xft-fonts.xml

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

<refentry id="pango-Xft-Fonts-and-Rendering">
<refmeta>
<refentrytitle role="top_of_page" id="pango-Xft-Fonts-and-Rendering.top_of_page">Xft Fonts and Rendering</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>PANGO Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>Xft Fonts and Rendering</refname>
<refpurpose>Font handling and rendering with the Xft backend</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>

<refsynopsisdiv id="pango-Xft-Fonts-and-Rendering.synopsis" role="synopsis">
<title role="synopsis.title">Synopsis</title>
<anchor id="PangoXftFont"/><anchor id="PangoXftFontMap"/><anchor id="PangoXftRenderer"/>
<synopsis>
                    <link linkend="PangoXftFont-struct">PangoXftFont</link>;
                    <link linkend="PangoXftFontMap-struct">PangoXftFontMap</link>;
#define             <link linkend="PANGO-RENDER-TYPE-XFT:CAPS">PANGO_RENDER_TYPE_XFT</link>
<link linkend="PangoContext">PangoContext</link>*       <link linkend="pango-xft-get-context">pango_xft_get_context</link>               (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);
<link linkend="PangoFontMap">PangoFontMap</link>*       <link linkend="pango-xft-get-font-map">pango_xft_get_font_map</link>              (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);
<link linkend="void">void</link>                <link linkend="pango-xft-set-default-substitute">pango_xft_set_default_substitute</link>    (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen,
                                                         <link linkend="PangoXftSubstituteFunc">PangoXftSubstituteFunc</link> func,
                                                         <link linkend="gpointer">gpointer</link> data,
                                                         <link linkend="GDestroyNotify">GDestroyNotify</link> notify);
<link linkend="void">void</link>                (<link linkend="PangoXftSubstituteFunc">*PangoXftSubstituteFunc</link>)           (<link linkend="FcPattern">FcPattern</link> *pattern,
                                                         <link linkend="gpointer">gpointer</link> data);
<link linkend="void">void</link>                <link linkend="pango-xft-substitute-changed">pango_xft_substitute_changed</link>        (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);
<link linkend="void">void</link>                <link linkend="pango-xft-shutdown-display">pango_xft_shutdown_display</link>          (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);
<link linkend="XftFont">XftFont</link>*            <link linkend="pango-xft-font-get-font">pango_xft_font_get_font</link>             (<link linkend="PangoFont">PangoFont</link> *font);
<link linkend="Display">Display</link>*            <link linkend="pango-xft-font-get-display">pango_xft_font_get_display</link>          (<link linkend="PangoFont">PangoFont</link> *font);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-xft-font-has-char">pango_xft_font_has_char</link>             (<link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="gunichar">gunichar</link> wc);
<link linkend="FT-Face">FT_Face</link>             <link linkend="pango-xft-font-lock-face">pango_xft_font_lock_face</link>            (<link linkend="PangoFont">PangoFont</link> *font);
<link linkend="void">void</link>                <link linkend="pango-xft-font-unlock-face">pango_xft_font_unlock_face</link>          (<link linkend="PangoFont">PangoFont</link> *font);
<link linkend="guint">guint</link>               <link linkend="pango-xft-font-get-glyph">pango_xft_font_get_glyph</link>            (<link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="gunichar">gunichar</link> wc);
<link linkend="PangoGlyph">PangoGlyph</link>          <link linkend="pango-xft-font-get-unknown-glyph">pango_xft_font_get_unknown_glyph</link>    (<link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="gunichar">gunichar</link> wc);
                    <link linkend="PangoXftRenderer-struct">PangoXftRenderer</link>;
                    <link linkend="PangoXftRendererClass">PangoXftRendererClass</link>;
