MAN fonts.conf
出自Gentoo Linux Wiki
[编辑] 名字
fonts.conf - 字体配置文件
[编辑] 概览
- /etc/fonts/fonts.conf
- /etc/fonts/fonts.dtd
- /etc/fonts/conf.d
- ~/.fonts.conf
[编辑] 描述
Fontconfig是一个库，用来提供系统范围的字体配置、定制以及应用。
[编辑] 功能概述
Fontconfig包括两个核心模块，配置模块把XML配置文件转换成Fontconfig的内部配置，匹配模块根据字体样式需求选择最相似的字体。
[编辑] 字体设置
The configuration module consists of the FcConfig datatype, libexpat and FcConfigParse which walks over an XML tree and amends a configuration with data found within. From an external perspective, configuration of the library consists of generating a valid XML tree and feeding that to FcConfigParse. The only other mechanism provided to applications for changing the running configuration is to add fonts and directories to the list of application-provided font files.
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.
[编辑] 字体属性
While font patterns may contain essentially any properties, there are some well known properties with associated types. Fontconfig uses some of these properties for font matching and font completion. Others are provided as a convenience for the applications’ rendering mechanism.
属性 类型 描述
--------------------------------------------------------------
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
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
outline Bool Whether the glyphs are outlines
scalable Bool Whether glyphs can be scaled
scale Double Scale factor for point->pixel conversions
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
embolden Bool Rasterizer should synthetically embolden the font
[编辑] 字体匹配
Fontconfig performs matching by measuring the distance from a provided pattern to all of the available fonts in the system. The closest matching font is selected. This ensures that a font will always be returned, but doesn’t ensure that it is anything like the requested pattern.
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 con‐ sists 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.
[编辑] 字体名称
Fontconfig provides a textual representation for patterns that the library can both accept and generate. The representation is in three parts, first a list of family names, second a list of point sizes and finally a list of additional properties:
<families>-<point sizes>:<name1>=<values1>:<name2>=<values2>...
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:
名称 含义
----------------------------------------------------------
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 preceeded by a ’\’ character to avoid having them misinterpreted. Similarly, values containing ’\’, ’=’, ’_’, ’:’ and ’,’ must also have them preceeded by a ’\’ character. The ’\’ characters are stripped out of the family name and values as the font name is read.
[编辑] 调试工具
To help diagnose font and applications problems, fontconfig is built with a large amount of internal debugging left enabled. It is controlled by means of the FC_DEBUG environment variable. The value of this variable is interpreted as a number, and each bit within that value controls different debugging messages.
名称 值 含义 --------------------------------------------------------- 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 OBJTYPES 4096 Display message when value typechecks fail
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.
[编辑] 语言标签
Each font in the database contains a list of languages it supports. This is computed by comparing the Unicode coverage of the font with the orthography of each language. Languages are tagged using an RFC-3066 compatible naming and occur in two parts -- the ISO 639 language tag followed a hyphen and then by the ISO 3166 country code. The hyphen and country code may be elided.
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.
[编辑] 配置文件格式
Fontconfig的配置文件是XML格式的，其好处是易于利用外部配置工具编辑，确保能写出语法正确的配置文件。因为XML文件是纯文本，所以高级用户也可以用一般的文本编辑器编辑。
Fontconfig的文件格式定义(document type definition)存储在文件fonts.dtd中，这个文件一般位于默认字体配置目录(/etc/fonts)中。每一个配置文件都应该包含如下的结构：
<?xml version="1.0"?> <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> <fontconfig> ... </fontconfig>
[编辑] <FONTCONFIG>
这是字体配置的顶级元素，可以以任意顺序包含<dir>, <cache>, <include>, <match> 和 <alias> 等元素。
[编辑] <DIR>
本元素包含一些目录名，通过在这些目录中搜索字体文件获得可用字体集。
[编辑] <CACHE>
This element contains a file name for the per-user cache of font information. If it starts with ’~’, it refers to a file in the users home directory. This file is used to hold information about fonts that isn’t present in the per-directory cache files. It is automatically maintained by the fontconfig library. The default for this file is ‘‘~/.fonts.cache-<version>’’, where <version> is the font configuration file version number (currently 2).
