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<?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>glActiveTexture</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glActiveTexture"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glActiveTexture — select active texture unit</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">glActiveTexture</b>(</code></td><td>GLenum  </td><td><var class="pdparam">texture</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>texture</code></em></span></dt><dd><p>
                    Specifies which texture unit to make active. The number
                    of texture units is implementation dependent, but must be at least
                    two. <em class="parameter"><code>texture</code></em> must be one of 
                    <code class="constant">GL_TEXTURE</code><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>,
                    where
                    i ranges from 0 to the larger of (<code class="constant">GL_MAX_TEXTURE_COORDS</code> - 1)
                    and (<code class="constant">GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</code> - 1). 
                    The initial value is <code class="constant">GL_TEXTURE0</code>.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glActiveTexture</code> selects which texture unit subsequent texture state calls will
            affect.  The number of texture units an implementation supports is
            implementation dependent, but must be at least 2.
        </p><p>
            Vertex arrays are client-side GL resources, which are selected by the
            <a class="citerefentry" href="glClientActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glClientActiveTexture</span></span></a> routine.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            <code class="function">glActiveTexture</code> is only supported if the GL version is 1.3 or greater, or if
            <code class="code">ARB_multitexture</code> is included in the string returned by
            <a class="citerefentry" href="glGetString.xml"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a> when called with the argument <code class="constant">GL_EXTENSIONS</code>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>texture</code></em> is not one of
            <code class="constant">GL_TEXTURE</code><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>,
            where i ranges from 0 to the larger of (<code class="constant">GL_MAX_TEXTURE_COORDS</code> - 1)
            and (<code class="constant">GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</code> - 1).
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_ACTIVE_TEXTURE</code>, <code class="constant">GL_MAX_TEXTURE_COORDS</code>, or <code class="constant">GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS</code>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glClientActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glClientActiveTexture</span></span></a>,
            <a class="citerefentry" href="glMultiTexCoord.xml"><span class="citerefentry"><span class="refentrytitle">glMultiTexCoord</span></span></a>,
            <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>
