upstream-man-pages/man2/xhtml/glXUseXFont.xml

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
   2 <!-- saved from url=(0013)about:internet -->
   3 <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glXUseXFont</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glXUseXFont"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glXUseXFont — create bitmap display lists from an X font</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glXUseXFont</b>(</code></td><td>Font  </td><td><var class="pdparam">font</var>, </td></tr><tr><td> </td><td>int  </td><td><var class="pdparam">first</var>, </td></tr><tr><td> </td><td>int  </td><td><var class="pdparam">count</var>, </td></tr><tr><td> </td><td>int  </td><td><var class="pdparam">listBase</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>font</code></em></span></dt><dd><p>
   4                     Specifies the font from which character glyphs are to be taken.
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>first</code></em></span></dt><dd><p>
   6                     Specifies the index of the first glyph to be taken.
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p>
   8                     Specifies the number of glyphs to be taken.
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>listBase</code></em></span></dt><dd><p>
  10                     Specifies the index of the first display list to be generated.
  11                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  12             <code class="function">glXUseXFont</code> generates <em class="parameter"><code>count</code></em> display lists,
  13             named <em class="parameter"><code>listBase</code></em> through
  14             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  15
  16                 <mml:mrow>
  17                     <mml:mi mathvariant="italic">listBase</mml:mi>
  18                     <mml:mo>+</mml:mo>
  19                     <mml:mi mathvariant="italic">count</mml:mi>
  20                     <mml:mo>-</mml:mo>
  21                     <mml:mn>1</mml:mn>
  22                 </mml:mrow>
  23             </mml:math>,
  24             each containing a single <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a> command.
  25             The parameters of the <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a> command of display list
  26             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  27
  28                 <mml:mrow>
  29                     <mml:mi mathvariant="italic">listBase</mml:mi>
  30                     <mml:mo>+</mml:mo>
  31                     <mml:mi mathvariant="italic">i</mml:mi>
  32                 </mml:mrow>
  33             </mml:math>
  34             are derived from glyph
  35             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  36
  37                 <mml:mrow>
  38                     <mml:mi mathvariant="italic">first</mml:mi>
  39                     <mml:mo>+</mml:mo>
  40                     <mml:mi mathvariant="italic">i</mml:mi>
  41                 </mml:mrow>
  42             </mml:math>.
  43             Bitmap parameters
  44             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">xorig</mml:mi></mml:math>,
  45             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">yorig</mml:mi></mml:math>,
  46             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>,
  47             and
  48             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">height</mml:mi></mml:math>
  49             are computed from font metrics as
  50             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  51
  52                 <mml:mrow>
  53                     <mml:mi mathvariant="italic">descent</mml:mi>
  54                     <mml:mo>-</mml:mo>
  55                     <mml:mn>1</mml:mn>
  56                 </mml:mrow>
  57             </mml:math>,
  58             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  59
  60                 <mml:mrow>
  61                     <mml:mo>-</mml:mo>
  62                     <mml:mi mathvariant="italic">lbearing</mml:mi>
  63                 </mml:mrow>
  64             </mml:math>,
  65             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  66
  67                 <mml:mrow>
  68                     <mml:mi mathvariant="italic">rbearing</mml:mi>
  69                     <mml:mo>-</mml:mo>
  70                     <mml:mi mathvariant="italic">lbearing</mml:mi>
  71                 </mml:mrow>
  72             </mml:math>,
  73             and
  74             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  75
  76                 <mml:mrow>
  77                     <mml:mi mathvariant="italic">ascent</mml:mi>
  78                     <mml:mo>+</mml:mo>
  79                     <mml:mi mathvariant="italic">descent</mml:mi>
  80                 </mml:mrow>
  81             </mml:math>,
  82             respectively.
  83             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">xmove</mml:mi></mml:math>
  84             is taken from the glyph's
  85             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>
  86             metric,
  87             and
  88             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">ymove</mml:mi></mml:math>
  89             is set to zero.
  90             Finally,
  91             the glyph's image is converted to the appropriate format for <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>.
  92         </p><p>
  93             Using <code class="function">glXUseXFont</code> may be more efficient than accessing the X font and generating
  94             the display lists explicitly,
  95             both because the display lists are created on the server without requiring
  96             a round trip of the glyph data,
  97             and because the server may choose to delay the creation of each
  98             bitmap until it is accessed.
  99         </p><p>
 100             Empty display lists are created for all glyphs that are requested and
 101             are not defined in <em class="parameter"><code>font</code></em>.
 102             <code class="function">glXUseXFont</code> is ignored if there is no current GLX context.
 103         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 104             <code class="constant">BadFont</code> is generated if <em class="parameter"><code>font</code></em> is not a valid font.
 105         </p><p>
 106             <code class="constant">GLXBadContextState</code> is generated if the current GLX context is
 107             in display-list construction mode.
 108         </p><p>
 109             <code class="constant">GLXBadCurrentWindow</code> is generated if the drawable associated
 110             with the current context of the calling thread is a window, and that
 111             window is no longer valid.
 112         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 113             <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>,
 114             <a class="citerefentry" href="glXMakeCurrent.xml"><span class="citerefentry"><span class="refentrytitle">glXMakeCurrent</span></span></a>
 115         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 116             Copyright <span class="trademark"></span>© 1991-2006
 117             Silicon Graphics, Inc. This document is licensed under the SGI
 118             Free Software B License. For details, see
 119             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 120         </p></div></div></body></html>