upstream-man-pages/man2/xhtml/gluTessEndPolygon.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>gluTessEndPolygon</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluTessEndPolygon"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluTessEndPolygon — delimit a polygon description</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">gluTessEndPolygon</b>(</code></td><td>GLUtesselator*  </td><td><var class="pdparam">tess</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>tess</code></em></span></dt><dd><p>
   4                     Specifies the tessellation object (created with <a class="citerefentry" href="gluNewTess.xml"><span class="citerefentry"><span class="refentrytitle">gluNewTess</span></span></a>).
   5                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   6             <a class="citerefentry" href="gluTessBeginPolygon.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginPolygon</span></span></a> and <code class="function">gluTessEndPolygon</code> delimit the
   7             definition of a convex, concave, or self-intersecting polygon. Within
   8             each <a class="citerefentry" href="gluTessBeginPolygon.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginPolygon</span></span></a>/<code class="function">gluTessEndPolygon</code> pair, there must be
   9             one or more calls to <a class="citerefentry" href="gluTessBeginContour.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginContour</span></span></a>/<a class="citerefentry" href="gluTessEndContour.xml"><span class="citerefentry"><span class="refentrytitle">gluTessEndContour</span></span></a>.
  10             Within each contour, there are zero or more calls to <a class="citerefentry" href="gluTessVertex.xml"><span class="citerefentry"><span class="refentrytitle">gluTessVertex</span></span></a>.
  11             The vertices specify a closed contour (the last vertex of each contour
  12             is automatically linked to the first). See the <a class="citerefentry" href="gluTessVertex.xml"><span class="citerefentry"><span class="refentrytitle">gluTessVertex</span></span></a>,
  13             <a class="citerefentry" href="gluTessBeginContour.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginContour</span></span></a>, and <a class="citerefentry" href="gluTessEndContour.xml"><span class="citerefentry"><span class="refentrytitle">gluTessEndContour</span></span></a> reference pages for
  14             more details.
  15         </p><p>
  16             Once <code class="function">gluTessEndPolygon</code> is called, the polygon is tessellated, and the
  17             resulting triangles are described through callbacks.
  18             See <a class="citerefentry" href="gluTessCallback.xml"><span class="citerefentry"><span class="refentrytitle">gluTessCallback</span></span></a> for descriptions of the callback functions.
  19         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="example"></a><h2>Example</h2><p>
  20             A quadrilateral with a triangular hole in it can be described like this:
  21             </p><pre class="programlisting">
  22 gluTessBeginPolygon(tobj, NULL);
  23    gluTessBeginContour(tobj);
  24       gluTessVertex(tobj, v1, v1);
  25       gluTessVertex(tobj, v2, v2);
  26       gluTessVertex(tobj, v3, v3);
  27       gluTessVertex(tobj, v4, v4);
  28    gluTessEndContour(tobj);
  29    gluTessBeginContour(tobj);
  30       gluTessVertex(tobj, v5, v5);
  31       gluTessVertex(tobj, v6, v6);
  32       gluTessVertex(tobj, v7, v7);
  33    gluTessEndContour(tobj);
  34 gluTessEndPolygon(tobj);
  35             </pre><p>
  36             In the above example the pointers,
  37             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">v1</mml:mi></mml:math>
  38             through
  39             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">v7</mml:mi></mml:math>,
  40             should point to different
  41             addresses,
  42             since the values stored at these addresses will not be read by
  43             the tesselator until <code class="function">gluTessEndPolygon</code> is called.
  44         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  45             <a class="citerefentry" href="gluNewTess.xml"><span class="citerefentry"><span class="refentrytitle">gluNewTess</span></span></a>,
  46             <a class="citerefentry" href="gluTessBeginContour.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginContour</span></span></a>,
  47             <a class="citerefentry" href="gluTessBeginPolygon.xml"><span class="citerefentry"><span class="refentrytitle">gluTessBeginPolygon</span></span></a>,
  48             <a class="citerefentry" href="gluTessCallback.xml"><span class="citerefentry"><span class="refentrytitle">gluTessCallback</span></span></a>,
  49             <a class="citerefentry" href="gluTessNormal.xml"><span class="citerefentry"><span class="refentrytitle">gluTessNormal</span></span></a>,
  50             <a class="citerefentry" href="gluTessProperty.xml"><span class="citerefentry"><span class="refentrytitle">gluTessProperty</span></span></a>,
  51             <a class="citerefentry" href="gluTessVertex.xml"><span class="citerefentry"><span class="refentrytitle">gluTessVertex</span></span></a>
  52         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  53             Copyright <span class="trademark"></span>© 1991-2006
  54             Silicon Graphics, Inc. This document is licensed under the SGI
  55             Free Software B License. For details, see
  56             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  57         </p></div></div></body></html>