/etc/fonts/fonts.conf /etc/fonts/fonts.dtd /etc/fonts/conf.d $XDG_CONFIG_HOME/fontconfig/conf.d $XDG_CONFIG_HOME/fontconfig/fonts.conf ~/.fonts.conf.d ~/.fonts.conf
The intent is to make font configurations relatively static, and shared by as many applications as possible. It is hoped that this will lead to more stable font selection when passing names from one application to another. XML was chosen as a configuration file format because it provides a format which is easy for external agents to edit while retaining the correct structure and syntax.
Font configuration is separate from font matching; applications needing to do their own matching can access the available fonts from the library and perform private matching. The intent is to permit applications to pick and choose appropriate functionality from the library instead of forcing them to choose between this library and a private configuration mechanism. The hope is that this will ensure that configuration of fonts for all applications can be centralized in one place. Centralizing font configuration will simplify and regularize font installation and customization.
Property Type Description -------------------------------------------------------------- family String Font family names familylang String Languages corresponding to each family style String Font style. Overrides weight and slant stylelang String Languages corresponding to each style fullname String Font full names (often includes style) fullnamelang String Languages corresponding to each fullname slant Int Italic, oblique or roman weight Int Light, medium, demibold, bold or black size Double Point size width Int Condensed, normal or expanded aspect Double Stretches glyphs horizontally before hinting pixelsize Double Pixel size spacing Int Proportional, dual-width, monospace or charcell foundry String Font foundry name antialias Bool Whether glyphs can be antialiased hinting Bool Whether the rasterizer should use hinting hintstyle Int Automatic hinting style verticallayout Bool Use vertical layout autohint Bool Use autohinter instead of normal hinter globaladvance Bool Use font global advance data (deprecated) file String The filename holding the font index Int The index of the font within the file ftface FT_Face Use the specified FreeType face object rasterizer String Which rasterizer is in use (deprecated) outline Bool Whether the glyphs are outlines scalable Bool Whether glyphs can be scaled color Bool Whether any glyphs have color scale Double Scale factor for point->pixel conversions (deprecated) dpi Double Target dots per inch rgba Int unknown, rgb, bgr, vrgb, vbgr, none - subpixel geometry lcdfilter Int Type of LCD filter minspace Bool Eliminate leading from line spacing charset CharSet Unicode chars encoded by the font lang String List of RFC-3066-style languages this font supports fontversion Int Version number of the font capability String List of layout capabilities in the font fontformat String String name of the font format embolden Bool Rasterizer should synthetically embolden the font embeddedbitmap Bool Use the embedded bitmap instead of the outline decorative Bool Whether the style is a decorative variant fontfeatures String List of the feature tags in OpenType to be enabled namelang String Language name to be used for the default value of familylang, stylelang, and fullnamelang prgname String String Name of the running program postscriptname String Font family name in PostScript
Font matching starts with an application constructed pattern. The desired attributes of the resulting font are collected together in a pattern. Each property of the pattern can contain one or more values; these are listed in priority order; matches earlier in the list are considered "closer" than matches later in the list.
The initial pattern is modified by applying the list of editing instructions specific to patterns found in the configuration; each consists of a match predicate and a set of editing operations. They are executed in the order they appeared in the configuration. Each match causes the associated sequence of editing operations to be applied.
After the pattern has been edited, a sequence of default substitutions are performed to canonicalize the set of available properties; this avoids the need for the lower layers to constantly provide default values for various font properties during rendering.
The canonical font pattern is finally matched against all available fonts. The distance from the pattern to the font is measured for each of several properties: foundry, charset, family, lang, spacing, pixelsize, style, slant, weight, antialias, rasterizer and outline. This list is in priority order -- results of comparing earlier elements of this list weigh more heavily than later elements.
There is one special case to this rule; family names are split into two bindings; strong and weak. Strong family names are given greater precedence in the match than lang elements while weak family names are given lower precedence than lang elements. This permits the document language to drive font selection when any document specified font is unavailable.
The pattern representing that font is augmented to include any properties found in the pattern but not found in the font itself; this permits the application to pass rendering instructions or any other data through the matching system. Finally, the list of editing instructions specific to fonts found in the configuration are applied to the pattern. This modified pattern is returned to the application.
The return value contains sufficient information to locate and rasterize the font, including the file name, pixel size and other rendering data. As none of the information involved pertains to the FreeType library, applications are free to use any rasterization engine or even to take the identified font file and access it directly.
The match/edit sequences in the configuration are performed in two passes because there are essentially two different operations necessary -- the first is to modify how fonts are selected; aliasing families and adding suitable defaults. The second is to modify how the selected fonts are rasterized. Those must apply to the selected font, not the original pattern as false matches will often occur.
