diff options
| author | Karl Berry <karl@freefriends.org> | 2021-05-13 21:53:18 +0000 |
|---|---|---|
| committer | Karl Berry <karl@freefriends.org> | 2021-05-13 21:53:18 +0000 |
| commit | 129370be960081d981db1fcafa1537482ff69c7e (patch) | |
| tree | e29775d3a4e2078f68e6a231b2611104f0bd95d9 /Master/texmf-dist/tex/optex/pdfextra | |
| parent | d709a52d36c0cd28bbe9e0805da7786c840b324a (diff) | |
optex/pdfextra
git-svn-id: svn://tug.org/texlive/trunk@59188 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/tex/optex/pdfextra')
| -rw-r--r-- | Master/texmf-dist/tex/optex/pdfextra/pdfextra.opm | 1702 |
1 files changed, 1702 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/optex/pdfextra/pdfextra.opm b/Master/texmf-dist/tex/optex/pdfextra/pdfextra.opm new file mode 100644 index 00000000000..b7cf70a981e --- /dev/null +++ b/Master/texmf-dist/tex/optex/pdfextra/pdfextra.opm @@ -0,0 +1,1702 @@ +% vim: tw=80 +\_def\_pdfextra_version{0.1} +\_codedecl \RM {Extra PDF features (v\_pdfextra_version)} + \_doc + \sec Package initialization + + We are in the \OpTeX/ package namespace. A couple of shortcuts are defined + here: \`\.isdefined`, \`\.trycs`, \`\.cs` \`\.slet`, \`\.slet`, \`\.sdef` and + \`\.xdef`. They all hard code the package name, because we already have too + many levels of indirection. + \_cod + +\_namespace{pdfextra} + +\_def\.isdefined#1{\_isdefined{_pdfextra_#1}} +\_def\.trycs#1{\_trycs{_pdfextra_#1}} +\_def\.cs#1{\_cs{_pdfextra_#1}} +\_def\.slet#1#2{\_slet{_pdfextra_#1}{_pdfextra_#2}} +\_def\.sdef#1{\_sdef{_pdfextra_#1}} +\_def\.sxdef#1{\_sxdef{_pdfextra_#1}} + + \_doc + \sec Helper macros + The macros here are just helpers for the macros to follow. They are not + useful generally, but proved useful in the expandable context of writing to + PDF files. + + Already the first one limits the use to \LuaTeX/ (but who needs other engines + anyways :). \`\.emptyor`<possibly empty text><text to use when first argument is + nonempty> checks whether the first argument is empty, if not it expands the + second argument which can use the text from the first argument with + \`\.nonempty`. \`\.attrorempty`<attribute name><value> builds upon the first + one and is really useful for PDF dictionaries, when we don't want to write an + attribute without a value (a default specified by standard will be used instead). + \_cod + +\_def\.emptyor#1#2{% + \_immediateassignment\_edef\.nonempty{#1}% + \_ifx\.nonempty\_empty\_else #2\_fi +} +\_def\.attrorempty#1#2{\.emptyor{#2}{/#1 \.nonempty}} + + \_doc + There is a dillema for handling colors. While typesetting it is possible to + use greyscale, CMYK or RGB colors. But there are contexts where it is + possible to only use RGB colors. We want to provide the user with two + possibilities of specifying colors: + + \begitems + * RGB color using PDF triplet (e.g. `1 0 0`), + * \OpTeX/ color using control sequence (e.g. `\Blue`) + \enditems + + Both are handled by \`\.colortorgbdef`<cs><color specification>, which + defines <cs> to the corresponding PDF RGB triplet. The indirection with + defining a macro is because we want to use the processed color within + expansion only contexts where grouping is not possible. + \_cod + +\_def\.colortorgbdef#1#2{\_bgroup + \_def\_setrgbcolor##1{##1}% + \_def\_setcmykcolor##1{\_cmyktorgb ##1 ;}% + \_def\_setgreycolor##1{##1 ##1 ##1}% + \_xdef#1{#2}% + \_egroup +} + + \_doc + \`\.xaddto``\macro`{<text>} is a natural extension of \OpTeX's `\addto` that + expands <text> and is global. + \_cod + +\_def\.xaddto#1#2{\_edef\.tmp{#2}% + \_global\_ea\_addto\_ea#1\_ea{\.tmp}% +} + + \_doc + This package defines a few commands in the form + `\macro[<name>][<optional arguments>]{<text>}`. To make it possible to omit + the `[<optional arguments>]` \`\.secondoptdef` is defined. + + `\.secondoptdef\<macro><parameters>{<body>}` + defines `\macro` with first mandatory argument in brackets (saved to + \`\.name`). Second optional argument in brackets is scanned using helper + macro defined with `\optdef` and is saved to `\_opt` token list). Additional + <parameters> can be specified as with `\optdef` (numbered from `#1`). + \_cod + +\_def\.secondoptdef#1{% + \_def#1[##1]{\_def\.name{##1}\.cs{sopt:\_string#1}}% + \_ea\_optdef\_csname _pdfextra_sopt:\_string#1\_endcsname[]% +} + + \_doc + When processing comma separated lists sometimes it is needed to ignore the + remaining text. For this we use \`\.untilend` macro which ignores everything + up to dummy \`\.end`. This is analogous to \OpTeX/'s `\_finbody` used for the + same purpose. Sometimes `\.end` is used as sentinel and compared in `\ifx` + tests, hence we define it to a unique value. + \_cod + +\_def\.untilend#1\.end{} +\_def\.end{_pdfextra_end} + + \_doc + For various uses it is necessary to know the number of page where something + happens. This has to be handled asynchronously with `\write`. Here we use + \OpTeX/ specific `.ref` file and associated macros, but this could be + replaced as long as the same interface is exposed. + + \`\.setpageof`<name> writes \`\.Xpageof`<name> to the `.ref` file. In the next + \TeX/ run `\.Xpageof` finds out the page number (`\gpageno`) from \OpTeX/'s + `\_currpage` and saves it so that \`\.pageof`<name> can retrieve it. In the + first run we can't be sure of the page where the content will end up. As a + rough estimate we take the current page~-- this actually works well for + slides where page breaks are manual. + + `\.pageof` is expandable, but we want to let the user know, that the document + needs to be processed twice. Therefore we use \LuaTeX's + `\immediateassignment` to increment the counter of unresolved references. + + When `.ref` file is read along with the defintion of `\.Xpageof` this package + has not been loaded yet. Hence we can't use namespaced variants of + `\.isdefined`, etc. + \_cod + +\_refdecl{% + \_def\.Xpageof#1{\_isdefined{_pdfextra_pageof:#1}\_iffalse + \_sxdef{_pdfextra_pageof:#1}{\_ea\_ignoresecond\_currpage}\_fi + }% +} + +\_def\.setpageof#1{\_openref \_ewref\.Xpageof{{#1}}} + +\_def\.pageof#1{% + \.trycs{pageof:#1}{% + \_immediateassignment\_incr\_unresolvedrefs + \_the\_numexpr\_gpageno+1\_relax % best effort = current page num + }% +} + + \_doc + \label[files] + \sec Handling of files + + Handling of files is a big topic of this package. Files are everywhere~-- + files containing multimedia, JavaScript script files, attachments, externally + referred files\dots Therefore a more sophisticated mechanism for handling + files is needed. The mechanism introduced in this section handles all three + cases of a {\em file specification}: + + \begitems + * files embedded in the PDF (\"e", embedded file), + * files determined by path (\"x", external file), + * files determined by URL (\"u", url file). + \enditems + + Although ideally all three would be interchangible this is not always the + case, because e.g. some media files must be embedded and linking to external + resources does not work with embedded files. + + In most cases there are two many names and other associated values involved: + \begitems + * Some kind of a \"friendly" name. This one is sometimes shown by PDF viewers. + * The real name of the file. Also shown but in different contexts. + * The path or URL used to determine the file. + * MIME type of the file. + \enditems + + For example when talking about \OpTeX/'s documentation we might have a + friendly name of \"opdoc", file name of \"`optex-doc.pdf`", URL of + \"\url{http://petr.olsak.net/ftp/olsak/optex/optex-doc.pdf}" and MIME type of + \"application/pdf". Different subset of them is required in different + contexts, but the user should only have to specify the friendly name (by + which they will refer to the file) and the path/URL of the file. The rest + will be deduced. The friendly name is used as a handle and {\em is usable} + in all places where file specification is required (although it may not + produce conforming output, see above). + + In this two step process~-- definition and (re)use~-- we introduce a command + for defining files: \`\filedef``/<type> [<friendly name>]{<path or URL>}`. The + macro itself does general definitions and dispatches the type dependant work + to other macros in the form `_filedef:<type>`. + \_cod + +\_def\.filedef/#1#2[#3]#4{% + \.sxdef{filename:#3}{(\.filename{#4})}% + \_edef\.tmp{\.exttomime{\.fileext{#4}}}% + \_ifx\.tmp\_empty + \_opwarning{MIME type of '#4' unknown, using '\.defaultmimetype'}% + \_edef\.tmp{\.defaultmimetype}% + \_fi + \.sxdef{filemime:#3}{\.tmp}% + \.cs{filedef:#1}{#3}{#4}% +} +\_nspublic \filedef ; + + \_doc + Types \"e", \"x", \"u" are predefined, anything else would essentialy be a + variant of these. + + External file (\"x") is determined only by path. + \_cod + +\.sdef{filedef:x}#1#2{% + \.slet{filespec:#1}{filename:#1}% +} + + \_doc + URL file (\"u") is determined by URL. Using all sorts of characters is + allowed by using `\_detokenize`. This time it is necessary to create full + {\em file specification}~-- a dictionary, where the \"file system" is URL. + \_cod + +\.sdef{filedef:u}#1#2{% + \.sdef{filespec:#1}{<</FS /URL /F (\_detokenize{#2})>>}% +} + + \_doc + Embedded files (\"e") are the most interesting ones. For further use (e.g. + for displaying the embedded files as attachments) MIME type is required. It + is saved in the stream as a `\Subtype`, encoded as a PDF name (e.g. + `/video#2Fmp4`). The embedded file stream must be wrapped in a full {\em file + specification}, which has the `/EF` (\"embedded file") entry. Also the + friendly name is used for some purpose by PDF viewers, so it set in `/Desc` + (description). + \_cod + +\.sdef{filedef:e}#1#2{% + \_edef\.tmp{\.cs{filemime:#1}}% + \_isfile{#2}\_iffalse + \_opwarning{file '#2' not found}% + \_fi + \_pdfobj stream + attr{/Type /EmbeddedFile /Subtype \_ea\.mimetoname\_ea[\.tmp]} + file {#2}% + \_pdfrefobj\_pdflastobj + \.sxdef{filestream:#1}{\_the\_pdflastobj\_space 0 R}% + \_pdfobj {<</Type /Filespec + /F \.cs{filename:#1} + /Desc (#1) + /EF << /F \_the\_pdflastobj \_space 0 R >>% + >>}% + \_pdfrefobj\_pdflastobj + \.sxdef{filespec:#1}{\_the\_pdflastobj\_space 0 R}% +} + + \_doc + Now the less interesting part~-- determining the file names from paths and + determining MIME types. The file name is the part after the last \"`/`" (if + any). The file extension is the part after last \"`.`" (if any). + \_cod + +\_def\.filename#1{\_ea\.filenameA#1/\.end} +\_def\.filenameA#1/#2{\_ifx\.end#2#1\_else\_afterfi{\.filenameA#2}\_fi} + +\_def\.fileext#1{\_ea\.fileextA#1.\.end} +\_def\.fileextA#1.#2{\_ifx\.end#2#1\_else\_afterfi{\.fileextA#2}\_fi} + + \_doc + MIME type is determined from file extension (e.g. `mp4` is \"video/mp4"). For + mapping of file extensions to MIME types we abuse \TeX/'s hash table which + gets populated with \"known MIME types". This necessarily means that the + database is incomplete. Users can define their own additional mappings, or + they can contribute generally useful ones to this package. + + The default MIME type (used for unknown file extensions) is + \"application/octet-stream"~-- binary data. + + The uninteresting MIME type database itself is at the very end (\ref[mime]). + \_cod + +\_def\.mimetoname[#1/#2]{/#1\_csstring\#2F#2} + +\_def\.defaultmimetype{application/octet-stream} +\_def\.exttomime#1{\.trycs{mimetype:#1}{}} + + \_doc + Here we define an \OpTeX/ style \"is-macro" that checks whether the file has + already been defined~-- \`\.isfiledefined``{<name>}\iftrue` (or `\iffalse`). + The case where the file has not + been defined using `\filedef` can be handled in a lot of ways. As a default + we interpret <name> as path and try to embed it. Because the path from <name> + is used as the \"friendly name" the file will be embedded only once even when + requested more times. + \_cod + +\_def\.isfiledefined#1#2{\.isdefined{filespec:#1}\_iftrue\_else + \_afterfi{\.fileundefined{#1}}\_fi#2% +} + +\_def\.fileundefined#1{\_isfile{#1}\_iftrue\.filedef/e[#1]{#1}\_else + \_opwarning{file '#1' not found, ignored}\_ea\_unless\_fi +} + +% strict requirement of preceeding `\filedef` can be set like this: +%\_def\.fileundefined#1{\_opwarning{file '#1' is not defined, ignored}\_unless} + + \_doc + \label[actions] + \sec PDF actions + + The core of interactivity in PDF are actions. They are all initialy handled + by \`\pdfaction``[<action spec>]`. <action spec> is a comma separated list of + `<type>:<arguments>`. Leading spaces in the elements of the list are ignored + using undelimited-delimited argument pair trick. + + An invocation could look like this: + + \begtt + \pdfaction[ + js:{app.alert("Yay JavaScript, going to page 5");}, + ilink:pg:5, + transition:Wipe, + ] + \endtt + + This is why we have to be very careful when loading the contents between `[]` + to arguments. In particular, we can't split immediatly using `[#1:#2]`, + because this would discard the braces guarding the comma in the JavaScript + code. However we also need to find out the {\em type} of action which is + taken as a type of the first action (`js` in this case). + \`\.pdfactiontype``[<action spec>]` does this~-- we don't mind that there the + braces are lost. + + `\pdfaction` processes the list, to create a chain of actions using `/Next` + field. The handling of each action type is up to macro + `\_pdfextra_<type>action`, which receives `[<type>:<arguments>]`. Because of + this a single type handler can handle multiple different actions, as is the + case with `\.ilinkaction` which is the fallback for unknown action types. + \_cod + +\_def\.pdfaction[#1#2]{\.pdfactionA#1#2,\.stop\.end} +\_def\.pdfactionA#1,#2#3\.end{% + <<% + \.pdfactionB[#1]% + % next action + \_ifx\.stop#3\_else\_space + /Next \_afterfi{\.pdfactionA#2#3\.end} % intentional space + \_fi + >> +} +\_def\.pdfactionB[#1:#2]{\.trycs{#1action}{\_ea\.ilinkaction}[#1:#2]} +\_nspublic \pdfaction ; + +\_def\.pdfactiontype[#1:#2]{#1} + + \_doc + \label[actions-additional] + \secc Additional actions + Some PDF objects, like pages and some annotations, can also have \"additional + actions". These are actions which will be executed when an event happens~-- + like page getting opened for `/O` action in page's additonal actions or `/PO` + in annotation's additional actions. For constructing these additional actions + we define a helper macro \`\.pdfaactions`. The use is as something follows: + \begtt \catcode`<=13 \adef|{\csstring<} + /AA || \.pdfaactions{ {O} {<action spec 1>} {C} {<action spec 2>} } >> + \endtt + To produce something this: + \begtt \catcode`<=13 \adef|{\csstring<} + /AA || /O ||<action 1>>> /C ||<action 2>>> >> + \endtt + \_cod + +\_def\.pdfaactions#1{<<\.pdfaactionsA #1\.end\.end>>} +\_def\.pdfaactionsA#1#2{\_ifx\.end#1\_else /#1 \_ea\.pdfaction\_ea[#2]\_ea\.pdfaactionsA\_fi} + + \_doc + \label[actions-link] + \secc Link annotations + The main use of actions~-- annotations of `/Subtype /Link`. + Annotation of this type creates an active rectangular area on the page that + executes a PDF action (or chain of them in the general case). + \`\hlinkactive``[<action spec>]<text>` is a natural extension of \OpTeX/'s + `\linkactive`, that supports the classic \"jump" actions of types `ref`, + `bib`, etc. But also other types of actions. No distinction between + \"internal" (`\ilink`) and external (`\ulink`) links is made. The mechanism is + completely generic. + + The `\pdfstartlink`/`\pdfendlink` primitives are used to denote the part of + the page where <text> appears as active. \LuaTeX/ will then handle even the + situations where <text> gets broken across multiple lines (by creating + multiple rectangular annotations to cover all `\hbox`es). + \_cod + +\_def\.hlinkactive[#1]#2{\_bgroup\_def\#{\_csstring\#}% + \_edef\.type{\.pdfactiontype[#1]}% + \_quitvmode\_pdfstartlink \.linkdimens + attr{\_pdfborder{\.type}}% + user{/Subtype /Link /A \.pdfaction[#1]}\_relax + \_localcolor\.linkcolor{\.type}#2\_pdfendlink\_egroup +} + + \_doc + `\hlinkactive` itself is dormant before `\hyperlinks` occurs. Until then, a + dummy \`\hlink` is used. \OpTeX/'s `\hyperlinks` is extended to hook `\hlink` + activation. The colors of internal/external links are remembered for + compatibility with \OpTeX/. + \_cod + +\_def\.hlink[#1]#2{\_quitvmode{#2}} +\_nspublic \hlink ; + +\_let\.oldhyperlinks\_hyperlinks +\_def\_hyperlinks#1#2{% + \.oldhyperlinks#1#2 + \_let\.ilinkcolor=#1% + \_let\.elinkcolor=#2% + \_let\.hlink=\.hlinkactive + \_let\hlink=\.hlink +} +\_public \hyperlinks ; + + \_doc + Two customizations of `\hlinks` are possible: + \begitems + * Dimensions of rectangular areas created by + `\pdfstartlink`/`\pdfendlink`. This is done using \`\.linkdimens` + (analogous to \OpTeX's `\linkdimens`). Dimensions that are unset are taken + from the respective `\hbox`es. \`\lininglinks` sets the dimensions for + running text~-- it covers all space of a line using `\baselineskip`. + \`\nolininglinks` sets no dimensions, this is useful