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Diffstat (limited to 'Master/texmf-dist/tex/optex/base/pdfuni-string.opm')
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diff --git a/Master/texmf-dist/tex/optex/base/pdfuni-string.opm b/Master/texmf-dist/tex/optex/base/pdfuni-string.opm new file mode 100644 index 00000000000..25781ddfb4f --- /dev/null +++ b/Master/texmf-dist/tex/optex/base/pdfuni-string.opm @@ -0,0 +1,127 @@ +%% This is part of the OpTeX project, see http://petr.olsak.net/optex + +\_codedecl \pdfunidef {PDFunicode strings for outlines <2021-02-08>} % preloaded in format + + \_doc ----------------------------- + \`\_hexprint` is a command defined in Lua, that scans a number and expands + to its UTF-16 Big Endian encoded form for use in PDF hexadecimal strings. + \_cod ----------------------------- + +\bgroup +\_catcode`\%=12 +\_gdef\_hexprint{\_directlua{ + local num = token.scan_int() + if num < 0x10000 then + tex.print(string.format("%04X", num)) + else + num = num - 0x10000 + local high = bit32.rshift(num, 10) + 0xD800 + local low = bit32.band(num, 0x3FF) + 0xDC00 + tex.print(string.format("%04X%04X", high, low)) + end +}} +\egroup + + \_doc ----------------------------- + \`\pdfunidef``\macro{<text>}` does more things than only converting to hexadecimal PDF string. + The <text> can be scanned in verbatim mode (it is true becuase \^`\_Xtoc` + reads the <text> in verbatim mode). First `\edef` do + `\_scantextokens\unexpanded` and second `\edef` expands the parameter + according to current values on selected macros from `\_regoul`. Then + \`\_removeoutmath` converts `..$x^2$..` to `..x^2..`, i.e removes dollars. + Then \`\_removeoutbraces` converts `..{x}..` to `..x..`. + Finally, the <text> is detokenized, spaces are preprocessed using \^`\replstring` + and then the \`\_pdfunidefB` is repeated on each character. It calls the + `\directlua` chunk to print hexadecimal numbers in the macro \^`\_hexprint`.\nl + Characters for quotes (and separators for quotes) are activated by first + `\_scatextokens` and they are defined as the same non-active characters. + But `\_regoul` can change this definition. + \_cod ----------------------------- + +\_def\_pdfunidef#1#2{% + \_begingroup + \_catcodetable\_optexcatcodes \_adef"{"}\_adef'{'}% + \_the\_regoul \_relax % \_regmacro alternatives of logos etc. + \_ifx\_savedttchar\_undefined \_def#1{\_scantextokens{\_unexpanded{#2}}}% + \_else \_lccode`\;=\_savedttchar \_lowercase{\_prepinverb#1;}{#2}\fi + \_edef#1{#1}% + \_escapechar=-1 + \_edef#1{#1\_empty}% + \_escapechar=`\\ + \_ea\_edef \_ea#1\_ea{\_ea\_removeoutmath #1$\_end$}% $x$ -> x + \_ea\_edef \_ea#1\_ea{\_ea\_removeoutbraces #1{\_end}}% {x} -> x + \_edef#1{\_detokenize\_ea{#1}}% + \_replstring#1{ }{{ }}% text text -> text{ }text + \_catcode`\\=12 \_let\\=\_bslash + \_edef\_out{<FEFF} + \_ea\_pdfunidefB#1^% text -> \_out in octal + \_ea + \_endgroup + \_ea\_def\_ea#1\_ea{\_out>} +} +\_def\_pdfunidefB#1{% + \_ifx^#1\_else + \_edef\_out{\_out \_hexprint `#1} + \_ea\_pdfunidefB \_fi +} + +\_def\_removeoutbraces #1#{#1\_removeoutbracesA} +\_def\_removeoutbracesA #1{\_ifx\_end#1\_else #1\_ea\_removeoutbraces\_fi} +\_def\_removeoutmath #1$#2${#1\_ifx\_end#2\_else #2\_ea\_removeoutmath\_fi} + + \_doc ----------------------------- + The \`\_prepinverb``<macro><separator>{<text>}`, + e.g.\ `\_prepinverb\tmpb|{aaa |bbb| cccc |dd| ee}` + does `\def\tmpb{<su>{aaa }bbb<su>{ cccc }dd<su>{ ee}}` where + <su> is `\scantextokens\unexpanded`. It means that in-line verbatim + are not argument of `\scantextoken`. First `\edef\tmpb` tokenizes again + the <text> but not the parts which were in the the in-line verbatim. + \_cod ----------------------------- + +\_def\_prepinverb#1#2#3{\_def#1{}% + \_def\_dotmpb ##1#2##2{\_addto#1{\_scantextokens{\_unexpanded{##1}}}% + \_ifx\_end##2\_else\_ea\_dotmpbA\_ea##2\_fi}% + \_def\_dotmpbA ##1#2{\_addto#1{##1}\_dotmpb}% + \_dotmpb#3#2\_end +} + + \_doc ----------------------------- + The \^`\regmacro` is used in order to sed the values of macros + `\em`, `\rm`, `\bf`, `\it`, `\bi`, `\tt`, `\/` and `~` to values usable in + PDF outlines. + \_cod ----------------------------- + +\_regmacro {}{}{\_let\em=\_empty \_let\rm=\_empty \_let\bf=\_empty + \_let\it=\_empty \_let\bi=\_empty \_let\tt=\_empty \_let\/=\_empty + \_let~=\_space +} +\public \pdfunidef ; + +\_endcode % -------------------------------- + +There are only two encodings for PDF strings (used in PDFoutlines, PDFinfo, +etc.). The first one is PDFDocEncoding which is single-byte encoding, but it +misses most international characters. + +The second encoding is Big Endian UTF-16 which is implemented in this file. It +encodes a single character in either two or four bytes. +This encoding is \TeX/-discomfortable because it looks like + +\begtt +<FEFF 0043 0076 0069 010D 0065 006E 00ED 0020 006A 0065 0020 007A 00E1 0074 +011B 017E 0020 0061 0020 0078 2208 D835DD44> +\endtt + +This example shows a hexadecimal PDF string (enclosed in \code{<>} as opposed +to the literal PDF string enclosed in `()`). In these strings each byte is +represented by two hexadecimal characters (`0-9`, `A-F`). You can tell the +encoding is UTF-16BE, becuase it starts with \"Byte order mark" `FEFF`. Each +unicode character is then encoded in one or two byte pairs. The example string +corresponds to the text \"Cvičení je zátěž a ${\rm x} ∈ 𝕄$". Notice the 4 bytes +for the last character, $𝕄$. (Even the whitespace would be OK in a PDF file, +because it should be ignored by PDF viewers, but \LuaTeX\ doesn't allow it.) + +\_endinput + +2021-02-08 \_octalprint -> \_hexprint +2020-03-12 Released |