<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><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>

Specifies what kind of primitives to render.

Symbolic constants

<code class="constant">GL_POINTS</code>,

<code class="constant">GL_LINE_STRIP</code>,

<code class="constant">GL_LINE_LOOP</code>,

<code class="constant">GL_LINES</code>,

<code class="constant">GL_TRIANGLE_STRIP</code>,

<code class="constant">GL_TRIANGLE_FAN</code>,

<code class="constant">GL_TRIANGLES</code>,

<code class="constant">GL_QUAD_STRIP</code>,

<code class="constant">GL_QUADS</code>,

and <code class="constant">GL_POLYGON</code> are accepted.

</p></dd><dt><span class="term"><em class="parameter"><code>count</code></em></span></dt><dd><p>

Specifies the number of elements to be rendered.

</p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>

Specifies the type of the values in <em class="parameter"><code>indices</code></em>. Must be one of

<code class="constant">GL_UNSIGNED_BYTE</code>, <code class="constant">GL_UNSIGNED_SHORT</code>, or

<code class="constant">GL_UNSIGNED_INT</code>.

</p></dd><dt><span class="term"><em class="parameter"><code>indices</code></em></span></dt><dd><p>

Specifies a pointer to the location where the indices are stored.

</p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>

<code class="function">glDrawElements</code> specifies multiple geometric primitives

with very few subroutine calls. Instead of calling a GL function

to pass each individual vertex, normal, texture coordinate, edge

flag, or color, you can prespecify

separate arrays of vertices, normals, and so on, and use them to

construct a sequence of primitives with a single

call to <code class="function">glDrawElements</code>.

</p><p>

When <code class="function">glDrawElements</code> is called, it uses <em class="parameter"><code>count</code></em> sequential elements from an

enabled array, starting at <em class="parameter"><code>indices</code></em> to construct a sequence of

geometric primitives. <em class="parameter"><code>mode</code></em> specifies what kind of primitives are

constructed and how the array elements construct these primitives. If

more than one array is enabled, each is used. If

<code class="constant">GL_VERTEX_ARRAY</code> is not enabled, no geometric primitives are

constructed.

</p><p>

Vertex attributes that are modified by <code class="function">glDrawElements</code> have an

unspecified value after <code class="function">glDrawElements</code> returns. For example, if

<code class="constant">GL_COLOR_ARRAY</code> is enabled, the value of the current color is

undefined after <code class="function">glDrawElements</code> executes. Attributes that aren't

modified maintain their previous values.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>

<code class="function">glDrawElements</code> is available only if the GL version is 1.1 or greater.

</p><p>

<code class="function">glDrawElements</code> is included in display lists. If <code class="function">glDrawElements</code> is entered into a

display list,

the necessary array data (determined by the array pointers and

enables) is also

entered into the display list. Because the array pointers and

enables are client-side state, their values affect display lists

when the lists are created, not when the lists are executed.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>

<code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not an accepted value.

</p><p>

<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> is negative.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to an

enabled array or the element array and the buffer object's data store is currently mapped.

</p><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glDrawElements</code> is executed between

the execution of <a class="citerefentry" href="glBegin"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding <a class="citerefentry" href="glEnd"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glArrayElement"><span class="citerefentry"><span class="refentrytitle">glArrayElement</span></span></a>,

<a class="citerefentry" href="glColorPointer"><span class="citerefentry"><span class="refentrytitle">glColorPointer</span></span></a>,

<a class="citerefentry" href="glDrawArrays"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a>,

<a class="citerefentry" href="glDrawRangeElements"><span class="citerefentry"><span class="refentrytitle">glDrawRangeElements</span></span></a>,

<a class="citerefentry" href="glEdgeFlagPointer"><span class="citerefentry"><span class="refentrytitle">glEdgeFlagPointer</span></span></a>,

<a class="citerefentry" href="glFogCoordPointer"><span class="citerefentry"><span class="refentrytitle">glFogCoordPointer</span></span></a>,

<a class="citerefentry" href="glGetPointerv"><span class="citerefentry"><span class="refentrytitle">glGetPointerv</span></span></a>,

<a class="citerefentry" href="glIndexPointer"><span class="citerefentry"><span class="refentrytitle">glIndexPointer</span></span></a>,

<a class="citerefentry" href="glInterleavedArrays"><span class="citerefentry"><span class="refentrytitle">glInterleavedArrays</span></span></a>,

<a class="citerefentry" href="glNormalPointer"><span class="citerefentry"><span class="refentrytitle">glNormalPointer</span></span></a>,

<a class="citerefentry" href="glSecondaryColorPointer"><span class="citerefentry"><span class="refentrytitle">glSecondaryColorPointer</span></span></a>,

<a class="citerefentry" href="glTexCoordPointer"><span class="citerefentry"><span class="refentrytitle">glTexCoordPointer</span></span></a>,

<a class="citerefentry" href="glVertexPointer"><span class="citerefentry"><span class="refentrytitle">glVertexPointer</span></span></a>

</p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 1991-2006

Silicon Graphics, Inc. This document is licensed under the SGI

Free Software B License. For details, see

<a class="ulink" href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.

</p></div></div></div>