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">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glActiveTexture
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glActiveTexture
</refname>
17 <refpurpose>select active texture unit
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glActiveTexture
</function></funcdef>
23 <paramdef>GLenum
<parameter>texture
</parameter></paramdef>
27 <!-- eqn: ignoring delim $$ -->
28 <refsect1 id=
"parameters"><title>Parameters
</title>
31 <term><parameter>texture
</parameter></term>
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>,
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>.
47 <refsect1 id=
"description"><title>Description
</title>
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.
54 Vertex arrays are client-side GL resources, which are selected by the
55 <citerefentry><refentrytitle>glClientActiveTexture
</refentrytitle></citerefentry> routine.
58 <refsect1 id=
"notes"><title>Notes
</title>
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>.
65 <refsect1 id=
"errors"><title>Errors
</title>
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).
73 <refsect1 id=
"associatedgets"><title>Associated Gets
</title>
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>
78 <refsect1 id=
"seealso"><title>See Also
</title>
80 <citerefentry><refentrytitle>glClientActiveTexture
</refentrytitle></citerefentry>,
81 <citerefentry><refentrytitle>glMultiTexCoord
</refentrytitle></citerefentry>,
82 <citerefentry><refentrytitle>glTexParameter
</refentrytitle></citerefentry>
85 <refsect1 id=
"Copyright"><title>Copyright
</title>
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>.