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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
              "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
<refentry id="glIsEnabled">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glIsEnabled</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glIsEnabled</refname>
        <refpurpose>test whether a capability is enabled</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>GLboolean <function>glIsEnabled</function></funcdef>
                <paramdef>GLenum <parameter>cap</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>cap</parameter></term>
            <listitem>
                <para>
                    Specifies a symbolic constant indicating a GL capability.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glIsEnabled</function> returns <constant>GL_TRUE</constant> if <parameter>cap</parameter> is an enabled capability
            and returns <constant>GL_FALSE</constant> otherwise.
            Initially all capabilities except <constant>GL_DITHER</constant> are disabled;
            <constant>GL_DITHER</constant> is initially enabled.
        </para>
        <para>
            The following capabilities are accepted for <parameter>cap</parameter>:
        </para>
        <para>
        </para>
        <informaltable frame="topbot">
            <tgroup cols="2" align="left">
                <colspec/>
                <colspec/>
                <thead>
                    <row>
                        <entry rowsep="1" align="left"><emphasis role="bold">
                        Constant
                        </emphasis></entry>
                        <entry rowsep="1" align="left"><emphasis role="bold">
                        See
                        </emphasis></entry>
                    </row>
                </thead>
                <tbody>
                    <row>
                        <entry align="left">
                        <constant>GL_ALPHA_TEST</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glAlphaFunc</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_AUTO_NORMAL</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEvalCoord</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_BLEND</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_CLIP_PLANE</constant><emphasis>i</emphasis>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glClipPlane</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_COLOR_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_COLOR_LOGIC_OP</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_COLOR_MATERIAL</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glColorMaterial</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_COLOR_SUM</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSecondaryColor</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_COLOR_TABLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glColorTable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_CONVOLUTION_1D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glConvolutionFilter1D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_CONVOLUTION_2D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glConvolutionFilter2D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_CULL_FACE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glCullFace</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_DEPTH_TEST</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glDepthFunc</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDepthRange</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_DITHER</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_EDGE_FLAG_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEdgeFlagPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_FOG</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glFog</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_FOG_COORD_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glFogCoordPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_HISTOGRAM</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glHistogram</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_INDEX_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_INDEX_LOGIC_OP</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_LIGHT</constant><emphasis>i</emphasis>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_LIGHTING</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMaterial</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_LINE_SMOOTH</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glLineWidth</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_LINE_STIPPLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glLineStipple</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_COLOR_4</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_INDEX</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_NORMAL</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_TEXTURE_COORD_1</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_TEXTURE_COORD_2</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_TEXTURE_COORD_3</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP1_TEXTURE_COORD_4</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap1</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_COLOR_4</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_INDEX</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_NORMAL</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_TEXTURE_COORD_1</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_TEXTURE_COORD_2</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_TEXTURE_COORD_3</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_TEXTURE_COORD_4</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_VERTEX_3</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MAP2_VERTEX_4</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMap2</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MINMAX</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glMinmax</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_MULTISAMPLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_NORMAL_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_NORMALIZE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POINT_SMOOTH</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPointSize</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POINT_SPRITE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POLYGON_SMOOTH</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonMode</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POLYGON_OFFSET_FILL</constant> 
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POLYGON_OFFSET_LINE</constant> 
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POLYGON_OFFSET_POINT</constant> 
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POLYGON_STIPPLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonStipple</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POST_COLOR_MATRIX_COLOR_TABLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glColorTable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_POST_CONVOLUTION_COLOR_TABLE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glColorTable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_RESCALE_NORMAL</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SAMPLE_ALPHA_TO_COVERAGE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SAMPLE_ALPHA_TO_ONE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SAMPLE_COVERAGE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SCISSOR_TEST</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glScissor</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SECONDARY_COLOR_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_SEPARABLE_2D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glSeparableFilter2D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_STENCIL_TEST</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glStencilOp</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_1D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_2D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_3D</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_COORD_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_CUBE_MAP</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_GEN_Q</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_GEN_R</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_GEN_S</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_TEXTURE_GEN_T</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_VERTEX_ARRAY</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glVertexPointer</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_VERTEX_PROGRAM_POINT_SIZE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                    <row>
                        <entry align="left">
                        <constant>GL_VERTEX_PROGRAM_TWO_SIDE</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
        <para>
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            If an error is generated,
            <function>glIsEnabled</function> returns 0.
