upstream-man-pages/manglsl/xhtml/log2.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>log2 - 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="log2"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>log2 — return the base 2 logarithm of the parameter</p></div><div class="refsynopsisdiv"><h2>Declaration</h2><div class="funcsynopsis"><p><code class="funcdef">genType <b class="fsfunc">log2</b>(</code>genType <var class="pdparam">x</var><code>)</code>;</p></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 value of which to take the base 2 logarithm.
   6                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   7             <code class="function">log2</code> returns the base 2 logarithm of <em class="parameter"><code>x</code></em>. i.e., the value
   8             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi>y</mml:mi></mml:math> which satisfies
   9             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:apply><mml:eq definitionURL="" encoding=""></mml:eq><mml:mi>x</mml:mi><mml:mrow><mml:msup><mml:mi>2</mml:mi><mml:mi>y</mml:mi></mml:msup></mml:mrow></mml:apply></mml:math>.
  10             Results are undefined if <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:apply><mml:leq definitionURL="" encoding=""></mml:leq><mml:mi>x</mml:mi><mml:mn>0</mml:mn></mml:apply></mml:math>.
  11         </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">log2</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>
  12             <a href="exp.xml"><span class="citerefentry"><span class="refentrytitle">exp</span></span></a>,
  13             <a href="log.xml"><span class="citerefentry"><span class="refentrytitle">log</span></span></a>,
  14             <a href="exp2.xml"><span class="citerefentry"><span class="refentrytitle">exp2</span></span></a>
  15         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  16             Copyright <span class="trademark"></span>© 2011 Khronos Group.
  17             This material may be distributed subject to the terms and conditions set forth in
  18             the Open Publication License, v 1.0, 8 June 1999.
  19             <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
  20         </p></div></div></body></html>