fields: \showfields{whatsit,pdf_start_thread}\crlf -Id: \showid{whatsit,pdf_start_thread} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC width \NC number \NC \NC \NR -\NC height \NC number \NC \NC \NR -\NC depth \NC number \NC \NC \NR -\NC named_id \NC number \NC is the tread_id a string value?\NC\NR -\NC tread_id \NC number or string \NC the thread id\NC\NR -\NC thread_attr\NC number \NC extra thread information\NC\NR -\stoptabulate - -\subsubsection{pdf_end_thread nodes} - -Valid fields: \showfields{whatsit,pdf_end_thread}\crlf -Id: \showid{whatsit,pdf_end_thread} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsubsection{pdf_save_pos nodes} - -Valid fields: \showfields{whatsit,pdf_save_pos}\crlf -Id: \showid{whatsit,pdf_save_pos} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsubsection{late_lua nodes} - -Valid fields: \showfields{whatsit,late_lua}\crlf -Id: \showid{whatsit,late_lua} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC data \NC string \NC data to execute\NC\NR -\NC string \NC string \NC data to execute (0.63)\NC\NR -\NC name \NC string \NC the name to use for lua error reporting\NC\NR -\stoptabulate - -The difference between \type{data} and \type{string} is that on -assignment, the \type{data} field is converted to a token list, cf. use as -\tex{latelua}. The \type{string} version is treated as a literal string. - -\subsubsection{pdf_colorstack nodes} - -Valid fields: \showfields{whatsit,pdf_colorstack}\crlf -Id: \showid{whatsit,pdf_colorstack} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC stack \NC number \NC colorstack id number\NC\NR -\NC cmd \NC number \NC command to execute\NC\NR -\NC data \NC string \NC data\NC\NR -\stoptabulate - -\subsubsection{pdf_setmatrix nodes} - -Valid fields: \showfields{whatsit,pdf_setmatrix}\crlf -Id: \showid{whatsit,pdf_setmatrix} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC data \NC string \NC data\NC\NR -\stoptabulate - -\subsubsection{pdf_save nodes} - -Valid fields: \showfields{whatsit,pdf_save}\crlf -Id: \showid{whatsit,pdf_save} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsubsection{pdf_restore nodes} - -Valid fields: \showfields{whatsit,pdf_restore}\crlf -Id: \showid{whatsit,pdf_restore} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\stoptabulate - -\subsubsection{user_defined nodes} - -User|-|defined whatsit nodes can only be created and handled from \LUA\ -code. In effect, they are an extension to the extension -mechanism. The \LUATEX\ engine will simply step over such whatsits -without ever looking at the contents. - -Valid fields: \showfields{whatsit,user_defined}\crlf -Id: \showid{whatsit,user_defined} - -\starttabulate[|lT|l|p|] -\NC \ssbf field \NC \bf type \NC \bf explanation \NC\NR -\NC attr \NC \syntax{<node>} \NC \NC\NR -\NC user_id \NC number \NC id number\NC\NR -\NC type \NC number \NC type of the value\NC\NR -\NC value \NC number \NC \NC\NR -\NC \NC string \NC \NC\NR -\NC \NC \syntax{<node>} \NC \NC\NR -\NC \NC table \NC \NC\NR -\stoptabulate - -The \type{type} can have one of five distinct values: - -\starttabulate[|lT|p|] -\NC \ssbf value \NC \bf explanation \NC\NR -\NC 97 \NC the value is an attribute node list \NC\NR -\NC 100 \NC the value is a number \NC\NR -\NC 110 \NC the value is a node list \NC\NR -\NC 115 \NC the value is a string\NC\NR -\NC 116 \NC the value is a token list in \LUA\ table form\NC\NR -\stoptabulate - -\section{Two access models} - -After doing lots of tests with \LUATEX\ and \LUAJITTEX\, with and without just in -time compilation enabled, and with and without using ffi, we came to the -conclusion that userdata prevents a speedup. We also found that the checking of -metatables as well as assignment comes with overhead that can't be neglected. -This is normally not really a problem but when processing fonts for more