<div class="refentry" id="glDrawElementsInstanced">

<div class="titlepage"></div>

<div class="refnamediv">

<h2>Name</h2>

<p>glDrawElementsInstanced — draw multiple instances of a set of elements</p>

</div>

<div class="refsynopsisdiv">

<h2>C Specification</h2>

<div class="funcsynopsis">

<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">

<tr>

<td>

<code class="funcdef">void <strong class="fsfunc">glDrawElementsInstanced</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 void * <var class="pdparam">indices</var>, </td>

</tr>

<tr>

<td> </td>

<td>GLsizei <var class="pdparam">primcount</var><code>)</code>;</td>

</tr>

</table>

<div class="funcprototype-spacer"> </div>

</div>

</div>

<div class="refsect1" id="parameters">

<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 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 byte offset (cast to a pointer type) into the buffer bound to <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>

to start reading indices from. If no buffer is bound, specifies a pointer to the location where the indices are stored.

</p>

</dd>

<dt>

<span class="term">

<em class="parameter">

<code>primcount</code>

</em>

</span>

</dt>

<dd>

<p>

Specifies the number of instances of the specified range of indices to be rendered.

</p>

</dd>

</dl>

</div>

</div>

<div class="refsect1" id="description">

<h2>Description</h2>

<p>

<code class="function">glDrawElementsInstanced</code> behaves identically to <a class="citerefentry" href="glDrawElements"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>

except that <em class="parameter"><code>primcount</code></em> instances of the set of elements are executed. Those attributes

that have divisor N where N is other than zero

(as specified by <a class="citerefentry" href="glVertexAttribDivisor"><span class="citerefentry"><span class="refentrytitle">glVertexAttribDivisor</span></span></a>)

advance once every N instances. Thus, the element transferred from instanced

vertex attributes is given by:

</p>

<div class="informalequation">

<math overflow="scroll">

<mrow>

<mfrac>

<mi mathvariant="italic">instance</mi>

<mn>divisor</mn>

</mfrac>

</mrow>

</math>

</div>

<p>

The value of <em class="parameter"><code>instance</code></em> may be read by a vertex shader as <code class="constant">gl_InstanceID</code>.

</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>

<p>

If an array corresponding to a generic attribute required by a vertex shader

is not enabled, then the corresponding element is taken from the current generic

attribute state.

</p>

</div>

<div class="refsect1" id="errors">

<h2>Errors</h2>

<p>

<code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not one of <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>, or <code class="constant">GL_TRIANGLES</code>.

</p>

<p>

<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>count</code></em> or <em class="parameter"><code>primcount</code></em> are 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 and the buffer object's data store is currently mapped.

</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>

<p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if transform feedback is active and not paused.

</p>

</div>

{$pipelinestall}{$examples}

<div class="refsect1" id="versions">

<h2>API Version Support</h2>

<div class="informaltable">

<table style="border-collapse: collapse; border-top: 2px solid ; border-bottom: 2px solid ; border-left: 2px solid ; border-right: 2px solid ; ">

<colgroup>

<col style="text-align: left; "/>

<col style="text-align: center; " class="firstvers"/>

<col style="text-align: center; "/>

<col style="text-align: center; " class="lastvers"/>

</colgroup>

<thead>

<tr>

<th style="text-align: left; border-right: 2px solid ; ">

</th>

<th style="text-align: center; border-bottom: 2px solid ; " colspan="3">

<span class="bold"><strong>OpenGL ES API Version</strong></span>

</th>

</tr>

<tr>

<th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">

<span class="bold"><strong>Function Name</strong></span>

</th>

<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">

<span class="bold"><strong>2.0</strong></span>

</th>

<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">

<span class="bold"><strong>3.0</strong></span>

</th>

<th style="text-align: center; border-bottom: 2px solid ; ">

<span class="bold"><strong>3.1</strong></span>

</th>

</tr>

</thead>

<tbody>

<tr>

<td style="text-align: left; border-right: 2px solid ; ">glDrawElementsInstanced</td>

<td style="text-align: center; border-right: 2px solid ; ">-</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; ">✔</td>

</tr>

</tbody>

</table>

</div>

</div>

<div class="refsect1" id="seealso">

<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="glDrawElements"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>,

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

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

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

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

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

</p>

</div>

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

<h2>Copyright</h2>

<p>

Copyright © 2010-2014 Khronos Group.

This material may be distributed subject to the terms and conditions set forth in

the Open Publication License, v 1.0, 8 June 1999.

<a class="link" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.

</p>

</div>

</div>