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

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glInvalidateSubFramebuffer">
    <info>
        <copyright>
            <year>2014</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glInvalidateSubFramebuffer</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glInvalidateSubFramebuffer</refname>
        <refname>glInvalidateNamedFramebufferSubData</refname>
        <refpurpose>invalidate the content of a region of some or all of a framebuffer's attachments</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glInvalidateSubFramebuffer</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLsizei <parameter>numAttachments</parameter></paramdef>
                <paramdef>const GLenum * <parameter>attachments</parameter></paramdef>
                <paramdef>GLint <parameter>x</parameter></paramdef>
                <paramdef>GLint <parameter>y</parameter></paramdef>
                <paramdef>GLint <parameter>width</parameter></paramdef>
                <paramdef>GLint <parameter>height</parameter></paramdef>
            </funcprototype>
            <funcprototype>
                <funcdef>void <function>glInvalidateNamedFramebufferSubData</function></funcdef>
                <paramdef>GLuint <parameter>framebuffer</parameter></paramdef>
                <paramdef>GLsizei <parameter>numAttachments</parameter></paramdef>
                <paramdef>const GLenum *<parameter>attachments</parameter></paramdef>
                <paramdef>GLint <parameter>x</parameter></paramdef>
                <paramdef>GLint <parameter>y</parameter></paramdef>
                <paramdef>GLsizei <parameter>width</parameter></paramdef>
                <paramdef>GLsizei <parameter>height</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 framebuffer object is
                    attached for
                    <function>glInvalidateSubFramebuffer</function>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>framebuffer</parameter></term>
            <listitem>
                <para>
                    Specifies the name of the framebuffer object for
                    <function>glInvalidateNamedFramebufferSubData</function>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>numAttachments</parameter></term>
            <listitem>
                <para>
                    Specifies the number of entries in the
                    <parameter>attachments</parameter> array.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>attachments</parameter></term>
            <listitem>
                <para>
                    Specifies a pointer to an array identifying the
                    attachments to be invalidated.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>x</parameter></term>
            <listitem>
                <para>
                    Specifies the X offset of the region to be invalidated.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>y</parameter></term>
            <listitem>
                <para>
                    Specifies the Y offset of the region to be invalidated.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>width</parameter></term>
            <listitem>
                <para>
                    Specifies the width of the region to be invalidated.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>height</parameter></term>
            <listitem>
                <para>
                    Specifies the height of the region to be invalidated.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glInvalidateSubFramebuffer</function> and
            <function>glInvalidateNamedFramebufferSubData</function>
            invalidate the contents of a specified region of a specified set
            of attachments of a framebuffer.
        </para>
        <para>
            For <function>glInvalidateSubFramebuffer</function>, the
            framebuffer object is that bound to
            <parameter>target</parameter>, which must be one of
            <constant>GL_FRAMEBUFFER</constant>,
            <constant>GL_READ_FRAMEBUFFER</constant> or
            <constant>GL_DRAW_FRAMEBUFFER</constant>.
            <constant>GL_FRAMEBUFFER</constant> is equivalent to
            <constant>GL_DRAW_FRAMEBUFFER</constant>. Default framebuffers
            may also be invalidated if bound to
            <parameter>target</parameter>.
        </para>
        <para>
            For <function>glInvalidateNamedFramebufferSubData</function>,
            <parameter>framebuffer</parameter> is the name of the
            framebuffer object. If <parameter>framebuffer</parameter> is
            zero, the default draw framebuffer is affected.
        </para>
        <para> 
            The set of attachments of which a region is to be invalidated
            are specified in the <parameter>attachments</parameter> array,
            which contains <parameter>numAttachments</parameter> elements.
        </para>
        <para> 
            If the specified framebuffer is a framebuffer object, each
            element of <parameter>attachments</parameter> must be one of
            <constant>GL_DEPTH_ATTACHMENT</constant>,
            <constant>GL_STENCIL_ATTACHMENT</constant>
            <constant>GL_DEPTH_STENCIL_ATTACHMENT</constant>, or
            <constant>GL_COLOR_ATTACHMENT</constant><emphasis>i</emphasis>,
            where <emphasis>i</emphasis> is between zero and the value of
            <constant>GL_MAX_FRAMEBUFFER_ATTACHMENTS</constant> minus one.
        </para>
        <para> 
            If the specified framebuffer is a default framebuffer, each
            element of <parameter>attachments</parameter> must be one of
            <constant>GL_FRONT_LEFT</constant>,
            <constant>GL_FRONT_RIGHT</constant>,
            <constant>GL_BACK_LEFT</constant>,
            <constant>GL_BACK_RIGHT</constant>,
            <constant>GL_AUX</constant><emphasis>i</emphasis>,
            <constant>GL_ACCUM</constant>, <constant>GL_COLOR</constant>,
            <constant>GL_DEPTH</constant>, or
            <constant>GL_STENCIL</constant>. <constant>GL_COLOR</constant>,
            is treated as <constant>GL_BACK_LEFT</constant> for a
            double-buffered context and <constant>GL_FRONT_LEFT</constant>
            for a single-buffered context. The other attachments identify
            the corresponding specific buffer.
        </para>
        <para>
            The contents of the specified region of each specified
            attachment become undefined after execution of
            <function>glInvalidateSubFramebuffer</function> or
            <function>glInvalidateNamedFramebufferSubData</function>. The
            region to be invalidated is specified by
            <parameter>x</parameter>, <parameter>y</parameter>,
            <parameter>width</parameter> and <parameter>height</parameter>
            where <parameter>x</parameter> and <parameter>y</parameter> give
            the offset from the origin (with lower-left corner at $(0,0)$)
            and <parameter>width</parameter> and
            <parameter>height</parameter> are the width and height,
            respectively, of the region. Any pixels lying outside of the
            window allocated to the current GL context (for the default
            framebuffer), or outside of the attachments of the framebuffer
            object, are ignored. If the framebuffer object is not complete,
            these commands may be ignored.
        </para>
        <para>
            If the framebuffer object is not complete,
            <function>glInvalidateSubFramebuffer</function> and
            <function>glInvalidateNamedFramebufferSubData</function> may be
            ignored. This is not an error.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> by
            <function>glInvalidateSubFramebuffer</function> if
            <parameter>target</parameter> is not one of the accepted
            framebuffer targets.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> by
            <function>glInvalidateNamedFramebufferSubData</function> if
            <parameter>framebuffer</parameter> is not zero of the name of an
            existing framebuffer object.
        </para>
        <para>
            <constant>GL_INVALID_VALUE</constant> is generated if
            <parameter>numAttachments</parameter>,
            <parameter>width</parameter> or <parameter>height</parameter> is
            negative.
        </para>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if any element
            of <parameter>attachments</parameter> is not one of the accepted
            framebuffer attachment points, as described above.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if
            element of <parameter>attachments</parameter> is
            <constant>GL_COLOR_ATTACHMENT</constant><emphasis>m</emphasis>
            where <emphasis>m</emphasis> is greater than or equal to the
            value of <constant>GL_MAX_COLOR_ATTACHMENTS</constant>.
        </para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_COLOR_ATTACHMENTS</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>glInvalidateNamedFramebufferSubData</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='45']/*)"/>
                    </row>
                    <row>
                        <entry><function>glInvalidateSubFramebuffer</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='43']/*)"/>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glInvalidateTexSubImage</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glInvalidateTexImage</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glInvalidateBufferSubData</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glInvalidateBufferData</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glInvalidateFramebuffer</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 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>
