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diff --git a/macros/luatex/optex/base/fonts-select.opm b/macros/luatex/optex/base/fonts-select.opm new file mode 100644 index 0000000000..83ded2f35b --- /dev/null +++ b/macros/luatex/optex/base/fonts-select.opm @@ -0,0 +1,670 @@ +%% This is part of OpTeX project, see http://petr.olsak.net/optex + +\_codedecl \fontfam {Fonts selection system <2020-03-18>} % preloaded in format + + \_doc ----------------------------- + The \`\initunifonts` initializes extended `\font` primitive + (to be able to load Unicode fonts). Unfortunately, this part of + \OpTeX/ depends on \LaTeX/ lua codes `ltluatex.lua` and + `luaotfload-main.lua`. And this code need to be declared a + control sequence `\e@alloc@attribute@count` by `\countdef` primitive. + Moreover, the `\initunifont` switches with + the \^`\_doresizefont` macro to OTF mode which is represented by the + macro \`\_doresizeunifont`. This mode includes + a fallback to TFM mode if \^`\_fontnamegen` is not defined. + Finally, the `\initunifnt` sets itself to relax because we need not to do + this work twice. + \_cod ----------------------------- + +\_def\_initunifonts {% + \_ea\_newcount \_csname e@alloc@attribute@count\_endcsname + \_global \_csname e@alloc@attribute@count\_endcsname=-1 + \_directlua{% + require("ltluatex") + require('luaotfload-main') local _void = luaotfload.main () + }% + \_gdef\_rfskipatX ##1" ##2\_relax{"##1"}% + \_global\_let \_doresizefont=\_doresizeunifont + \_gdef\_tryloadtt {\_fontdef\_tentt{\_def\_fontnamegen{[lmmono10-regular]}\_rm}}% + \_global\_let \_initunifonts=\_relax % we need not to do this work twice + \_global\_let \initunifonts=\_relax +} +\_gdef\_doresizeunifont #1{\_logfont{#1}% + \_ifx\_fontnamegen\_undefined \_doresizetfmfont#1\_else + \_font#1={\_fontnamegen} \_sizespec \_relax \_setwsp#1\_relax + \_fi +} +\_public \initunifonts ; + + \_doc ----------------------------- + The \`\_famdecl` `[<Family Name>] \<Famselector> {<comment>} {<modifiers>} {<variants>} {<math>}`\nl + `{<font for testing>} {\def`\^`\_fontnamegen``{<data>}}` runs \^`\initunifonts`, then + checks if `\<Famselector>` is defined. If it is true, then closes the file by + `\endinput`. Else it defines `\<Famselector>` and saves it to the \`\_mainfamcommand` + macro because the \`\_initfontfamily` needs it. The \`\_currfamily` is set + to the `<Famselector>` because the following \^`\moddef` commands need to + be in the right font family context. The `\_currfamily` is set to the + `<Famselector>` by the `\<Famselector>` too, because `\<Famselector>` + must set the right faily context. The font family context is given by the current + `\_currfamily` value and by the actual meaning of the \^`\_fontnamegen` macro. + \_cod ----------------------------- + +\_def\_famdecl [#1]#2#3#4#5#6#7#8{% + \_initunifonts \_uniaccents + \_ifx #2\_undefined + \_isfont{#7}\_iffalse + \_opwarning{Family [#1] skipped, font "#7" not found}\_ea\_ea\_ea\_endinput \_else + \_edef\_currfamily {\_csstring #2}% + \_def\_mainfamcommand{#2}\_def\_mathfaminfo{#6}% + \_protected\_edef#2{\_def\_noexpand\_currfamily{\_csstring #2}\_unexpanded{#8\_resetmod}}% + \_wterm {FONT: [#1] -- \_string#2 \_detokenize{(#3)^^J mods:{#4} vars:{#5} math:{#6}}}% + \_fi + \_else \_ea #2\_ea\_endinput \_fi +} +\_def\_initfontfamily{% + \_mainfamcommand \_reloading \_rm +} + + \_doc ----------------------------- + \`\_regoptsizes` `<internal-template> <left-output>?<right-output> <resizing-data>` + prepares data for using by the \`\_optname` `<internal-template>` macro. + The data are saved to the `\_oz:<internal-template>` macro. + When the `\_optname` is expanded then the data are scanned by the macro + \`\_optnameA` `<left-output>?