<div class="refentry"><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" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glDrawElements</strong>(</code></td><td>GLenum <var class="pdparam">mode</var>, </td></tr><tr><td> </td><td>GLsizei <var class="pdparam">count</var>, </td></tr><tr><td> </td><td>GLenum <var class="pdparam">type</var>, </td></tr><tr><td> </td><td>const GLvoid * <var class="pdparam">indices</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>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>, and

<code class="constant">GL_TRIANGLES</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

<code class="constant">GL_UNSIGNED_BYTE</code> or <code class="constant">GL_UNSIGNED_SHORT</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"><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 vertex attribute, you can use

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

to prespecify separate arrays of vertex attributes 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.

</p><p>

To enable and disable a generic vertex attribute array, call

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

and

<a class="citerefentry" href="glDisableVertexAttribArray"><span class="citerefentry"><span class="refentrytitle">glDisableVertexAttribArray</span></span></a>.

</p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><p>

If the current program object, as set by

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

is invalid, rendering results are undefined. However, no error is generated

for this case.

</p></div><div class="refsect1"><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_ENUM</code> is generated if <em class="parameter"><code>type</code></em> is not

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

</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_FRAMEBUFFER_OPERATION</code> is generated if

the currently bound framebuffer is not framebuffer complete (i.e. the

return value from <a class="citerefentry" href="glCheckFramebufferStatus"><span class="citerefentry"><span class="refentrytitle">glCheckFramebufferStatus</span></span></a>

is not <code class="constant">GL_FRAMEBUFFER_COMPLETE</code>).

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>

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

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

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

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

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

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

</p></div><div class="refsect1"><div id="Copyright"><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></div>