upstream-man-pages/man2/xhtml/glGetHistogramParameter.xml

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   3 <?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" /><title>glGetHistogramParameter</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetHistogramParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetHistogramParameter — get histogram parameters</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetHistogramParameterfv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat *  </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetHistogramParameteriv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint *  </td><td><var class="pdparam">params</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>target</code></em></span></dt><dd><p>
   4                     Must be one of
   5                     <code class="constant">GL_HISTOGRAM</code> or
   6                     <code class="constant">GL_PROXY_HISTOGRAM</code>.
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
   8                     The name of the parameter to be retrieved.
   9                     Must be one of
  10                     <code class="constant">GL_HISTOGRAM_WIDTH</code>,
  11                     <code class="constant">GL_HISTOGRAM_FORMAT</code>,
  12                     <code class="constant">GL_HISTOGRAM_RED_SIZE</code>,
  13                     <code class="constant">GL_HISTOGRAM_GREEN_SIZE</code>,
  14                     <code class="constant">GL_HISTOGRAM_BLUE_SIZE</code>,
  15                     <code class="constant">GL_HISTOGRAM_ALPHA_SIZE</code>,
  16                     <code class="constant">GL_HISTOGRAM_LUMINANCE_SIZE</code>, or
  17                     <code class="constant">GL_HISTOGRAM_SINK</code>.
  18                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  19                     Pointer to storage for the returned values.
  20                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  21             <code class="function">glGetHistogramParameter</code> is used to query parameter values for the current histogram or for
  22             a proxy.  The histogram state information may be queried by calling
  23             <code class="function">glGetHistogramParameter</code> with a <em class="parameter"><code>target</code></em> of <code class="constant">GL_HISTOGRAM</code> (to
  24             obtain information for the current histogram table) or
  25             <code class="constant">GL_PROXY_HISTOGRAM</code> (to obtain information from the most recent
  26             proxy request) and one of the following values for the <em class="parameter"><code>pname</code></em> argument:
  27         </p><p>
  28         </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
  29                         Parameter
  30                         </strong></span></th><th align="left"><span class="bold"><strong>
  31                         Description
  32                         </strong></span></th></tr></thead><tbody><tr><td align="left">
  33                         <code class="constant">GL_HISTOGRAM_WIDTH</code>
  34                         </td><td align="left">
  35                         Histogram table width
  36                         </td></tr><tr><td align="left">
  37                         <code class="constant">GL_HISTOGRAM_FORMAT</code>
  38                         </td><td align="left">
  39                         Internal format
  40                         </td></tr><tr><td align="left">
  41                         <code class="constant">GL_HISTOGRAM_RED_SIZE</code>
  42                         </td><td align="left">
  43                         Red component counter size, in bits
  44                         </td></tr><tr><td align="left">
  45                         <code class="constant">GL_HISTOGRAM_GREEN_SIZE</code>
  46                         </td><td align="left">
  47                         Green component counter size, in bits
  48                         </td></tr><tr><td align="left">
  49                         <code class="constant">GL_HISTOGRAM_BLUE_SIZE</code>
  50                         </td><td align="left">
  51                         Blue component counter size, in bits
  52                         </td></tr><tr><td align="left">
  53                         <code class="constant">GL_HISTOGRAM_ALPHA_SIZE</code>
  54                         </td><td align="left">
  55                         Alpha component counter size, in bits
  56                         </td></tr><tr><td align="left">
  57                         <code class="constant">GL_HISTOGRAM_LUMINANCE_SIZE</code>
  58                         </td><td align="left">
  59                         Luminance component counter size, in bits
  60                         </td></tr><tr><td align="left">
  61                         <code class="constant">GL_HISTOGRAM_SINK</code>
  62                         </td><td align="left">
  63                         Value of the <span class="emphasis"><em>sink</em></span> parameter
  64                         </td></tr></tbody></table></div><p>
  65         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  66             <code class="function">glGetHistogramParameter</code> is present only if <code class="code">ARB_imaging</code> is returned when <a class="citerefentry" href="glGetString.xml"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a>
  67             is called with an argument of <code class="constant">GL_EXTENSIONS</code>.
  68         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  69             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not one of the allowable
  70             values.
  71         </p><p>
  72             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>pname</code></em> is not one of the allowable
  73             values.
  74         </p><p>
  75             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetHistogramParameter</code> is executed
  76             between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
  77             execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  78         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  79             <a class="citerefentry" href="glGetHistogram.xml"><span class="citerefentry"><span class="refentrytitle">glGetHistogram</span></span></a>,
  80             <a class="citerefentry" href="glHistogram.xml"><span class="citerefentry"><span class="refentrytitle">glHistogram</span></span></a>
  81         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  82             Copyright <span class="trademark"></span>© 1991-2006
  83             Silicon Graphics, Inc. This document is licensed under the SGI
  84             Free Software B License. For details, see
  85             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  86         </p></div></div></body></html>