% language=uk \environment luatex-style \environment luatex-logos \startcomponent luatex-fontloader \startchapter[reference=fontloader,title={The fontloader}] The fontloader library is sort of independent of the rest in the sense that it can load font into a \LUA\ table that then can be converted into a table suitable for \TEX. The library is an adapted subset of \FONTFORGE\ and as such gives a similar view on a font (which has advantages when you want to debug.) \section{Getting quick information on a font} When you want to locate font by name you need some basic information that is hidden in the font files. For that reason we provide an efficient helper that gets the basic information without loading all of the font. Normally this helper is used to create a font (name) database. \startfunctioncall info = fontloader.info( filename) \stopfunctioncall This function returns either \type {nil}, or a \type {table}, or an array of small tables (in the case of a \TRUETYPE\ collection). The returned table(s) will contain some fairly interesting information items from the font(s) defined by the file: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC fontname \NC string \NC the \POSTSCRIPT\ name of the font\NC \NR \NC fullname \NC string \NC the formal name of the font\NC \NR \NC familyname \NC string \NC the family name this font belongs to\NC \NR \NC weight \NC string \NC a string indicating the color value of the font\NC \NR \NC version \NC string \NC the internal font version\NC \NR \NC italicangle \NC float \NC the slant angle\NC \NR \NC units_per_em \NC number \NC 1000 for \POSTSCRIPT-based fonts, usually 2048 for \TRUETYPE\NC \NR \NC pfminfo \NC table \NC (see \in{section}[fontloaderpfminfotable])\NC \NR \stoptabulate Getting information through this function is (sometimes much) more efficient than loading the font properly, and is therefore handy when you want to create a dictionary of available fonts based on a directory contents. \section{Loading an \OPENTYPE\ or \TRUETYPE\ file} If you want to use an \OPENTYPE\ font, you have to get the metric information from somewhere. Using the \type {fontloader} library, the simplest way to get that information is thus: \starttyping function load_font (filename) local metrics = nil local font = fontloader.open(filename) if font then metrics = fontloader.to_table(font) fontloader.close(font) end return metrics end myfont = load_font('/opt/tex/texmf/fonts/data/arial.ttf') \stoptyping The main function call is \startfunctioncall f,
w = fontloader.open( filename) f,
w = fontloader.open( filename, fontname) \stopfunctioncall The first return value is a userdata representation of the font. The second return value is a table containing any warnings and errors reported by fontloader while opening the font. In normal typesetting, you would probably ignore the second argument, but it can be useful for debugging purposes. For \TRUETYPE\ collections (when filename ends in 'ttc') and \DFONT\ collections, you have to use a second string argument to specify which font you want from the collection. Use the \type {fontname} strings that are returned by \type {fontloader.info} for that. To turn the font into a table, \type {fontloader.to_table} is used on the font returned by \type {fontloader.open}. \startfunctioncall
f = fontloader.to_table( font) \stopfunctioncall This table cannot be used directly by \LUATEX\ and should be turned into another one as described in~\in {chapter} [fonts]. Do not forget to store the \type {fontname} value in the \type {psname} field of the metrics table to be returned to \LUATEX, otherwise the font inclusion backend will not be able to find the correct font in the collection. See \in {section} [fontloadertables] for details on the userdata object returned by \type {fontloader.open()} and the layout of the \type {metrics} table returned by \type {fontloader.to_table()}. The font file is parsed and partially interpreted by the font loading routines from \FONTFORGE. The file format can be \OPENTYPE, \TRUETYPE, \TRUETYPE\ Collection, \CFF, or \TYPEONE. There are a few advantages to this approach compared to reading the actual font file ourselves: \startitemize \startitem The font is automatically re|-|encoded, so that the \type {metrics} table for \TRUETYPE\ and \OPENTYPE\ fonts is using \UNICODE\ for the character indices. \stopitem \startitem Many features are pre|-|processed into a format that is easier to handle than just the bare tables would be. \stopitem \startitem \POSTSCRIPT|-|based \OPENTYPE\ fonts do not store the character height and depth in the font file, so the character boundingbox has to be calculated in some way. \stopitem \startitem In the future, it may be interesting to allow \LUA\ scripts access to the font program itself, perhaps even creating or changing the font. \stopitem \stopitemize A loaded font is discarded with: \startfunctioncall fontloader.close( font) \stopfunctioncall \section{Applying a \quote{feature file}} You can apply a \quote{feature file} to a loaded font: \startfunctioncall
