upstream-doc/man2/glIndex.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="glIndex">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glIndex</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glIndex</refname>
  17         <refpurpose>set the current color index</refpurpose>
  18     </refnamediv>
  19     <para>
  20     </para>
  21     <refsynopsisdiv><title>C Specification</title>
  22         <funcsynopsis>
  23             <funcprototype>
  24                 <funcdef>void <function>glIndexs</function></funcdef>
  25                 <paramdef>GLshort <parameter>c</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glIndexi</function></funcdef>
  31                 <paramdef>GLint <parameter>c</parameter></paramdef>
  32             </funcprototype>
  33         </funcsynopsis>
  34         <funcsynopsis>
  35             <funcprototype>
  36                 <funcdef>void <function>glIndexf</function></funcdef>
  37                 <paramdef>GLfloat <parameter>c</parameter></paramdef>
  38             </funcprototype>
  39         </funcsynopsis>
  40         <funcsynopsis>
  41             <funcprototype>
  42                 <funcdef>void <function>glIndexd</function></funcdef>
  43                 <paramdef>GLdouble <parameter>c</parameter></paramdef>
  44             </funcprototype>
  45         </funcsynopsis>
  46         <funcsynopsis>
  47             <funcprototype>
  48                 <funcdef>void <function>glIndexub</function></funcdef>
  49                 <paramdef>GLubyte <parameter>c</parameter></paramdef>
  50             </funcprototype>
  51         </funcsynopsis>
  52     </refsynopsisdiv>
  53     <refsect1 id="parameters"><title>Parameters</title>
  54         <variablelist>
  55         <varlistentry>
  56             <term><parameter>c</parameter></term>
  57             <listitem>
  58                 <para>
  59                     Specifies the new value for the current color index.
  60                 </para>
  61                 <para>
  62                 </para>
  63             </listitem>
  64         </varlistentry>
  65         </variablelist>
  66     </refsect1>
  67     <refsynopsisdiv><title>C Specification</title>
  68         <funcsynopsis>
  69             <funcprototype>
  70                 <funcdef>void <function>glIndexsv</function></funcdef>
  71                 <paramdef>const GLshort * <parameter>c</parameter></paramdef>
  72             </funcprototype>
  73         </funcsynopsis>
  74         <funcsynopsis>
  75             <funcprototype>
  76                 <funcdef>void <function>glIndexiv</function></funcdef>
  77                 <paramdef>const GLint * <parameter>c</parameter></paramdef>
  78             </funcprototype>
  79         </funcsynopsis>
  80         <funcsynopsis>
  81             <funcprototype>
  82                 <funcdef>void <function>glIndexfv</function></funcdef>
  83                 <paramdef>const GLfloat * <parameter>c</parameter></paramdef>
  84             </funcprototype>
  85         </funcsynopsis>
  86         <funcsynopsis>
  87             <funcprototype>
  88                 <funcdef>void <function>glIndexdv</function></funcdef>
  89                 <paramdef>const GLdouble * <parameter>c</parameter></paramdef>
  90             </funcprototype>
  91         </funcsynopsis>
  92         <funcsynopsis>
  93             <funcprototype>
  94                 <funcdef>void <function>glIndexubv</function></funcdef>
  95                 <paramdef>const GLubyte * <parameter>c</parameter></paramdef>
  96             </funcprototype>
  97         </funcsynopsis>
  98     </refsynopsisdiv>
  99     <refsect1 id="parameters2"><title>Parameters</title>
 100         <variablelist>
 101         <varlistentry>
 102             <term><parameter>c</parameter></term>
 103             <listitem>
 104                 <para>
 105                     Specifies a pointer to a one-element array that contains
 106                     the new value for the current color index.
 107                 </para>
 108             </listitem>
 109         </varlistentry>
 110         </variablelist>
 111     </refsect1>
 112     <refsect1 id="description"><title>Description</title>
 113         <para>
 114             <function>glIndex</function> updates the current (single-valued) color index.
 115             It takes one argument, the new value for the current color index.
 116         </para>
 117         <para>
 118             The current index is stored as a floating-point value.
 119             Integer values are converted directly to floating-point values,
 120             with no special mapping.
 121             The initial value is 1.
 122         </para>
 123         <para>
 124             Index values outside the representable range of the color index buffer
 125             are not clamped.
 126             However,
 127             before an index is dithered (if enabled) and written to the frame buffer,
 128             it is converted to fixed-point format.
 129             Any bits in the integer portion of the resulting fixed-point value
 130             that do not correspond to bits in the frame buffer are masked out.
 131         </para>
 132     </refsect1>
 133     <refsect1 id="notes"><title>Notes</title>
 134         <para>
 135             <function>glIndexub</function> and <function>glIndexubv</function> are available only if the GL version is
 136             1.1 or greater.
 137         </para>
 138         <para>
 139             The current index can be updated at any time.
 140             In particular,
 141             <function>glIndex</function> can be called between a call to <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding
 142             call to <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
 143         </para>
 144     </refsect1>
 145     <refsect1 id="associatedgets"><title>Associated Gets</title>
 146         <para>
 147             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_INDEX</constant>
 148         </para>
 149     </refsect1>
 150     <refsect1 id="seealso"><title>See Also</title>
 151         <para>
 152             <citerefentry><refentrytitle>glColor</refentrytitle></citerefentry>,
 153             <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>
 154         </para>
 155     </refsect1>
 156     <refsect1 id="Copyright"><title>Copyright</title>
 157         <para>
 158             Copyright <trademark class="copyright"></trademark> 1991-2006
 159             Silicon Graphics, Inc. This document is licensed under the SGI
 160             Free Software B License. For details, see
 161             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 162         </para>
 163     </refsect1>
 164 </refentry>