[编辑] <INCLUDE IGNORE_MISSING= NO">"
This element contains the name of an additional configuration file or directory. If a directory, every file within that directory starting with an ASCII digit (U+0030 - U+0039) and ending with the string ‘‘.conf’’ will be processed in sorted order. When the XML datatype is traversed by FcConfigParse, the contents of the file(s) will also be incorporated into the configuration by passing the filename(s) to FcConfigLoadAndParse. If ’ignore_missing’ is set to "yes" instead of message from the library.
[编辑] <CONFIG>
This element provides a place to consolidate additional configuration information. <config> can contain <blank> and <rescan> elements in any order.
[编辑] <BLANK>
Fonts often include "broken" glyphs which appear in the encoding but are drawn as blanks on the screen. Within the <blank> element, place each Unicode characters which is supposed to be blank in an <int> element. Characters outside of this set which are drawn as blank will be elided from the set of characters supported by the font.
[编辑] <RESCAN>
<rescan>元素中包含一个<int>元素，表示自动检测字体配置变更的默认时间间隔。 每经过这一时间间隔，fontconfig就会识别配置文件和目录，并自动重建内部数据结构。
[编辑] <SELECTFONT>
本元素用来将字体加入白名单或黑名单，以控制字体是否被列出以及是否会被匹配。包括<acceptfont>和<rejectfont>两种元素。
[编辑] <ACCEPTFONT>
Fonts matched by an acceptfont element are "whitelisted"; such fonts
are explicitly included in the set of fonts used to resolve list and
match requests; including them in this list protects them from being
"blacklisted" by a rejectfont element. Acceptfont elements include
glob and pattern elements which are used to match fonts.
[编辑] <REJECTFONT>
Fonts matched by an rejectfont element are "blacklisted"; such fonts
are excluded from the set of fonts used to resolve list and match
requests as if they didn’t exist in the system. Rejectfont elements
include glob and pattern elements which are used to match fonts.
[编辑] <GLOB>
Glob elements hold shell-style filename matching patterns (including ?
and *) which match fonts based on their complete pathnames. This can
be used to exclude a set of directories (/usr/share/fonts/uglyfont*),
or particular font file types (*.pcf.gz), but the latter mechanism
relies rather heavily on filenaming conventions which can’t be relied
upon. Note that globs only apply to directories, not to individual
fonts.
[编辑] <PATTERN>
Pattern elements perform list-style matching on incoming fonts; that
is, they hold a list of elements and associated values. If all of
those elements have a matching value, then the pattern matches the
font. This can be used to select fonts based on attributes of the font
(scalable, bold, etc), which is a more reliable mechanism than using
file extensions. Pattern elements include patelt elements.
[编辑] <PATELT NAME= PROPERTY">"
Patelt elements hold a single pattern element and list of values. They
must have a ’name’ attribute which indicates the pattern element name.
Patelt elements include int, double, string, matrix, bool, charset and
const elements.
[编辑] <MATCH TARGET= PATTERN">"
This element holds first a (possibly empty) list of <test> elements and
then a (possibly empty) list of <edit> elements. Patterns which match
all of the tests are subjected to all the edits. If ’target’ is set to
"font" instead of the default "pattern", then this element applies to
the font name resulting from a match rather than a font pattern to be
matched. If ’target’ is set to "scan", then this element applies when
the font is scanned to build the fontconfig database.
[编辑] <TEST QUAL= ANY" NAME="PROPERTY" TARGET="DEFAULT" COMPARE="EQ">"
This element contains a single value which is compared with the target
(’pattern’, ’font’, ’scan’ or ’default’) property "property" (substi‐
tute any of the property names seen above). ’compare’ can be one of
"eq", "not_eq", "less", "less_eq", "more", or "more_eq". ’qual’ may
either be the default, "any", in which case the match succeeds if any
value associated with the property matches the test value, or "all", in
which case all of the values associated with the property must match
the test value. When used in a <match target="font"> element, the tar‐
get= attribute in the <test> element selects between matching the orig‐
inal pattern or the font. "default" selects whichever target the outer
<match> element has selected.