errors = fontloader.apply_featurefile( font, filename) \stopfunctioncall A \quote {feature file} is a textual representation of the features in an \OPENTYPE\ font. See \starttyping http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html \stoptyping and \starttyping http://fontforge.sourceforge.net/featurefile.html \stoptyping for a more detailed description of feature files. If the function fails, the return value is a table containing any errors reported by fontloader while applying the feature file. On success, \type {nil} is returned. \section{Applying an \quote{\AFM\ file}} You can apply an \quote {\AFM\ file} to a loaded font: \startfunctioncall
errors = fontloader.apply_afmfile( font, filename) \stopfunctioncall An \AFM\ file is a textual representation of (some of) the meta information in a \TYPEONE\ font. See \starttyping ftp://ftp.math.utah.edu/u/ma/hohn/linux/postscript/5004.AFM_Spec.pdf \stoptyping for more information about \AFM\ files. Note: If you \type {fontloader.open()} a \TYPEONE\ file named \type {font.pfb}, the library will automatically search for and apply \type {font.afm} if it exists in the same directory as the file \type {font.pfb}. In that case, there is no need for an explicit call to \type {apply_afmfile()}. If the function fails, the return value is a table containing any errors reported by fontloader while applying the AFM file. On success, \type {nil} is returned. \section[fontloadertables]{Fontloader font tables} As mentioned earlier, the return value of \type {fontloader.open()} is a userdata object. One way to have access to the actual metrics is to call \type {fontloader.to_table()} on this object, returning the table structure that is explained in the following sections. In teh following sections we will not explain each field in detail. Most fields are self descriptive and for the more technical aspects you need to consult the relevant font references. It turns out that the result from \type {fontloader.to_table()} sometimes needs very large amounts of memory (depending on the font's complexity and size) so it is possible to access the userdata object directly. \startitemize \startitem All top|-|level keys that would be returned by \type {to_table()} can also be accessed directly. \stopitem \startitem The top|-|level key \quote {glyphs} returns a {\it virtual\/} array that allows indices from \type {f.glyphmin} to (\type {f.glyphmax}). \stopitem \startitem The items in that virtual array (the actual glyphs) are themselves also userdata objects, and each has accessors for all of the keys explained in the section \quote {Glyph items} below. \stopitem \startitem The top|-|level key \quote {subfonts} returns an {\it actual} array of userdata objects, one for each of the subfonts (or nil, if there are no subfonts). \stopitem \stopitemize A short example may be helpful. This code generates a printout of all the glyph names in the font \type {PunkNova.kern.otf}: \starttyping local f = fontloader.open('PunkNova.kern.otf') print (f.fontname) local i = 0 if f.glyphcnt > 0 then for i=f.glyphmin,f.glyphmax do local g = f.glyphs[i] if g then print(g.name) end i = i + 1 end end fontloader.close(f) \stoptyping In this case, the \LUATEX\ memory requirement stays below 100MB on the test computer, while the internal structure generated by \type {to_table()} needs more than 2GB of memory (the font itself is 6.9MB in disk size). Only the top|-|level font, the subfont table entries, and the glyphs are virtual objects, everything else still produces normal \LUA\ values and tables. If you want to know the valid fields in a font or glyph structure, call the \type {fields} function on an object of a particular type (either glyph or font): \startfunctioncall
fields = fontloader.fields( font)