for buttons, that may + have larger height/depth than a line. + * The color is determined from the type of link (that is the first action in + <action spec>) by checking `\_<type>linkcolor` (compatible with \OpTeX/) or + `\_pdfextra_<type>linkcolor`. + As a fallback \`\.ilinkcolor` is used (set by `\hyperlinks`). + \enditems + \_cod + +\_def\.lininglinks{% + \_def\.linkdimens{height.75\_baselineskip depth.25\_baselineskip}% +} +\_def\.nolininglinks{\_def\.linkdimens{}} +\.lininglinks + +\_nspublic \lininglinks \nolininglinks ; + +\_def\.linkcolor#1{\_trycs{_#1linkcolor}{\.trycs{#1linkcolor}{\.ilinkcolor}}} +\_def\.ilinkcolor{} + + \_doc + \secc Open action + The document itself has one action defined in the document catalog. It is + called `/OpenAction`. We allow the user to set it using the familiar + <action spec> syntax with the command \`\openaction``[<action spec>]`. + + Internally we could directly set it by appending to the catalog + using the primitive `\pdfcatalog`, but \LuaTeX/ (pdf\TeX/ really) allows + setting the action with special syntax. This has the benefit that it is not + allowed to set the action more than once. + \_cod + +\_def\.openaction[#1]{\_pdfcatalog{} openaction user{\.pdfaction[#1]}\_relax} +\_nspublic \openaction ; + + \_doc + \label[actions-jump] + \secc Jump actions + + These are the most typical actions. Even \LuaTeX/ itself handles them, + although we don't use the possibility for maintaining generality. There are a + few types of jump actions: + \begitems + * `/GoTo` actions are the classic internal links to named destinations in the + PDF file (created by `\pdfdest` primitive or \OpTeX/'s `\dest`). The + destination names include also the type of internal link (e.g. + `ref:section1`). They are handled by \`\.ilinkaction``[<type>:<name>]`. + * `/URI` actions which are in most cases used as \"goto URL" actions. These + are not that useful directly, because special characters should be handled + before this actions is used (like with `\url`). The low level use is + \`\.urlaction``[url:<url>]`. + * \"Goto remote" actions, which can jump to a destination in another PDF file~-- + either determined by name, or by page number. The external files are + expected to be defined by `\filedef` (but not the embedded variant). The + use is either \`\.extrefaction``[extref:<name>:<named destination>]` for + links to named destination or \`\.extpgrefaction``[extpgref:<name>:<page number>]` + for page destinations. Customization is possible with \`\.extrefextra`, by + default opening in a new windows is requested. + \enditems + \_cod + +\_def\.ilinkaction[#1:#2]{/S /GoTo /D (#1:#2)} + +\_def\.urlaction[#1:#2]{/S /URI /URI (#2)} + +\_def\.extrefaction[#1:#2:#3]{/S /GoToR + /F \.cs{filespec:#2} + /D (#3) + \.extrefextra +} +\_def\.extpgrefaction[#1:#2:#3]{/S /GoToR + /F \.cs{filespec:#2} + /D [\_the\_numexpr#3-1\_relax\_space /Fit] + \.extrefextra +} + +\_def\.extrefextra{/NewWindow true} + + + \_doc + Transition action is not really a jump action in of itself, but is only + useful when chained after jump actions, so we define it here. Transitions + (as page attributes) are handled more thoroughly in section~\ref[transitions]. + + The use would look something like:\nl + \`\.transitionaction`% + `[transition:<animation type>:<duration>:<raw PDF attributes>]`, where all fields + omitted from right take the default values. + \_cod + +\_def\.transitionaction[#1:#2]{/S /Trans \.attrorempty{Trans}{\.maketrans[#2]}} + + \_doc + \secc Named actions + + User can request arbitrary \"named" action with + \`\.namedaction``[named:<name>]`. See user documentation for details. + \_cod + +\_def\.namedaction[#1:#2]{/S /Named /N /#2} + + \_doc + \secc JavaScript actions + + JavaScript actions have two forms, either \`\.jsaction``[js:<name>]` or + `\.jsaction``[js:<script>]`. The first variant uses contents of `\filedef`'d + <name>, the second one uses <script> directly. There is no special catcode + handling. + + \_cod + +\_def\.jsaction[#1:#2]{/S /JavaScript + /JS \_ifcsname _pdfextra_filestream:#2\_endcsname \_lastnamedcs \_else + (#2) + \_fi +} + + \_doc + \sec Page attributes + + PDF represents pages as dictionaries. The dictionaries get generated by \LuaTeX/, + which fills in some attributes {\em attributes} (like `/Content` with + contents of the page and `/Annots` with array of annotations). We can add + more using `\pdfpageattr` primitive token list register. While not that many + are generally useful, there are a few interesting ones. For example + transitions can be set using page attributes, or we might want to set + additional actions (`/AA`) to listen for page events. + + While the so called \"page objects" are in a tree structure (for fast lookup), + only the leaves are real \"pages". PDF allows some attributes to be inherited + from parent page objects, but not all of them and certainly not those we are + interested in. + + The mechanism introduced in this section is optional, because it takes + complete control over `\pdfpageattr`. It gets activated when + \`\initpageattributes` is first used (which happens automatically for some + functionality exposed by this package), but may be activated by the user for + any other purpose. Only attributes listed in \`\pageattributes` are + processed. + + We set the attributes anew for each page, by hooking into \OpTeX/'s + `\_begoutput`. Because `\pdfpageattr` token list doesn't get expanded before + written out to PDF, we expand it using the assignment in `\edef` trick. The + token list gets expanded, but the assignment is not made until it reaches + main processor when the temporary control sequence gets expanded. + \_cod + +% pdfpagattr managament (default for all pages vs current page override) +\_def\.pageattributes{{Trans}{Dur}{Rotate}{AA}} +\_def\.initpageattributes{% + % add hook for setting primitive \pdfpageattr + \_addto\_begoutput{\_edef\.tmp{\_pdfpageattr={\.pdfpageattributes}}\.tmp}% + % no need to do this twice + \_let\.initpageattributes=\_relax +} +\_nspublic \pageattributes \initpageattributes ; + + \_doc + The user interface we want to expose has two parts: + \begitems + * setting the page attribute for just this one page (\`\.pdfcurrentpageattr`), + * setting the default attribute (used when current page value is not set) + (\`\.pdfdefaultpageattr`). + \enditems + + The first one of course brings in the typical \TeX/ problem of knowing the + page where something occurs. As always, the page number contained in + `\gpageno` during processing of said content may of course not actually be + the number of the page where the content ends up! Hence, we need to note the + page number with a delayed write, using `\.setpageof` and later `\.pageof`. + The different settings of page attributes should have distinct names, we use + the \`\.pageattrcount` counter for this. + \_cod + +\_newcount\.pageattrcount +\_def\.pdfcurrentpageattr#1#2{\.initpageattributes + \_incr\.pageattrcount + \.setpageof{pageattr:\_the\.pageattrcount}% + \.sxdef{pdfpgattr:\.pageof{pageattr:\_the\.pageattrcount}:#1}{#2}% +} +\_def\.pdfdefaultpageattr#1#2{\.initpageattributes + \.sxdef{pdfpgattr:#1}{#2}% +} + + \_doc + Finally, the macro \`\pdfpageattributes` takes care of setting generating the + contents of `\pdfpageattr`. For each attribute in `\pageattributes` it first + checks its current page value, only then the default value. If neither is + set, nothing is added. + \_cod + +\_def\.pdfpageattributes{\_ea\.pdfpageattributesA\.pageattributes\.end} +\_def\.pdfpageattributesA#1{\_ifx\.end#1\_else + % use current page override or "default" + % don't emit anything if the value is empty + \.attrorempty{#1}{% + \.trycs{pdfpgattr:\_the\_gpageno:#1}{\.trycs{pdfpgattr:#1}{}}% + }% + \_ea\.pdfpageattributesA\_fi +} + + \_doc + Each attributes then has two switches for the respective default and current + values. For defining a few of them a helper is introduced:\nl\indent + \`\.pdfpageattributesetters`` <attribute> \<default setter> \<current setter> {<value>}`, + \nl + where <attribute> is name of the attribute without the slash + (e.g. `MediaBox`), the two control sequences name the future user setters, + which will take single argument in brackets + (e.g. `\mediabox` and `\thismediabox`) and the <value> can use the + argument. + \_cod + +\_def\.pdfpageattributesetters#1 #2#3#4{% + \.sdef{\_csstring#2}[##1]{\.pdfdefaultpageattr{#1}{#4}}% + \.sdef{\_csstring#3}[##1]{\.pdfcurrentpageattr{#1}{#4}}% + \_nspublic #2 #3 ; +} + + \_doc + Some of the useful attributes are `/Rotate`, which rotates the pages visually + (can be set with \`\defaultpagerotate` and \`\pagerotate`), and the additional + actions (`/AA`, see section~\ref[actions-additional], set using + \`\defaultpageactions` \`\pageactions`). + \_cod + +\.pdfpageattributesetters Rotate \defaultpagerotate \pagerotate {#1} + +\.pdfpageattributesetters AA \defaultpageactions \pageactions {\.pdfaactions{#1}} + + \_doc + \label[transitions] + \secc Transitions, page durations + + There are predefined types of transitions, like `/Wipe`, `/Box`, `/Split`, + etc. Most have other customizible attributes~-- usually directions set in + different ways depending on the animation type at hand, but the most + important attribute is the duration of the animation. Parsing friendly user + notation in the form of + `[<animation type>:<duration>:<other raw attributes>]`, where fields from the + right may be omitted to produce the default value, is handled by + \`\.maketrans`. This macro is also used by transition actions + (see~\ref[actions-jump]). The defaults are simply those defined by PDF + standard (no transition, 1 second duration and the respective default + directions). + \_cod + +\_def\.maketrans[#1]{\.maketransA#1:::\.end} +\_def\.maketransA#1:#2:#3:#4\.end{% + \.emptyor{#1}{<</S /\.nonempty \.attrorempty{D}{#2} #3>>} +} + + \_doc + The attribute setters for transitions (\`\transitions`, \`\transition`) are a + simple wrappers. Similiar is the + setting of page duration in seconds after which PDF viewer automatically + advances to the next page (\`\defaultpageduration`, \`\pageduration`). + \_cod + +\.pdfpageattributesetters Trans \transitions \transition {\.maketrans[#1]} + +\.pdfpageattributesetters Dur \defaultpageduration \pageduration {#1} + + \_doc + \sec Attachments and document level JavaScript + + These don't have any last place to be in, so they are documented separately, + here. Attaching files using `/FileAttachment` annotations: + \begitems \style n + * is intended more towards viewers of the document for extra additions and + * doesn't work in the viewers as well as one would like. + \enditems + + That is why instead embed files using normal `\filedef` and then allow them + to be added to the document level `/EmbeddedFiles` entry, which means they + will be shown in the user interface by PDF viewers. `/EmbeddedFiles` is a + document level name tree (contained inside `/Names` entry of `/Catalog`) that + maps names of files to their objects. Although we simplify matters by + constructing more of an array. + + What works very similiarly is document level JavaScript. It is a name tree + within `/JavaScript` field. It maps names of JavaScript actions to their + object numbers. The names aren't very useful, but the actions have their + purpose. They are executed in turn after the document is opened. Hence they + can be used to predefine JavaScript functions in the global context, to be + used later within actions explicitly activated by the user. + + The user level commands are \`\attach``[<name>]` (to attach a previously + `\filedef`'d name with fallback to embedding now if it is a valid path) and + \`\dljavascript``[<name>]{<script>}` (adds action that executes <script> + after document is opened, <name> is more or less meaningless). + + Internally both commands construct lists of what ends up in the resulting name + array, i.e. pairs {\visiblesp `(<name>) <object number> 0 R `}. Intermediate + macros \`\.embeddedfiles` and \`\.dljavascripts` are used for this. + + In the case of file attachments, nothing happens if file is defined and not + found by the fallback. + + \_cod + +% file attachment +\_def\.embeddedfiles{} +\_def\.attach[#1]{\.isfiledefined{\.name}\_iftrue + \.xaddto\.embeddedfiles{(#1) \.cs{filespec:#1} }\_fi +} +\_nspublic \attach ; + +\_def\.dljavascripts{} +\_def\.dljavascript[#1]#2{% + \_immediate\_pdfobj{<< \.jsaction[js:{#2}] >>}% + \.xaddto\.dljavascripts{(#1) \_the\_pdflastobj \_space 0 R }% +} +\_nspublic \dljavascript ; + + \_doc + Object creation, which is common to both, is handled by\nl\indent + \`\.makenamearray``<name tree name><name tree content>`.\nl + It doesn't do anything + for empty lists, to not bloat PDF files when this mechanism isn't used. + \_cod + +\_def\.makenamearray#1#2{\_ifx#2\_empty\_else + \_immediate\_pdfobj {<< /Names [ #2 ] >>}% + \_pdfnames{/#1 \_the\_pdflastobj \_space 0 R }\_fi +} + + \_doc + The lists themselves can only be written out to the PDF file at the very end + of the run. We use \OpTeX/'s `\_byehook`, which is run in `\_bye`. But `\bye` + itself may be predefined by the user, for example when using some of the + \OpTeX/ tricks. We just hope that user keeps `\_byehook`. + \_cod + +\_addto\_byehook{% + \.makenamearray{EmbeddedFiles}\.embeddedfiles + \.makenamearray{JavaScript}\.dljavascripts +} + + \_doc + \sec Viewer preferences + + There are a few customizations of display (and other preferences of PDF + viewers) possible in the document catalog or its subdictionary + `/ViewerPreferences`. Most are not that useful. The interesting + ones are implemented by \`\fullscreen`, \`\showoutlines`, \`\showattached`. + They all set the page mode using \`\.setpagemode`. We don't handle respecting + the last setting (using \`\_byehook`). To prevent invalid PDF files, we set + `\.setpagemode` to `\_relax` after use. + \_cod + +\_def\.setpagemode#1{\_pdfcatalog{/PageMode /#1}\_glet\.setpagemode=\_relax} + +\_def\.fullscreen{\.setpagemode{FullScreen}} +\_def\.showoutlines{\.setpagemode{UseOutlines}} +\_def\.showattached{\.setpagemode{UseAttachments}} + +\_nspublic \fullscreen \showoutlines \showattached ; + + \_doc + Only the setting of duplex / double sided printing and display is in the + nested dictionary. It is handled by \`\duplexdisplay`. The simplistic version + does not handle more attributes in `/ViewerPreferences`. We also set the + meaning to `\_relax` to prevent more (erroneous) uses. + \_cod + +\_def\.duplexdisplay{\_pdfcatalog{% + /PageLayout /TwoPageRight + /ViewerPreferences << + /Duplex /DuplexFlipLongEdge + >>}% + \_glet\.duplexdisplay=\_relax +} + +\_def\duplexdisplay{\.duplexdisplay} + + \_doc + \sec Multimedia + + PDF essentially allows insertion of different types of multimedia: + \begitems + * images, + * audio/video, + * 3D art. + \enditems + + The first is pretty standard and handled normally by the engine (\LuaTeX). + Others are possible, but have to be done manually according to one of the + mechanisms specified by PDF standard: + + \begitems + * Sounds (audio only), + * Movies (video and/or audio), + * Renditions (video and/or audio), + * 3D annotations (3D art), + * Rich Media (video and/or audio, 3D art) + \enditems + + Sadly all these mechanisms are badly flawed, each in different ways. At least + we try to use the one that works in the viewers. + + For audio/video \"Movies" are the simplest mechanism, but they have been + deprecated in PDF 2.0 and no longer work in Acrobat/Foxit (same for + \"Sounds"). + + \"Renditions" are complicated, partly dependant on JavaScript, but at least + supported by Acrobat, Foxit, Evince and Okular. + + \"Rich media" annotations were designed for Flash. This use case is no longer possible + today, but the obscurities remain. They are unnecessiraly complicated, but can + be used without Flash too. Although the result is very plain for audio/video~-- + no controls can be displayed and there are no associated actions. + + \"3D annotations" are reasonably simple, but also flawed. They cannot reuse + embedded file as a source for 3D data. Hence it is better and more consistent + to use Rich Media for 3D annotations. It even has additional benefits, like + the possibility of using multiple initialization scripts. + + In the end, this package exposes two user commands corresponding to two + mechanisms~-- first are Renditions (`\render`) for audio/video that works in most + browsers and Rich Media (`\RM`) mainly for 3D art, but also for audio/video + with limited possibilities. + + Both mechanisms have an annotation at their core. Annotations is essentially + a rectangular area on page. The area corresponds to where the + multimedium will show up. After activating the area somehow (by user click, + or action) the multimedium will start playing. Before annotations the + rectangular area will show something that is called \"normal appearance". + This appearance is of type form