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

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   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>gluLoadSamplingMatrices</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluLoadSamplingMatrices"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluLoadSamplingMatrices — load NURBS sampling and culling matrices</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">gluLoadSamplingMatrices</b>(</code></td><td>GLUnurbs*  </td><td><var class="pdparam">nurb</var>, </td></tr><tr><td> </td><td>const GLfloat *  </td><td><var class="pdparam">model</var>, </td></tr><tr><td> </td><td>const GLfloat *  </td><td><var class="pdparam">perspective</var>, </td></tr><tr><td> </td><td>const GLint *  </td><td><var class="pdparam">view</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>nurb</code></em></span></dt><dd><p>
   4                     Specifies the NURBS object (created with <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>).
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>model</code></em></span></dt><dd><p>
   6                     Specifies a modelview matrix (as from a <a class="citerefentry" href="glGetFloatv.xml"><span class="citerefentry"><span class="refentrytitle">glGetFloatv</span></span></a> call).
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>perspective</code></em></span></dt><dd><p>
   8                     Specifies a projection matrix (as from a <a class="citerefentry" href="glGetFloatv.xml"><span class="citerefentry"><span class="refentrytitle">glGetFloatv</span></span></a> call).
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>view</code></em></span></dt><dd><p>
  10                     Specifies a viewport (as from a <a class="citerefentry" href="glGetIntegerv.xml"><span class="citerefentry"><span class="refentrytitle">glGetIntegerv</span></span></a> call).
  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">gluLoadSamplingMatrices</code> uses <em class="parameter"><code>model</code></em>, <em class="parameter"><code>perspective</code></em>, and <em class="parameter"><code>view</code></em> to recompute the sampling and culling
  13             matrices stored in <em class="parameter"><code>nurb</code></em>.
  14             The sampling matrix determines how finely a NURBS curve or surface
  15             must be tessellated to satisfy the sampling tolerance (as determined by the
  16             <code class="constant">GLU_SAMPLING_TOLERANCE</code> property).
  17             The culling matrix is used in deciding if a NURBS curve or surface
  18             should be culled before
  19             rendering (when the <code class="constant">GLU_CULLING</code> property is turned on).
  20         </p><p>
  21             <code class="function">gluLoadSamplingMatrices</code> is necessary only if the <code class="constant">GLU_AUTO_LOAD_MATRIX</code> property is turned
  22             off (see <a class="citerefentry" href="gluNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluNurbsProperty</span></span></a>).
  23             Although it can be convenient to leave the <code class="constant">GLU_AUTO_LOAD_MATRIX</code>
  24             property turned on, there can be a performance penalty for doing so.
  25             (A round trip to the GL server is needed to fetch the current values
  26             of the modelview matrix, projection matrix, and viewport.)
  27         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  28             <a class="citerefentry" href="gluGetNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluGetNurbsProperty</span></span></a>,
  29             <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>,
  30             <a class="citerefentry" href="gluNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluNurbsProperty</span></span></a>
  31         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  32             Copyright <span class="trademark"></span>© 1991-2006
  33             Silicon Graphics, Inc. This document is licensed under the SGI
  34             Free Software B License. For details, see
  35             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  36         </p></div></div></body></html>