fields = fontloader.fields( font_glyph) \stopfunctioncall For instance: \startfunctioncall local fields = fontloader.fields(f) local fields = fontloader.fields(f.glyphs[0]) \stopfunctioncall \section{Table types} \subsection{Top-level} The top|-|level keys in the returned table are (the explanations in this part of the documentation are not yet finished): \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC table_version \NC number \NC indicates the metrics version (currently~0.3)\NC \NR \NC fontname \NC string \NC \POSTSCRIPT\ font name\NC \NR \NC fullname \NC string \NC official (human-oriented) font name\NC \NR \NC familyname \NC string \NC family name\NC \NR \NC weight \NC string \NC weight indicator\NC \NR \NC copyright \NC string \NC copyright information\NC \NR \NC filename \NC string \NC the file name\NC \NR \NC version \NC string \NC font version\NC \NR \NC italicangle \NC float \NC slant angle\NC \NR \NC units_per_em \NC number \NC 1000 for \POSTSCRIPT-based fonts, usually 2048 for \TRUETYPE\NC \NR \NC ascent \NC number \NC height of ascender in \type {units_per_em}\NC \NR \NC descent \NC number \NC depth of descender in \type {units_per_em}\NC \NR \NC upos \NC float \NC \NC \NR \NC uwidth \NC float \NC \NC \NR \NC uniqueid \NC number \NC \NC \NR \NC glyphs \NC array \NC \NC \NR \NC glyphcnt \NC number \NC number of included glyphs\NC \NR \NC glyphmax \NC number \NC maximum used index the glyphs array\NC \NR \NC glyphmin \NC number \NC minimum used index the glyphs array\NC \NR \NC notdef_loc \NC number \NC location of the \type {.notdef} glyph or \type {-1} when not present \NC \NR \NC hasvmetrics \NC number \NC \NC \NR \NC onlybitmaps \NC number \NC \NC \NR \NC serifcheck \NC number \NC \NC \NR \NC isserif \NC number \NC \NC \NR \NC issans \NC number \NC \NC \NR \NC encodingchanged \NC number \NC \NC \NR \NC strokedfont \NC number \NC \NC \NR \NC use_typo_metrics \NC number \NC \NC \NR \NC weight_width_slope_only \NC number \NC \NC \NR \NC head_optimized_for_cleartype \NC number \NC \NC \NR \NC uni_interp \NC enum \NC \type {unset}, \type {none}, \type {adobe}, \type {greek}, \type {japanese}, \type {trad_chinese}, \type {simp_chinese}, \type {korean}, \type {ams}\NC \NR \NC origname \NC string \NC the file name, as supplied by the user\NC \NR \NC map \NC table \NC \NC \NR \NC private \NC table \NC \NC \NR \NC xuid \NC string \NC \NC \NR \NC pfminfo \NC table \NC \NC \NR \NC names \NC table \NC \NC \NR \NC cidinfo \NC table \NC \NC \NR \NC subfonts \NC array \NC \NC \NR \NC commments \NC string \NC \NC \NR \NC fontlog \NC string \NC \NC \NR \NC cvt_names \NC string \NC \NC \NR \NC anchor_classes \NC table \NC \NC \NR \NC ttf_tables \NC table \NC \NC \NR \NC ttf_tab_saved \NC table \NC \NC \NR \NC kerns \NC table \NC \NC \NR \NC vkerns \NC table \NC \NC \NR \NC texdata \NC table \NC \NC \NR \NC lookups \NC table \NC \NC \NR \NC gpos \NC table \NC \NC \NR \NC gsub \NC table \NC \NC \NR \NC mm \NC table \NC \NC \NR \NC chosenname \NC string \NC \NC \NR \NC macstyle \NC number \NC \NC \NR \NC fondname \NC string \NC \NC \NR %NC design_size \NC number \NC \NC \NR \NC fontstyle_id \NC number \NC \NC \NR \NC fontstyle_name \NC table \NC \NC \NR %NC design_range_bottom \NC number \NC \NC \NR %NC design_range_top \NC number \NC \NC \NR \NC strokewidth \NC float \NC \NC \NR \NC mark_classes \NC table \NC \NC \NR \NC creationtime \NC number \NC \NC \NR \NC modificationtime \NC number \NC \NC \NR \NC os2_version \NC number \NC \NC \NR \NC sfd_version \NC number \NC \NC \NR \NC math \NC table \NC \NC \NR \NC validation_state \NC table \NC \NC \NR \NC horiz_base \NC table \NC \NC \NR \NC vert_base \NC table \NC \NC \NR \NC extrema_bound \NC number \NC \NC \NR \NC truetype \NC boolean \NC signals a \TRUETYPE\ font \NC \NR \stoptabulate \subsection{Glyph items} The \type {glyphs} is an array containing the per|-|character information (quite a few of these are only present if nonzero). \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC name \NC string \NC the glyph name \NC \NR \NC unicode \NC number \NC unicode code point, or -1 \NC \NR \NC boundingbox \NC array \NC array of four numbers, see note below \NC \NR \NC width \NC number \NC only for horizontal fonts \NC \NR \NC vwidth \NC number \NC only for vertical fonts \NC \NR \NC tsidebearing \NC number \NC only for vertical ttf/otf fonts, and only if nonzero \NC \NR \NC lsidebearing \NC number \NC only if nonzero and not equal to boundingbox[1] \NC \NR \NC class \NC string \NC one of "none", "base", "ligature", "mark", "component" (if not present, the glyph class is \quote {automatic}) \NC \NR \NC kerns \NC array \NC only for horizontal fonts, if set \NC \NR \NC vkerns \NC array \NC only for vertical fonts, if set \NC \NR \NC dependents \NC array \NC linear array