upstream-man-pages/manglsl/xhtml/gl_SamplePosition.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
   3 <!-- saved from url=(0013)about:internet -->
   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_SamplePosition - 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_SamplePosition"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_SamplePosition — contains the location of the current sample within the current fragment</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><code class="function">in vec2 gl_SamplePosition;</code></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   5             <code class="function">gl_SamplePosition</code> is a fragment language input variable that contains
   6             the location within a fragment of the sample currently being processed. The x and y components
   7             of <code class="function">gl_SamplePosition</code> contain the sub-pixel coordinate of the current
   8             sample and will have values in the range 0.0 to 1.0. The sub-pixel coordinates of the center
   9             of the pixel are always (0.5, 0.5). Any static use of <code class="function">gl_SamplePosition</code>
  10             causes the entire fragment shader to be evaluated per-sample rather than per-fragment. When rendering
  11             to a non-multisample buffer, or if multisample rasterization is disabled, <code class="function">gl_SamplePosition</code>
  12             will be (0.5, 0.5).
  13         </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>
  14                         Variable
  15                         </strong></span></th><th align="left"><span class="bold"><strong>
  16                         Version 1.10
  17                         </strong></span></th><th align="left"><span class="bold"><strong>
  18                         Version 1.20
  19                         </strong></span></th><th align="left"><span class="bold"><strong>
  20                         Version 1.30
  21                         </strong></span></th><th align="left"><span class="bold"><strong>
  22                         Version 1.40
  23                         </strong></span></th><th align="left"><span class="bold"><strong>
  24                         Version 1.50
  25                         </strong></span></th><th align="left"><span class="bold"><strong>
  26                         Version 3.30
  27                         </strong></span></th><th align="left"><span class="bold"><strong>
  28                         Version 4.00
  29                         </strong></span></th><th align="left"><span class="bold"><strong>
  30                         Version 4.10
  31                         </strong></span></th></tr><tr><th align="left">
  32                             gl_SamplePosition
  33                         </th><th align="center">
  34                             <span class="emphasis"><em>-</em></span>
  35                         </th><th align="center">
  36                             <span class="emphasis"><em>-</em></span>
  37                         </th><th align="center">
  38                             <span class="emphasis"><em>-</em></span>
  39                         </th><th align="center">
  40                             <span class="emphasis"><em>-</em></span>
  41                         </th><th align="center">
  42                             <span class="emphasis"><em>-</em></span>
  43                         </th><th align="center">
  44                             <span class="emphasis"><em>-</em></span>
  45                         </th><th align="center">
  46                             <span class="emphasis"><em>Y</em></span>
  47                         </th><th align="center">
  48                             <span class="emphasis"><em>Y</em></span>
  49                         </th></tr></thead></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  50             <a href="gl_SampleID.xml"><span class="citerefentry"><span class="refentrytitle">gl_SampleID</span></span></a>,
  51             <a href="gl_SampleMask.xml"><span class="citerefentry"><span class="refentrytitle">gl_SampleMask</span></span></a>,
  52             <a href="gl_FragCoord.xml"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a>
  53         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  54             Copyright <span class="trademark"></span>© 2011 Khronos Group.
  55             This material may be distributed subject to the terms and conditions set forth in
  56             the Open Publication License, v 1.0, 8 June 1999.
  57             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  58         </p></div></div></body></html>