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<refentry id="glCullFace">
<refmeta>
<refentrytitle>glCullFace</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glCullFace</refname>
<refpurpose>specify whether front- or back-facing polygons are
culled</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glCullFace</function></funcdef>
<paramdef>GLenum <parameter>mode</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term>
<parameter>mode</parameter>
</term>
<listitem>
<para>Specifies whether front- or back-facing polygons are
culled. Symbolic constants
<constant>GL_FRONT</constant>,
<constant>GL_BACK</constant>, and
<constant>GL_FRONT_AND_BACK</constant>
are accepted. The initial value is
<constant>GL_BACK</constant>.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
<function>glCullFace</function>
specifies whether front- or back-facing polygons are culled (as
specified by <parameter>mode</parameter>)
when culling is enabled.
To enable and disable culling, call
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
and
<citerefentry><refentrytitle>glDisable</refentrytitle></citerefentry>
with argument <constant>GL_CULL_FACE</constant>.
Culling is initially disabled.
</para>
<para>
<citerefentry><refentrytitle>glFrontFace</refentrytitle></citerefentry>
specifies which of the clockwise and counterclockwise polygons
are front-facing and back-facing.</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>If <parameter>mode</parameter> is
<constant>GL_FRONT_AND_BACK</constant>,
no polygons are drawn, but other primitives such as points and
lines are drawn.</para>
</refsect1>
<refsect1>
<title>Errors</title>
<para><constant>GL_INVALID_ENUM</constant> is generated if
<parameter>mode</parameter> is not an accepted value.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glFrontFace</refentrytitle></citerefentry>
</para>
</refsect1>
</refentry>