<right-output> <mid-output> `\code{<}`<size>` + in the loop.\nl + \`\_optfontalias` `{<template A>}{<template B>}` is defined as + `\let\_oz:<templateA>=\_oz:<templateB>`. + \_cod ----------------------------- + +\_def\_regoptsizes #1 #2?#3 #4*{\_sdef{_oz:#1}{#2?#3 #4* }} +\_def\_optname #1{\_ifcsname _oz:#1\_endcsname + \_ea\_ea\_ea \_optnameA \_csname _oz:#1\_ea\_endcsname + \_else \_failedoptname{#1}\_fi +} +\_def\_failedoptname #1{optname-fails:(#1)} +\_def\_optnameA #1?#2 #3 <#4 {\_ifx*#4#1#3#2\_else + \_ifdim\_optsize<#4pt #1#3#2\_optnameC + \_else \_afterfifi \_optnameA #1?#2 \_fi\_fi +} +\_def\_optnameC #1* {\_fi\_fi} +\_def\_afterfifi #1\_fi\_fi{\_fi\_fi #1} +\_def\_optfontalias #1#2{\_slet{_oz:#1}{_oz:#2}} + + \_doc ----------------------------- + \`\_fvars` `<rm-template> <bf-template> <it-template> <bi-template>` + saves data for usage by the `\_currV` macro. If a template is only dot + then previous template is used (it can be used if the font family doesn't + dispose with all standard variants). + \nl + \`\_currV` expands to a template declared by `\_fvars` depending on the + `<variant name>`. Usable only of standard four variants. Next variants + can be declared by the \^`\famvardef` macro. + \nl + \`\_fset` `<key>=<value>,...,<key>=<value>` expands to + `\def\_<key>V{<value>}` in the loop. + \nl + \`\_onlyif` `<key>=<value-a>,<value-b>...,<value-z>: {<what>}` + runs <what> only if the `\_<key>V` is defined as `<value-a>` or + `<value-b>` or ... or `<value-z>`. + \_cod ----------------------------- + +\_def\_fvars #1 #2 #3 #4 {% + \_sdef{_fvar:rm}{#1}% + \_sdef{_fvar:bf}{#2}% + \_ifx.#2\_slet{_fvar:bf}{_fvar:rm}\_fi + \_sdef{_fvar:it}{#3}% + \_ifx.#3\_slet{_fvar:it}{_fvar:rm}\_fi + \_sdef{_fvar:bi}{#4}% + \_ifx.#4\_slet{_fvar:bi}{_fvar:it}\_fi +} +\_def\_currV{\_cs{_fvar:\_whatresize}} +\_def\_V{ } +\_def \_fsetV #1 {\_fsetVa #1,=,} +\_def \_fsetVa #1=#2,{\_isempty{#1}\_iffalse + \_ifx,#1\_else\_sdef{_#1V}{#2}\_ea\_ea\_ea\_fsetVa\_fi\_fi +} +\_def \_onlyif #1=#2:#3{% + \_edef\_act{\_noexpand\_isinlist{,#2,}{,\_cs{_#1V},}}\_act + \_iftrue #3\_fi +} + + \_doc ----------------------------- + The \`\moddef` `\<modifier> {<data>}` simply speaking does + `\def\<modifier>{<data>}`, but we need to respect + the family context. In fact, `\protected\def\_f:<current family>:<modifier>{<data>}` is + performed and the `\<modifier>` is defined as + \`\_famdepend``\<modifier>{_f:\_currfamily:<modifier>}`. It expands to + `\_f:\_currfamily:<modifier>` value if it is defined or it prints + warning. When the `\_currfamily` value is + changed then we can declare the same `\<modifier>` with different meaning. + + When user declare a prefixed variant of the `\<modifier>` then unprefixed + modifier name is used in internal macros, this is reason why we are using + the \`\_remifirstunderscore``\_tmp` (where `\_tmp` expands to + `_<something>` or to `<something>`. The `\_remifirstunderscore` + redefines `\_tmp` in the way that it + expands only to `<something>` without the first `_`. + \_cod ----------------------------- + +\_def \_moddef #1#2{\_edef\_tmp{\_csstring#1}\_remfirstunderscore\_tmp + \_sdef{_f:\_currfamily:\_tmp}{#2\_reloading}% + \_protected \_edef #1{\noexpand\_famdepend\noexpand#1{_f:\noexpand\_currfamily:\_tmp}}% + \_ea \_ifx \_csname\_tmp\_endcsname #1\_else + \_ea \_public \_csname\_tmp\_endcsname ;\_fi +} +\_def\_remfirstunderscore#1{\_ea\_remfirstunderscoreA#1\_relax#1} +\_def\_remfirstunderscoreA#1#2\_relax#3{\_if _#1\_def#3{#2}\_fi} + +\_protected \_def\_resetmod {\_cs{_f:\_currfamily:resetmod}} % private variant of \resetmod +\_def\_currfamily{} % default current family is empty + +\_def\_famdepend#1#2{\_ifcsname#2\_endcsname \_csname#2\_ea\_endcsname \_else + \_opwarning{\_string#1 is undeclared in current family "\_currfamily", ignored}\_fi +} +\_public \moddef ; + + \_doc ----------------------------- + The \`\famvardef` `\<XX> {<data>}` + uses analogical trick like \^`\moddef` with + the \^`\_famdepend` macro. The auxiliary + \`\_famvardefA` `\<XX> \_ten<XX> \_tryload<XX> {<data>}` is used. + It does: + \begitems + * `\protected\def \<XX> {\_famdepend \<XX> {_f:\_currfamily:<XX>}}`, + * `\def \_f:<current family>:<XX> {\_tryload<XX>\_ten<XX>}` keeps family dependent definition, + * `\def \_tryload<XX> {`\^`\fontdef`` \_ten<XX> {<data>}}` loads actually the font `\_ten<XX>`, + * `\def \_currvar:_ten<XX> {\<XX>}` in ordef to the \^`\currvar` macro + work correctly. + \enditems + \_cod ----------------------------- + +\_def\_famvardef#1{\_edef\_tmp{\_csstring#1}\_remfirstunderscore\_tmp + \_ea\_famvardefA \_ea#1\_csname _ten\_tmp\_ea\_endcsname + \_csname _tryload:\_tmp\_endcsname +} +\_def\_famvardefA #1#2#3#4{% #1=\_XX #2=\_tenXX #3=\_tryloadXX #4=data + \_isinlist{.\_rm\_bf\_it\_bi\currvar\_currvar}#1\_iftrue + \_opwarning{\_string\famvardef: + You cannot re-declare private standard variant selector \_string#1}% + \_else + \_protected\_edef #1{\_noexpand\_famdepend\_noexpand#1{_f:\_noexpand\_currfamily:\_tmp}}% + \_sdef{_f:\_currfamily:\_tmp}{#3#2}% + \_def#3{\_fontdef#2{#4}}% + \_ifx#1\tt \_addto#1{\_fam\_ttfam}\_fi + \_sdef{_currvar:\_csstring#2}{#1}% + \_fi +} +\_public \famvardef ; + + \_doc ----------------------------- + The \`\fontfam` `[<Font Family>]` does: + \begitems + * Convert its parameter to lower case and without spaces, e.g.\ `<fontfamily>`. + * If the file `f-<fontfamily>.opm` exists read it and finish. + * Try to load user defined `fams-local.opm`. + * If the `<fontfamily>` is declared in `fams-local.opm` or `fams-ini.opm` + read relevant file and finish. + * Print the list of declared families. + \enditems + The `fams-local.opm` is read by the \`\_tryloadfamslocal` macro. It sets + itself to `\_relax` because we need not to load this file twice. + The \`\_listfamnames` macro prints registered font families to the + terminal and to the log file. + \_cod ----------------------------- + +\_def\_fontfam[#1]{% + \_lowercase{\_edef\_famname{\_ea\_removespaces #1 {} }}% + \_isfile {f-\_famname.opm}\_iftrue \_opinput {f-\_famname.opm}% + \_else + \_tryloadfamslocal + \_edef\_famfile{\_trycs{_famf:\_famname}{}}% + \_ifx\_famfile\_empty \_listfamnames + \_else \_opinput {\_famfile.opm}% + \_fi\_fi +} +\_def\_tryloadfamslocal{% + \_isfile {fams-local.opm}\_iftrue + \_opinput {fams-local.opm} + \_fi + \_let \_tryloadfamslocal=\_relax % need not to load fams-local.opm twice +} +\_def\_listfamnames {% + \_wterm{===== List of font families ======} + \_begingroup + \_let\_famtext=\_wterm + \_def\_faminfo [##1]##2##3##4{% + \_wterm{ \_space\_noexpand\fontfam [##1] -- ##2}% + \_let\_famalias=\_famaliasA}% + \_opinput {fams-ini.opm} + \_isfile {fams-local.opm}\_iftrue \_opinput {fams-local.opm}\_fi + \_message{^^J}% + \_endgroup +} +\_def\_famaliasA{\_message{ \_space\_space\_space\_space -- alias:} + \_def\_famalias[##1]{\_message{[##1]}}\_famalias +} +\_public \fontfam ; + + \_doc ----------------------------- + When the `fams-ini.opm` or `fams-loca.opm` files are read then we need + to save ony a mapping from family names or alias names to the font family file + names. All other information is ignored in this case. But if these files + are read by the `\_listfamnames` macro or when printing a catalog then + more infrormation is used and printed.