of glyph name strings, only if nonempty\NC \NR \NC lookups \NC table \NC only if nonempty \NC \NR \NC ligatures \NC table \NC only if nonempty \NC \NR \NC anchors \NC table \NC only if set \NC \NR \NC comment \NC string \NC only if set \NC \NR \NC tex_height \NC number \NC only if set \NC \NR \NC tex_depth \NC number \NC only if set \NC \NR \NC italic_correction \NC number \NC only if set \NC \NR \NC top_accent \NC number \NC only if set \NC \NR \NC is_extended_shape \NC number \NC only if this character is part of a math extension list \NC \NR \NC altuni \NC table \NC alternate \UNICODE\ items \NC \NR \NC vert_variants \NC table \NC \NC \NR \NC horiz_variants \NC table \NC \NC \NR \NC mathkern \NC table \NC \NC \NR \stoptabulate On \type {boundingbox}: The boundingbox information for \TRUETYPE\ fonts and \TRUETYPE-based \OTF\ fonts is read directly from the font file. \POSTSCRIPT-based fonts do not have this information, so the boundingbox of traditional \POSTSCRIPT\ fonts is generated by interpreting the actual bezier curves to find the exact boundingbox. This can be a slow process, so the boundingboxes of \POSTSCRIPT-based \OTF\ fonts (and raw \CFF\ fonts) are calculated using an approximation of the glyph shape based on the actual glyph points only, instead of taking the whole curve into account. This means that glyphs that have missing points at extrema will have a too|-|tight boundingbox, but the processing is so much faster that in our opinion the tradeoff is worth it. The \type {kerns} and \type {vkerns} are linear arrays of small hashes: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC char \NC string \NC \NC \NR \NC off \NC number \NC \NC \NR \NC lookup \NC string \NC \NC \NR \stoptabulate The \type {lookups} is a hash, based on lookup subtable names, with the value of each key inside that a linear array of small hashes: % TODO: fix this description \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC type \NC enum \NC \type {position}, \type {pair}, \type {substitution}, \type {alternate}, \type {multiple}, \type {ligature}, \type {lcaret}, \type {kerning}, \type {vkerning}, \type {anchors}, \type {contextpos}, \type {contextsub}, \type {chainpos}, \type {chainsub}, \type {reversesub}, \type {max}, \type {kernback}, \type {vkernback} \NC \NR \NC specification \NC table \NC extra data \NC \NR \stoptabulate For the first seven values of \type {type}, there can be additional sub|-|information, stored in the sub-table \type {specification}: \starttabulate[|lT|l|p|] \NC \rmbf value \NC \bf type \NC \bf explanation \NC \NR \NC position \NC table \NC a table of the \type {offset_specs} type \NC \NR \NC pair \NC table \NC one string: \type {paired}, and an array of one or two \type {offset_specs} tables: \type {offsets} \NC \NR \NC substitution \NC table \NC one string: \type {variant} \NC \NR \NC alternate \NC table \NC one string: \type {components} \NC \NR \NC multiple \NC table \NC one string: \type {components} \NC \NR \NC ligature \NC table \NC two strings: \type {components}, \type {char} \NC \NR \NC lcaret \NC array \NC linear array of numbers \NC \NR \stoptabulate Tables for \type {offset_specs} contain up to four number|-|valued fields: \type {x} (a horizontal offset), \type {y} (a vertical offset), \type {h} (an advance width correction) and \type {v} (an advance height correction). The \type {ligatures} is a linear array of small hashes: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC lig \NC table \NC uses the same substructure as a single item in the \type {lookups} table explained above \NC \NR \NC char \NC string \NC \NC \NR \NC components \NC array \NC linear array of named components \NC \NR \NC ccnt \NC number \NC \NC \NR \stoptabulate The \type {anchor} table is indexed by a string signifying the anchor type, which is one of \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC mark \NC table \NC placement mark \NC \NR \NC basechar \NC table \NC mark for attaching combining items to a base char \NC \NR \NC baselig \NC table \NC mark for attaching combining items to a ligature \NC \NR \NC basemark \NC table \NC generic mark for attaching combining items to connect to \NC \NR \NC centry \NC table \NC cursive entry point \NC \NR \NC cexit \NC table \NC cursive exit point \NC \NR \stoptabulate The content of these is a short array of defined anchors, with the entry keys being the anchor names. For all except \type {baselig}, the value is a single table with this definition: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC x \NC