Values in a list are separated with commas. The name needn't include either families or point sizes; they can be elided. In addition, there are symbolic constants that simultaneously indicate both a name and a value. Here are some examples:
Name Meaning ---------------------------------------------------------- Times-12 12 point Times Roman Times-12:bold 12 point Times Bold Courier:italic Courier Italic in the default size Monospace:matrix=1 .1 0 1 The users preferred monospace font with artificial obliquing
The '\', '-', ':' and ',' characters in family names must be preceded by a '\' character to avoid having them misinterpreted. Similarly, values containing '\', '=', '_', ':' and ',' must also have them preceded by a '\' character. The '\' characters are stripped out of the family name and values as the font name is read.
Name Value Meaning --------------------------------------------------------- MATCH 1 Brief information about font matching MATCHV 2 Extensive font matching information EDIT 4 Monitor match/test/edit execution FONTSET 8 Track loading of font information at startup CACHE 16 Watch cache files being written CACHEV 32 Extensive cache file writing information PARSE 64 (no longer in use) SCAN 128 Watch font files being scanned to build caches SCANV 256 Verbose font file scanning information MEMORY 512 Monitor fontconfig memory usage CONFIG 1024 Monitor which config files are loaded LANGSET 2048 Dump char sets used to construct lang values MATCH2 4096 Display font-matching transformation in patterns
Add the value of the desired debug levels together and assign that (in base 10) to the FC_DEBUG environment variable before running the application. Output from these statements is sent to stdout.
Fontconfig has orthographies for several languages built into the library. No provision has been made for adding new ones aside from rebuilding the library. It currently supports 122 of the 139 languages named in ISO 639-1, 141 of the languages with two-letter codes from ISO 639-2 and another 30 languages with only three-letter codes. Languages with both two and three letter codes are provided with only the two letter code.
For languages used in multiple territories with radically different character sets, fontconfig includes per-territory orthographies. This includes Azerbaijani, Kurdish, Pashto, Tigrinya and Chinese.
The fontconfig document type definition resides in the external entity "fonts.dtd"; this is normally stored in the default font configuration directory (/etc/fonts). Each configuration file should contain the following structure:
<?xml version="1.0"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <fontconfig> ... </fontconfig>
Mode With Match Without Match --------------------------------------------------------------------- "assign" Replace matching value Replace all values "assign_replace" Replace all values Replace all values "prepend" Insert before matching Insert at head of list "prepend_first" Insert at head of list Insert at head of list "append" Append after matching Append at end of list "append_last" Append at end of list Append at end of list "delete" Delete matching value Delete all values "delete_all" Delete all values Delete all values
Constant Property Value ------------------------------------- thin weight 0 extralight weight 40 ultralight weight 40 light weight 50 demilight weight 55 semilight weight 55 book weight 75 regular weight 80 normal weight 80 medium weight 100 demibold weight 180 semibold weight 180 bold weight 200 extrabold weight 205 black weight 210 heavy weight 210 roman slant 0 italic slant 100 oblique slant 110 ultracondensed width 50 extracondensed width 63 condensed width 75 semicondensed width 87 normal width 100 semiexpanded width 113 expanded width 125 extraexpanded width 150 ultraexpanded width 200 proportional spacing 0 dual spacing 90 mono spacing 100 charcell spacing 110 unknown rgba 0 rgb rgba 1 bgr rgba 2 vrgb rgba 3 vbgr rgba 4 none rgba 5 lcdnone lcdfilter 0 lcddefault lcdfilter 1 lcdlight lcdfilter 2 lcdlegacy lcdfilter 3 hintnone hintstyle 0 hintslight hintstyle 1 hintmedium hintstyle 2 hintfull hintstyle 3
<?xml version="1.0"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <!-- /etc/fonts/fonts.conf file to configure system font access --> <fontconfig> <!-- Find fonts in these directories --> <dir>/usr/share/fonts</dir> <dir>/usr/X11R6/lib/X11/fonts</dir> <!-- Accept deprecated 'mono' alias, replacing it with 'monospace' --> <match target="pattern"> <test qual="any" name="family"><string>mono</string></test> <edit name="family" mode="assign"><string>monospace</string></edit> </match> <!-- Names not including any well known alias are given 'sans-serif' --> <match target="pattern"> <test qual="all" name="family" compare="not_eq"><string>sans-serif</string></test> <test qual="all" name="family" compare="not_eq"><string>serif</string></test> <test qual="all" name="family" compare="not_eq"><string>monospace</string></test> <edit name="family" mode="append_last"><string>sans-serif</string></edit> </match> <!-- Load per-user customization file, but don't complain if it doesn't exist --> <include ignore_missing="yes" prefix="xdg">fontconfig/fonts.conf</include> <!-- Load local customization files, but don't complain if there aren't any --> <include ignore_missing="yes">conf.d</include> <include ignore_missing="yes">local.conf</include> <!