complex -scripts it could have quite some overhead. - -Because the userdata approach has some benefits, this remains the recommended way -to access nodes. We did several experiments with faster access using this model, -but eventually settled for the \quote {direct} approach. For code that is proven -to be okay, one can use this access model that operates on nodes more directly. - -Deep down in \TEX\ a node has a number which is an entry in a memory table. In -fact, this model, where \TEX\ manages memory is real fast and one of the reasons -why plugging in callbacks that operate on nodes is quite fast. No matter what -future memory model \LUATEX\ has, an internal reference will always be a simple data -type (like a number or light userdata in \LUA\ speak). So, if you use the direct -model, even if you know that you currently deal with numbers, you should not depend -on that property but treat it an abstraction just like traditional nodes. In fact, -the fact that we use a simple basic datatype has the penalty that less checking can -be done, but less checking is also the reason why it's somewhat faster. An -important aspect is that one cannot mix both methods, but you can cast both -models. - -So our advice is: use the indexed approach when possible and investigate the -direct one when speed might be an issue. For that reason we also provide the -\type {get*} and \type {set*} functions in the top level node namespace. There is -a limited set of getters. When implementing this direct approach the regular -index by key variant was also optimized, so direct access only makes sense when -we're accessing nodes millions of times (which happens in some font processing -for instance). - -We're talking mostly of getters because setters are less important. Documents -have not that many content related nodes and setting many thousands of properties -is hardly a burden contrary to millions of consultations. - -Normally you will access nodes like this: - -\starttyping -local next = current.next -if next then - -- do something -end -\stoptyping - -Here \type {next} is not a real field, but a virtual one. Accessing it results in -a metatable method being called. In practice it boils down to looking up the -node type and based on the node type checking for the field name. In a worst case -you have a node type that sits at the end of the lookup list and a field that is -last in the lookup chain. However, in successive versions of \LUATEX\ these lookups -have been optimized and the most frequently accessed nodes and fields have a higher -priority. - -Because in practice the \type {next} accessor results in a function call, there -is some overhead involved. The next code does the same and performs a tiny bit -faster (but not that much because it is still a function call but one that -knows what to look up). - -\starttyping -local next = node.next(current) -if next then - -- do something -end -\stoptyping - -There are several such function based accessors now: - -\starttabulate[|T|p|] -\NC getnext \NC parsing nodelist always involves this one \NC \NR -\NC getprev \NC used less but is logical companion to getnext \NC \NR -\NC getid \NC consulted a lot \NC \NR -\NC getsubtype \NC consulted less but also a topper \NC \NR -\NC getfont \NC used a lot in otf handling (glyph nodes are consulted a lot) \NC \NR -\NC getchar \NC idem and also in other places \NC \NR -\NC getlist \NC we often parse nested lists so this is a convenient one too - (only works for hlist and vlist!) \NC \NR -\NC getleader \NC comparable to list, seldom used in \TEX\ (but needs frequent consulting - like lists; leaders could have been made a dedicated node type) \NC \NR -\NC getfield \NC generic getter, sufficient for the rest (other field names are - often shared so a specific getter makes no sense then) \NC \NR -\stoptabulate - -It doesn't make sense to add more. Profiling demonstrated that these fields can -get accesses way more times than other fields. Even in complex documents, many -node and fields types never get seen, or seen only a few times. Most functions in the -\type {node} namespace have a companion in \type {node.direct}, but of course not the -ones that don't deal with nodes themselves. The following table summarized this: - -\start \def\yes{$+$} \def\nop{$-$} - -\starttabulate[|T|c|c|] -\HL -\NC \bf function \NC \bf node \NC \bf direct \NC \NR -\HL -\NC copy \NC \yes \NC \yes \NC \NR -\NC copy_list \NC \yes \NC \yes \NC \NR -\NC count \NC \yes \NC \yes \NC \NR -\NC current_attr \NC \yes \NC \yes \NC \NR -\NC dimensions \NC \yes \NC \yes \NC \NR -\NC do_ligature_n \NC \yes \NC \yes \NC \NR -\NC end_of_math \NC \yes \NC \yes \NC \NR -\NC family_font \NC \yes \NC \nop \NC \NR -\NC fields \NC \yes \NC \nop \NC \NR -\NC first_character \NC \yes \NC \nop \NC \NR -\NC first_glyph \NC \yes \NC \yes \NC \NR -\NC flush_list \NC \yes \NC \yes \NC \NR -\NC flush_node \NC \yes \NC \yes \NC \NR -\NC free \NC \yes \NC \yes \NC \NR -\NC getbox \NC \nop \NC \yes \NC \NR -\NC getchar \NC \yes \NC \yes \NC \NR -\NC getfield \NC \yes \NC \yes \NC \NR -\NC getfont \NC \yes \NC \yes \NC \NR -\NC getid \NC \yes \NC \yes \NC \NR -\NC getnext \NC \yes \NC \yes \NC \NR -\NC getprev \NC \yes \NC \yes \NC \NR -\NC getlist \NC \yes \NC \yes \NC \NR -\NC getleader \NC \yes \NC \yes \NC \NR -\NC getsubtype \NC \yes \NC \yes \NC \NR -\NC has_glyph \NC \yes \NC \yes \NC \NR -\NC has_attribute \NC \yes \NC \yes \NC \NR -\NC has_field \NC \yes \NC \yes \NC \NR -\NC hpack \NC \yes \NC \yes \NC \NR -\NC id \NC \yes \NC \nop \NC \NR -\NC insert_after \NC \yes \NC \yes \NC \NR -\NC insert_before \NC \yes \NC \yes \NC \NR -\NC is_direct \NC \nop \NC \yes \NC \NR -\NC is_node \NC \yes \NC \yes \NC \NR -\NC kerning \NC \yes \NC \nop \NC \NR -\NC last_node \NC \yes \NC \yes \NC \NR -\NC length \NC \yes \NC \yes \NC \NR -\NC ligaturing \NC \yes \NC \nop \NC \NR -\NC mlist_to_hlist \NC \yes \NC \nop \NC \NR -\NC new \NC \yes \NC \yes \NC \NR -\NC next \NC \yes \NC \nop \NC \NR -\NC prev \NC \yes \NC \nop \NC \NR -\NC tostring \NC \yes \NC \yes \NC \NR -\NC protect_glyphs \NC \yes \NC \yes \NC \NR -\NC protrusion_skippable \NC \yes \NC \yes \NC \NR -\NC remove \NC \yes \NC \yes \NC \NR -\NC set_attribute \NC \yes \NC \yes \NC \NR -\NC setbox \NC \yes \NC \yes \NC \NR -\NC setfield \NC \yes \NC \yes \NC \NR -\NC slide \NC \yes \NC \yes \NC \NR -\NC subtype \NC \yes \NC \nop \NC \NR -\NC tail \NC \yes \NC \yes \NC \NR -\NC todirect \NC \yes \NC \yes \NC \NR -\NC tonode \NC \yes \NC \yes \NC \NR -\NC traverse \NC \yes \NC \yes \NC \NR -\NC traverse_id \NC \yes \NC \yes \NC \NR -\NC type \NC \yes \NC \nop \NC \NR -\NC types \NC \yes \NC \nop \NC \NR -\NC unprotect_glyphs \NC \yes \NC \yes \NC \NR -\NC unset_attribute \NC \yes \NC \yes \NC \NR -\NC usedlist \NC \yes \NC \yes \NC \NR -\NC vpack \NC \yes \NC \yes \NC \NR -\NC whatsits \NC \yes \NC \nop \NC \NR -\NC write \NC \yes \NC \yes \NC \NR -\stoptabulate - -\stop - -The \type {node.next} and \type {node.prev} functions will stay but for -consistency there are variants called \type {getnext} and \type {getprev}. -We had to use \type{get} because \type {node.id} and \type {node.subtype} are -already taken for providing meta information about nodes. -Note: The getters do only basic checking for valid keys. -You should just stick to the keys mentioned in the sections that describe node properties. - -\chapter{Modifications} - -Besides the expected changes caused by new functionality, there are a -number of not|-|so|-|expected changes. These are sometimes a side|-|effect -of a new (conflicting) feature, or, more often than not, a change -necessary to clean