XObject. Those are really similiar to pages~-- + they have dimensions, contents made up of PDF graphics operators, \dots, + but they are reusable. Not that useful for annotations where we will need the + form only once, but nice anyways. pdf\TeX/ has primitives for creating them~-- + `\pdfxform` and friends. They essentially do the same code like `\shipout` + does, but instead of page, they make this reusable object. One can then + either use this reusable object in another page/form, but we will indirectly + refer to it for the appearance. + + Important aspect of annotations is that they are really only rectangular + areas on the page, but they are not really part of the page. They sort of sit + on another level and are not influenced by PDF graphic operators which make + the page. In pdf\TeX/ annotations are handled by {\em whatsit} nodes. While + most nodes map to known primitive \TeX/ concepts (like typeset characters, + boxes, rules, etc.) Whatsits are essentially commands for \TeX/ that are + delayed until page is being shipped out (written to PDF file). `\write`, + `\special`, and most pdf\TeX/ commands create whatsits. For annotationos this + is important, because this means that the engine only stores the information + about annotation that we specify, but creates it at due time, when it should + be written to PDF. + + Because whatsits are essentially dimensionless and we want it to be a part of + normal \TeX/ typesetting material we create the annotation (whatsit) in + `\hbox`. This box will be otherwise empty, because the apperance of the + rectangular area is determined by the normal appearance field (`/N` in + `/AP`). We set the dimensions of the box to the dimensions of normal + appearance. Everything will line up nicely, because when processed, the + annotation will take dimensions from the box. + + All of these concepts are implemented in:\nl\indent + \`\.boxedannot``[<type>:<name>]{<appearance>}{<special text>}{<annotation attributes>}`\nl + <type> is used to determine the annotation border (same principle as with + Link annotations, section~\ref[actions-link]), <name> will be used as the + annotation name (`/NM`), <special text> is used for influencing the + `\pdfannot` primitive, and <annotation attributes> will become the body of + the annotation. + + \_cod + +\_def\.boxedannot[#1:#2]#3#4#5{% + \_setbox0=\_hbox{#3}\_setbox2=\_null + \_ht2=\_ht0 \_wd2=\_wd0 \_dp2=\_dp0 + \_immediate\_pdfxform0 + % box with annotation both stretching to dimensions of appearance + \_hbox{\.setpageof{#1:#2}% + \_pdfannot #4 {#5 + /AP <</N \_the\_pdflastxform \_space 0 R>> + \_pdfborder{#1} + /NM (#2) + /Contents (#1 '#2') + }% + \_copy2 + }% +} + + \_doc + There is another weird thing common to both multimedia mechanisms~-- + the redefinition of `\.name`. It is initially + set by `\.secondoptdef` to <name>, but may be redefined by user supplied + `name` key-value parameter. This should be used when there are multiple uses + of the same content. Otherwise samely named annotations would be + indistinguishable both for PDF viewer and our handling of actions (which + would all refer only to the first instance). + + To somewhat overcome this, trying to use the same <name> (within the same + type of annotaiton) will use dummy name from \`\.unnamedannotcount` (for + uniqueness). This means that <name> will always refer to the first instance. + \`\.redefinename` handles this. + \_cod + +\_newcount\.unnamedannotcount +\_def\.redefinename#1{% + \.isdefined{#1:\.name}\_iftrue + \_incr\.unnamedannotcount + \_edef\.name{\_the\.unnamedannotcount}% + \_else + \_edef\.name{\_kv{name}}% + \_fi +} + + \_doc + \label[mm-renditions] + \secc Renditions (audio/video) + + There are three main types of PDF objects involved in the Renditions + (\"Multimedia") mechanism: + + \begitems + * Screen annotations define the area for playing multimedia. + * Rendition objects define the multimedia to play. + * Rendition actions associate Rendition objects with Screen annotations. + \enditems + + You can theoretically arbitrarily mix and match rendition objects and screen + annotations by invoking different actions. In practice Evince and Okular do + really simplistic parsing and don't fully support the actions fully. But by + keeping it simple it is possible to make it work almost the same in all + viewers that support renditions. + + Different sources of audio/video should be possible. In fact all three file + specifications (embedded files, files specified by URL/path) could work. + Again in practice embedded file is the safest bet, that works in all viewers + that support renditions. + + The user facing command is:\nl\indent + \`\render``[<name>][<optional key-value paramers>]{<horizontal material>}`\nl\noindent + <name> is the friendly name set using `\filedef` or file path if <name> isn't + `\filedef`d and is to be embedded. The key-value parameters in brackets + can be entirely omitted. They can influence the playback (except for `controls` + most are not well supported). Default values are taken from + `\.renderdefaults`. + + `\render` doesn't do anything (except print warning) if file <name> isn't + defined and <name> isn't a path to file that can be embedded. + + The first PDF object it defines is Rendition, which specifies information + about the multimedium (name, file specification, MIME type and options from + key-value parameters). Some of the fields are in `/BE` (\"best effort") + dictionaries. This is due to the very general design of Renditions, which + theoretically allows the PDF viewer to choose from multiple Renditions if + they know they can't support some of the requested features. But that is not + much useful in practice, so we just don't complicate it. + + Next defined object is Screen annotation, which complicates thing by + requiring (`/P`) reference to the page where the annotation is (handled by + `\setpageof` and `\pageof` pair). Important field is `/A` which specifies + actions that shall be executed when the screen area is clicked. We let the + user change the action, but the sensible default of starting to play the + multimedium is used (and this is the only thing that works in some viewers + anyways). Additional actions `/AA` may be used to react to events like mouse + over or page open/close~-- the most probable use case is autoplay on page + open, for which shortcut of \`\renditionautoplay` is defined. + + The code is slightly complicated by the fact, that actions need to reference + the Rendition and Screen objects. In the case of the action contained in + Screen annotation this essentialy involves a self reference. Hence it is + needed to first reserve an object number and later use it for the annotation. + Because the object numbers may also be needed by actions defined later, we need + to save them to `\_pdfextra_rendition:<name>` and `\_pdfextra_screen:<name>` + respectively, but also define aliases with empty names, so users can easily + reference the latest rendition. + + \_cod + +\.secondoptdef\.render#1{\.isfiledefined{\.name}\_iftrue\_bgroup + \_ea\_readkv\_ea{\_ea\.renderdefaults\_ea,\_the\_opt}% + \.colortorgbdef\.bgcolor{\_kv{background}}% + % rendition object ("media specifaction") + \_pdfobj {<</Type /Rendition + /S /MR + /N \.cs{filename:\.name} + /C <<%/Type /MediaClip + /S /MCD % subtype MediaClipData + /D \.cs{filespec:\.name} + /CT (\.cs{filemime:\.name}) + /P << /TF (TEMPALWAYS) >> % allow creating temporary files + >> + /P <<%/Type /MediaPlayParams + /BE << /C \_kv{controls} /V \_kv{volume} /RC \_kv{repeat} >> + >> + /SP <<%/Type /MediaScreenParams + /BE << /O \_kv{opacity} /B [\.bgcolor] >> + >> + >>}\_pdfrefobj\_pdflastobj + \.redefinename{rendition}% + \.sxdef{rendition:\.name}{\_the\_pdflastobj}% + % screen annotation ("screen space allocation") + \_pdfannot reserveobjnum% "self" reference will be needed inside screen annot. + \.sxdef{screen:\.name}{\_the\_pdflastannot}% + % aliases to latest rendition/screen with empty name + \_global\.slet{rendition:}{rendition:\.name}% + \_global\.slet{screen:}{screen:\.name}% + \_edef\.action{\_kv{action}}\_edef\.aactions{\_kv{aactions}}% + \.boxedannot[rendition:\.name]{#1}{useobjnum\_the\_pdflastannot}{% + /Subtype /Screen + % reference to page of the rendition (\setpageof done by \.boxedannot) + % the spaces are weird, but \pdfpageref eats them + /P \_pdfpageref\.pageof{rendition:\.name} \_space 0 R + /A \_ea\.pdfaction\_ea[\.action] + /AA \_ea\.pdfaactions\_ea{\.aactions} + }% + \_egroup\_fi +} +\_nspublic \render ; + + \_doc + Here are the defaults used for `\render`~-- \`\.renderdefaults`. Users can + redefine them all together or override as needed with key-value parameters. + The defaults correspond to values specified by PDF standard. Other values may + not be respected by all viewers. + \_cod + +\_def\.renderdefaults{% + name=\.name, + controls=false, + volume=100, + repeat=1, + opacity=1.0, + background=1 1 1, + action=rendition::play, + aactions={}, +} + + \_doc + Most probable use of additional actions is to start auto-start playing of the + multimedium. For this purpose \`\renditionautoplay` is defined as a shorthand + for action to play the lastly defined rendition on page visible event. + \_cod + +\_def\.renditionautoplay{{PV}{rendition::play}} +\_nspublic \renditionautoplay ; + + \_doc + \seccc Rendition actions + + Rendition actions unfortunately use cryptic symbolic numbers (`0`, `1`, `2` + and `3`) for actions that could be called `play`, `stop`, `pause` and + `resume` respectively. Except for these predefined actions (that use `/OP`) + running of JavaScript is possible using `/JS (<script>)` with potential + fallback to `/OP`. This is dangerous teritory, because support of the right + API in the viewer is very low. Although it is possible to define such action + type by: + + \begtt +\.sdef{renditionaction:myaction}{/JS (app.alert("something useful");) /OP 0} + \endtt + + The use of rendition action is: + \`\.renditionaction``[rendition:<name>:<action type>]`. Empty name refers to + last rendition, so e.g.`\.renditionaction``[rendition::pause]` is possible. + \_cod + +\.sdef{renditionaction:play}{/OP 0} +\.sdef{renditionaction:stop}{/OP 1} +\.sdef{renditionaction:pause}{/OP 2} +\.sdef{renditionaction:resume}{/OP 3} +\_def\.renditionaction[#1:#2:#3]{/S /Rendition + \.cs{renditionaction:#3} + /R \.cs{rendition:#2} 0 R + /AN \.cs{screen:#2} 0 R% +} + + \_doc + \secc Rich Media (3D/audio/video) + + Some principles seen with Renditions (section~\ref[mm-renditions]) apply here + too. But additionally we deal with 3D specifics and unfortunate Flash + leftovers. + + Unlike Renditions both page area and multimedium specifaction are handled in + a single annotation~-- the Rich Media annotation. The code is unfortunately + obscured due to the weird requirements, but this is essentially what we are + trying to create with \`\RM`: +\begtt +/Type /Annot +/Subtype /RichMedia +/RichMediaSettings << + /Activation << + /Condition /PV + /Scripts [ 14 0 R ] + >> + /Deactivation << /Condition /XD >> +>> +/RichMediaContent << + /Assets << /Names [ (kladka.prc) 2 0 R (wireframe.js) 14 0 R ] >> + /Configurations [ << + /Type /RichMediaConfiguration + /Subtype /3D + /Instances [ << + /Type /RichMediaInstance + /Subtype /3D + /Asset 2 0 R + >> ] + >> ] +>> +\endtt + + The activation/deactivation will be dealt with later. But we see that to + insert a simple 3D file, we have to pack it inside a file specification + (indirect reference to object `2 0 R`), then in \"instance", inside a + \"configuration" inside \"content". As if it wasn't enough the names + (normally contained in the file specification) have to be specified again in + `Assets` name tree that uselessly maps names to file specifications. Because + this is a 3D Rich Media annotation there are other files at play~-- + initialization scripts. These are specified in `/Scripts` and are executed in + turn when the annotation is activated. Not shown is, that some + \"configurations" and \"instances" actually have to be specified indirectly. + + If it wasn't for Flash we could do with something like: + +\begtt +/Type /Annot +/Subtype /RichMedia +/Activation /PV +/Scripts [ 14 0 R ] +/Deactivation /XD +/Content 2 0 R +\endtt + + Which contains equivalent information. But unfortunately here we are\dots + \_cod + +\.secondoptdef\.RM#1{\.isfiledefined{\.name}\_iftrue + \_edef\.tmp{\.cs{filemime:\.name}}% + \_edef\.subtype{\_ea\.mimetormsubtype\_ea[\.tmp]\_space}% + \_ifx\.subtype\_space + \_opwarning{unknown rich media type for '\.name', ignored}\_else + \_bgroup + \_ea\_readkv\_ea{\_ea\.RMdefaults\_ea,\_the\_opt}% + % Instance that has the media file as an asset + \_pdfobj {<</Type /RichMediaInstance + /Subtype /\.subtype + /Asset \.cs{filespec:\.name} + >>}\_pdfrefobj\_pdflastobj + % Configuration with one single instance (the above) + \_pdfobj {<</Type /RichMediaConfiguration + /Subtype /\.subtype + /Instances [ \_the\_pdflastobj \_space 0 R ] + >>}\_pdfrefobj\_pdflastobj \_edef\.configuration{\_the\_pdflastobj}% + \_edef\.names{\.cs{filename:\.name} \.cs{filespec:\.name} }% initial asset + \.redefinename{rm}% + \_def\.scriptfilespecs{}% + \_edef\.views{\_kv{views}}\_edef\.scripts{\_kv{scripts}}% + \_ifx\.views\_empty \_edef\.views{\.name}\_fi + \_ea\.DDDscripts\_ea{\.scripts}% + % annotation in hbox + \.boxedannot[rm:\.name]{#1}{}{% + /Subtype /RichMedia + /RichMediaSettings << + /Activation << + /Condition \.cs{activation:\_kv{activation}} + \.emptyor{\.scriptfilespecs}{/Scripts [ \.nonempty ]} + /Presentation << /Toolbar \_kv{toolbar} \.RMpresentationextra >> + >> + /Deactivation << /Condition \.cs{deactivation:\_kv{deactivation}} >> + >> + /RichMediaContent << + /Assets << /Names [ \.names ] >> + /Configurations [ \.configuration \_space 0 R ] + \.emptyor{\_ea\.DDDviews\_ea{\.views}}{/Views [ \.nonempty ]} + >> + }% + \.sxdef{rm:\.name}{\_the\_pdflastannot}% + \_global\.slet{rm:}{rm:\.name}% + \_egroup\_fi\_fi +} +\_nspublic \RM ; + + \_doc + The code is similiar to `\render`, but we also ignore everything if we don't + recognize the type of media (`Video`, `Sound` or `3D`). For that we use a + simple mapping from MIME types with \`\.mimetormsubtype`. This means that + although we aim Rich Media mostly for 3D art it may also be used for Video + and Sound. + \_cod + +\_def\.mimetormsubtype[#1/#2]{\.cs{rmtype:#1}} + +\.sdef{rmtype:model}{3D} +\.sdef{rmtype:video}{Video} +\.sdef{rmtype:audio}{Sound} + + \_doc + Then we also need to construct the weird name \"tree" (essentialy an array in + our case) and script array. \`\.DDDscripts` and \`\.DDDviews` do this. + Name tree is accumulated in `\.names`, and starts with the media file. After + that each script is added to \`\.names` and \`\.scriptfilespecs`. The scripts + are passed as a comma separated array. Ignoring initial spaces is done using + undelimited-delimited argument pair trick. + \_cod + +\_def\.DDDscripts#1{\.DDDscriptsA#1,,,\.end} +\_def\.DDDscriptsA#1#2,{\_ifx,#1\_ea\.untilend\_else + \.isfiledefined{#1#2}\_iftrue% + \_addto\.scriptfilespecs{\.cs{filespec:#1#2} }% + \_addto\.names{\.cs{filename:#1#2} \.cs{filespec:#1#2} }% + \_fi + \_ea\.DDDscriptsA\_fi +} + + \_doc + For 3D views we need to process yet another comma separated list, this time + with \`\.DDDviews`. The result has to be separated by spaces and we also + don't want to emit something if the specified view was invalid. Unfortunately + this is expansion only context, so we can't issue a warning. + + As a user convenience, before `\.DDDview` is executed, view with the name of + `\.name` is tried instead of empty view array. This means that for simple 3D + art with one view, one can create view with the same name as the 3D object + and not have to specify anything. We also take the name only after it is + redefined from optional key-value parameters~-- this is so we can support + even the case of e.g. `screw` 3D model used twice, once with `name=screw1`, + another time with `name=screw2` (with the corresponding `screw1` and `screw2` + views). This is probably less useful, but\dots + \_cod + +\_def\.DDDviews#1{\.DDDviewsA#1,,,\.end} +\_def\.DDDviewsA#1#2,{\_ifx,#1\_ea\.untilend\_else + \.isdefined{3dview:#1#2}\_iftrue + \_lastnamedcs\_space \_fi + \_ea\.DDDviewsA\_fi +} + + \_doc + The activation/deactivation names are kind of cryptic, so we give them + descriptive names. Default is explicit (de)activation. Instead of `/PV` (page + visible) and `/PI` (page invisible) it would be possible to use \"page open" + and \"page close". These are slightly different in cases when more pages are + shown on screen at once, because only one page is \"open", while multiple are + \"visible". + \_cod + +\.sdef{activation:explicit}{/XA} +\.sdef{activation:auto}{/PV} +\.sdef{deactivation:explicit}{/XD} +\.sdef{deactivation:auto}{/PI} + + \_doc + Additional means of customization are here. \`\.RMdefaults` contains the + default key-value