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<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>gl_PrimitiveIDIn - OpenGL Shading Language (GLSL)</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gl_PrimitiveIDIn"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_PrimitiveIDIn — contains the index of the current primitive</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><code class="function">in int gl_PrimitiveIDIn;</code></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">gl_PrimitiveIDIn</code> is a geometry language input variable that holds
            the number of primitives processed by the shader since the current set of rendering
            primitives was started. The first primitive processed by the drawing command is numbered
            zero and the primitive ID counter is incremented after every individual point, line
            or triangle primitive is processed. For triangles drawn in point or line mode, the
            primitive ID counter is incremented only once, even through multiple points or lines
            may actually be drawn. Restarting a primitive topology using the primitive restart
            index has no effect on the primitive ID counter.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="versions"></a><h2>Version Support</h2><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="center" /><col align="center" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
                        Variable
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 1.10
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 1.20
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 1.30
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 1.40
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 1.50
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 3.30
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 4.00
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Version 4.10
                        </strong></span></th></tr><tr><th align="left">
                            gl_PrimitiveIDIn
                        </th><th align="center">
                            <span class="emphasis"><em>-</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>-</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>-</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>-</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>Y</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>Y</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>Y</em></span>  
                        </th><th align="center">
                            <span class="emphasis"><em>Y</em></span>  
                        </th></tr></thead></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a href="gl_InstanceID.xml"><span class="citerefentry"><span class="refentrytitle">gl_InstanceID</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 2011 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 href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
        </p></div></div></body></html>
