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<refentry id="glEdgeFlagPointer">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glEdgeFlagPointer</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glEdgeFlagPointer</refname>
        <refpurpose>define an array of edge flags</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glEdgeFlagPointer</function></funcdef>
                <paramdef>GLsizei <parameter>stride</parameter></paramdef>
                <paramdef>const GLvoid * <parameter>pointer</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>stride</parameter></term>
            <listitem>
                <para>
                    Specifies the byte offset between consecutive edge flags.
                    If <parameter>stride</parameter> is 0, the edge flags are understood
                    to be tightly packed in the array. The initial value is 0.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pointer</parameter></term>
            <listitem>
                <para>
                    Specifies a pointer to the first edge flag in the array. The initial
                    value is 0.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glEdgeFlagPointer</function> specifies the location and data format of an array of boolean edge
            flags to use when rendering. <parameter>stride</parameter> specifies the byte stride from one
            edge flag to the next, allowing vertices and attributes
            to be packed into a single array or stored in separate arrays.
        </para>
        <para>
            If a non-zero named buffer object is bound to the <constant>GL_ARRAY_BUFFER</constant> target 
            (see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while an edge flag array is
            specified, <parameter>pointer</parameter> is treated as a byte offset into the buffer object's data store.
            Also, the buffer object binding (<constant>GL_ARRAY_BUFFER_BINDING</constant>) is saved as edge flag vertex array
            client-side state (<constant>GL_EDGE_FLAG_ARRAY_BUFFER_BINDING</constant>).
        </para>
        <para>
            When an edge flag array is
            specified, <parameter>stride</parameter> and <parameter>pointer</parameter> are saved as client-side
            state, in addition to the current vertex array buffer object binding.
        </para>
        <para>
            To enable and disable the edge flag array, call
            <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry> with the argument
            <constant>GL_EDGE_FLAG_ARRAY</constant>. If
            enabled, the edge flag array is used
            when <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>, or
            <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry> is called.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            <function>glEdgeFlagPointer</function> is available only if the GL version is 1.1 or greater.
        </para>
        <para>
            Edge flags are not supported for interleaved vertex array formats
            (see <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>).
        </para>
        <para>
            The edge flag array is initially disabled and isn't accessed when
            <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, or <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>
            is called.
        </para>
        <para>
            Execution of <function>glEdgeFlagPointer</function> is not allowed between the execution of
            <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>,
            but an error may or may not be generated. If no error is generated,
            the operation is undefined.
        </para>
        <para>
            <function>glEdgeFlagPointer</function> is typically implemented on the client side.
        </para>
        <para>
            Edge flag array parameters are client-side state and are therefore
            not saved or restored by <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glPopAttrib</refentrytitle></citerefentry>.
            Use <citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry> and
            <citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry> instead.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>stride</parameter> is negative.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glIsEnabled</refentrytitle></citerefentry> with argument <constant>GL_EDGE_FLAG_ARRAY</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_EDGE_FLAG_ARRAY_STRIDE</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_EDGE_FLAG_ARRAY_BUFFER_BINDING</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ARRAY_BUFFER_BINDING</constant>
        </para>
        <para>
            <citerefentry><refentrytitle>glGetPointerv</refentrytitle></citerefentry> with argument <constant>GL_EDGE_FLAG_ARRAY_POINTER</constant>
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glEdgeFlag</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glFogCoordPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glVertexPointer</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>