parameters. \`\.RMpresentationextra` can be used to set + more attributes in `/RichMediaPresentation` dictionary (although those are + more specific and not generally useful). + \_cod + +\_def\.RMdefaults{% + name=\.name, + activation=explicit, + deactivation=explicit, + toolbar=true, + views=, + scripts=, +} +\_def\.RMpresentationextra{} + + \_doc + For scripting using JavaScript actions one needs to access the 3D context of + the 3D / Rich Media annotation. This requires the page number. We can't use + `this.pageNum` from [TODO], because the script strictly doesn't have to be on + the same page. We use `\.pageof` (`\.setpageof` was done in `\.boxedannot`) + to retrieve the page number in next run. Also PDF indexes page numbers from + 0. \`\DDDannot``{<name>}`. and \`\DDDcontext``{<name>}` allow this. + \_cod + +\_def\.DDDannot#1{% + this.getAnnotRichMedia(\_the\_numexpr\.pageof{rm:#1}-1\_relax, '#1')% +} +\_def\.DDDcontext#1{\.DDDannot{#1}.context3D} + +\_nspublic \DDDannot \DDDcontext ; + + \_doc + \label[mm-3dviews] + \secc 3D views + + This is the interesting part about 3D art. They can have a set of predefined + views~-- although a user may start from one, they can interactively change + all the aspects by dragging with mouse or messing with the settings shown by + right click menu. + + There are several transformations that have to be done before it is possible + to display 3D scene on a computer screen: + + \begitems \style n + * 3D transformation from the coordinate system of 3D artwork (\"model") to the \"world + coordinate system". + * 3D transformation from the world coordinate system to camera coordinate + system. + * projection to 2D (3D to 2D transformation). + \enditems + + When talking about PDF, positive $x$ goes to the right, positive $y$ up, and + positive $z$ \"away" from us (\"into the page"). This means we are working + with a left handed coordinate system. In camera space, the camera sits at + $(0, 0, 0)$ facing towards positive $z$ with positive $x$ and $y$ going right + and up respectively. Projection (one way or another) discards the $z$ + coordinate. + + Although the transformations are not strictly linear, they are essentially + done using multiplication by {\em transformation matrices}. The matrix for + \"model to world" (or \"model") transformation is part of the 3D art file and can't + be changed. However, we can make it up, because we can fully control the + second transformation (\"world to camera" or \"view" transformation)~-- + although we don't specify the \"world to camera" matrix but rather its + inverse, the \"camera to world" matrix (`/C2W`). This matrix has the $4 \times 4$ + form, which also allows {\em linear transformation} and {\em translation}: + + $$ + M_{c2w} = \pmatrix{a & d & g & t_x \cr b & e & h & t_y \cr c & f & i & t_z \cr 0 & 0 & 0 & 1} + $$ + + Here we use the column major convention, which is also the order how we would + write the matrix to PDF file, where it is an array of 12 elements: + + \begtt \catcode`\$=3 + /C2W [$a$ $b$ $c$ $d$ $e$ $f$ $g$ $h$ $i$ $t_x$ $t_y$ $t_z$] + \endtt + + In the rendering pipeline everything is transformed from world coordinates to + camera space coordinates. We can think about the process also in the other + way. Using $M_{c2w}$ we specify camera's position and orientation in the + world coordinate system. Due to how transformation using matrix + multiplication works, the first column in the $M_{c2w}$ matrix (vector $(a, + b, c)^T$) specifies how \"positive $x$ direcetion" (\"right") from camera + space ends up in world coordinate system. Similiarly for $(d, e, f)^T$ being + the image of positive $y$ (\"up") and $(g, h, i)^T$ being the image of + positive $z$ (\"forward"). The last column, $(t_x, t_y, t_z)^T$ represents + translation from camera space to world. Translation of origin (camera + position) will leave it in the point with coordinates $(t_x, t_y, t_z)$. + Because of these associations with the intuitive meanings of $x$, + $y$, $z$ in camera space we also sometimes call the vectors in the first + three columns of $M_{c2w}$ \"right", \"up" and \"forward" and the last one + \"eye": + + $$ + \vec{R} = \pmatrix{a \cr b \cr c}\!, \quad + \vec{U} = \pmatrix{d \cr e \cr f}\!, \quad + \vec{F} = \pmatrix{g \cr h \cr i}\!, \quad + \vec{E} = \pmatrix{t_x \cr t_y \cr t_z}\!. + $$ + + We usually want $\vec{R}$, $\vec{U}$ and $\vec{F}$ to form an orthonormal set + of vectors, i.e. all of unit length and each pair is orthogonal. The + orthoganility will come from the way we calculate them, but the normality has + to be ensured by normalizing the vectors after computing them, which will not + be explicitly written out in the following text. $\vec{E}$ is a positional, + not directional, vector and it's length will be preserved. + + Now we only need a convenient way to calculate all four vectors. A wide spread + method is sometimes called \"look at". It essentially involves having two + points: \"eye" ($E$, position of the camera) and \"target" ($T$, the point + where the camera is pointing at). The camera position is already provided: + $$ + \vec{E} = E + $$ + From these two points alone we can easily calculate the forward vector, which + corresponds to the direction of the camera: + $$ + \vec{F} = \overrightarrow{ET} = T - E + $$ + When we now imagine the point $E$ and vector $\vec{F}$ looking towards $T$ we + can see that there is a degree of freedom~-- the camera can rotate about the + forward vector. There is no other way than to arbitrarily choose + either up or right vector. Usually we choose an arbitrary \"global up" vector + $U_G$, which will influence the general direction of the final up vector. + This is because we use it to calculate the right vector: + $$ + \vec{R} = \vec{U}_G \times \vec{F} + $$ + The cross product makes it so that: + \begitems \style n + * $\vec{R}$ is perpendicular to $\vec{F}$ + * it is also perpendicular to global up vector ($\vec{U}_G$) which we used to + get rid of remaining degree of freedom. + \enditems + Now that we have two orthonormal vectors (with the normalization not being + explicit) we can calculate the remaining up vector: + $$ + \vec{U} = \vec{F} \times \vec{R} + $$ + + The last mysterious part about the calculation are the cross products. They + are of course not commutitative, so why e.g. $\vec{U}_G \times \vec{F}$ and + not the other way around? This is because we have to preserve the relations + these vectors had as directions of positive axes of the original camera + space. There we had positive $x$ going right, positive $y$ up and positive + $z$ forward in a left handed coordinate system. This means that following + holds (according the left hand rule): + + $$\eqalign{ + \vec{R} &= \vec{U} \times \vec{F} \cr % j * k = i + \vec{U} &= \vec{F} \times \vec{R} \cr % k * i = j + \vec{F} &= \vec{R} \times \vec{U} \cr % i * j = k + }$$ + + The scheme has one flaw though. When the directions of global up vector + $\vec{U}_G$ and forward vector $\vec{F}$ are linearly dependent the computed + right vector will be $(0, 0, 0)$. Hence some handling of this special case is + needed. + + The \"look at" method is essentially what is used in Alexander Grahn's + package movie15\fnote{\url{https://www.ctan.org/pkg/movie15}}. Although the + input aren't two points, but rather a \"center of orbit" point ($COO$, our + \"target"), \"center of orbit to camera vector" ($\overrightarrow{C2C}$, + default is $(0, -1, 0)$) and distance of camera from the center of orbit + ($ROO$). The value used for the arbitrary \"global up" vector is $(0, 0, 1)$. + When forward vector is $(0, 0, z)$, then global up is chosen to be $(0, -1, + 0)$ or $(0, 1, 0)$ to handle the \"0 right vector" issue. + + Because the movie15 method of providing the parameters is used in essentially + all packages that handle PDF 3D art (movie15, media9, rmannot, Con\TeX/t) we + also follow the suite. + + \`\DDDview`[<view name>][<key-value parameters>] is the command for defining + 3D views. These have to be saved into separate PDF objects anyways, using + this interface we allow their reuse. If <view name> is same as <name> of + `\RM` argument and no other views are specified <view name> view is + automatically used (see `\RM` for details). + + Key-value parameters are not optional this time, because rarely one suffices + with default values~-- different 3D views are about customization. Handling + of them is not as straightforward as before. We initially read