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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>glGetTransformFeedback - OpenGL 4 Reference Pages</title>
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<header/>
<div class="refentry" id="glGetTransformFeedback">
<div class="titlepage"/>
<div class="refnamediv">
<h2>Name</h2>
<p>glGetTransformFeedbackiv — query the state of a transform feedback object.</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">glGetTransformFeedbackiv</strong>(</code>
</td>
<td>GLuint <var class="pdparam">xfb</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLenum <var class="pdparam">pname</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLint *<var class="pdparam">param</var><code>)</code>;</td>
</tr>
</table>
<div class="funcprototype-spacer"> </div>
</div>
<div class="funcsynopsis">
<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">
<tr>
<td>
<code class="funcdef">void <strong class="fsfunc">glGetTransformFeedbacki_v</strong>(</code>
</td>
<td>GLuint <var class="pdparam">xfb</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLenum <var class="pdparam">pname</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLuint <var class="pdparam">index</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLint *<var class="pdparam">param</var><code>)</code>;</td>
</tr>
</table>
<div class="funcprototype-spacer"> </div>
</div>
<div class="funcsynopsis">
<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">
<tr>
<td>
<code class="funcdef">void <strong class="fsfunc">glGetTransformFeedbacki64_v</strong>(</code>
</td>
<td>GLuint <var class="pdparam">xfb</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLenum <var class="pdparam">pname</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLuint <var class="pdparam">index</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLint64 *<var class="pdparam">param</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>xfb</code>
</em>
</span>
</dt>
<dd>
<p>The name of an existing transform feedback object, or zero for
the default transform feedback object.</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>pname</code>
</em>
</span>
</dt>
<dd>
<p>Property to use for the query. Must be one of the values:
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_BINDING</code>,
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_START</code>,
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_SIZE</code>,
<code class="constant">GL_TRANSFORM_FEEDBACK_PAUSED</code>,
<code class="constant">GL_TRANSFORM_FEEDBACK_ACTIVE</code>.</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>index</code>
</em>
</span>
</dt>
<dd>
<p>Index of the transform feedback stream (for indexed
state).</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>param</code>
</em>
</span>
</dt>
<dd>
<p>The address of a buffer into which will be written the
requested state information.</p>
</dd>
</dl>
</div>
</div>
<div class="refsect1" id="description">
<h2>Description</h2>
<p>In order to use the Transform Feedback functionality, you need to
configure the Transform Feedback Buffer indexed bindings. This can be
achieved by either using <code class="function">glBindBufferBase</code> or
<code class="function">glBindBuffersBase</code> to associate whole buffer object
storage to one of the Transform Feedback Binding Points, or by calling
<code class="function">glBindBufferRange</code> or
<code class="function">glBindBuffersRange</code> to use a region of a buffer object
storage for the binding. You may want to (but are not required to) bind a
Transform Feedback Object first, in order to cache the binding
configuration. This usually allows you to restore the Transform Feedback
configuration faster, than if you were to execute a list of API calls
necessary to set up the Transform Feedback state of your liking.</p>
<p>This reference page discusses two types of getters that operate on
Transform Feedback Objects and their bindings.</p>
<p>The first class operates on general Transform Feedback binding point
and includes <code class="function">glGetTransformFeedbackiv</code> function.
