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<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_BLEND</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glBlendFunc</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>glDepthRangef</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_POLYGON_OFFSET_FILL</constant> 
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glPolygonOffset</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_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_STENCIL_TEST</constant>
                        </entry>
                        <entry align="left">
                        <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glStencilOp</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>
    </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>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glEnable</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>
