upstream-man-pages/manglsl/gl_InvocationID.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="gl_InvocationID">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>gl_InvocationID</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>gl_InvocationID</refname>
  17         <refpurpose>contains the invocation index of the current shader</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <function>in int gl_InvocationID;</function>
  22         </funcsynopsis>
  23     </refsynopsisdiv>
  24     <refsect1 id="description"><title>Description</title>
  25         <para>
  26             In the tessellation control language, <function>gl_InvocationID</function>
  27             contains the index of the output patch vertex assigned to the shader invocation.
  28             It is assigned an integer value in the range [0, N-1] where N is the number of output
  29             patch vertices.
  30         </para>
  31         <para>
  32             In the geometry language, <function>gl_InvocationID</function> identifies
  33             the invocation number assigned to the geometry shader invocation. It is assigned
  34             an integer value in the range [0, N-1] where N is the number of geometry shader
  35             invocations per primitive.
  36         </para>
  37     </refsect1>
  38     <refsect1 id="versions"><title>Version Support</title>
  39         <informaltable frame="topbot">
  40             <tgroup cols="3" align="left">
  41                 <colspec colwidth="1.1*" />
  42                 <colspec colwidth="1*" align="center" />
  43                 <colspec colwidth="1*" align="center" />
  44                 <colspec colwidth="1*" align="center" />
  45                 <colspec colwidth="1*" align="center" />
  46                 <colspec colwidth="1*" align="center" />
  47                 <colspec colwidth="1*" align="center" />
  48                 <colspec colwidth="1*" align="center" />
  49                 <colspec colwidth="1*" align="center" />
  50                 <thead>
  51                     <row>
  52                         <entry rowsep="1" align="left"><emphasis role="bold">
  53                         Variable
  54                         </emphasis></entry>
  55                         <entry rowsep="1" align="left"><emphasis role="bold">
  56                         Version 1.10
  57                         </emphasis></entry>
  58                         <entry rowsep="1" align="left"><emphasis role="bold">
  59                         Version 1.20
  60                         </emphasis></entry>
  61                         <entry rowsep="1" align="left"><emphasis role="bold">
  62                         Version 1.30
  63                         </emphasis></entry>
  64                         <entry rowsep="1" align="left"><emphasis role="bold">
  65                         Version 1.40
  66                         </emphasis></entry>
  67                         <entry rowsep="1" align="left"><emphasis role="bold">
  68                         Version 1.50
  69                         </emphasis></entry>
  70                         <entry rowsep="1" align="left"><emphasis role="bold">
  71                         Version 3.30
  72                         </emphasis></entry>
  73                         <entry rowsep="1" align="left"><emphasis role="bold">
  74                         Version 4.00
  75                         </emphasis></entry>
  76                         <entry rowsep="1" align="left"><emphasis role="bold">
  77                         Version 4.10
  78                         </emphasis></entry>
  79                     </row>
  80                     <row>
  81                         <entry>
  82                             gl_InvocationID
  83                         </entry>
  84                         <entry>
  85                             <emphasis>-</emphasis>  <!-- 1.10, OpenGL 2.0 -->
  86                         </entry>
  87                         <entry>
  88                             <emphasis>-</emphasis>  <!-- 1.20, OpenGL 2.1 -->
  89                         </entry>
  90                         <entry>
  91                             <emphasis>-</emphasis>  <!-- 1.30, OpenGL 3.0 -->
  92                         </entry>
  93                         <entry>
  94                             <emphasis>-</emphasis>  <!-- 1.40, OpenGL 3.1 -->
  95                         </entry>
  96                         <entry>
  97                             <emphasis>Y</emphasis><superscript>1</superscript>  <!-- 1.50, OpenGL 3.2 -->
  98                         </entry>
  99                         <entry>
 100                             <emphasis>Y</emphasis><superscript>1</superscript>  <!-- 3.30, OpenGL 3.3 -->
 101                         </entry>
 102                         <entry>
 103                             <emphasis>Y</emphasis>  <!-- 4.00, OpenGL 4.0 -->
 104                         </entry>
 105                         <entry>
 106                             <emphasis>Y</emphasis>  <!-- 4.10, OpenGL 4.1 -->
 107                         </entry>
 108                     </row>
 109                 </thead>
 110             </tgroup>
 111         </informaltable>
 112         <para>[1] Versions 1.50 to 3.30 - geometry shaders only.</para>
 113     </refsect1>
 114     <refsect1 id="seealso"><title>See Also</title>
 115         <para>
 116             <citerefentry><refentrytitle>gl_InstanceID</refentrytitle></citerefentry>
 117         </para>
 118     </refsect1>
 119     <refsect1 id="Copyright"><title>Copyright</title>
 120         <para>
 121             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 122             This material may be distributed subject to the terms and conditions set forth in
 123             the Open Publication License, v 1.0, 8 June 1999.
 124             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 125         </para>
 126     </refsect1>
 127 </refentry>