<!DOCTYPE refentry [ <!ENTITY % mathent SYSTEM "math.ent"> %mathent; ]>

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glUnmapBuffer">
    <info>
        <copyright>
            <year>2005</year>
            <holder>Addison-Wesley Group</holder>
        </copyright>
        <copyright>
            <year>2010-2014</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glUnmapBuffer</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glUnmapBuffer</refname>
        <refname>glUnmapNamedBuffer</refname>
        <refpurpose>release the mapping of a buffer object's data store into the client's address space</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>GLboolean <function>glUnmapBuffer</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
            </funcprototype>
            <funcprototype>
                <funcdef>GLboolean <function>glUnmapNamedBuffer</function></funcdef>
                <paramdef>GLuint <parameter>buffer</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>target</parameter></term>
            <listitem>
                <para>
                    Specifies the target to which the buffer object is bound
                    for <function>glUnmapBuffer</function>, which must be
                    one of the buffer binding targets in the following
                    table:
                </para>
                <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="bufferbindings.xml"/>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>buffer</parameter></term>
            <listitem>
                <para>
                    Specifies the name of the buffer object for
                    <function>glUnmapNamedBuffer</function>.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glUnmapBuffer</function> and
            <function>glUnmapNamedBuffer</function> unmap (release) any
            mapping of a specified buffer object into the client's address
            space (see
            <citerefentry><refentrytitle>glMapBufferRange</refentrytitle></citerefentry>
            and
            <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>).
        </para>
        <para>
            If a mapping is not unmapped before the corresponding buffer
            object's data store is used by the GL, an error will be
            generated by any GL command that attempts to dereference the
            buffer object's data store, unless the buffer was successfully
            mapped with <constant>GL_MAP_PERSISTENT_BIT</constant> (see
            <citerefentry><refentrytitle>glMapBufferRange</refentrytitle></citerefentry>).
            When a data store is unmapped, the mapped pointer becomes
            invalid.
        </para>
        <para>
            <function>glUnmapBuffer</function> returns
            <constant>GL_TRUE</constant> unless the data store contents have
            become corrupt during the time the data store was mapped. This
            can occur for system-specific reasons that affect the
            availability of graphics memory, such as screen mode changes. In
            such situations, <constant>GL_FALSE</constant> is returned and
            the data store contents are undefined. An application must
            detect this rare condition and reinitialize the data store.
        </para>
        <para>
            A buffer object's mapped data store is automatically unmapped
            when the buffer object is deleted or its data store is recreated
            with
            <citerefentry><refentrytitle>glBufferData</refentrytitle></citerefentry>).
        </para>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            If an error is generated, <function>glUnmapBuffer</function>
            returns <constant>GL_FALSE</constant>.
        </para>
        <para>
            The <constant>GL_ATOMIC_COUNTER_BUFFER</constant> target is
            accepted only if the GL version is 4.2 or greater.
        </para>
        <para>
            The <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> and
            <constant>GL_SHADER_STORAGE_BUFFER</constant> targets are
            available only if the GL version is 4.3 or greater.
        </para>
        <para>
            The <constant>GL_QUERY_BUFFER</constant> target is available
            only if the GL version is 4.4 or greater.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated by
            <function>glUnmapBuffer</function> if
            <parameter>target</parameter> is not one of the buffer binding
            targets listed above.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated by
            <function>glUnmapBuffer</function> if zero is bound to
            <parameter>target</parameter>.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated by
            <function>glUnmapNamedBuffer</function> if
            <parameter>buffer</parameter> is not the name of an existing
            buffer object.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if the
            buffer object is not in a mapped state.
        </para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGetBufferParameter</refentrytitle></citerefentry>
            with argument <constant>GL_BUFFER_MAPPED</constant>.
        </para>
    </refsect1>
    <refsect1 xml:id="versions"><title>Version Support</title>
        <informaltable>
            <tgroup cols="13" align="left">
                <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
                <tbody>
                    <row>
                        <entry><function>glUnmapBuffer</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='20']/*)"/>
                    </row>
                    <row>
                        <entry><function>glUnmapNamedBuffer</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='45']/*)"/>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glBufferData</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glDeleteBuffers</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glMapBufferRange</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 2005 Addison-Wesley.
            Copyright <trademark class="copyright"/> 2010-2014 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.
            <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://opencontent.org/openpub/">http://opencontent.org/openpub/</link>.
        </para>
    </refsect1>
</refentry>