up the internal interfaces. - -\section{Changes from \TEX\ 3.1415926} - -\startitemize - -\item The current code base is written in C, not Pascal web (as of \LUATEX~0.42.0). - -\item See~\in{chapter}[languages] for many small changes related to paragraph - building, language handling, and hyphenation. Most important change: - adding a brace group in the middle of a word (like in \type{of{}fice}) - does not prevent ligature creation. - -\item There is no pool file, all strings are embedded during compilation. - -\item \type {plus 1 fillll} does not generate an error. The extra \quote{l} is -simply typeset. - -\item The upper limit to \tex{endlinechar} and \tex{newlinechar} is 127. - -\stopitemize - -\section{Changes from \ETEX\ 2.2} - -\startitemize - -\item The \ETEX\ functionality is always present and enabled - (but see below about \TEXXET), so the prepended asterisk or - \type{-etex} switch for \INITEX\ is not needed. - -\item \TEXXET\ is not present, so the primitives - -\starttyping -\TeXXeTstate -\beginR -\beginL -\endR -\endL -\stoptyping - -are missing. - -\item Some of the tracing information that is output by \ETEX's \tex{tracingassigns} and - \tex{tracingrestores} is not there. - -\item Register management in \LUATEX\ uses the \ALEPH\ model, so the maximum value is 65535 - and the implementation uses a flat array instead of the mixed - flat|\&|sparse model from \ETEX. - -\item \type{savinghyphcodes} is a no-op. -See~\in{chapter}[languages] for details. - -\item When kpathsea is used to find files, \LUATEX\ uses the -\type{ofm} file format to search for font metrics. In turn, this means -that \LUATEX\ looks at the \type{OFMFONTS} configuration variable -(like \OMEGA\ and \ALEPH) instead of \type{TFMFONTS} (like \TEX\ and -\PDFTEX). Likewise for virtual fonts (\LUATEX\ uses the variable -\type{OVFFONTS} instead of \type{VFFONTS}). - - -\stopitemize - -\section{Changes from \PDFTEX\ 1.40} - -\startitemize - -\item The (experimental) support for snap nodes has been removed, because -it is much more natural to build this functionality on top of node -processing and attributes. The associated primitives that are now gone -are: \tex{pdfsnaprefpoint}, \tex{pdfsnapy}, and \tex{pdfsnapycomp}. - -\item The (experimental) support for specialized spacing around nodes -has also been removed. The associated primitives that are now gone are: -\tex{pdfadjustinterwordglue}, \tex{pdfprependkern}, and \tex{pdfappendkern}, -as well as the five supporting primitives \tex{knbscode}, \tex{stbscode}, -\tex{shbscode}, \tex{knbccode}, and \tex{knaccode}. - -\item A number of \quote{utility functions} is removed: - -\startcolumns[n=3] -\starttyping -\pdfelapsedtime -\pdfescapehex -\pdfescapename -\pdfescapestring -\pdffiledump -\pdffilemoddate -\pdffilesize -\pdflastmatch -\pdfmatch -\pdfmdfivesum -\pdfresettimer -\pdfshellescape -\pdfstrcmp -\pdfunescapehex -\stoptyping -\stopcolumns - -\item The four primitives that were already marked obsolete in \PDFTEX~1.40 -have been removed since \LUATEX~0.42: - -\startcolumns[n=2] -\starttyping -\pdfoptionalwaysusepdfpagebox -\pdfoptionpdfinclusionerrorlevel -\pdfforcepagebox -\pdfmovechars -\stoptyping -\stopcolumns - - -\item A few other experimental primitives are also provided without the - extra \luatex {pdf} prefix, so they can also be called like this: - -\startcolumns[n=3] -\starttyping -\primitive -\ifprimitive -\ifabsnum -\ifabsdim -\stoptyping -\stopcolumns - -\item The \tex{pdftexversion} is set to 200. - -\item The PNG transparency fix from 1.40.6 is not applied -(high-level support is pending) - -\item LFS (\PDF\ Files larger than 2GiB) support is not working yet. - -\item \LUATEX~0.45.0 introduces two extra token lists, \tex{pdfxformresources} -and \tex{pdfxformattr}, as an alternative to \tex{pdfxform} keywords. - -\item As of \LUATEX~0.50.0 is no longer possible for fonts from embedded pdf files - to be replaced by / merged with the document fonts of the enveloping - pdf document. This regression may be temporary, depending on how the - rewritten font backend will look after beta 0.60. - - -\stopitemize - -\section{Changes from \ALEPH\ RC4} - -\startitemize - -\item Starting with \LUATEX\ 0.75.0, the extended 16-bit math primitives - (\tex{omathcode} etc.