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<?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 V1.78.1" /></head><body><div class="refentry"><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" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">gluLoadSamplingMatrices</strong>(</code></td><td>GLUnurbs* <var class="pdparam">nurb</var>, </td></tr><tr><td> </td><td>const GLfloat * <var class="pdparam">model</var>, </td></tr><tr><td> </td><td>const GLfloat * <var class="pdparam">perspective</var>, </td></tr><tr><td> </td><td>const GLint * <var class="pdparam">view</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>nurb</code></em></span></dt><dd><p>
                    Specifies the NURBS object (created with <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>).
                </p></dd><dt><span class="term"><em class="parameter"><code>model</code></em></span></dt><dd><p>
                    Specifies a modelview matrix (as from a <a class="citerefentry" href="glGetFloatv.xml"><span class="citerefentry"><span class="refentrytitle">glGetFloatv</span></span></a> call).
                </p></dd><dt><span class="term"><em class="parameter"><code>perspective</code></em></span></dt><dd><p>
                    Specifies a projection matrix (as from a <a class="citerefentry" href="glGetFloatv.xml"><span class="citerefentry"><span class="refentrytitle">glGetFloatv</span></span></a> call).
                </p></dd><dt><span class="term"><em class="parameter"><code>view</code></em></span></dt><dd><p>
                    Specifies a viewport (as from a <a class="citerefentry" href="glGetIntegerv.xml"><span class="citerefentry"><span class="refentrytitle">glGetIntegerv</span></span></a> call).
                </p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>
            <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 
            matrices stored in <em class="parameter"><code>nurb</code></em>.
            The sampling matrix determines how finely a NURBS curve or surface
            must be tessellated to satisfy the sampling tolerance (as determined by the
            <code class="constant">GLU_SAMPLING_TOLERANCE</code> property).
            The culling matrix is used in deciding if a NURBS curve or surface
            should be culled before 
            rendering (when the <code class="constant">GLU_CULLING</code> property is turned on).
        </p><p>
            <code class="function">gluLoadSamplingMatrices</code> is necessary only if the <code class="constant">GLU_AUTO_LOAD_MATRIX</code> property is turned
            off (see <a class="citerefentry" href="gluNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluNurbsProperty</span></span></a>).
            Although it can be convenient to leave the <code class="constant">GLU_AUTO_LOAD_MATRIX</code>
            property turned on, there can be a performance penalty for doing so.
            (A round trip to the GL server is needed to fetch the current values
            of the modelview matrix, projection matrix, and viewport.)
        </p></div><div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="gluGetNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluGetNurbsProperty</span></span></a>,
            <a class="citerefentry" href="gluNewNurbsRenderer.xml"><span class="citerefentry"><span class="refentrytitle">gluNewNurbsRenderer</span></span></a>,
            <a class="citerefentry" href="gluNurbsProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluNurbsProperty</span></span></a>
        </p></div><div class="refsect1"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>