upstream-man-pages/man2/xhtml/glGetColorTable.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>glGetColorTable</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetColorTable"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetColorTable — retrieve contents of a color lookup table</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">glGetColorTable</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">format</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">type</var>, </td></tr><tr><td> </td><td>GLvoid *  </td><td><var class="pdparam">table</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 <code class="constant">GL_COLOR_TABLE</code>,
   5                     <code class="constant">GL_POST_CONVOLUTION_COLOR_TABLE</code>,
   6                     or
   7                     <code class="constant">GL_POST_COLOR_MATRIX_COLOR_TABLE</code>.
   8                 </p></dd><dt><span class="term"><em class="parameter"><code>format</code></em></span></dt><dd><p>
   9                     The format of the pixel data in <em class="parameter"><code>table</code></em>.
  10                     The possible values are
  11                     <code class="constant">GL_RED</code>,
  12                     <code class="constant">GL_GREEN</code>,
  13                     <code class="constant">GL_BLUE</code>,
  14                     <code class="constant">GL_ALPHA</code>,
  15                     <code class="constant">GL_LUMINANCE</code>,
  16                     <code class="constant">GL_LUMINANCE_ALPHA</code>,
  17                     <code class="constant">GL_RGB</code>,
  18                     <code class="constant">GL_BGR</code>,
  19                     <code class="constant">GL_RGBA</code>, and
  20                     <code class="constant">GL_BGRA</code>.
  21                 </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
  22                     The type of the pixel data in <em class="parameter"><code>table</code></em>.
  23                     Symbolic constants
  24                     <code class="constant">GL_UNSIGNED_BYTE</code>,
  25                     <code class="constant">GL_BYTE</code>,
  26                     <code class="constant">GL_BITMAP</code>,
  27                     <code class="constant">GL_UNSIGNED_SHORT</code>,
  28                     <code class="constant">GL_SHORT</code>,
  29                     <code class="constant">GL_UNSIGNED_INT</code>,
  30                     <code class="constant">GL_INT</code>,
  31                     <code class="constant">GL_FLOAT</code>,
  32                     <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
  33                     <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
  34                     <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>,
  35                     <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>,
  36                     <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
  37                     <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
  38                     <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
  39                     <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
  40                     <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
  41                     <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
  42                     <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>, and
  43                     <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>
  44                     are accepted.
  45                 </p></dd><dt><span class="term"><em class="parameter"><code>table</code></em></span></dt><dd><p>
  46                     Pointer to a one-dimensional array of pixel data containing the contents
  47                     of the color table.
  48                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  49             <code class="function">glGetColorTable</code> returns in <em class="parameter"><code>table</code></em> the contents of the color table specified
  50             by <em class="parameter"><code>target</code></em>. No pixel transfer operations are performed, but pixel
  51             storage modes that are applicable to
  52             <a class="citerefentry" href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a> are performed.
  53         </p><p>
  54             If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_PACK_BUFFER</code> target
  55             (see <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a histogram table is
  56             requested, <em class="parameter"><code>table</code></em> is treated as a byte offset into the buffer object's data store.
  57         </p><p>
  58             Color components that are requested in
  59             the specified <em class="parameter"><code>format</code></em>, but which are not included in the internal
  60             format of the color lookup table, are returned as zero.  The
  61             assignments of internal color components to the components
  62             requested by <em class="parameter"><code>format</code></em> are
  63         </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
  64                         Internal Component
  65                         </strong></span></th><th align="left"><span class="bold"><strong>
  66                         Resulting Component
  67                         </strong></span></th></tr></thead><tbody><tr><td align="left">
  68                         Red
  69                         </td><td align="left">
  70                         Red
  71                         </td></tr><tr><td align="left">
  72                         Green
  73                         </td><td align="left">
  74                         Green
  75                         </td></tr><tr><td align="left">
  76                         Blue
  77                         </td><td align="left">
  78                         Blue
  79                         </td></tr><tr><td align="left">
  80                         Alpha
  81                         </td><td align="left">
  82                         Alpha
  83                         </td></tr><tr><td align="left">
  84                         Luminance
  85                         </td><td align="left">
  86                         Red
  87                         </td></tr><tr><td align="left">
  88                         Intensity
  89                         </td><td align="left">
  90                         Red
  91                         </td></tr></tbody></table></div><p>
  92         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  93             <code class="function">glGetColorTable</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>
  94             is called with an argument of <code class="constant">GL_EXTENSIONS</code>.
  95         </p><p>
  96         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  97             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not one of the allowable
  98             values.
  99         </p><p>
 100             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>format</code></em> is not one of the allowable
 101             values.
 102         </p><p>
 103             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>type</code></em> is not one of the allowable
 104             values.
 105         </p><p>
 106             <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>type</code></em> is one of
 107             <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
 108             <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
 109             <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>, or
 110             <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>
 111             and <em class="parameter"><code>format</code></em> is not <code class="constant">GL_RGB</code>.
 112         </p><p>
 113             <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>type</code></em> is one of
 114             <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
 115             <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
 116             <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
 117             <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
 118             <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
 119             <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
 120             <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>, or
 121             <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>
 122             and <em class="parameter"><code>format</code></em> is neither <code class="constant">GL_RGBA</code> nor <code class="constant">GL_BGRA</code>.
 123         </p><p>
 124             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 125             <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the buffer object's data store is currently mapped.
 126         </p><p>
 127             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 128             <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the data would be packed to the buffer
 129             object such that the memory writes required would exceed the data store size.
 130         </p><p>
 131             <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
 132             <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and <em class="parameter"><code>table</code></em> is not evenly divisible
 133             into the number of bytes needed to store in memory a datum indicated by <em class="parameter"><code>type</code></em>.
 134         </p><p>
 135             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetColorTable</code> is executed
 136             between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
 137             execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 138         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 139             <a class="citerefentry" href="glGetColorTableParameter.xml"><span class="citerefentry"><span class="refentrytitle">glGetColorTableParameter</span></span></a>
 140         </p><p>
 141             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_PACK_BUFFER_BINDING</code>
 142         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 143             <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,
 144             <a class="citerefentry" href="glColorTableParameter.xml"><span class="citerefentry"><span class="refentrytitle">glColorTableParameter</span></span></a>
 145         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 146             Copyright <span class="trademark"></span>© 1991-2006
 147             Silicon Graphics, Inc. This document is licensed under the SGI
 148             Free Software B License. For details, see
 149             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 150         </p></div></div></body></html>