<link linkend="PangoRenderer">PangoRenderer</link>*      <link linkend="pango-xft-renderer-new">pango_xft_renderer_new</link>              (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);
<link linkend="void">void</link>                <link linkend="pango-xft-renderer-set-draw">pango_xft_renderer_set_draw</link>         (<link linkend="PangoXftRenderer">PangoXftRenderer</link> *xftrenderer,
                                                         <link linkend="XftDraw">XftDraw</link> *draw);
<link linkend="void">void</link>                <link linkend="pango-xft-renderer-set-default-color">pango_xft_renderer_set_default_color</link>
                                                        (<link linkend="PangoXftRenderer">PangoXftRenderer</link> *xftrenderer,
                                                         <link linkend="PangoColor">PangoColor</link> *default_color);
<link linkend="void">void</link>                <link linkend="pango-xft-render">pango_xft_render</link>                    (<link linkend="XftDraw">XftDraw</link> *draw,
                                                         <link linkend="XftColor">XftColor</link> *color,
                                                         <link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs,
                                                         <link linkend="gint">gint</link> x,
                                                         <link linkend="gint">gint</link> y);
<link linkend="void">void</link>                <link linkend="pango-xft-picture-render">pango_xft_picture_render</link>            (<link linkend="Display">Display</link> *display,
                                                         <link linkend="Picture">Picture</link> src_picture,
                                                         <link linkend="Picture">Picture</link> dest_picture,
                                                         <link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs,
                                                         <link linkend="gint">gint</link> x,
                                                         <link linkend="gint">gint</link> y);
<link linkend="void">void</link>                <link linkend="pango-xft-render-transformed">pango_xft_render_transformed</link>        (<link linkend="XftDraw">XftDraw</link> *draw,
                                                         <link linkend="XftColor">XftColor</link> *color,
                                                         <link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                                         <link linkend="PangoFont">PangoFont</link> *font,
                                                         <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs,
                                                         <link linkend="int">int</link> x,
                                                         <link linkend="int">int</link> y);
<link linkend="void">void</link>                <link linkend="pango-xft-render-layout-line">pango_xft_render_layout_line</link>        (<link linkend="XftDraw">XftDraw</link> *draw,
                                                         <link linkend="XftColor">XftColor</link> *color,
                                                         <link linkend="PangoLayoutLine">PangoLayoutLine</link> *line,
                                                         <link linkend="int">int</link> x,
                                                         <link linkend="int">int</link> y);
<link linkend="void">void</link>                <link linkend="pango-xft-render-layout">pango_xft_render_layout</link>             (<link linkend="XftDraw">XftDraw</link> *draw,
                                                         <link linkend="XftColor">XftColor</link> *color,
                                                         <link linkend="PangoLayout">PangoLayout</link> *layout,
                                                         <link linkend="int">int</link> x,
                                                         <link linkend="int">int</link> y);
</synopsis>
</refsynopsisdiv>