~) have been removed. - -\item Starting with \LUATEX\ 0.63.0, OCP processing is no longer - supported at all. As a consequence, the following primitives have - been removed: - -\startcolumns[n=2] -\starttyping -\ocp -\externalocp -\ocplist -\pushocplist -\popocplist -\clearocplists -\addbeforeocplist -\addafterocplist -\removebeforeocplist -\removeafterocplist -\ocptracelevel -\stoptyping -\stopcolumns - -\item \LUATEX\ only understands 4~of the 16~direction -specifiers of \ALEPH: \type{TLT} (latin), \type{TRT} (arabic), -\type{RTT} (cjk), \type{LTL} (mongolian). All other direction -specifiers generate an error (\LUATEX\ 0.45). - -\item The input translations from \ALEPH\ are not implemented, the - related primitives are not available: - -\startcolumns[n=2] -\starttyping -\DefaultInputMode -\noDefaultInputMode -\noInputMode -\InputMode -\DefaultOutputMode -\noDefaultOutputMode -\noOutputMode -\OutputMode -\DefaultInputTranslation -\noDefaultInputTranslation -\noInputTranslation -\InputTranslation -\DefaultOutputTranslation -\noDefaultOutputTranslation -\noOutputTranslation -\OutputTranslation -\stoptyping -\stopcolumns - -\item The \tex{hoffset} bug when \tex{pagedir TRT} is fixed, -removing the need for an explicit fix to \tex{hoffset} - -\item A bug causing \tex{fam} to fail for family numbers above - 15 is fixed. - -\item A fair amount of other minor bugs are fixed as well, most of these -related to \tex{tracingcommands} output. - -\item The internal function \type{scan_dir()} has been renamed to -\type{scan_direction()} to prevent a naming clash, and it now allows -an optional space after the direction is completely parsed. - -\item The \type{^^} notation can come in five and six item repetitions also, to -insert characters that do not fit in the BMP. - -\item Glues {\it immediately after} direction change commands are not -legal breakpoints. - -\stopitemize - -\section{Changes from standard \WEBC} - -\startitemize - -\item There is no mltex - -\item There is no enctex - -\item The following commandline switches are silently ignored, even -in non|-|\LUA\ mode: - -\starttyping --8bit --translate-file=TCXNAME --mltex --enc --etex -\stoptyping - -\item \tex{openout} whatsits are not written to the log file. - -\item Some of the so|-|called web2c extensions are hard to set up - in non|-|\KPSE\ mode because texmf.cnf is not read: \type{shell-escape} - is off (but that is not a problem because of \LUA's - \lua{os.execute}), and the paranoia checks on \type{openin} and - \type{openout} do not happen (however, it is easy for a \LUA\ script - to do this itself by overloading \lua{io.open}). - -\item The \quote{E} option does not do anything useful. - -\stopitemize - -\chapter{Implementation notes} - -\section{Primitives overlap} - -The primitives - -\starttabulate[|l|l|] -\NC \tex{pdfpagewidth} \NC \tex{pagewidth} \NC \NR -\NC \tex{pdfpageheight}\NC \tex{pageheight} \NC \NR -\NC \tex{fontcharwd} \NC \tex{charwd} \NC \NR -\NC \tex{fontcharht} \NC \tex{charht} \NC \NR -\NC \tex{fontchardp} \NC \tex{chardp} \NC \NR -\NC \tex{fontcharic} \NC \tex{charit} \NC \NR -\stoptabulate - -are all aliases of each other. - -\section{Memory allocation} - -The single internal memory heap that traditional \TEX\ used for tokens -and nodes is split into two separate arrays. Each of these will grow -dynamically when needed. - -The \type{texmf.cnf} settings