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<refentry id="glBlendColor">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glBlendColor</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glBlendColor</refname>
        <refpurpose>set the blend color</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glBlendColor</function></funcdef>
                <paramdef>GLfloat <parameter>red</parameter></paramdef>
                <paramdef>GLfloat <parameter>green</parameter></paramdef>
                <paramdef>GLfloat <parameter>blue</parameter></paramdef>
                <paramdef>GLfloat <parameter>alpha</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>red</parameter></term>
            <term><parameter>green</parameter></term>
            <term><parameter>blue</parameter></term>
            <term><parameter>alpha</parameter></term>
            <listitem>
                <para>
                    specify the components of <constant>GL_BLEND_COLOR</constant>
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            The <constant>GL_BLEND_COLOR</constant> may be used to calculate the source and destination
            blending factors. The color components are clamped to the range
            <inlineequation><mml:math>
                <!-- eqn: [0,1]: -->
                <mml:mfenced open="[" close="]">
                    <mml:mn>0</mml:mn>
                    <mml:mn>1</mml:mn>
                </mml:mfenced>
            </mml:math></inlineequation>
            before being stored. See <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> for a complete description of the
            blending operations.
            Initially the <constant>GL_BLEND_COLOR</constant> is set to (0, 0, 0, 0).
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            The type of the <parameter>red</parameter>,
            <parameter>green</parameter>, <parameter>blue</parameter>,
            and <parameter>alpha</parameter> parameters was changed from
            GLclampf to GLfloat. This change is transparent to user code
            and is described in detail on the
            <citerefentry><refentrytitle>removedTypes</refentrytitle></citerefentry>
            page.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_COLOR</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glBlendEquation</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>removedTypes</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>
