upstream-man-pages/man2/glActiveTexture.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="glActiveTexture">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glActiveTexture</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glActiveTexture</refname>
  17         <refpurpose>select active texture unit</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glActiveTexture</function></funcdef>
  23                 <paramdef>GLenum <parameter>texture</parameter></paramdef>
  24             </funcprototype>
  25         </funcsynopsis>
  26     </refsynopsisdiv>
  27     <!-- eqn: ignoring delim $$ -->
  28     <refsect1 id="parameters"><title>Parameters</title>
  29         <variablelist>
  30         <varlistentry>
  31             <term><parameter>texture</parameter></term>
  32             <listitem>
  33                 <para>
  34                     Specifies which texture unit to make active. The number
  35                     of texture units is implementation dependent, but must be at least
  36                     two. <parameter>texture</parameter> must be one of
  37                     <constant>GL_TEXTURE</constant><inlineequation><mml:math><mml:mi mathvariant="italic">i</mml:mi></mml:math></inlineequation>,
  38                     where
  39                     i ranges from 0 to the larger of (<constant>GL_MAX_TEXTURE_COORDS</constant> - 1)
  40                     and (<constant>GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</constant> - 1).
  41                     The initial value is <constant>GL_TEXTURE0</constant>.
  42                 </para>
  43             </listitem>
  44         </varlistentry>
  45         </variablelist>
  46     </refsect1>
  47     <refsect1 id="description"><title>Description</title>
  48         <para>
  49             <function>glActiveTexture</function> selects which texture unit subsequent texture state calls will
  50             affect.  The number of texture units an implementation supports is
  51             implementation dependent, but must be at least 2.
  52         </para>
  53         <para>
  54             Vertex arrays are client-side GL resources, which are selected by the
  55             <citerefentry><refentrytitle>glClientActiveTexture</refentrytitle></citerefentry> routine.
  56         </para>
  57     </refsect1>
  58     <refsect1 id="notes"><title>Notes</title>
  59         <para>
  60             <function>glActiveTexture</function> is only supported if the GL version is 1.3 or greater, or if
  61             <code>ARB_multitexture</code> is included in the string returned by
  62             <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry> when called with the argument <constant>GL_EXTENSIONS</constant>.
  63         </para>
  64     </refsect1>
  65     <refsect1 id="errors"><title>Errors</title>
  66         <para>
  67             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>texture</parameter> is not one of
  68             <constant>GL_TEXTURE</constant><inlineequation><mml:math><mml:mi mathvariant="italic">i</mml:mi></mml:math></inlineequation>,
  69             where i ranges from 0 to the larger of (<constant>GL_MAX_TEXTURE_COORDS</constant> - 1)
  70             and (<constant>GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</constant> - 1).
  71         </para>
  72     </refsect1>
  73     <refsect1 id="associatedgets"><title>Associated Gets</title>
  74         <para>
  75             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ACTIVE_TEXTURE</constant>, <constant>GL_MAX_TEXTURE_COORDS</constant>, or <constant>GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</constant>
  76         </para>
  77     </refsect1>
  78     <refsect1 id="seealso"><title>See Also</title>
  79         <para>
  80             <citerefentry><refentrytitle>glClientActiveTexture</refentrytitle></citerefentry>,
  81             <citerefentry><refentrytitle>glMultiTexCoord</refentrytitle></citerefentry>,
  82             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
  83         </para>
  84     </refsect1>
  85     <refsect1 id="Copyright"><title>Copyright</title>
  86         <para>
  87             Copyright <trademark class="copyright"></trademark> 1991-2006
  88             Silicon Graphics, Inc. This document is licensed under the SGI
  89             Free Software B License. For details, see
  90             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
  91         </para>
  92     </refsect1>
  93 </refentry>