related to main memory are no longer -used (these are: \type{main_memory}, \type{mem_bot}, -\type{extra_mem_top} and \type{extra_mem_bot}). \quote{Out of main -memory} errors can still occur, but the limiting factor is now the -amount of RAM in your system, not a predefined limit. - -Also, the memory (de)allocation routines for nodes are completely -rewritten. The relevant code now lives in the C file \type{texnode.c}, -and basically uses a dozen or so \quote{avail} lists instead of a -doubly|-|linked model. An extra function layer is added so that the -code can ask for nodes by type instead of directly requisitioning -a certain amount of memory words. - -Because of the split into two arrays and the resulting differences in the data -structures, some of the macros have been duplicated. For instance, there are now -\type{vlink} and \type{vinfo} as well as \type{token_link} and \type{token_info}. All -access to the variable memory array is now hidden behind a macro called \type{vmem}. - -The implementation of the growth of two arrays (via reallocation) -introduces a potential pitfall: the memory arrays should never be used -as the left hand side of a statement that can modify the array in -question. - -The input line buffer and pool size are now also reallocated when -needed, and the \type{texmf.cnf} settings \type{buf_size} and -\type{pool_size} are silently ignored. - -\section{Sparse arrays} - -The \tex{mathcode}, \tex{delcode}, \tex{catcode}, -\tex{sfcode}, \tex{lccode} and \tex{uccode} tables are now -sparse arrays that are implemented in~C. They are no longer part of -the \TEX\ \quote{equivalence table} and because each had 1.1 million -entries with a few memory words each, this makes a major difference -in memory usage. - -The \tex{catcode}, \tex{sfcode}, \tex{lccode} and \tex{uccode} assignments -do not yet show up when using the etex tracing routines \tex{tracingassigns} -and \tex{tracingrestores} (code simply not written yet). - -A side|-|effect of the current implementation is that \tex{global} is -now more expensive in terms of processing than non|-|global assignments. - -See \type{mathcodes.c} and \type{textcodes.c} if you are interested in -the details. - -Also, the glyph ids within a font are now managed by means -of a sparse array and glyph ids can go up to index $2^{21}-1$. - -\section{Simple single-character csnames} - -Single|-|character commands are no longer treated specially in the -internals, they are stored in the hash just like the multiletter -csnames. - -The code that displays control sequences explicitly checks if -the length is one when it has to decide whether or not to add a -trailing space. - -Active characters are internally implemented as a special type -of multi-letter control sequences that uses a prefix that is -otherwise impossible to obtain. - -\section{Compressed format} - -The format is passed through zlib, allowing it to shrink to roughly -half of the size it would have had in uncompressed form. This takes a -bit more CPU cycles but much less disk I/O, so it should still be -faster. - -\section{Binary file reading} - -All of the internal code is changed in such a way that if one of the -\type{read_xxx_file} callbacks is not set, then the file is read by -a C function using basically the same convention as the callback: a -single read into a buffer big enough to hold the entire file -contents. While this uses more memory than the previous code (that -mostly used \type{getc} calls), it can be quite a bit faster -(depending on your I/O subsystem). - -\chapter{Known bugs and limitations, TODO} - -There used to be a lists of bugs and planned features below here, but that did not -work out too well. There are lists of open bugs and feature requests in the tracker at -\hyphenatedurl{http://tracker.luatex.org}. - -\stoptext |