upstream-doc/manglsl/xhtml/mix.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>mix - 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="mix"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>mix — linearly interpolate between two values</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><p><code class="funcdef">genType <b class="fsfunc">mix</b>(</code>genType <var class="pdparam">x</var>, genType <var class="pdparam">y</var>, genType <var class="pdparam">a</var><code>)</code>;</p></div><div class="funcsynopsis"><p><code class="funcdef">genType <b class="fsfunc">mix</b>(</code>genType <var class="pdparam">x</var>, genType <var class="pdparam">y</var>, float <var class="pdparam">a</var><code>)</code>;</p></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">genDType <b class="fsfunc">mix</b>(</code></td><td>genDType  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>genDType  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>genDType  </td><td><var class="pdparam">a</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><p><code class="funcdef">genDType <b class="fsfunc">mix</b>(</code>genDType <var class="pdparam">x</var>, genDType <var class="pdparam">y</var>, double <var class="pdparam">a</var><code>)</code>;</p></div><div class="funcsynopsis"><p><code class="funcdef">genType <b class="fsfunc">mix</b>(</code>genType <var class="pdparam">x</var>, genType <var class="pdparam">y</var>, genBType <var class="pdparam">a</var><code>)</code>;</p></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">genDType <b class="fsfunc">mix</b>(</code></td><td>genDType  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>genDType  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>genBType  </td><td><var class="pdparam">a</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>x</code></em></span></dt><dd><p>
   5                     Specify the start of the range in which to interpolate.
   6                 </p></dd><dt><span class="term"><em class="parameter"><code>y</code></em></span></dt><dd><p>
   7                     Specify the end of the range in which to interpolate.
   8                 </p></dd><dt><span class="term"><em class="parameter"><code>a</code></em></span></dt><dd><p>
   9                     Specify the value to use to interpolate between <em class="parameter"><code>x</code></em> and <em class="parameter"><code>y</code></em>.
  10                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  11             <code class="function">mix</code> performs a linear interpolation between <em class="parameter"><code>x</code></em>
  12             and <em class="parameter"><code>y</code></em> using <em class="parameter"><code>a</code></em> to weight between them. The return value
  13             is computed as follows:
  14             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  15                     <mml:mi>x</mml:mi>
  16                     <mml:mo lspace="2px" rspace="2px">⋅</mml:mo>
  17                     <mml:mo stretchy="false">(</mml:mo>
  18                     <mml:mn>1</mml:mn>
  19                     <mml:mo>−</mml:mo>
  20                     <mml:mi>a</mml:mi>
  21                     <mml:mo stretchy="false">)</mml:mo>
  22                     <mml:mo>+</mml:mo>
  23                     <mml:mi>y</mml:mi>
  24                     <mml:mo lspace="2px" rspace="2px">⋅</mml:mo>
  25                     <mml:mi>a</mml:mi>
  26                 </mml:math>.
  27         </p><p>
  28             For the variants of <code class="function">mix</code> where <em class="parameter"><code>a</code></em> is <code class="constant">genBType</code>,
  29             elements for which <em class="parameter"><code>a</code></em>[<span class="emphasis"><em>i</em></span>] is <code class="constant">false</code>, the result for that
  30             element is taken from <em class="parameter"><code>x</code></em>, and where <em class="parameter"><code>a</code></em>[<span class="emphasis"><em>i</em></span>] is
  31             <code class="constant">true</code>, it will be taken from <em class="parameter"><code>y</code></em>.
  32         </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>Function</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">mix (genType)</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><tr><th align="left">mix (genDType)</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>
  33             <a href="min.xml"><span class="citerefentry"><span class="refentrytitle">min</span></span></a>,
  34             <a href="max.xml"><span class="citerefentry"><span class="refentrytitle">max</span></span></a>
  35         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  36             Copyright <span class="trademark"></span>© 2011 Khronos Group.
  37             This material may be distributed subject to the terms and conditions set forth in
  38             the Open Publication License, v 1.0, 8 June 1999.
  39             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  40         </p></div></div></body></html>