number \NC x location \NC \NR \NC y \NC number \NC y location \NC \NR \NC ttf_pt_index \NC number \NC truetype point index, only if given \NC \NR \stoptabulate For \type {baselig}, the value is a small array of such anchor sets sets, one for each constituent item of the ligature. For clarification, an anchor table could for example look like this : \starttyping ['anchor'] = { ['basemark'] = { ['Anchor-7'] = { ['x']=170, ['y']=1080 } }, ['mark'] ={ ['Anchor-1'] = { ['x']=160, ['y']=810 }, ['Anchor-4'] = { ['x']=160, ['y']=800 } }, ['baselig'] = { [1] = { ['Anchor-2'] = { ['x']=160, ['y']=650 } }, [2] = { ['Anchor-2'] = { ['x']=460, ['y']=640 } } } } \stoptyping Note: The \type {baselig} table can be sparse! \subsection{map table} The top|-|level map is a list of encoding mappings. Each of those is a table itself. \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC enccount \NC number \NC \NC \NR \NC encmax \NC number \NC \NC \NR \NC backmax \NC number \NC \NC \NR \NC remap \NC table \NC \NC \NR \NC map \NC array \NC non|-|linear array of mappings\NC \NR \NC backmap \NC array \NC non|-|linear array of backward mappings\NC \NR \NC enc \NC table \NC \NC \NR \stoptabulate The \type {remap} table is very small: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC firstenc \NC number \NC \NC \NR \NC lastenc \NC number \NC \NC \NR \NC infont \NC number \NC \NC \NR \stoptabulate The \type {enc} table is a bit more verbose: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC enc_name \NC string \NC \NC \NR \NC char_cnt \NC number \NC \NC \NR \NC char_max \NC number \NC \NC \NR \NC unicode \NC array \NC of \UNICODE\ position numbers\NC \NR \NC psnames \NC array \NC of \POSTSCRIPT\ glyph names\NC \NR \NC builtin \NC number \NC \NC \NR \NC hidden \NC number \NC \NC \NR \NC only_1byte \NC number \NC \NC \NR \NC has_1byte \NC number \NC \NC \NR \NC has_2byte \NC number \NC \NC \NR \NC is_unicodebmp \NC number \NC only if nonzero\NC \NR \NC is_unicodefull \NC number \NC only if nonzero\NC \NR \NC is_custom \NC number \NC only if nonzero\NC \NR \NC is_original \NC number \NC only if nonzero\NC \NR \NC is_compact \NC number \NC only if nonzero\NC \NR \NC is_japanese \NC number \NC only if nonzero\NC \NR \NC is_korean \NC number \NC only if nonzero\NC \NR \NC is_tradchinese \NC number \NC only if nonzero [name?]\NC \NR \NC is_simplechinese \NC number \NC only if nonzero\NC \NR \NC low_page \NC number \NC \NC \NR \NC high_page \NC number \NC \NC \NR \NC iconv_name \NC string \NC \NC \NR \NC iso_2022_escape \NC string \NC \NC \NR \stoptabulate \subsection{private table} This is the font's private \POSTSCRIPT\ dictionary, if any. Keys and values are both strings. \subsection{cidinfo table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC registry \NC string \NC \NC \NR \NC ordering \NC string \NC \NC \NR \NC supplement \NC number \NC \NC \NR \NC version \NC number \NC \NC \NR \stoptabulate \subsection[fontloaderpfminfotable]{pfminfo table} The \type {pfminfo} table contains most of the OS/2 information: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC pfmset \NC number \NC \NC \NR \NC winascent_add \NC number \NC \NC \NR \NC windescent_add \NC number \NC \NC \NR \NC hheadascent_add \NC number \NC \NC \NR \NC hheaddescent_add \NC number \NC \NC \NR \NC typoascent_add \NC number \NC \NC \NR \NC typodescent_add \NC number \NC \NC \NR \NC subsuper_set \NC number \NC \NC \NR \NC panose_set \NC number \NC \NC \NR \NC hheadset \NC number \NC \NC \NR \NC vheadset \NC number \NC \NC \NR \NC pfmfamily \NC number \NC \NC \NR \NC weight \NC number \NC \NC \NR \NC width \NC number \NC \NC \NR \NC avgwidth \NC number \NC \NC \NR \NC firstchar \NC number \NC \NC \NR \NC lastchar \NC number \NC \NC \NR \NC fstype \NC number \NC \NC \NR \NC linegap \NC number \NC \NC \NR \NC vlinegap \NC number \NC \NC \NR \NC hhead_ascent \NC number \NC \NC \NR \NC hhead_descent \NC number \NC \NC \NR \NC os2_typoascent \NC number \NC \NC \NR \NC os2_typodescent \NC number \NC \NC \NR \NC os2_typolinegap \NC number \NC \NC \NR \NC os2_winascent \NC number \NC \NC \NR \NC os2_windescent \NC number \NC \NC \NR \NC os2_subxsize \NC number \NC \NC \NR \NC os2_subysize \NC number \NC \NC \NR \NC os2_subxoff \NC number \NC \NC \NR \NC os2_subyoff \NC number \NC \NC \NR \NC os2_supxsize \NC number \NC \NC \NR \NC os2_supysize \NC number \NC \NC \NR \NC os2_supxoff \NC number \NC \NC \NR \NC os2_supyoff \NC number \NC \NC \NR \NC os2_strikeysize \NC number \NC \NC \NR \NC os2_strikeypos \NC number \NC \NC \NR \NC