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

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

<div class="refnamediv">

<h2>Name</h2>

<p>glDispatchComputeIndirect — launch one or more compute work groups using parameters stored in a buffer</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">glDispatchComputeIndirect</strong>(</code>

</td>

<td>GLintptr <var class="pdparam">indirect</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>indirect</code>

</em>

</span>

</dt>

<dd>

<p>

The offset into the buffer object currently bound to the

<code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code> buffer target at

which the dispatch parameters are stored.

</p>

</dd>

</dl>

</div>

</div>

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

<h2>Description</h2>

<p>

<code class="function">glDispatchComputeIndirect</code> launches one or more compute

work groups using parameters stored in the buffer object currently bound

to the <code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code> target.

Each work group is processed by the active program object for the compute

shader stage. While the individual shader invocations within a work group are

executed as a unit, work groups are executed completely independently and in

unspecified order. <em class="parameter"><code>indirect</code></em> contains the offset

into the data store of the buffer object bound to the <code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code>

target at which the parameters are stored.

</p>

<p>

The parameters addressed by <em class="parameter"><code>indirect</code></em> are packed a structure,

which takes the form (in C):

</p>

<pre class="programlisting"> typedef struct {

uint num_groups_x;

uint num_groups_y;

uint num_groups_z;

} DispatchIndirectCommand;</pre>

<p>

</p>

<p>

A call to <code class="function">glDispatchComputeIndirect</code> is equivalent, assuming no

errors are generated, to:

</p>

<pre class="programlisting"> cmd = (const DispatchIndirectCommand *)indirect;

glDispatchComputeIndirect(cmd-&gt;num_groups_x, cmd-&gt;num_groups_y, cmd-&gt;num_groups_z);

}</pre>

<p>

</p>

<p>

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

no error is generated if any of the <code class="code">num_groups_x</code>,

<code class="code">num_groups_y</code> or <code class="code">num_groups_z</code> members

of the <code class="code">DispatchIndirectCommand</code> is larger than the

value of <code class="constant">GL_MAX_COMPUTE_WORK_GROUP_COUNT</code> for the

corresponding dimension. In such circumstances, behavior is undefined and

may lead to application termination.

</p>

</div>

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

<h2>Errors</h2>

<p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if there is no active program

for the compute shader stage.

</p>

<p>

<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>indirect</code></em> is

less than zero or not a multiple of four.

</p>

<p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if no buffer is bound to the

<code class="constant">GL_DISPATCH_INDIRECT_BUFFER</code> target or if the command would

source data beyond the end of the buffer object's data store.

</p>

</div>

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

<h2>Associated Gets</h2>

<p>

<a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MAX_COMPUTE_WORK_GROUP_COUNT</code>

</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 ; ">

<code class="function">glDispatchComputeIndirect</code>

</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="glDispatchCompute"><span class="citerefentry"><span class="refentrytitle">glDispatchCompute</span></span></a>.

</p>

</div>

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

<h2>Copyright</h2>

<p>

Copyright © 2012-2014 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="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.

</p>

</div>

</div>