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1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<HTML 3><HEAD 4><TITLE 5>FUNCTIONAL OVERVIEW</TITLE 6><META 7NAME="GENERATOR" 8CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9REL="HOME" 10HREF="t1.html"><LINK 11REL="PREVIOUS" 12HREF="t1.html"><LINK 13REL="NEXT" 14TITLE="Datatypes" 15HREF="x31.html"></HEAD 16><BODY 17CLASS="SECT1" 18BGCOLOR="#FFFFFF" 19TEXT="#000000" 20LINK="#0000FF" 21VLINK="#840084" 22ALINK="#0000FF" 23><DIV 24CLASS="NAVHEADER" 25><TABLE 26SUMMARY="Header navigation table" 27WIDTH="100%" 28BORDER="0" 29CELLPADDING="0" 30CELLSPACING="0" 31><TR 32><TH 33COLSPAN="3" 34ALIGN="center" 35></TH 36></TR 37><TR 38><TD 39WIDTH="10%" 40ALIGN="left" 41VALIGN="bottom" 42><A 43HREF="t1.html" 44ACCESSKEY="P" 45><<< Previous</A 46></TD 47><TD 48WIDTH="80%" 49ALIGN="center" 50VALIGN="bottom" 51></TD 52><TD 53WIDTH="10%" 54ALIGN="right" 55VALIGN="bottom" 56><A 57HREF="x31.html" 58ACCESSKEY="N" 59>Next >>></A 60></TD 61></TR 62></TABLE 63><HR 64ALIGN="LEFT" 65WIDTH="100%"></DIV 66><DIV 67CLASS="SECT1" 68><H1 69CLASS="SECT1" 70><A 71NAME="AEN19" 72>FUNCTIONAL OVERVIEW</A 73></H1 74><P 75>Fontconfig contains two essential modules, the configuration module which 76builds an internal configuration from XML files and the matching module 77which accepts font patterns and returns the nearest matching font. 78 </P 79><DIV 80CLASS="SECT2" 81><H2 82CLASS="SECT2" 83><A 84NAME="AEN22" 85>FONT CONFIGURATION</A 86></H2 87><P 88>The configuration module consists of the FcConfig datatype, libexpat and 89FcConfigParse which walks over an XML tree and amends a configuration with 90data found within. From an external perspective, configuration of the 91library consists of generating a valid XML tree and feeding that to 92FcConfigParse. The only other mechanism provided to applications for 93changing the running configuration is to add fonts and directories to the 94list of application-provided font files. 95 </P 96><P 97>The intent is to make font configurations relatively static, and shared by 98as many applications as possible. It is hoped that this will lead to more 99stable font selection when passing names from one application to another. 100XML was chosen as a configuration file format because it provides a format 101which is easy for external agents to edit while retaining the correct 102structure and syntax. 103 </P 104><P 105>Font configuration is separate from font matching; applications needing to 106do their own matching can access the available fonts from the library and 107perform private matching. The intent is to permit applications to pick and 108choose appropriate functionality from the library instead of forcing them to 109choose between this library and a private configuration mechanism. The hope 110is that this will ensure that configuration of fonts for all applications 111can be centralized in one place. Centralizing font configuration will 112simplify and regularize font installation and customization. 113 </P 114></DIV 115><DIV 116CLASS="SECT2" 117><H2 118CLASS="SECT2" 119><A 120NAME="AEN27" 121>FONT PROPERTIES</A 122></H2 123><P 124>While font patterns may contain essentially any properties, there are some 125well known properties with associated types. Fontconfig uses some of these 126properties for font matching and font completion. Others are provided as a 127convenience for the application's rendering mechanism. 