os2_family_class \NC number \NC \NC \NR \NC os2_xheight \NC number \NC \NC \NR \NC os2_capheight \NC number \NC \NC \NR \NC os2_defaultchar \NC number \NC \NC \NR \NC os2_breakchar \NC number \NC \NC \NR \NC os2_vendor \NC string \NC \NC \NR \NC codepages \NC table \NC A two-number array of encoded code pages\NC \NR \NC unicoderages \NC table \NC A four-number array of encoded unicode ranges\NC \NR \NC panose \NC table \NC \NC \NR \stoptabulate The \type {panose} subtable has exactly 10 string keys: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC familytype \NC string \NC Values as in the \OPENTYPE\ font specification: \type {Any}, \type {No Fit}, \type {Text and Display}, \type {Script}, \type {Decorative}, \type {Pictorial} \NC \NR \NC serifstyle \NC string \NC See the \OPENTYPE\ font specification for values \NC \NR \NC weight \NC string \NC id. \NC \NR \NC proportion \NC string \NC id. \NC \NR \NC contrast \NC string \NC id. \NC \NR \NC strokevariation \NC string \NC id. \NC \NR \NC armstyle \NC string \NC id. \NC \NR \NC letterform \NC string \NC id. \NC \NR \NC midline \NC string \NC id. \NC \NR \NC xheight \NC string \NC id. \NC \NR \stoptabulate \subsection[fontloadernamestable]{names table} Each item has two top|-|level keys: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC lang \NC string \NC language for this entry \NC \NR \NC names \NC table \NC \NC \NR \stoptabulate The \type {names} keys are the actual \TRUETYPE\ name strings. The possible keys are: \starttabulate[|lT|p|] \NC \rmbf key \NC \bf explanation \NC \NR \NC copyright \NC \NC \NR \NC family \NC \NC \NR \NC subfamily \NC \NC \NR \NC uniqueid \NC \NC \NR \NC fullname \NC \NC \NR \NC version \NC \NC \NR \NC postscriptname \NC \NC \NR \NC trademark \NC \NC \NR \NC manufacturer \NC \NC \NR \NC designer \NC \NC \NR \NC descriptor \NC \NC \NR \NC venderurl \NC \NC \NR \NC designerurl \NC \NC \NR \NC license \NC \NC \NR \NC licenseurl \NC \NC \NR \NC idontknow \NC \NC \NR \NC preffamilyname \NC \NC \NR \NC prefmodifiers \NC \NC \NR \NC compatfull \NC \NC \NR \NC sampletext \NC \NC \NR \NC cidfindfontname \NC \NC \NR \NC wwsfamily \NC \NC \NR \NC wwssubfamily \NC \NC \NR \stoptabulate \subsection{anchor_classes table} The anchor_classes classes: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC name \NC string \NC a descriptive id of this anchor class\NC \NR \NC lookup \NC string \NC \NC \NR \NC type \NC string \NC one of \type {mark}, \type {mkmk}, \type {curs}, \type {mklg} \NC \NR \stoptabulate % type is actually a lookup subtype, not a feature name. Officially, these % strings should be gpos_mark2mark etc. \subsection{gpos table} The \type {gpos} table has one array entry for each lookup. (The \type {gpos_} prefix is somewhat redundant.) \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC type \NC string \NC one of \type {gpos_single}, \type {gpos_pair}, \type {gpos_cursive}, \type {gpos_mark2base},\crlf \type {gpos_mark2ligature}, \type {gpos_mark2mark}, \type {gpos_context},\crlf \type {gpos_contextchain} \NC \NR \NC flags \NC table \NC \NC \NR \NC name \NC string \NC \NC \NR \NC features \NC array \NC \NC \NR \NC subtables \NC array \NC \NC \NR \stoptabulate The flags table has a true value for each of the lookup flags that is actually set: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC r2l \NC boolean \NC \NC \NR \NC ignorebaseglyphs \NC boolean \NC \NC \NR \NC ignoreligatures \NC boolean \NC \NC \NR \NC ignorecombiningmarks \NC boolean \NC \NC \NR \NC mark_class \NC string \NC \NC \NR \stoptabulate The features subtable items of gpos have: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC tag \NC string \NC \NC \NR \NC scripts \NC table \NC \NC \NR \stoptabulate The scripts table within features has: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC script \NC string \NC \NC \NR \NC langs \NC array of strings \NC \NC \NR \stoptabulate The subtables table has: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC name \NC string \NC \NC \NR \NC suffix \NC string \NC (only if used)\NC \NR % used by gpos_single to get a default \NC anchor_classes \NC number \NC (only if used)\NC \NR \NC vertical_kerning \NC number \NC (only if used)\NC \NR \NC kernclass \NC table \NC (only if used)\NC \NR \stoptabulate The kernclass with subtables table has: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC firsts \NC array of strings \NC \NC \NR \NC seconds \NC array of strings \NC \NC \NR \NC lookup \NC string or array \NC associated lookup(s) \NC \NR \NC offsets \NC array