\nl + \`\_famtext` does nothing or prints the text on the terminal. + \nl + \`\_faminfo` `[<Family Name>] {<comments>} {<file-name>} {<mod-plus-vars>}` + does\nl `\_def \_famf:<familyname> {<file-name>}` or prints information on + the terminal. + \nl + \`\_famalias` `[<Family Alias>]` does `\def \_famf:<familyalias> {<file-name>}` + where `<file-name>` is stored from the previous `\_faminfo` command. Or + prints information on the terminal. + \_cod ----------------------------- + +\_def\_famtext #1{} +\_def\_faminfo [#1]#2#3#4{% + \_lowercase{\_edef\_tmp{\_ea\_removespaces #1 {} }}% + \_sdef{_famf:\_tmp}{#3}% + \_def\_famfile{#3}% +} +\_def\_famalias [#1]{% + \_lowercase{\_edef\_famname{\_ea\_removespaces #1 {} }}% + \_sdef{_famf:\_famname\_ea}\_ea{\_famfile}% +} +\_input fams-ini.opm +\_let\_famfile=\_undefined + + \_doc ----------------------------- + When the \^`\fontfam``[catalog]` is used then the file + `fonts-tatalog.opm` is read. The macro \^`\_faminfo` is redefined here + in order to print catalog samples of all declared modifiers/variant + pairs. The user can declare different samples and different behavior of + the catalog, see the end of catalog listing for more information. + The default parameters + \`\catalogsample`, \`\catalogmathsample`, \`\catalogonly` and + \`\catalogexclude` of the catalog are declared here. + \_cod ----------------------------- + +\_newtoks \_catalogsample +\_newtoks \_catalogmathsample +\_newtoks \_catalogonly +\_newtoks \_catalogexclude +\_catalogsample={ABCDabcd Qsty fi fl áéíóúüů řžč ÁÉÍÓÚ ŘŽČ 0123456789} + +\_public \catalogonly \catalogexclude \catalogsample \catalogmathsample ; + + \_doc ----------------------------- + The font features are managed in the \`\_fontfeatures` macro. + They have their implicit values saved in the \`\_defaultfontfeatures` + and the \`\setff` `{<features>}` + can add next font features. If there is the same font feature as the newly + added one then the old value is removed from the `\_fontfeatures` list. + \_cod ----------------------------- + +\_def \_defaultfontfeatures {+tlig;} +\_def \_setff #1{% + \_ifx^#1^\_let \_fontfeatures=\_defaultfontfeatures + \_else \_edef\_fontfeatures{\_fontfeatures #1;}\_fi + \_reloading +} +\_setff {} % default font features: +tlig; +\_def\_removefeature #1{% + \_isinlist\_fontfeatures{#1}\_iftrue + \_def\_tmp ##1#1##2;##3\_relax{\_def\_fontfeatures{##1##3}}% + \_ea \_tmp \_fontfeatures \_relax + \_fi +} +\_public \setff ; + + \_doc ----------------------------- + The \`\setfontcolor` and \`\setletterspace` are macros based on the + special font features provided by \LuaTeX/ (and by \XeTeX/ too but it is not + our business). The \`\setwordspace` recalulates the `\fontdimen2,3,4` + of the font using the \`\setwsp` macro which is used by the + \^`\_doresizeunifont` macro. It activates a dummy font feature `+Ws` too in + order the font is reloded by the `\font` primitive (with independent + `\fontdimen` registers). + \_cod ----------------------------- + +\_def\_savedfontcolor{} +\_def\_savedletterspace{} +\_def\_savedwsp{} + +\_def \_setfontcolor #1{\_removefeature{color=}% + \_edef\_tmp{\_calculatefontcolor{#1}}% + \_ifx\_tmp\_empty \_else \_edef\_fontfeatures{\_fontfeatures color=\_tmp;}\_fi + \_reloading +} +\_def \_setletterspace #1{\_removefeature{letterspace=}% + \_if^#1^\_else \_edef\_fontfeatures{\_fontfeatures letterspace=#1;}\_fi + \_reloading +} +\_def \_setwordspace #1{% + \_if^#1^\_def\_setwsp##1{}\_removefeature{+Ws}% + \_else \_def\_setwsp{\_setwspA{#1}}\_setff{+Ws}\_fi + \_reloading +} +\_def\_setwsp #1{} +\_def\_setwspA #1#2{\_fontdimen2#2=#1\_fontdimen2#2% + \_fontdimen3#2=#1\_fontdimen3#2\_fontdimen4#2=#1\_fontdimen4#2} + +\_def\_calculatefontcolor#1{\_trycs{_fc:#1}{#1}} % you can define more smart macro ... +\_sdef{_fc:red}{FF0000FF} \_sdef{_fc:green}{00FF00FF} \_sdef{_fc:blue}{0000FFFF} +\_sdef{_fc:yellow}{FFFF00FF} \_sdef{_fc:cyan}{00FFFFFF} \_sdef{_fc:magenta}{FF00FFFF} +\_sdef{_fc:white}{FFFFFFFF} \_sdef{_fc:grey}{00000080} \_sdef{_fc:lgrey}{00000025} +\_sdef{_fc:black}{} % ... you can declare more colors... + +\_public \setfontcolor \setletterspace \setwordspace ; + +\_endcode %--------------------------------------------------- + + +\sec[fontsystem] The Font Selection System +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +The basic principles of the Font Selection System used in \OpTeX/ +was documented in the section~\ref[fontfam]. + +\secc Terminology + +We distinguish between +\begitems +* {\em font switchers}, they are declared by the `\font` primitive or by + \^`\fontlet` or \^`\fontdef` macros, +* {\em variant selectors}, there are four basic variant selectors + `\rm`, `\bf`, `\it`, `\bi`, there is a special selector `\currvar` + and more variant selectors can be declared by the \^`\famvardef` macro. +* {\em font modifiers} (for example `\cond`, `\caps`, \^`\setfontsize``{<size spec>}`), + they are in two types: bulid in (like \^`\setfontsize`) or + declared modifiers (by by the \^`\moddef` macro). +* {\em family selectors} (for example `\Termes`, `\LMfonts`), + they are declared typically in the {\em font family files}. +\enditems + +These selectors / switchers sets its values locally. When the \TeX/ group is +leaved then selected font and the {\em font context} are returned back to the values +used when the group was opened. They have the following features: + +\begitems +* The {\em font switchers} select fonts independent on the font context. +* The {\em variant selectors} select the font depending on the font context and on + the specified variant. +* The {\em font modifiers} create a change in the font context but they + don't select the font itself. +* The {\em family selectors} set a family in the font context and resets all + font modifiers. They dont't select the font itself. +\enditems + +The variant selectors and declared font modifiers are +defined in the family context. They can behave differently in different +families. + +The fonts registered in \OpTeX/ have their macros in the {\em font family files}, +each family is declared in one font family file with the name `f-famname.opm`. +All families are collected in `fams-ini.opm` and user can give more +declarations in the file `fams-local.opm`. + +\secc Font families, selecting fonts + +The \^`\fontfam` `[<Font Family>]` opens the relevant font family file where +the `<Font Family>` is declared. The family selector is defined here by rules +described in the section~\ref[fontfamfiles]. Font modifiers and variant +selectors may be declared here. Their definitions depends on given family. +The family is set as active in the font context and `\rm` variant selector is run. + +The available declared font modifiers and declared variant selectors are +listed in the log file when font family is load. Or you can print +`\fontfam[catalog]` to show available font modifiers and variant selectors. + +The font modifiers can be independent, like `\cond` and `\light`. They can +be arbitrary combined (in