-- Alias well known font names to available TrueType fonts. These substitute TrueType faces for similar Type1 faces to improve screen appearance. --> <alias> <family>Times</family> <prefer><family>Times New Roman</family></prefer> <default><family>serif</family></default> </alias> <alias> <family>Helvetica</family> <prefer><family>Arial</family></prefer> <default><family>sans</family></default> </alias> <alias> <family>Courier</family> <prefer><family>Courier New</family></prefer> <default><family>monospace</family></default> </alias> <!-- Provide required aliases for standard names Do these after the users configuration file so that any aliases there are used preferentially --> <alias> <family>serif</family> <prefer><family>Times New Roman</family></prefer> </alias> <alias> <family>sans</family> <prefer><family>Arial</family></prefer> </alias> <alias> <family>monospace</family> <prefer><family>Andale Mono</family></prefer> </alias> <-- The example of the requirements of OR operator; If the 'family' contains 'Courier New' OR 'Courier' add 'monospace' as the alternative --> <match target="pattern"> <test name="family" compare="eq"> <string>Courier New</string> </test> <edit name="family" mode="prepend"> <string>monospace</string> </edit> </match> <match target="pattern"> <test name="family" compare="eq"> <string>Courier</string> </test> <edit name="family" mode="prepend"> <string>monospace</string> </edit> </match> </fontconfig>
<?xml version="1.0"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <!-- $XDG_CONFIG_HOME/fontconfig/fonts.conf for per-user font configuration --> <fontconfig> <!-- Private font directory --> <dir prefix="xdg">fonts</dir> <!-- use rgb sub-pixel ordering to improve glyph appearance on LCD screens. Changes affecting rendering, but not matching should always use target="font". --> <match target="font"> <edit name="rgba" mode="assign"><const>rgb</const></edit> </match> <!-- use WenQuanYi Zen Hei font when serif is requested for Chinese --> <match> <!-- If you don't want to use WenQuanYi Zen Hei font for zh-tw etc, you can use zh-cn instead of zh. Please note, even if you set zh-cn, it still matches zh. if you don't like it, you can use compare="eq" instead of compare="contains". --> <test name="lang" compare="contains"> <string>zh</string> </test> <test name="family"> <string>serif</string> </test> <edit name="family" mode="prepend"> <string>WenQuanYi Zen Hei</string> </edit> </match> <!-- use VL Gothic font when sans-serif is requested for Japanese --> <match> <test name="lang" compare="contains"> <string>ja</string> </test> <test name="family"> <string>sans-serif</string> </test> <edit name="family" mode="prepend"> <string>VL Gothic</string> </edit> </match> </fontconfig>
conf.d is the conventional name for a directory of additional configuration files managed by external applications or the local administrator. The filenames starting with decimal digits are sorted in lexicographic order and used as additional configuration files. All of these files are in XML format. The master fonts.conf file references this directory in an <include> directive.
fonts.dtd is a DTD that describes the format of the configuration files.
$XDG_CONFIG_HOME/fontconfig/conf.d and ~/.fonts.conf.d is the conventional name for a per-user directory of (typically auto-generated) configuration files, although the actual location is specified in the global fonts.conf file. please note that ~/.fonts.conf.d is deprecated now. it will not be read by default in the future version.
$XDG_CONFIG_HOME/fontconfig/fonts.conf and ~/.fonts.conf is the conventional location for per-user font configuration, although the actual location is specified in the global fonts.conf file. please note that ~/.fonts.conf is deprecated now. it will not be read by default in the future version.
$XDG_CACHE_HOME/fontconfig/*.cache-* and ~/.fontconfig/*.cache-* is the conventional repository of font information that isn't found in the per-directory caches. This file is automatically maintained by fontconfig. please note that ~/.fontconfig/*.cache-* is deprecated now. it will not be read by default in the future version.
FONTCONFIG_PATH is used to override the default configuration directory.
FONTCONFIG_SYSROOT is used to set a default sysroot directory.
FC_DEBUG is used to output the detailed debugging messages. see Debugging Applications section for more details.
FC_DBG_MATCH_FILTER is used to filter out the patterns. this takes a comma-separated list of object names and effects only when FC_DEBUG has MATCH2. see Debugging Applications section for more details.
FC_LANG is used to specify the default language as the weak binding in the query. if this isn't set, the default language will be determined from current locale.
FONTCONFIG_USE_MMAP is used to control the use of mmap(2) for the cache files if available. this take a boolean value. fontconfig will checks if the cache files are stored on the filesystem that is safe to use mmap(2). explicitly setting this environment variable will causes skipping this check and enforce to use or not use mmap(2) anyway.
SOURCE_DATE_EPOCH is used to ensure fc-cache(1) generates files in a deterministic manner in order to support reproducible builds. When set to a numeric representation of UNIX timestamp, fontconfig will prefer this value over using the modification timestamps of the input files in order to identify which cache files require regeneration. If SOURCE_DATE_EPOCH is not set (or is newer than the mtime of the directory), the existing behaviour is unchanged.
|05 October 2018|