of numbers \NC \NC \NR \stoptabulate Note: the kernclass (as far as we can see) always has one entry so it could be one level deep instead. Also the seconds start at \type {[2]} which is close to the fontforge internals so we keep that too. \subsection{gsub table} This has identical layout to the \type {gpos} table, except for the type: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC type \NC string \NC one of \type {gsub_single}, \type {gsub_multiple}, \type {gsub_alternate}, \type {gsub_ligature},\crlf \type {gsub_context}, \type {gsub_contextchain}, \type {gsub_reversecontextchain} \NC \NR \stoptabulate \subsection{ttf_tables and ttf_tab_saved tables} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC tag \NC string \NC \NC \NR \NC len \NC number \NC \NC \NR \NC maxlen \NC number \NC \NC \NR \NC data \NC number \NC \NC \NR \stoptabulate \subsection{mm table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC axes \NC table \NC array of axis names \NC \NR \NC instance_count \NC number \NC \NC \NR \NC positions \NC table \NC array of instance positions (\#axes * instances )\NC \NR \NC defweights \NC table \NC array of default weights for instances \NC \NR \NC cdv \NC string \NC \NC \NR \NC ndv \NC string \NC \NC \NR \NC axismaps \NC table \NC \NC \NR \stoptabulate The \type {axismaps}: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC blends \NC table \NC an array of blend points \NC \NR \NC designs \NC table \NC an array of design values \NC \NR \NC min \NC number \NC \NC \NR \NC def \NC number \NC \NC \NR \NC max \NC number \NC \NC \NR \stoptabulate \subsection{mark_classes table} The keys in this table are mark class names, and the values are a space|-|separated string of glyph names in this class. \subsection{math table} \starttabulate[|lT|p|] \NC ScriptPercentScaleDown \NC \NC \NR \NC ScriptScriptPercentScaleDown \NC \NC \NR \NC DelimitedSubFormulaMinHeight \NC \NC \NR \NC DisplayOperatorMinHeight \NC \NC \NR \NC MathLeading \NC \NC \NR \NC AxisHeight \NC \NC \NR \NC AccentBaseHeight \NC \NC \NR \NC FlattenedAccentBaseHeight \NC \NC \NR \NC SubscriptShiftDown \NC \NC \NR \NC SubscriptTopMax \NC \NC \NR \NC SubscriptBaselineDropMin \NC \NC \NR \NC SuperscriptShiftUp \NC \NC \NR \NC SuperscriptShiftUpCramped \NC \NC \NR \NC SuperscriptBottomMin \NC \NC \NR \NC SuperscriptBaselineDropMax \NC \NC \NR \NC SubSuperscriptGapMin \NC \NC \NR \NC SuperscriptBottomMaxWithSubscript \NC \NC \NR \NC SpaceAfterScript \NC \NC \NR \NC UpperLimitGapMin \NC \NC \NR \NC UpperLimitBaselineRiseMin \NC \NC \NR \NC LowerLimitGapMin \NC \NC \NR \NC LowerLimitBaselineDropMin \NC \NC \NR \NC StackTopShiftUp \NC \NC \NR \NC StackTopDisplayStyleShiftUp \NC \NC \NR \NC StackBottomShiftDown \NC \NC \NR \NC StackBottomDisplayStyleShiftDown \NC \NC \NR \NC StackGapMin \NC \NC \NR \NC StackDisplayStyleGapMin \NC \NC \NR \NC StretchStackTopShiftUp \NC \NC \NR \NC StretchStackBottomShiftDown \NC \NC \NR \NC StretchStackGapAboveMin \NC \NC \NR \NC StretchStackGapBelowMin \NC \NC \NR \NC FractionNumeratorShiftUp \NC \NC \NR \NC FractionNumeratorDisplayStyleShiftUp \NC \NC \NR \NC FractionDenominatorShiftDown \NC \NC \NR \NC FractionDenominatorDisplayStyleShiftDown \NC \NC \NR \NC FractionNumeratorGapMin \NC \NC \NR \NC FractionNumeratorDisplayStyleGapMin \NC \NC \NR \NC FractionRuleThickness \NC \NC \NR \NC FractionDenominatorGapMin \NC \NC \NR \NC FractionDenominatorDisplayStyleGapMin \NC \NC \NR \NC SkewedFractionHorizontalGap \NC \NC \NR \NC SkewedFractionVerticalGap \NC \NC \NR \NC OverbarVerticalGap \NC \NC \NR \NC OverbarRuleThickness \NC \NC \NR \NC OverbarExtraAscender \NC \NC \NR \NC UnderbarVerticalGap \NC \NC \NR \NC UnderbarRuleThickness \NC \NC \NR \NC UnderbarExtraDescender \NC \NC \NR \NC RadicalVerticalGap \NC \NC \NR \NC RadicalDisplayStyleVerticalGap \NC \NC \NR \NC RadicalRuleThickness \NC \NC \NR \NC RadicalExtraAscender \NC \NC \NR \NC RadicalKernBeforeDegree \NC \NC \NR \NC RadicalKernAfterDegree \NC \NC \NR \NC RadicalDegreeBottomRaisePercent \NC \NC \NR \NC MinConnectorOverlap \NC \NC \NR \NC FractionDelimiterSize \NC \NC \NR \NC FractionDelimiterDisplayStyleSize \NC \NC \NR \stoptabulate \subsection{validation_state table} \starttabulate[|lT|p|] \NC \rmbf key \NC \bf explanation \NC \NR \NC bad_ps_fontname \NC \NC \NR \NC bad_glyph_table \NC \NC \NR \NC bad_cff_table \NC \NC \NR \NC bad_metrics_table \NC \NC \NR \NC bad_cmap_table \NC \NC \NR \NC bad_bitmaps_table \NC \NC \NR \NC bad_gx_table \NC \NC \NR \NC bad_ot_table \NC \NC \NR \NC bad_os2_version \NC \NC \NR \NC bad_sfnt_header \NC \NC \NR \stoptabulate \subsection{horiz_base and vert_base table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC tags \NC table \NC an array of script list tags\NC \NR \NC scripts \NC table \NC \NC \NR \stoptabulate The \type {scripts} subtable: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC baseline \NC table \NC \NC \NR \NC default_baseline \NC number \NC \NC \NR \NC lang \NC table \NC \NC \NR \stoptabulate The \type {lang} subtable: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC tag \NC string \NC a script tag \NC \NR \NC ascent \NC number \NC \NC \NR \NC descent \NC number \NC \NC \NR \NC features \NC table \NC \NC \NR \stoptabulate The \type {features} points to an array of tables with the same layout except that in those nested tables, the tag represents a language. \subsection{altuni table} An array of alternate \UNICODE\ values. Inside that array are hashes with: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC unicode \NC number \NC this glyph is also used for this unicode \NC \NR \NC variant \NC number \NC the alternative is driven by this unicode selector \NC \NR \stoptabulate \subsection{vert_variants and horiz_variants table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC variants \NC string \NC \NC \NR \NC italic_correction \NC number \NC \NC \NR \NC parts \NC table \NC \NC \NR \stoptabulate The \type {parts} table is an array of smaller tables: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC component \NC string \NC \NC \NR \NC extender \NC number \NC \NC \NR \NC start \NC number \NC \NC \NR \NC end \NC number \NC \NC \NR \NC advance \NC number \NC \NC \NR \stoptabulate \subsection{mathkern table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC top_right \NC table \NC \NC \NR \NC bottom_right \NC table \NC \NC \NR \NC top_left \NC table \NC \NC \NR \NC bottom_left \NC table \NC \NC \NR \stoptabulate Each of the subtables is an array of small hashes with two keys: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC height \NC number \NC \NC \NR \NC kern \NC number \NC \NC \NR \stoptabulate \subsection{kerns table} Substructure is identical to the per|-|glyph subtable. \subsection{vkerns table} Substructure is identical to the per|-|glyph subtable. \subsection{texdata table} \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC type \NC string \NC \type {unset}, \type {text}, \type {math}, \type {mathext} \NC \NR \NC params \NC array \NC 22 font numeric parameters \NC \NR \stoptabulate \subsection{lookups table} Top|-|level \type {lookups} is quite different from the ones at character level. The keys in this hash are strings, the values the actual lookups, represented as dictionary tables. \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC type \NC string \NC \NC \NR \NC format \NC enum \NC one of \type {glyphs}, \type {class}, \type {coverage}, \type {reversecoverage} \NC \NR \NC tag \NC string \NC \NC \NR \NC current_class \NC array \NC \NC \NR \NC before_class \NC array \NC \NC \NR \NC after_class \NC array \NC \NC \NR \NC rules \NC array \NC an array of rule items\NC \NR \stoptabulate Rule items have one common item and one specialized item: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC lookups \NC array \NC a linear array of lookup names\NC \NR \NC glyphs \NC array \NC only if the parent's format is \type {glyphs}\NC \NR \NC class \NC array \NC only if the parent's format is \type {class}\NC \NR \NC coverage \NC array \NC only if the parent's format is \type {coverage}\NC \NR \NC reversecoverage \NC array \NC only if the parent's format is \type {reversecoverage}\NC \NR \stoptabulate A glyph table is: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC names \NC string \NC \NC \NR \NC back \NC string \NC \NC \NR \NC fore \NC string \NC \NC \NR \stoptabulate A class table is: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC current \NC array \NC of numbers \NC \NR \NC before \NC array \NC of numbers \NC \NR \NC after \NC array \NC of numbers \NC \NR \stoptabulate coverage: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC current \NC array \NC of strings \NC \NR \NC before \NC array \NC of strings\NC \NR \NC after \NC array \NC of strings \NC \NR \stoptabulate reversecoverage: \starttabulate[|lT|l|p|] \NC \rmbf key \NC \bf type \NC \bf explanation \NC \NR \NC current \NC array \NC of strings \NC \NR \NC before \NC array \NC of strings\NC \NR \NC after \NC array \NC of strings \NC \NR \NC replacements \NC string \NC \NC \NR \stoptabulate \stopcomponent