upstream-man-pages/man2/glGetHistogramParameter.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glGetHistogramParameter">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetHistogramParameter</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetHistogramParameter</refname>
  17         <refpurpose>get histogram parameters</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetHistogramParameterfv</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  25                 <paramdef>GLfloat * <parameter>params</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glGetHistogramParameteriv</function></funcdef>
  31                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  32                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  33                 <paramdef>GLint * <parameter>params</parameter></paramdef>
  34             </funcprototype>
  35         </funcsynopsis>
  36     </refsynopsisdiv>
  37     <refsect1 id="parameters"><title>Parameters</title>
  38         <variablelist>
  39         <varlistentry>
  40             <term><parameter>target</parameter></term>
  41             <listitem>
  42                 <para>
  43                     Must be one of
  44                     <constant>GL_HISTOGRAM</constant> or
  45                     <constant>GL_PROXY_HISTOGRAM</constant>.
  46                 </para>
  47             </listitem>
  48         </varlistentry>
  49         <varlistentry>
  50             <term><parameter>pname</parameter></term>
  51             <listitem>
  52                 <para>
  53                     The name of the parameter to be retrieved.
  54                     Must be one of
  55                     <constant>GL_HISTOGRAM_WIDTH</constant>,
  56                     <constant>GL_HISTOGRAM_FORMAT</constant>,
  57                     <constant>GL_HISTOGRAM_RED_SIZE</constant>,
  58                     <constant>GL_HISTOGRAM_GREEN_SIZE</constant>,
  59                     <constant>GL_HISTOGRAM_BLUE_SIZE</constant>,
  60                     <constant>GL_HISTOGRAM_ALPHA_SIZE</constant>,
  61                     <constant>GL_HISTOGRAM_LUMINANCE_SIZE</constant>, or
  62                     <constant>GL_HISTOGRAM_SINK</constant>.
  63                 </para>
  64             </listitem>
  65         </varlistentry>
  66         <varlistentry>
  67             <term><parameter>params</parameter></term>
  68             <listitem>
  69                 <para>
  70                     Pointer to storage for the returned values.
  71                 </para>
  72             </listitem>
  73         </varlistentry>
  74         </variablelist>
  75     </refsect1>
  76     <refsect1 id="description"><title>Description</title>
  77         <para>
  78             <function>glGetHistogramParameter</function> is used to query parameter values for the current histogram or for
  79             a proxy.  The histogram state information may be queried by calling
  80             <function>glGetHistogramParameter</function> with a <parameter>target</parameter> of <constant>GL_HISTOGRAM</constant> (to
  81             obtain information for the current histogram table) or
  82             <constant>GL_PROXY_HISTOGRAM</constant> (to obtain information from the most recent
  83             proxy request) and one of the following values for the <parameter>pname</parameter> argument:
  84         </para>
  85         <para>
  86         </para>
  87         <informaltable frame="topbot">
  88             <tgroup cols="2" align="left">
  89                 <colspec/>
  90                 <colspec/>
  91                 <thead>
  92                     <row>
  93                         <entry rowsep="1" align="left"><emphasis role="bold">
  94                         Parameter
  95                         </emphasis></entry>
  96                         <entry rowsep="1" align="left"><emphasis role="bold">
  97                         Description
  98                         </emphasis></entry>
  99                     </row>
 100                 </thead>
 101                 <tbody>
 102                     <row>
 103                         <entry align="left">
 104                         <constant>GL_HISTOGRAM_WIDTH</constant>
 105                         </entry>
 106                         <entry align="left">
 107                         Histogram table width
 108                         </entry>
 109                     </row>
 110                     <row>
 111                         <entry align="left">
 112                         <constant>GL_HISTOGRAM_FORMAT</constant>
 113                         </entry>
 114                         <entry align="left">
 115                         Internal format
 116                         </entry>
 117                     </row>
 118                     <row>
 119                         <entry align="left">
 120                         <constant>GL_HISTOGRAM_RED_SIZE</constant>
 121                         </entry>
 122                         <entry align="left">
 123                         Red component counter size, in bits
 124                         </entry>
 125                     </row>
 126                     <row>
 127                         <entry align="left">
 128                         <constant>GL_HISTOGRAM_GREEN_SIZE</constant>
 129                         </entry>
 130                         <entry align="left">
 131                         Green component counter size, in bits
 132                         </entry>
 133                     </row>
 134                     <row>
 135                         <entry align="left">
 136                         <constant>GL_HISTOGRAM_BLUE_SIZE</constant>
 137                         </entry>
 138                         <entry align="left">
 139                         Blue component counter size, in bits
 140                         </entry>
 141                     </row>
 142                     <row>
 143                         <entry align="left">
 144                         <constant>GL_HISTOGRAM_ALPHA_SIZE</constant>
 145                         </entry>
 146                         <entry align="left">
 147                         Alpha component counter size, in bits
 148                         </entry>
 149                     </row>
 150                     <row>
 151                         <entry align="left">
 152                         <constant>GL_HISTOGRAM_LUMINANCE_SIZE</constant>
 153                         </entry>
 154                         <entry align="left">
 155                         Luminance component counter size, in bits
 156                         </entry>
 157                     </row>
 158                     <row>
 159                         <entry align="left">
 160                         <constant>GL_HISTOGRAM_SINK</constant>
 161                         </entry>
 162                         <entry align="left">
 163                         Value of the <emphasis>sink</emphasis> parameter
 164                         </entry>
 165                     </row>
 166                 </tbody>
 167             </tgroup>
 168         </informaltable>
 169         <para>
 170         </para>
 171     </refsect1>
 172     <refsect1 id="notes"><title>Notes</title>
 173         <para>
 174             <function>glGetHistogramParameter</function> is present only if <code>ARB_imaging</code> is returned when <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>
 175             is called with an argument of <constant>GL_EXTENSIONS</constant>.
 176         </para>
 177     </refsect1>
 178     <refsect1 id="errors"><title>Errors</title>
 179         <para>
 180             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not one of the allowable
 181             values.
 182         </para>
 183         <para>
 184             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not one of the allowable
 185             values.
 186         </para>
 187         <para>
 188             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glGetHistogramParameter</function> is executed
 189             between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding
 190             execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
 191         </para>
 192     </refsect1>
 193     <refsect1 id="seealso"><title>See Also</title>
 194         <para>
 195             <citerefentry><refentrytitle>glGetHistogram</refentrytitle></citerefentry>,
 196             <citerefentry><refentrytitle>glHistogram</refentrytitle></citerefentry>
 197         </para>
 198     </refsect1>
 199     <refsect1 id="Copyright"><title>Copyright</title>
 200         <para>
 201             Copyright <trademark class="copyright"></trademark> 1991-2006
 202             Silicon Graphics, Inc. This document is licensed under the SGI
 203             Free Software B License. For details, see
 204             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 205         </para>
 206     </refsect1>
 207 </refentry>