upstream-man-pages/manglsl/xhtml/gl_FragDepth.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_FragDepth - 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_FragDepth"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gl_FragDepth — establishes a depth value for the current fragment</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><code class="function">out float gl_FragDepth;</code></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   5             Available only in the fragment language, <code class="function">gl_FragDepth</code> is an output variable
   6             that is used to establish the depth value for the current fragment. If depth buffering is enabled
   7             and no shader writes to <code class="function">gl_FragDepth</code>, then the fixed function value for
   8             depth will be used (this value is contained in the z component of <a href="gl_FragCoord.xml"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a>)
   9             otherwise, the value written to <code class="function">gl_FragDepth</code> is used.
  10             If a shader statically assigns to <code class="function">gl_FragDepth</code>, then the value of the fragment's depth
  11             may be undefined for executions of the shader that take that path. That is, if the set of linked fragment
  12             shaders statically contain a write to <code class="function">gl_FragDepth</code>, then it is responsible for always
  13             writing it.
  14         </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_FragDepth</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><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><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>
  15             <a href="gl_FragCoord.xml"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a>
  16         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  17             Copyright <span class="trademark"></span>© 2011 Khronos Group.
  18             This material may be distributed subject to the terms and conditions set forth in
  19             the Open Publication License, v 1.0, 8 June 1999.
  20             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  21         </p></div></div></body></html>