<code class="function">glGetTransformFeedbackiv</code> can be used to retrieve
information about Transform Feedback object bound to the general Transform
Feedback binding point, as configured with a
<code class="function">glBindTransformFeedback</code> call. In this case, you can
check:</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>What the ID of the currently bound Transform Feedback Object
is;
(<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_BINDING</code>)</p>
</li>
<li class="listitem">
<p>Whether the Transform Feedback process is currently paused;
(<code class="constant">GL_TRANSFORM_FEEDBACK_PAUSED</code>)</p>
</li>
<li class="listitem">
<p>Whether the Transform Feedback process has been begun and is
currently undergoing;
(<code class="constant">GL_TRANSFORM_FEEDBACK_ACTIVE</code>)</p>
</li>
</ul>
</div>
<p>The latter class, which includes
<code class="function">glGetTransformFeedbacki_v</code> and
<code class="function">glGetTransformFeedbacki64_v</code> functions, can be used to
check what the current configuration of each of the buffer object regions
bound to Transform Feedback Buffer binding points is. This allows you to
query for the following information:</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p><code class="function">glGetTransformFeedbacki_v</code> only: What the
ID of the Buffer Object bound to a Transform Feedback Binding Point
of user-specified index is;
(<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_BINDING</code>).</p>
</li>
<li class="listitem">
<p><code class="function">glGetTransformFeedbacki64_v</code> only: What
the start offset configured for the binding is;
(<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_START</code>);</p>
</li>
<li class="listitem">
<p><code class="function">glGetTransformFeedbacki64_v</code> only: What
the length of the region used for the binding is;
(<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_SIZE</code>);</p>
</li>
</ul>
</div>
</div>
<div class="refsect1" id="errors">
<h2>Errors</h2>
<p><code class="constant">GL_INVALID_OPERATION</code> error is generated if
<em class="parameter"><code>xfb</code></em> is not zero or the name of an existing
transform feedback object.</p>
<p><code class="constant">GL_INVALID_ENUM</code> error is generated by
<code class="function">glGetTransformFeedbackiv</code> if
<em class="parameter"><code>pname</code></em> is not
<code class="constant">GL_TRANSFORM_FEEDBACK_PAUSED</code> or
<code class="constant">GL_TRANSFORM_FEEDBACK_ACTIVE</code>.</p>
<p><code class="constant">GL_INVALID_ENUM</code> error is generated by
<code class="function">glGetTransformFeedbacki_v</code> if
<em class="parameter"><code>pname</code></em> is not
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_BINDING</code>.</p>
<p><code class="constant">GL_INVALID_ENUM</code> error is generated by
<code class="function">glGetTransformFeedbacki64_v</code> if
<em class="parameter"><code>pname</code></em> is not
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_START</code> or
<code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER_SIZE</code>.</p>
<p><code class="constant">GL_INVALID_VALUE</code> error is generated by
<code class="function">glGetTransformFeedbacki_v</code> and
<code class="function">glGetTransformFeedbacki64_v</code> if
<em class="parameter"><code>index</code></em> is greater than or equal to the number of
binding points for transform feedback (the value of
<code class="constant">GL_MAX_TRANSFORM_FEEDBACK_BUFFERS</code>).</p>
</div>
<div class="refsect1" id="versions">
<h2>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; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<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="12">
<span class="bold"><strong>OpenGL Version</strong></span>
</th>
</tr>
<tr>
<th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>Function / Feature 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>2.1</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-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.1</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.2</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.3</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.0</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.1</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.2</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.3</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.4</strong></span>
</th>
<th style="text-align: center; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.5</strong></span>
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
<code class="function">glGetTransformFeedbackiv</code>
</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-bottom: 2px solid ; ">✔</td>
</tr>
<tr>
<td style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
<code class="function">glGetTransformFeedbacki_v</code>
</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">-</td>
<td style="text-align: center; border-bottom: 2px solid ; ">✔</td>
</tr>
<tr>
<td style="text-align: left; border-right: 2px solid ; ">
<code class="function">glGetTransformFeedbacki64v</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; border-right: 2px solid ; ">-</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; border-right: 2px solid ; ">-</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; border-right: 2px solid ; ">-</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="glBindBufferBase.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindBufferBase</span></span></a>, <a class="citerefentry" href="glBindBufferRange.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindBufferRange</span></span></a>, <a class="citerefentry" href="glBindBuffersBase.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindBuffersBase</span></span></a>, <a class="citerefentry" href="glBindBuffersRange.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindBuffersRange</span></span></a>, <a class="citerefentry" href="glBindTransformFeedback.xhtml"><span class="citerefentry"><span class="refentrytitle">glBindTransformFeedback</span></span></a></p>
</div>
<div class="refsect1" id="Copyright">
<h2>Copyright</h2>
<p>
Copyright <span class="trademark"/>© 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>
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