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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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<refentry id="glIsEnabled">
<refentryinfo>
<copyright>
<year>1991-2006</year>
<holder>Silicon Graphics, Inc.</holder>
</copyright>
<copyright>
<year>2010-2013</year>
<holder>Khronos Group</holder>
</copyright>
</refentryinfo>
<refmeta>
<refentrytitle>glIsEnabled</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glIsEnabled, glIsEnabledi</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>
<funcsynopsis>
<funcprototype>
<funcdef>GLboolean <function>glIsEnabledi</function></funcdef>
<paramdef>GLenum <parameter>cap</parameter></paramdef>
<paramdef>GLuint <parameter>index</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>
<varlistentry>
<term><parameter>index</parameter></term>
<listitem>
<para>
Specifies the index of the 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. Boolean states that are indexed may be tested with <function>glIsEnabledi</function>.
For <function>glIsEnabledi</function>, <parameter>index</parameter> specifies the index of the capability to test. <parameter>index</parameter>
must be between zero and the count of indexed capabilities for <parameter>cap</parameter>.
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>, <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>
</entry>
</row>
<row>
<entry align="left">
<constant>GL_CLIP_DISTANCE</constant><emphasis>i</emphasis>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</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_CULL_FACE</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glCullFace</refentrytitle></citerefentry>
</entry>
</row>
<row>
<entry align="left">
<constant>GL_DEPTH_CLAMP</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
</entry>
</row>
<row>
<entry align="left">
<constant>GL_DEBUG_OUTPUT</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
</entry>
</row>
<row>
<entry align="left">
<constant>GL_DEBUG_OUTPUT_SYNCHRONOUS</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</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_FRAMEBUFFER_SRGB</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</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_MULTISAMPLE</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glSampleCoverage</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_PROGRAM_POINT_SIZE</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PRIMITIVE_RESTART</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glPrimitiveRestartIndex</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_SAMPLE_MASK</constant>
</entry>
<entry align="left">
<citerefentry><refentrytitle>glEnable</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>
<row>
<entry align="left">
<constant>GL_TEXTURE_CUBE_MAP_SEAMLESS</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> and <function>glIsEnabledi</function> return <constant>GL_FALSE</constant>.
</para>
<para>
<constant>GL_DEBUG_OUTPUT</constant> and <constant>GL_DEBUG_OUTPUT_SYNCHRONOUS</constant> are available only if the GL version is 4.3 or greater.
</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_VALUE</constant> is generated by <function>glIsEnabledi</function> if <parameter>index</parameter> is outside the
valid range for the indexed state <parameter>cap</parameter>.
</para>
</refsect1>
<refsect1 id="seealso"><title>See Also</title>
<para>
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDisable</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.
Copyright <trademark class="copyright"></trademark> 2010-2013 Khronos Group.
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>