upstream-doc/manglsl/xhtml/gl_SampleID.xml

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   4 <?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_SampleID - 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_SampleID"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_SampleID — contains the index of the sample currently being processed</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><code class="function">in int gl_SampleID;</code></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   5             <code class="function">gl_SampleID</code> is a fragment language input variable that contains
   6             the index of the sample currently being processed. This variable is in the range
   7             0 to <a href="gl_NumSamples.xml"><span class="citerefentry"><span class="refentrytitle">gl_NumSamples</span></span></a> - 1, where
   8             <a href="gl_NumSamples.xml"><span class="citerefentry"><span class="refentrytitle">gl_NumSamples</span></span></a>
   9             is the total number of samples in each fragment for the current framebuffer (and thus 1 if
  10             rendering to a non-multisample buffer). Any static use of this variable in a fragment
  11             shader causes the entire shader to be evaluated per-sample rather than per-fragment.
  12         </p><p>
  13             When rendering to a non-multisample buffer, or if multisample rasterization is disabled,
  14             <code class="function">gl_SampleID</code> will always be zero. <a href="gl_NumSamples.xml"><span class="citerefentry"><span class="refentrytitle">gl_NumSamples</span></span></a>
  15             is the sample count of the framebuffer regardless of whether multisample rasterization is
  16             enabled or not.
  17         </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" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><col align="center" /><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><th align="left"><span class="bold"><strong>Version 4.20</strong></span></th><th align="center"><span class="bold"><strong>Version 4.30</strong></span></th></tr><tr><th align="left">gl_SampleID</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>-</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>
  18             <a href="gl_SamplePosition.xml"><span class="citerefentry"><span class="refentrytitle">gl_SamplePosition</span></span></a>,
  19             <a href="gl_NumSamples.xml"><span class="citerefentry"><span class="refentrytitle">gl_NumSamples</span></span></a>
  20         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  21             Copyright <span class="trademark"></span>© 2011 Khronos Group.
  22             This material may be distributed subject to the terms and conditions set forth in
  23             the Open Publication License, v 1.0, 8 June 1999.
  24             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  25         </p></div></div></body></html>