<refsect1 id="pango-Xft-Fonts-and-Rendering.object-hierarchy" role="object_hierarchy">
<title role="object_hierarchy.title">Object Hierarchy</title>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----<link linkend="PangoFont">PangoFont</link>
         +----<link linkend="PangoFcFont">PangoFcFont</link>
               +----PangoXftFont
</synopsis>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----<link linkend="PangoFontMap">PangoFontMap</link>
         +----<link linkend="PangoFcFontMap">PangoFcFontMap</link>
               +----PangoXftFontMap
</synopsis>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----<link linkend="PangoRenderer">PangoRenderer</link>
         +----PangoXftRenderer
</synopsis>

</refsect1>





<refsect1 id="pango-Xft-Fonts-and-Rendering.properties" role="properties">
<title role="properties.title">Properties</title>
<synopsis>
  &quot;<link linkend="PangoXftRenderer--display">display</link>&quot;                  <link linkend="gpointer">gpointer</link>              : Write / Construct Only
  &quot;<link linkend="PangoXftRenderer--screen">screen</link>&quot;                   <link linkend="gint">gint</link>                  : Write / Construct Only
</synopsis>
</refsect1>



<refsect1 id="pango-Xft-Fonts-and-Rendering.description" role="desc">
<title role="desc.title">Description</title>
<para>
The Xft library is a library for displaying fonts on the X window
system; internally it uses the fontconfig library to locate font
files, and the FreeType library to load and render fonts. The
Xft backend is the recommended Pango font backend for screen
display with X. (The <link linkend="pango-Cairo-Rendering">Cairo back end</link> is another possibility.)
</para>
<para>
Using the Xft backend is generally straightforward;
<link linkend="pango-xft-get-context"><function>pango_xft_get_context()</function></link> creates a context for a specified display
and screen. You can then create a <link linkend="PangoLayout"><type>PangoLayout</type></link> with that context
and render it with <link linkend="pango-xft-render-layout"><function>pango_xft_render_layout()</function></link>. At a more advanced
level, the low-level fontconfig options used for rendering fonts
can be affected using <link linkend="pango-xft-set-default-substitute"><function>pango_xft_set_default_substitute()</function></link>, and
<link linkend="pango-xft-substitute-changed"><function>pango_xft_substitute_changed()</function></link>.
</para>
<para>
A range of functions for drawing pieces of a layout, such as
individual layout lines and glyphs strings are provided.  You can also
directly create a <link linkend="PangoXftRenderer"><type>PangoXftRenderer</type></link>. Finally, in some advanced cases, it
is useful to derive from <link linkend="PangoXftRenderer"><type>PangoXftRenderer</type></link>. Deriving from
<link linkend="PangoXftRenderer"><type>PangoXftRenderer</type></link> is useful for two reasons. One reason is be to
support custom attributes by overriding <link linkend="PangoRendererClass"><type>PangoRendererClass</type></link> virtual
functions like 'prepare_run' or 'draw_shape'. The reason is to
customize exactly how the final bits are drawn to the destination by
overriding the <link linkend="PangoXftRendererClass"><type>PangoXftRendererClass</type></link> virtual functions
'composite_glyphs' and 'composite_trapezoids'.
</para>
</refsect1>

<refsect1 id="pango-Xft-Fonts-and-Rendering.details" role="details">
<title role="details.title">Details</title>
<refsect2 id="PangoXftFont-struct" role="struct">
<title>PangoXftFont</title>
<indexterm zone="PangoXftFont-struct"><primary>PangoXftFont</primary></indexterm><programlisting>typedef struct _PangoXftFont PangoXftFont;</programlisting>
<para>
<link linkend="PangoXftFont"><type>PangoXftFont</type></link> is an implementation of <link linkend="PangoFcFont"><type>PangoFcFont</type></link> using the Xft
library for rendering.  It is used in conjunction with <link linkend="PangoXftFontMap"><type>PangoXftFontMap</type></link>.
</para></refsect2>
<refsect2 id="PangoXftFontMap-struct" role="struct">
<title>PangoXftFontMap</title>
<indexterm zone="PangoXftFontMap-struct"><primary>PangoXftFontMap</primary></indexterm><programlisting>typedef struct _PangoXftFontMap PangoXftFontMap;</programlisting>
<para>
<link linkend="PangoXftFontMap"><type>PangoXftFontMap</type></link> is an implementation of <link linkend="PangoFcFontMap"><type>PangoFcFontMap</type></link> suitable for
the Xft library as the renderer.  It is used in to create fonts of
type <link linkend="PangoXftFont"><type>PangoXftFont</type></link>.
</para></refsect2>
<refsect2 id="PANGO-RENDER-TYPE-XFT:CAPS" role="macro" condition="deprecated:">
<title>PANGO_RENDER_TYPE_XFT</title>
<indexterm zone="PANGO-RENDER-TYPE-XFT:CAPS" role="deprecated"><primary>PANGO_RENDER_TYPE_XFT</primary></indexterm><programlisting>#define PANGO_RENDER_TYPE_XFT "PangoRenderXft"
</programlisting>
<warning><para><literal>PANGO_RENDER_TYPE_XFT</literal> is deprecated and should not be used in newly-written code.</para></warning>
<para>
A string constant that was used to identify shape engines that work
with the Xft backend. See <link linkend="PANGO-RENDER-TYPE-FC:CAPS"><literal>PANGO_RENDER_TYPE_FC</literal></link> for the replacement.
</para></refsect2>
<refsect2 id="pango-xft-get-context" role="function">
<title>pango_xft_get_context ()</title>
<indexterm zone="pango-xft-get-context"><primary>pango_xft_get_context</primary></indexterm><programlisting><link linkend="PangoContext">PangoContext</link>*       pango_xft_get_context               (<link linkend="Display">Display</link> *display,
                                                         <link linkend="int">int</link> screen);</programlisting>
<para>
Retrieves a <link linkend="PangoContext"><type>PangoContext</type></link> appropriate for rendering with
Xft fonts on the given screen of the given display.</para>