128 </P 129><TABLE 130BORDER="0" 131BGCOLOR="#E0E0E0" 132WIDTH="100%" 133><TR 134><TD 135><PRE 136CLASS="PROGRAMLISTING" 137> Property Definitions 138 139 Property C Preprocessor Symbol Type Description 140 ---------------------------------------------------- 141 family FC_FAMILY String Font family names 142 familylang FC_FAMILYLANG String Language corresponding to 143 each family name 144 style FC_STYLE String Font style. Overrides weight 145 and slant 146 stylelang FC_STYLELANG String Language corresponding to 147 each style name 148 fullname FC_FULLNAME String Font face full name where 149 different from family and 150 family + style 151 fullnamelang FC_FULLNAMELANG String Language corresponding to 152 each fullname 153 slant FC_SLANT Int Italic, oblique or roman 154 weight FC_WEIGHT Int Light, medium, demibold, 155 bold or black 156 size FC_SIZE Double Point size 157 width FC_WIDTH Int Condensed, normal or expanded 158 aspect FC_ASPECT Double Stretches glyphs horizontally 159 before hinting 160 pixelsize FC_PIXEL_SIZE Double Pixel size 161 spacing FC_SPACING Int Proportional, dual-width, 162 monospace or charcell 163 foundry FC_FOUNDRY String Font foundry name 164 antialias FC_ANTIALIAS Bool Whether glyphs can be 165 antialiased 166 hinting FC_HINTING Bool Whether the rasterizer should 167 use hinting 168 hintstyle FC_HINT_STYLE Int Automatic hinting style 169 verticallayout FC_VERTICAL_LAYOUT Bool Use vertical layout 170 autohint FC_AUTOHINT Bool Use autohinter instead of 171 normal hinter 172 globaladvance FC_GLOBAL_ADVANCE Bool Use font global advance data (deprecated) 173 file FC_FILE String The filename holding the font 174 index FC_INDEX Int The index of the font within 175 the file 176 ftface FC_FT_FACE FT_Face Use the specified FreeType 177 face object 178 rasterizer FC_RASTERIZER String Which rasterizer is in use (deprecated) 179 outline FC_OUTLINE Bool Whether the glyphs are outlines 180 scalable FC_SCALABLE Bool Whether glyphs can be scaled 181 scale FC_SCALE Double Scale factor for point->pixel 182 conversions 183 dpi FC_DPI Double Target dots per inch 184 rgba FC_RGBA Int unknown, rgb, bgr, vrgb, 185 vbgr, none - subpixel geometry 186 lcdfilter FC_LCD_FILTER Int Type of LCD filter 187 minspace FC_MINSPACE Bool Eliminate leading from line 188 spacing 189 charset FC_CHARSET CharSet Unicode chars encoded by 190 the font 191 lang FC_LANG LangSet Set of RFC-3066-style 192 languages this font supports 193 fontversion FC_FONTVERSION Int Version number of the font 194 capability FC_CAPABILITY String List of layout capabilities in 195 the font 196 embolden FC_EMBOLDEN Bool Rasterizer should 197 synthetically embolden the font 198 fontfeatures FC_FONT_FEATURES String List of extra feature tags in 199 OpenType to be enabled 200 namelang FC_NAMELANG String Language name to be used for the 201 default value of familylang, 202 stylelang and fullnamelang 203 prgname FC_PRGNAME String Name of the running program 204 hash FC_HASH String SHA256 hash value of the font data 205 with "sha256:" prefix. 206 postscriptname FC_POSTSCRIPT_NAME String Font name in PostScript 207 </PRE 208></TD 209></TR 210></TABLE 211></DIV 212></DIV 213><DIV 214CLASS="NAVFOOTER" 215><HR 216ALIGN="LEFT" 217WIDTH="100%"><TABLE 218SUMMARY="Footer navigation table" 219WIDTH="100%" 220BORDER="0" 221CELLPADDING="0" 222CELLSPACING="0" 223><TR 224><TD 225WIDTH="33%" 226ALIGN="left" 227VALIGN="top" 228><A 229HREF="t1.html" 230ACCESSKEY="P" 231><<< Previous</A 232></TD 233><TD 234WIDTH="34%" 235ALIGN="center" 236VALIGN="top" 237><A 238HREF="t1.html" 239ACCESSKEY="H" 240>Home</A 241></TD 242><TD 243WIDTH="33%" 244ALIGN="right" 245VALIGN="top" 246><A 247HREF="x31.html" 248ACCESSKEY="N" 249>Next >>></A 250></TD 251></TR 252><TR 253><TD 254WIDTH="33%" 255ALIGN="left" 256VALIGN="top" 257></TD 258><TD 259WIDTH="34%" 260ALIGN="center" 261VALIGN="top" 262> </TD 263><TD 264WIDTH="33%" 265ALIGN="right" 266VALIGN="top" 267>Datatypes</TD 268></TR 269></TABLE 270></DIV 271></BODY 272></HTML 273>