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><head><title>glPassThrough</title><link rel="stylesheet" href="style.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"/><link rel="home" href="index.xml" title="PyOpenGL 2.0.1.07 Man Pages"/><link rel="up" href="reference-GL.xml" title="GL"/><link rel="previous" href="glOrtho.3G.xml" title="glOrtho"/><link rel="next" href="glPixelMap.3G.xml" title="glPixelMap"/></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">glPassThrough</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="glOrtho.3G.xml">Prev</a> </td><th width="60%" align="center">GL</th><td width="20%" align="right"> <a accesskey="n" href="glPixelMap.3G.xml">Next</a></td></tr></table><hr/></div><div class="refentry" lang="en"><a name="glPassThrough.3G"/><div class="titlepage"/><div class="refnamediv"><a name="glPassThrough.3G-name"/><h2>Name</h2><p>glPassThrough &#8212; place a marker in the feedback buffer</p></div><div class="refsynopsisdiv"><a name="glPassThrough.3G-c_spec"/><h2>C Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code>void <tt>glPassThrough</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code>GLfloat <i><tt>token</tt></i>);</code></td></tr></table></div><div class="refsynopsisdiv"><a name="glPassThrough.3G-python_spec"/><h2>Python Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code><tt>glPassThrough</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code><i><tt>token</tt></i>) &#8594; <tt>None</tt></code></td></tr></table></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-parameters"/><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><i><tt>token</tt></i></span></dt><dd>
						Specifies a marker value to be placed in the feedback buffer following a
						<tt>GL_PASS_THROUGH_TOKEN</tt>.
					</dd></dl></div></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-description"/><h2>Description</h2><p>
			Feedback is a GL render mode. The mode is selected by calling <a href="glRenderMode.3G.xml"><tt>glRenderMode</tt></a>
			with <tt>GL_FEEDBACK</tt>. When the GL is in feedback mode, no pixels are produced by rasterization.
			Instead, information about primitives that would have been rasterized is fed back to the application using the GL. See
			the <a href="glFeedbackBuffer.3G.xml"><tt>glFeedbackBuffer</tt></a> reference page for a description of the feedback buffer
			and the values in it.
		</p><p>
			<tt>glPassThrough</tt> inserts a user-defined marker in the feedback buffer when it is executed in feedback
			mode. <i><tt>token</tt></i> is returned as if it were a primitive; it is indicated with its own unique
			identifying value: <tt>GL_PASS_THROUGH_TOKEN</tt>. The order of <tt>glPassThrough</tt> commands
			with respect to the specification of graphics primitives is maintained.
		</p></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-notes"/><h2>Notes</h2><p>
			<tt>glPassThrough</tt> is ignored if the GL is not in feedback mode.
		</p></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-errors"/><h2>Errors</h2><p>
			<tt>GL_INVALID_OPERATION</tt> is generated if <tt>glPassThrough</tt> is executed between the
			execution of <a href="glBegin.3G.xml"><tt>glBegin</tt></a> and the corresponding execution of <a href="glBegin.3G.xml"><tt>glEnd</tt></a>.
		</p></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-associated_gets"/><h2>Associated Gets</h2><p>
			<tt>glGet</tt> with argument <tt>GL_RENDER_MODE</tt>
		</p></div><div class="refsect1" lang="en"><a name="glPassThrough.3G-see_also"/><h2>See Also</h2><p>
			<span class="simplelist"><a href="glFeedbackBuffer.3G.xml">glFeedbackBuffer</a>, <a href="glRenderMode.3G.xml">glRenderMode</a></span>
		</p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="glOrtho.3G.xml">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-GL.xml">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="glPixelMap.3G.xml">Next</a></td></tr><tr><td width="40%" align="left" valign="top">glOrtho </td><td width="20%" align="center"><a accesskey="h" href="index.xml">Home</a></td><td width="40%" align="right" valign="top"> glPixelMap</td></tr></table></div></body></html>