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<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glStencilMask">
    <info>
        <copyright>
            <year>1991-2006</year>
            <holder>Silicon Graphics, Inc.</holder>
        </copyright>
        <copyright>
            <year>2010-2015</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glStencilMask</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glStencilMask</refname>
        <refpurpose>control the front and back writing of individual bits in the stencil planes</refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glStencilMask</function></funcdef>
                <paramdef>GLuint <parameter>mask</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>mask</parameter></term>
            <listitem>
                <para>
                    Specifies a bit mask to enable and disable writing of individual bits
                    in the stencil planes.
                    Initially, the mask is all 1's.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glStencilMask</function> controls the writing of individual bits in the stencil planes.
            The least significant
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
            bits of <parameter>mask</parameter>,
            where
            <inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
            is the number of bits in the stencil buffer,
            specify a mask.
            Where a 1 appears in the mask,
            it's possible to write to the corresponding bit in the stencil buffer.
            Where a 0 appears,
            the corresponding bit is write-protected.
            Initially, all bits are enabled for writing.
        </para>
        <para>
            There can be two separate <parameter>mask</parameter> writemasks; one affects back-facing polygons, and the other
            affects front-facing polygons as well as other non-polygon primitives.
            <function>glStencilMask</function> sets both front
            and back stencil writemasks to the same values. Use <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>
            to set front and back stencil writemasks to different values.
        </para>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            <function>glStencilMask</function> is the same as
            calling <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>
            with <parameter>face</parameter> set to <constant>GL_FRONT_AND_BACK</constant>.
        </para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
            <constant>GL_STENCIL_WRITEMASK</constant>, <constant>GL_STENCIL_BACK_WRITEMASK</constant>,
            or <constant>GL_STENCIL_BITS</constant>
        </para>
    </refsect1>
    <refsect1 xml:id="versions">
        <title>API Version Support</title>
        <informaltable>
            <tgroup cols="5" align="left">
                <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
                <tbody>
                    <row>
                        <entry>glStencilMask</entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='es20']/*)"/>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glColorMask</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDepthMask</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glStencilFuncSeparate</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glStencilMaskSeparate</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glStencilOp</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glStencilOpSeparate</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 1991-2006 Silicon Graphics, Inc.
            Copyright <trademark class="copyright"/> 2010-2015 Khronos Group.
            This document is licensed under the SGI Free Software B License.
            For details, see
            <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</link>.
        </para>
    </refsect1>
</refentry>