        </para>
        <para>
            <constant>GL_COLOR_LOGIC_OP</constant>,
            <constant>GL_COLOR_ARRAY</constant>,
            <constant>GL_EDGE_FLAG_ARRAY</constant>,
            <constant>GL_INDEX_ARRAY</constant>,
            <constant>GL_INDEX_LOGIC_OP</constant>,
            <constant>GL_NORMAL_ARRAY</constant>,
            <constant>GL_POLYGON_OFFSET_FILL</constant>,
            <constant>GL_POLYGON_OFFSET_LINE</constant>,
            <constant>GL_POLYGON_OFFSET_POINT</constant>,
            <constant>GL_TEXTURE_COORD_ARRAY</constant>, and
            <constant>GL_VERTEX_ARRAY</constant>
            are available only
            if the GL version is 1.1 or greater.
        </para>
        <para>
            <constant>GL_RESCALE_NORMAL</constant>, and <constant>GL_TEXTURE_3D</constant> are available only if the GL
            version is 1.2 or greater.
        </para>
        <para>
            <constant>GL_MULTISAMPLE</constant>,
            <constant>GL_SAMPLE_ALPHA_TO_COVERAGE</constant>,
            <constant>GL_SAMPLE_ALPHA_TO_ONE</constant>,
            <constant>GL_SAMPLE_COVERAGE</constant>,
            <constant>GL_TEXTURE_CUBE_MAP</constant>
            are available only if the GL version is 1.3 or greater.
        </para>
        <para>
            <constant>GL_FOG_COORD_ARRAY</constant> and <constant>GL_SECONDARY_COLOR_ARRAY</constant>
            are available only if the GL version is 1.4 or greater.
        </para>
        <para>
            <constant>GL_POINT_SPRITE</constant>,
            <constant>GL_VERTEX_PROGRAM_POINT_SIZE</constant>, and
            <constant>GL_VERTEX_PROGRAM_TWO_SIDE</constant>
            are available only if the GL version is 2.0 or greater.
        </para>
        <para>
            <constant>GL_COLOR_TABLE</constant>, <constant>GL_CONVOLUTION_1D</constant>, <constant>GL_CONVOLUTION_2D</constant>,
            <constant>GL_HISTOGRAM</constant>, <constant>GL_MINMAX</constant>,
            <constant>GL_POST_COLOR_MATRIX_COLOR_TABLE</constant>,
            <constant>GL_POST_CONVOLUTION_COLOR_TABLE</constant>, and
            <constant>GL_SEPARABLE_2D</constant> are available only if <code>ARB_imaging</code> is
            returned when <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> is called with <constant>GL_EXTENSIONS</constant>.
        </para>
        <para>
            For OpenGL versions 1.3 and greater, or when the <code>ARB_multitexture</code> extension is supported, the following
            parameters return the associated value for the active texture unit:
            <constant>GL_TEXTURE_1D</constant>,
            <constant>GL_TEXTURE_2D</constant>,
            <constant>GL_TEXTURE_3D</constant>,
            <constant>GL_TEXTURE_CUBE_MAP</constant>,
            <constant>GL_TEXTURE_GEN_S</constant>,
            <constant>GL_TEXTURE_GEN_T</constant>,
            <constant>GL_TEXTURE_GEN_R</constant>,
            <constant>GL_TEXTURE_GEN_Q</constant>,
            <constant>GL_TEXTURE_MATRIX</constant>, and
            <constant>GL_TEXTURE_STACK_DEPTH</constant>.
            Likewise, the following parameters return the associated value for the
            active client texture unit:
            <constant>GL_TEXTURE_COORD_ARRAY</constant>,
            <constant>GL_TEXTURE_COORD_ARRAY_SIZE</constant>,
            <constant>GL_TEXTURE_COORD_ARRAY_STRIDE</constant>,
            <constant>GL_TEXTURE_COORD_ARRAY_TYPE</constant>.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>cap</parameter> is not an accepted value.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <function>glIsEnabled</function>
            is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
            and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
        </para>
    </refsect1>
</refentry>