arbitrary order) and if the font family disposes +with all such sub-variants then the desired font is selected (after variant +selector is used). On the other hand there are font modifiers which negates +the previous font modifier, for example `\cond`, `\extend`. You can reset +all modifiers to their initial value by the \^`\resetmod` command. + +You can open more font families by more \^`\fontfam` commands. Then the +general method to selecting the individual font is: + +\begtt \catcode`\<=13 +<family selector> <font modifiers> <variant selector> +\endtt +For example: +\begtt +\fontfam [Heros] % Heros family is active here, default \rm variant. +\fontfam [Termes] % Termes family is active here, default \rm variant. +{\Heros \caps \cond \it The caps+condensed italics in Heros family is here.} +The Termes roman is here. +\endtt + +There is one special command \^`\currvar` which acts as variant selector. +It keeps the current variant and the font of such variant is +reloaded with respect to the current font context by previously given family +selector and font modifiers. + +You can use the \^`\setfontsize` `{<sizespec>}` command in the same sense as +other font modifiers. It saves only information about font size to the font +context. See section~\ref[setfontsize]. Example: + +\begtt +\rm default size \setfontsize{at14pt}\rm here is 14pt size \it italic is +in 14pt size too \bf bold too. +\endtt + +Much more comfortable way to resize fonts is using OPmac-like command +`\typosize`, `\typoscale`. +These commands prepare the right sizes for math +fonts too and re-calculates many internal parameters like `\baselineskip`. +See section~\ref[opmac-fonts] for more information. + + +\secc Math Fonts +%--------------- + +Most font families are connected with a preferred Unicode-math font. This +Unicode-math is activated when the font family is loaded. If you don't prefer +this and you are satisfied with 8bit math CM+AMS fonts preloaded in the +\OpTeX/ format then you can use command \^`\noloadmath` before you load a first +font family. + +If you want to use your specially selected Unicode-math font then use +\^`\loadmath` `{[<font_file>]}` or \^`\loadmath` `{<font_name>}` before first +`\fontfam` is used. + + +\secc Declaring font commands +%---------------------------- + +The font switches can be declared by `\font` primitive or by \^`\fontdef` or +\^`\fontlet` macros. See the sections~\ref[fontdef] and~\ref[fontlet] +for more details. The general format for \^`\fontdef` is +\begtt \catcode`\<=13 +\fontdef\<font switch> {\<family selector> <font modifiers> \<variant selector>} +\endtt + +Such font switches should be used in `\output` routine (headers, footers) for +example. We need fixed sizes here. But they are less usable in common +text. For example the document includes notices in smaller font. +When the notice is started then we want +to do all variants smaller: `\rm`, `\it`, `\bf`, etc. +It means that the smaller font for notices should be initialized by +`\setfontsize{at9pt}\rm` for example. If you want a \"notices font selector" +then you can do `\def\noticefont{\setfontsize{at9pt}\rm}`. This font +selector does not change the `\baselineskip`. If you want to do this then +put different `\baselineskip` setting to your definition. But you must not +forget that the end of group before `\par` is a typical mistake of \TeX/ +users: the last paragraph is in smaller font but in normal baselineskip, +because `\baselineskip` setting is taken into account when `\par` +command is processed. + +Somewhat more complicated task is the \"title font selector", because titles are +not only bigger but they are typically in bold variant. When the user puts +`{\it...