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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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<refentry id="glGetBufferPointerv">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2005</year>
                <holder>Sams Publishing</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetBufferPointerv</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetBufferPointerv</refname>
        <refpurpose>return the pointer to a mapped buffer object's data store</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetBufferPointerv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLvoid ** <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>target</parameter></term>
            <listitem>
                <para>
                    Specifies the target buffer object.
                    The symbolic constant must be <constant>GL_ARRAY_BUFFER</constant>, 
                    <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,
                    <constant>GL_PIXEL_PACK_BUFFER</constant>, or
                    <constant>GL_PIXEL_UNPACK_BUFFER</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies the pointer to be returned.  The symbolic constant must be <constant>GL_BUFFER_MAP_POINTER</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Returns the pointer value specified by <parameter>pname</parameter>.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetBufferPointerv</function> returns pointer information. <parameter>pname</parameter> is a symbolic constant
            indicating the pointer to be returned, which must be <constant>GL_BUFFER_MAP_POINTER</constant>, the pointer
            to which the buffer object's data store is mapped.  If the data store is not currently mapped, <constant>NULL</constant> is returned.
            <parameter>params</parameter> is a pointer to a location in which to place the returned pointer value.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            If an error is generated,
            no change is made to the contents of <parameter>params</parameter>.
        </para>
        <para>
            <function>glGetBufferPointerv</function> is available only if the GL version is 1.5 or greater.
        </para>
        <para>
            Targets <constant>GL_PIXEL_PACK_BUFFER</constant> and <constant>GL_PIXEL_UNPACK_BUFFER</constant> are available 
            only if the GL version is 2.1 or greater.
        </para>
        <para>
            The initial value for the pointer is <constant>NULL</constant>.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
            accepted value.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if the reserved buffer object name 0 is bound to <parameter>target</parameter>.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <function>glGetBufferParameteriv</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="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley. 
            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>
