upstream-man-pages/man2/xhtml/glDrawElements.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>glDrawElements</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glDrawElements"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDrawElements — render primitives from array data</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">glDrawElements</b>(</code></td><td>GLenum  </td><td><var class="pdparam">mode</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">count</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">type</var>, </td></tr><tr><td> </td><td>const GLvoid *  </td><td><var class="pdparam">indices</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>mode</code></em></span></dt><dd><p>
   4                     Specifies what kind of primitives to render.
   5                     Symbolic constants
   6                     <code class="constant">GL_POINTS</code>,
   7                     <code class="constant">GL_LINE_STRIP</code>,
   8                     <code class="constant">GL_LINE_LOOP</code>,
   9                     <code class="constant">GL_LINES</code>,
  10                     <code class="constant">GL_TRIANGLE_STRIP</code>,
  11                     <code class="constant">GL_TRIANGLE_FAN</code>,
  12                     <code class="constant">GL_TRIANGLES</code>,
  13                     <code class="constant">GL_QUAD_STRIP</code>,
  14                     <code class="constant">GL_QUADS</code>,
  15                     and <code class="constant">GL_POLYGON</code> are accepted.
  16                 </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p>
  17                     Specifies the number of elements to be rendered.
  18                 </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
  19                     Specifies the type of the values in <em class="parameter"><code>indices</code></em>. Must be one of
  20                     <code class="constant">GL_UNSIGNED_BYTE</code>, <code class="constant">GL_UNSIGNED_SHORT</code>, or
  21                     <code class="constant">GL_UNSIGNED_INT</code>.
  22                 </p></dd><dt><span class="term"><em class="parameter"><code>indices</code></em></span></dt><dd><p>
  23                     Specifies a pointer to the location where the indices are stored.
  24                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  25             <code class="function">glDrawElements</code> specifies multiple geometric primitives
  26             with very few subroutine calls. Instead of calling a GL function
  27             to pass each individual vertex, normal, texture coordinate, edge
  28             flag, or color, you can prespecify
  29             separate arrays of vertices, normals, and so on, and use them to
  30             construct a sequence of primitives with a single
  31             call to <code class="function">glDrawElements</code>.
  32         </p><p>
  33             When <code class="function">glDrawElements</code> is called, it uses <em class="parameter"><code>count</code></em> sequential elements from an
  34             enabled array, starting at <em class="parameter"><code>indices</code></em> to construct a sequence of
  35             geometric primitives. <em class="parameter"><code>mode</code></em> specifies what kind of primitives are
  36             constructed and how the array elements construct these primitives. If
  37             more than one array is enabled, each is used. If
  38             <code class="constant">GL_VERTEX_ARRAY</code> is not enabled, no geometric primitives are
  39             constructed.
  40         </p><p>
  41             Vertex attributes that are modified by <code class="function">glDrawElements</code> have an
  42             unspecified value after <code class="function">glDrawElements</code> returns. For example, if
  43             <code class="constant">GL_COLOR_ARRAY</code> is enabled, the value of the current color is
  44             undefined after <code class="function">glDrawElements</code> executes. Attributes that aren't
  45             modified maintain their previous values.
  46         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  47             <code class="function">glDrawElements</code> is available only if the GL version is 1.1 or greater.
  48         </p><p>
  49             <code class="function">glDrawElements</code> is included in display lists. If <code class="function">glDrawElements</code> is entered into a
  50             display list,
  51             the necessary array data (determined by the array pointers and
  52             enables) is also
  53             entered into the display list. Because the array pointers and
  54             enables are client-side state, their values affect display lists
  55             when the lists are created, not when the lists are executed.
  56         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  57             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not an accepted value.
  58         </p><p>
  59             <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> is negative.
  60         </p><p>
  61             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to an
  62             enabled array or the element array and the buffer object's data store is currently mapped.
  63         </p><p>
  64             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glDrawElements</code> is executed between
  65             the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  66         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  67             <a class="citerefentry" href="glArrayElement.xml"><span class="citerefentry"><span class="refentrytitle">glArrayElement</span></span></a>,
  68             <a class="citerefentry" href="glColorPointer.xml"><span class="citerefentry"><span class="refentrytitle">glColorPointer</span></span></a>,
  69             <a class="citerefentry" href="glDrawArrays.xml"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>,
  70             <a class="citerefentry" href="glDrawRangeElements.xml"><span class="citerefentry"><span class="refentrytitle">glDrawRangeElements</span></span></a>,
  71             <a class="citerefentry" href="glEdgeFlagPointer.xml"><span class="citerefentry"><span class="refentrytitle">glEdgeFlagPointer</span></span></a>,
  72             <a class="citerefentry" href="glFogCoordPointer.xml"><span class="citerefentry"><span class="refentrytitle">glFogCoordPointer</span></span></a>,
  73             <a class="citerefentry" href="glGetPointerv.xml"><span class="citerefentry"><span class="refentrytitle">glGetPointerv</span></span></a>,
  74             <a class="citerefentry" href="glIndexPointer.xml"><span class="citerefentry"><span class="refentrytitle">glIndexPointer</span></span></a>,
  75             <a class="citerefentry" href="glInterleavedArrays.xml"><span class="citerefentry"><span class="refentrytitle">glInterleavedArrays</span></span></a>,
  76             <a class="citerefentry" href="glNormalPointer.xml"><span class="citerefentry"><span class="refentrytitle">glNormalPointer</span></span></a>,
  77             <a class="citerefentry" href="glSecondaryColorPointer.xml"><span class="citerefentry"><span class="refentrytitle">glSecondaryColorPointer</span></span></a>,
  78             <a class="citerefentry" href="glTexCoordPointer.xml"><span class="citerefentry"><span class="refentrytitle">glTexCoordPointer</span></span></a>,
  79             <a class="citerefentry" href="glVertexPointer.xml"><span class="citerefentry"><span class="refentrytitle">glVertexPointer</span></span></a>
  80         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  81             Copyright <span class="trademark"></span>© 1991-2006
  82             Silicon Graphics, Inc. This document is licensed under the SGI
  83             Free Software B License. For details, see
  84             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  85         </p></div></div></body></html>