}` into the title then he/she expects bold italic here, no normal +italic. You can remember the great song by John Lennon \"Let It Be" and +define: + +\begtt +\def\titlefont{\setfontsize{at14pt}\bf \let\it\bi} +... +{\titlefont here we have bold 14pt font and {\it here} was bold 14pt italics} +\endtt + +You can declare a new variant slector by the \^`\famvardef` macro. This +macro has similar syntax as \^`\fontdef`: +\begtt \catcode`\<=13 +\famvardef\<new variant selector> {<font modifiers> \<variant selector>} +\endtt +% +The `\<new variant selector>` should be used in the same sense as `\rm`, +`\bf` etc. It can be used as the final command in the +`\fontdef` or `\famvardef` declarators +too. When the `\<new variant selector>` is used in normal text then it does +following steps: pushes current font context to a stack, modifies font +context by declared `<font modifiers>`, runs following `\<variant selector>`. +It selects a font. Then pops the stack. The font context have its original +values but new font is selected. + +The \^`\famvardef` creates the `\<new variant selector>` family dependent. +When the selector is used in another family than it is defined then warning is +printed on the terminal \"<var selector> is undeclared in current family" +and nothing happens. But you can declare the same variant selector by +\^`\famvardef` macro in the context of new family. Then the same command +will be do different work depending on the current font family. + +Suppose that the selected font family provides the font modifier `\medium` for +mediate weight of fonts but supports only basic variant selectors `\rm`, `\bf`, `\it`, +and `\bi`. Then you can declare: +\begtt +\famvardef \mr {\medium\rm} +\famvardef \mi {\medium\it} +\endtt +Now, you can use six independent variant selectors `\rm`, `\bf`, `\it`, +`\bi`, `\mr` and `\mi` in the selected font family. + +A `\<family selector>` can be written before `<font modifiers>` in the +`\famvardef` parameter. Then the `\<new variant selector>` is declared in +the current family but it can use fonts from another family represented by +the `\<family selector>`. + +When you are mixing fonts from more families then you probably run +into problem with incompatible ex-heights. This problem can be solved using +\^`\setfontsize` and \^`\famvardef` macros: +\begtt +\fontfam[Heros] \fontfam[Termes] + +\def\exhcorr{\setfontsize{mag.88}} +\famvardef\rmsans{\Heros\exhcorr\rm} +\famvardef\itsans{\Heros\exhcorr\it} + +Compare ex-height of Termes \rmsans with Heros \rm and Termes. +\endtt + +There exists analogical declarator `\moddef` for declaration family dependent +font modifiers. It is described in detail the section~\ref[fontfamfiles]. + + +\secc Modifying font features +%---------------------------- + +Each OTF font provides \"font features". You can list these font features +by `otfinfo -f font.otf`. For example LinLibertine fonts provide `frac` font +feature. If it is active then fractions like 1/2 are printed in a special +form. + +The font features are part of the font context data. +The macro \^`\setff` `{<feature>}` acts like family independent font modifier and +prepares a new <feature>. You must use a variant selector in order to +reinitialize the font with the new font feature. For example +\^`\setff``{+frac}\rm` or \^`\setff``{+frac}`\^`\currvar`. You can declare a new variant +selector too: + +\begtt + \fontfam[LinLibertine] + \famvardef \fraclig {\setff{+frac}\currvar} + Compare 1/2 or 1/10 \fraclig to 1/2 or 