the key-value + parameters only to determine the `method` used for calculating the `/C2W` + matrix. Then we reread key-value parameters again, this time with also with + the default values for this particular method. Not that the general 3d views + details are changed, but the methods themselves have key-value parameters of + their own, and we support specifying them in this \"flat" way. + + Additionally we allow the different methods used to compute `/C2W` to not be + expandable. Hence they are executed outside of expansion only context and are + fully processed~-- the text they add to 3D view PDF object is temporarily + stored in \`\.viewparams`. + + The rest is simply setting sensible defaults (or user overrides) for + internal/external name of the view (`/IN` and `/XN`, one is used for + scripting, one is shown by the PDF viewer), background color, rendering mode, + and lighting. Cross sections and nodes are currently not supported, although + users can hook in their own code using `\.DDDviewextra`, + `\.DDDrendermodeextra` or `\.DDDprojectionextra`. + + We have to be careful about setting rendering mode and lighting scheme, + because they normally fall back to the values specified in 3D art file, which + we can't access, so better not set them to anything if they are empty. + \_cod + +\_def\.DDDview[#1][#2]{\_bgroup + \_readkv{\.DDDviewdefaults,#2}% + \_edef\.tmp{\.DDDviewdefaults,\.cs{3dview:\_kv{method}:defaults}}% + \_readkv{\.tmp,#2}% + \.colortorgbdef\.bgcolor{\_kv{background}}% + \.cs{3dview:\_kv{method}}% sets \.viewparams (/MS, /C2W, /CO) + \_pdfobj {<</Type /3DView + /XN (#1) + /IN (#1) + \.viewparams % /MS, /C2W, /CO + /P << + \.cs{3dprojection:\_kv{projection}} + \.DDDprojectionextra + >> + /BG <<%/Type /3DBG + /Subtype /SC + /C [\.bgcolor] + >> + \.emptyor{\_kv{rendermode}}{% + /RM <<%/Type /3DRenderMode + /Subtype /\.nonempty + \.DDDrendermodeextra >> }% + \.emptyor{\_kv{lighting}}{% + /LS <<%/Type /3DLightingScheme + /Subtype /\.nonempty >> }% + >>}% + \_pdfrefobj\_pdflastobj + \.sxdef{3dview:#1}{\_the\_pdflastobj \_space 0 R}% + \_egroup +} + +\_nspublic \DDDview ; + + + \_doc + \`\.DDDviewdefaults` stores default key-value parameters for 3D views. They + are mostly the PDF standard defaults or what movie15/media9 uses (for + compatibility).\`\.DDDviewextra`, \`\.DDDrendermodeextra` or + \`\.DDDprojectionextra` can be used by the users to hook themself into 3D + view object creation. + \_cod + +\_def\.DDDviewdefaults{ + projection=perspective, + scale=1, + ps=Min, + FOV=30, + background=1 1 1, + rendermode=, + lighting=, + method=media9, +} +\_def\.DDDprojectionextra{} +\_def\.DDDrendermodeextra{} +\_def\.DDDviewextra{} + + \_doc + There are two different projection methods: + \begitems + * Orthographic: $z$ coordinate is simply thrown away, `scale` is used for scaling + the result. For technical parts where we want lines that are parallel stay + parallel in the view. + * Perspective: is the way human eye sees. `FOV` can be used to set field of + view. (`ps` parameter for additonal scaling to fit width/height is also + available, but the default is fine for casual users). + \enditems + \_cod + +\.sdef{3dprojection:ortho}{/Subtype /O /OS \_kv{scale}} +\.sdef{3dprojection:perspective}{/Subtype /P /FOV \_kv{FOV} /PS /\_kv{ps}} + + + \_doc + We offer the possibility of setting`/C2W` matrix and `/CO` (distance from + camera to center of orbit) directly using `method=manual`. + \_cod + +\.sdef{3dview:manual:defaults}{ + matrix=1 0 0 0 1 0 0 0 1 0 0 0 , + centeroforbit=0, +} +\.sdef{3dview:manual}{\_edef\.viewparams{ + /MS /M + /C2W [\_kv{matrix}] + /CO \_kv{centeroforbit} +}} + + \_doc + Another simple way of specifying camera position/orientation is to use a + named setting of U3D file using a U3D path with `method=u3d`. + \_cod + +\.sdef{3dview:u3d:defaults}{ + u3dpath=, +} +\.sdef{3dview:u3d}{% + \_pdfunidef\.tmp{\_kv{u3dpath}}% + \_edef\.viewparams{ + /MS /U3D + /U3DPath \.tmp \_space +}} + + \_doc + The most advanced method of setting `/C2W` matrix and `/CO` is + `method=media9`. It is thoroughly explained above, the few differences are + because the input values are not two points. Also for conciseness \"x", \"y" + and \"z" are used instead of right, up and forward. The calculations are + done in Lua, for simplicity. + + We expect the user to supply the numbers in the form \"`1 2 3`", but in Lua we + need them comma separated (\"1, 2, 3"). \`\.luatriplet` does this. Just in + case the code is somehow adapted without ensuring that $x$ and $z$ are + orthonormal, we normalize also $y$ after the second cross product. + \_cod + +\_def\.luatriplet#1 #2 #3 {#1, #2, #3} + +\.sdef{3dview:media9:defaults}{% + roo=0, + coo=0 0 0, + c2c=0 -1 0, +} +\.sdef{3dview:media9}{\_edef\.coo{\_kv{coo}}\_edef\.c2c{\_kv{c2c}}\_edef\.viewparams{ + /MS /M + /C2W [\_directlua{ + local function normalize(x, y, z) + local len = math.sqrt(x*x + y*y + z*z) + if len ~= 0 then return x/len, y/len, z/len else return 0, 0, 0 end + end + local function cross(ux, uy, uz, vx, vy, vz) + return uy*vz - uz*vy, uz*vx - ux*vz, ux*vy - uy*vx + end + local function printmat(...) + local arr = table.pack(...) + for k, v in ipairs(arr) do + arr[k] = string.format("\_pcent.6f", v) + end + tex.print(table.concat(arr, " ")) + end + + local roo = \_kv{roo} + local coo_x, coo_y, coo_z = \_ea\.luatriplet\_expanded{\_kv{coo}} + local c2c_x, c2c_y, c2c_z = normalize(\_ea\.luatriplet\_expanded{\_kv{c2c}}) + + local eye_x, eye_y, eye_z = coo_x + c2c_x*roo, coo_y + c2c_y*roo, coo_z + c2c_z*roo + + local z_x, z_y, z_z = -c2c_x, -c2c_y, -c2c_z + + local up_x, up_y, up_z = 0, 0, 1 + if math.abs(z_x) + math.abs(z_y) < 0.0000001 then % z_x == 0 and z_y == 0 + if z_z < 0.0000001 then % z_z <= 0 + up_x, up_y, up_z = 0, 1, 0 + else + up_x, up_y, up_z = 0, -1, 0 + end + end + + local x_x, x_y, x_z = normalize(cross(up_x, up_y, up_z, z_x, z_y, z_z)) + local y_x, y_y, y_z = normalize(cross(z_x, z_y, z_z, x_x, x_y, x_z)) + + local eye_x, eye_y, eye_z = coo_x - z_x*roo, coo_y - z_y*roo, coo_z - z_z*roo + + printmat(x_x, x_y, x_z, y_x, y_y, y_z, z_x, z_y, z_z, eye_x, eye_y, eye_z) + }] + /CO \_kv{roo} +}} + + \_doc + Last, but not least, is an action for setting the 3D view of a 3D/RM annotation + using an action. \`\.goto3dviewaction``[goto3dview:<name>:<view>]`. <name> is + name of the annotation which will be influenced. <view> is passed directly to + PDF. Therefore it can be either an index to the view array (starting at 0) or name + of view in parentheses~-- \"`(<view name>)`". + \_cod + +\.sdef{goto3dviewaction}[#1:#2:#3]{/S /GoTo3DView + /TA \.cs{rm:#2} 0 R + /V #3 +} + + \_doc + \label[mime] + \sec MIME type database + + This is the uninteresting MIME type database teased in section~\ref[files]. + Ideally this would only be a subset of what IANA defines at + \url{https://www.iana.org/assignments/media-types/media-types.xhtml}. + But there are additions like `model/u3d` and `model/prc`, which don't + seem to be official, yet. Other \"unofficial" MIME types are taken from + Mozilla's \"common" lists: + \begitems + * \url{https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types}. + * \url{https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types} + \enditems + + + \`\.mimetype``{<extension>}{<MIME type>}` is a shortcut of mapping + <extension> to <MIME type>. + \_cod + +\_def\.mimetype#1#2{\_sdef{_pdfextra_mimetype:#1}{#2}} + +\.mimetype{js}{application/javascript} +\.mimetype{pdf}{application/pdf} + +\.mimetype{prc}{model/prc} +\.mimetype{u3d}{model/u3d} + +\.mimetype{wav}{audio/x-wav} +\.mimetype{mp3}{audio/mpeg} +\.mimetype{opus}{audio/opus} + +\.mimetype{avi}{video/x-msvideo} +\.mimetype{mp4}{video/mp4} +\.mimetype{webm}{video/webm} + +\_endnamespace +\_endcode + +This is the technical documentation. It is intended for those who want to know +how this package works internally. Casual users shouldn't need to read this. But +if you would like to customize anything or perhaps just use some part of this +package, feel free to copy paste and use anything you want in \OpTeX/'s spirit. + +This documentation is interleaved within the source itself, both are contained +in a single file, `pdfextra.opm` (according to \OpTeX/ conventions). The user +documentation is instead contained in `pdfextra-doc.tex`, which itself +`\input`'s the documented source file `pdfextra.opm` so that the user and +technical documentation is available in a single PDF file, `pdfextra-doc.pdf`. |