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<refentry id="glVertexAttribDivisor">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2010</year>
                <holder>Khronos Group</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glVertexAttribDivisor</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glVertexAttribDivisor</refname>
        <refpurpose>modify the rate at which generic vertex attributes advance during instanced rendering</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glVertexAttribDivisor</function></funcdef>
                <paramdef>GLuint <parameter>index</parameter></paramdef>
                <paramdef>GLuint <parameter>divisor</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>index</parameter></term>
            <listitem>
                <para>
                    Specify the index of the generic vertex attribute.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>divisor</parameter></term>
            <listitem>
                <para>
                    Specify the number of instances that will pass between updates of the generic attribute at slot <parameter>index</parameter>.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glVertexAttribDivisor</function> modifies the rate at which generic vertex attributes advance when rendering
            multiple instances of primitives in a single draw call. If <parameter>divisor</parameter> is zero, the attribute at slot
            <parameter>index</parameter> advances once per vertex. If <parameter>divisor</parameter> is non-zero, the attribute advances
            once per <parameter>divisor</parameter> instances of the set(s) of vertices being rendered.  An attribute
            is referred to as instanced if its <constant>GL_VERTEX_ATTRIB_ARRAY_DIVISOR</constant> value is non-zero.
        </para>
        <para>
            <parameter>index</parameter> must be less than the value of <constant>GL_MAX_VERTEX_ATTRIBUTES</constant>.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            <function>glVertexAttribDivisor</function> is available only if the GL version is 3.3 or higher.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>index</parameter> is greater
            than or equal to the value of <constant>GL_MAX_VERTEX_ATTRIBUTES</constant>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glEnableVertexAttribArray</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDisableVertexAttribArray</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. 
            This material may be distributed subject to the terms and conditions set forth in 
            the Open Publication License, v 1.0, 8 June 1999.
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
        </para>
    </refsect1>
</refentry>