1/10. +\endtt + +If the used font does not supports given font feature then font is realoaded +without warning nor error, silently. The font feature is not activated. + +The `onum` font feature (old style digits) is connected to `\caps` macro for +Caps+SmallCaps variant in \OpTeX/ font family files. So you need not to +create a new modifier, just use `{\caps`\^`\currvar`` 012345}`. + + +\secc Special font modifiers +%--------------------------- + +Despite the font modifiers declared in the font family file (and dependent on +the font family), we have following font modifiers (independent of font +family): + +\begtt \catcode`\<=13 +\setfontsize{<sizespec>} % sets the font size +\setff{<font feature>} % adds the font feature +\setfontcolor{<color>} % sets font color +\setletterspace{<number>} % sets letter spacing +\setwordspace{<scaling>} % modifies word spacing +\endtt + +The \^`\setfontsize` command is described in the section \ref[setfontsize]. +The \^`\setff` command was described in previous subsection. + +\^`\setfontcolor` `{<color>}` specifies the color and the opacity of the text. +The <color> parameter should be in hexadecimal format of four bytes +`<red><green><blue><opacity>`, for example `FF0080FF` means full red, zero +green, half blue and full opacity. You can use names `red`, `green`, `blue`, +`yellow`, `cyan`, `magenta`, `white`, `grey`, `lgrey` (without backslash) +instead of the hexadecimal specification. +The empty parameter `<color>` means default black color. + +That colors of fonts are implemented using \LuaTeX/ internal font feature. This +is different approach than using colors in section \ref[colors]. + +\^`\setletterspace` `{<number>}` specifies letter spacing of the font. The +`<number>` is decimal number without unit. The unit is supposed as 1/100 of +the font size. I.e. `2.5` means 0.25 pt when the font is at 10 pt size. The +empty parameter `<number>` means no letter spacing which is default. + +\^`\setwordspace` `{<scaling>}` scales the default inter word space (defined in the +font) and its stretching and shrinking parameters by given `<scaling>` +factor. For example `\setwordspace{2.5}` multiplies inter word space by 2.5. + +If you need another font transformations, you can use `\setff` +with following font features provided by Lua\TeX/: + +\begtt +\setff{embolden=1.5}\rm % font is bolder because outline has nonzero width +\setff{slant=0.2}\rm % font is slanted by a linear transformation +\setff{extend=1.2}\rm % font is extended by a linear transformation. +\setff{colr=yes}\rm % if the font includes colored characters, use colors +\endtt + +Use font transformations mentioned above and \^`\setletterspace`, +\^`\setwordspace` with care. The best setting of these values is default +setting in every font, of course. If you really needs to set a different +letter spacing then it is strongly recommended to add `\setff{-liga}` in +order to disable ligatures. And setting a positive letter spacing probably +needs to scale inter word spacing too. + +All mentioned font modifiers (with the exception of `\setfontsize`) work only +with Unicode fonts loaded by \^`\fontfam`. + +\secc[fontfamfiles] How to create the font family file +%------------------------------------------------------ + +\printdoctail f-heros.opm + +\printdoctail f-lmfonts.opm + +\secc How to register the font family in the Font Selection System +%--------------------------------------------------------------- + +\printdoctail fams-ini.opm + +\endinput + +2020-04-18 \_tryloadfamslocal introduced + \_fontdecl -> \_famdecl with different concept +2020-03-18 released |