| 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 4 | <?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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glDrawElements</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></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> |
| 5 | Specifies what kind of primitives to render. |
| 6 | Symbolic constants |
| 7 | <code class="constant">GL_POINTS</code>, |
| 8 | <code class="constant">GL_LINE_STRIP</code>, |
| 9 | <code class="constant">GL_LINE_LOOP</code>, |
| 10 | <code class="constant">GL_LINES</code>, |
| 11 | <code class="constant">GL_LINE_STRIP_ADJACENCY</code>, |
| 12 | <code class="constant">GL_LINES_ADJACENCY</code>, |
| 13 | <code class="constant">GL_TRIANGLE_STRIP</code>, |
| 14 | <code class="constant">GL_TRIANGLE_FAN</code>, |
| 15 | <code class="constant">GL_TRIANGLES</code>, |
| 16 | <code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code> and |
| 17 | <code class="constant">GL_TRIANGLES_ADJACENCY</code> |
| 18 | are accepted. |
| 19 | </p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p> |
| 20 | Specifies the number of elements to be rendered. |
| 21 | </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p> |
| 22 | Specifies the type of the values in <em class="parameter"><code>indices</code></em>. Must be one of |
| 23 | <code class="constant">GL_UNSIGNED_BYTE</code>, <code class="constant">GL_UNSIGNED_SHORT</code>, or |
| 24 | <code class="constant">GL_UNSIGNED_INT</code>. |
| 25 | </p></dd><dt><span class="term"><em class="parameter"><code>indices</code></em></span></dt><dd><p> |
| 26 | Specifies a pointer to the location where the indices are stored. |
| 27 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 28 | <code class="function">glDrawElements</code> specifies multiple geometric primitives |
| 29 | with very few subroutine calls. Instead of calling a GL function |
| 30 | to pass each individual vertex, normal, texture coordinate, edge |
| 31 | flag, or color, you can prespecify |
| 32 | separate arrays of vertices, normals, and so on, and use them to |
| 33 | construct a sequence of primitives with a single |
| 34 | call to <code class="function">glDrawElements</code>. |
| 35 | </p><p> |
| 36 | When <code class="function">glDrawElements</code> is called, it uses <em class="parameter"><code>count</code></em> sequential elements from an |
| 37 | enabled array, starting at <em class="parameter"><code>indices</code></em> to construct a sequence of |
| 38 | geometric primitives. <em class="parameter"><code>mode</code></em> specifies what kind of primitives are |
| 39 | constructed and how the array elements construct these primitives. If |
| 40 | more than one array is enabled, each is used. |
| 41 | </p><p> |
| 42 | Vertex attributes that are modified by <code class="function">glDrawElements</code> have an |
| 43 | unspecified value after <code class="function">glDrawElements</code> returns. Attributes that aren't |
| 44 | modified maintain their previous values. |
| 45 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> |
| 46 | <code class="constant">GL_LINE_STRIP_ADJACENCY</code>, |
| 47 | <code class="constant">GL_LINES_ADJACENCY</code>, |
| 48 | <code class="constant">GL_TRIANGLE_STRIP_ADJACENCY</code> and |
| 49 | <code class="constant">GL_TRIANGLES_ADJACENCY</code> |
| 50 | are available only if the GL version is 3.2 or greater. |
| 51 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> |
| 52 | <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not an accepted value. |
| 53 | </p><p> |
| 54 | <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> is negative. |
| 55 | </p><p> |
| 56 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a geometry shader is active and <em class="parameter"><code>mode</code></em> |
| 57 | is incompatible with the input primitive type of the geometry shader in the currently installed program object. |
| 58 | </p><p> |
| 59 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to an |
| 60 | enabled array or the element array and the buffer object's data store is currently mapped. |
| 61 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 62 | <a href="glDrawArrays.xml"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>, |
| 63 | <a href="glDrawElementsInstanced.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElementsInstanced</span></span></a>, |
| 64 | <a href="glDrawElementsBaseVertex.xml"><span class="citerefentry"><span class="refentrytitle">glDrawElementsBaseVertex</span></span></a>, |
| 65 | <a href="glDrawRangeElements.xml"><span class="citerefentry"><span class="refentrytitle">glDrawRangeElements</span></span></a> |
| 66 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 67 | Copyright <span class="trademark"></span>© 1991-2006 |
| 68 | Silicon Graphics, Inc. This document is licensed under the SGI |
| 69 | Free Software B License. For details, see |
| 70 | <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. |
| 71 | </p></div></div></body></html> |