[编辑] <EDIT NAME= PROPERTY" MODE="ASSIGN" BINDING="WEAK">"
This element contains a list of expression elements (any of the value
or operator elements). The expression elements are evaluated at run-
time and modify the property "property". The modification depends on
whether "property" was matched by one of the associated <test> ele‐
ments, if so, the modification may affect the first matched value. Any
values inserted into the property are given the indicated binding
("strong", "weak" or "same") with "same" binding using the value from
the matched pattern element. ’mode’ is one of:
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
[编辑] <INT>, <DOUBLE>, <STRING>, <BOOL>
These elements hold a single value of the indicated type. <bool> ele‐
ments hold either true or false. An important limitation exists in the
parsing of floating point numbers -- fontconfig requires that the man‐
tissa start with a digit, not a decimal point, so insert a leading zero
for purely fractional values (e.g. use 0.5 instead of .5 and -0.5
instead of -.5).
[编辑] <MATRIX>
This element holds the four <double> elements of an affine transforma‐
tion.
[编辑] <NAME>
Holds a property name. Evaluates to the first value from the property
of the font, not the pattern.
[编辑] <CONST>
Holds the name of a constant; these are always integers and serve as symbolic names for common font values:
常量 属性 值
-------------------------------------
thin weight 0
extralight weight 40
ultralight weight 40
light weight 50
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
[编辑] <OR>, <AND>, <PLUS>, <MINUS>, <TIMES>, <DIVIDE>
These elements perform the specified operation on a list of expression
elements. <or> and <and> are boolean, not bitwise.
[编辑] <EQ>, <NOT_EQ>, <LESS>, <LESS_EQ>, <MORE>, <MORE_EQ>
These elements compare two values, producing a boolean result.
[编辑] <NOT>
Inverts the boolean sense of its one expression element
[编辑] <IF>
This element takes three expression elements; if the value of the first
is true, it produces the value of the second, otherwise it produces the
value of the third.
[编辑] <ALIAS>
Alias elements provide a shorthand notation for the set of common match
operations needed to substitute one font family for another. They con‐
tain a <family> element followed by optional <prefer>, <accept> and
<default> elements. Fonts matching the <family> element are edited to
prepend the list of <prefer>ed families before the matching <family>,
append the <accept>able families after the matching <family> and append
the <default> families to the end of the family list.
[编辑] <FAMILY>
Holds a single font family name
[编辑] <PREFER>, <ACCEPT>, <DEFAULT>
These hold a list of <family> elements to be used by the <alias> ele‐
ment.
[编辑] 配置文件样例
[编辑] 系统配置文件
| 文件： 系统配置文件样例 |
<?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’
-->
<match target="pattern">
<test qual="all" name="family" mode="not_eq">sans</test>
<test qual="all" name="family" mode="not_eq">serif</test>
<test qual="all" name="family" mode="not_eq">monospace</test>
<edit name="family" mode="append_last"><string>sans</string></edit>
</match>
<!--
Load per-user customization file, but don’t complain
if it doesn’t exist
-->
<include ignore_missing="yes">~/.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>
</fontconfig>
|
[编辑] 用户配置文件
| 文件： 用户配置文件样例，位于~/.fonts.conf |
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<!-- ~/.fonts.conf for per-user font configuration -->
<fontconfig>
<!--
Private font directory
-->
<dir>~/.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>
</fontconfig>
|
[编辑] 文件
fonts.conf contains configuration information for the fontconfig library consisting of directories to look at for font information as well as instructions on editing program specified font patterns before attempting to match the available fonts. It is in xml format.
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.
~/.fonts.conf is the conventional location for per-user font configuration, although the actual location is specified in the global fonts.conf file.
~/.fonts.cache-* is the conventional repository of font information that isn’t found in the per-directory caches. This file is automatically maintained by fontconfig.
[编辑] 参见
fc-cache(1), fc-match(1), fc-list(1)
[编辑] 版本
Fontconfig version 2.6.0
