xenocara/lib/fontconfig/doc/fontconfig-devel/x19.html

264 lines
8.0 KiB
HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>FUNCTIONAL OVERVIEW</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
HREF="t1.html"><LINK
REL="PREVIOUS"
HREF="t1.html"><LINK
REL="NEXT"
TITLE="Datatypes"
HREF="x31.html"></HEAD
><BODY
CLASS="SECT1"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="t1.html"
ACCESSKEY="P"
>&#60;&#60;&#60; Previous</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="x31.html"
ACCESSKEY="N"
>Next &#62;&#62;&#62;</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="AEN19"
>FUNCTIONAL OVERVIEW</A
></H1
><P
>Fontconfig contains two essential modules, the configuration module which
builds an internal configuration from XML files and the matching module
which accepts font patterns and returns the nearest matching font.
</P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN22"
>FONT CONFIGURATION</A
></H2
><P
>The configuration module consists of the FcConfig datatype, libexpat and
FcConfigParse which walks over an XML tree and ammends 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.
</P
><P
>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.
</P
><P
>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.
</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN27"
>FONT PROPERTIES</A
></H2
><P
>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.
</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
> Property Definitions
Property CPP Symbol Type Description
----------------------------------------------------
family FC_FAMILY String Font family names
familylang FC_FAMILYLANG String Language cooresponding to
each family name
style FC_STYLE String Font style. Overrides weight
and slant
stylelang FC_STYLELANG String Language cooresponding to
each style name
fullname FC_FULLNAME String Font face full name where
different from family and
family + style
fullnamelang FC_FULLNAMELANG String Language cooresponding to
each fullname
slant FC_SLANT Int Italic, oblique or roman
weight FC_WEIGHT Int Light, medium, demibold,
bold or black
size FC_SIZE Double Point size
width FC_WIDTH Int Condensed, normal or expanded
aspect FC_ASPECT Double Stretches glyphs horizontally
before hinting
pixelsize FC_PIXEL_SIZE Double Pixel size
spacing FC_SPACING Int Proportional, dual-width,
monospace or charcell
foundry FC_FOUNDRY String Font foundry name
antialias FC_ANTIALIAS Bool Whether glyphs can be
antialiased
hinting FC_HINTING Bool Whether the rasterizer should
use hinting
hintstyle FC_HINT_STYLE Int Automatic hinting style
verticallayout FC_VERTICAL_LAYOUT Bool Use vertical layout
autohint FC_AUTOHINT Bool Use autohinter instead of
normal hinter
globaladvance FC_GLOBAL_ADVANCE Bool Use font global advance data
file FC_FILE String The filename holding the font
index FC_INDEX Int The index of the font within
the file
ftface FC_FT_FACE FT_Face Use the specified FreeType
face object
rasterizer FC_RASTERIZER String Which rasterizer is in use
outline FC_OUTLINE Bool Whether the glyphs are outlines
scalable FC_SCALABLE Bool Whether glyphs can be scaled
scale FC_SCALE Double Scale factor for point-&#62;pixel
conversions
dpi FC_DPI Double Target dots per inch
rgba FC_RGBA Int unknown, rgb, bgr, vrgb,
vbgr, none - subpixel geometry
lcdfilter FC_LCD_FILTER Int Type of LCD filter
minspace FC_MINSPACE Bool Eliminate leading from line
spacing
charset FC_CHARSET CharSet Unicode chars encoded by
the font
lang FC_LANG LangSet Set of RFC-3066-style
languages this font supports
fontversion FC_FONTVERSION Int Version number of the font
capability FC_CAPABILITY String List of layout capabilities in
the font
embolden FC_EMBOLDEN Bool Rasterizer should
synthetically embolden the font
</PRE
></TD
></TR
></TABLE
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="t1.html"
ACCESSKEY="P"
>&#60;&#60;&#60; Previous</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="t1.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="x31.html"
ACCESSKEY="N"
>Next &#62;&#62;&#62;</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
>&nbsp;</TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Datatypes</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>