
<refentry id="glClearAccum">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glClearAccum</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glClearAccum</refname>
        <refpurpose>specify clear values for the accumulation buffer</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glClearAccum</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>
    <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 red, green, blue, and alpha values used when the
                    accumulation buffer is cleared.
                    The initial values are all 0.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glClearAccum</function> specifies the red, green, blue, and alpha values used by <citerefentry><refentrytitle>glClear</refentrytitle></citerefentry>
            to clear the accumulation buffer.
        </para>
        <para>
            Values specified by <function>glClearAccum</function> are clamped to the
            range 
            <inlineequation><mml:math>
                <!-- eqn: [-1,1]:-->
                <mml:mfenced open="[" close="]">
                    <mml:mn>-1</mml:mn>
                    <mml:mn>1</mml:mn>
                </mml:mfenced>
            </mml:math></inlineequation>.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <function>glClearAccum</function>
            is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
            and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ACCUM_CLEAR_VALUE</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glAccum</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glClear</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>
