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

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glGetFramebufferParameter">
    <info>
        <copyright>
            <year>2014</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glGetFramebufferParameter</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetFramebufferParameteriv</refname>
        <refname>glGetNamedFramebufferParameteriv</refname>
        <refpurpose>query a named parameter of a framebuffer object</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetFramebufferParameteriv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint *<parameter>params</parameter></paramdef>
            </funcprototype>
            <funcprototype>
                <funcdef>void <function>glGetNamedFramebufferParameteriv</function></funcdef>
                <paramdef>GLuint <parameter>framebuffer</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint *<parameter>param</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
                    bound for
                    <function>glGetFramebufferParameteriv</function>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>framebuffer</parameter></term>
            <listitem>
                <para>
                    Specifies the name of the framebuffer object for
                    <function>glGetNamedFramebufferParameteriv</function>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies the parameter of the framebuffer object to
                    query.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Returns the value of parameter
                    <parameter>pname</parameter> for the framebuffer object.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glGetFramebufferParameteriv</function> and
            <function>glGetNamedFramebufferParameteriv</function> query
            parameters of a specified framebuffer object.
        </para>
        <para>
            For <function>glGetFramebufferParameteriv</function>,
            the framebuffer object is that bound to
            <parameter>target</parameter>, which must be one of
            <constant>GL_DRAW_FRAMEBUFFER</constant>,
            <constant>GL_READ_FRAMEBUFFER</constant> or
            <constant>GL_FRAMEBUFFER</constant>.
            <constant>GL_FRAMEBUFFER</constant> is equivalent to
            <constant>GL_DRAW_FRAMEBUFFER</constant>. Default framebuffers
            may also be queried if bound to <parameter>target</parameter>.
        </para>
        <para>
            For <function>glGetNamedFramebufferParameteriv</function>,
            <parameter>framebuffer</parameter> is the name of the
            framebuffer object. If <parameter>framebuffer</parameter> is
            zero, the default draw framebuffer is queried.
        </para>
        <para>
            Upon successful return, <parameter>param</parameter> will
            contain the value of the framebuffer parameter specified by
            <parameter>pname</parameter>, as described below.
        </para>
        <para>
            The following parameters can only be queried for framebuffer objects:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_FRAMEBUFFER_DEFAULT_WIDTH</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the value of
                        <constant>GL_FRAMEBUFFER_DEFAULT_WIDTH</constant>
                        for the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_FRAMEBUFFER_DEFAULT_HEIGHT</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the value of
                        <constant>GL_FRAMEBUFFER_DEFAULT_HEIGHT</constant>
                        for the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_FRAMEBUFFER_DEFAULT_LAYERS</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the value of
                        <constant>GL_FRAMEBUFFER_DEFAULT_LAYERS</constant>
                        for the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_FRAMEBUFFER_DEFAULT_SAMPLES</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the value of
                        <constant>GL_FRAMEBUFFER_DEFAULT_SAMPLES</constant>
                        for the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_FRAMEBUFFER_DEFAULT_FIXED_SAMPLE_LOCATIONS</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the boolean
                        value of
                        <constant>GL_FRAMEBUFFER_DEFAULT_FIXED_SAMPLE_LOCATIONS</constant>.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
        <para>
            The following parameters can be queried for both default framebuffers 
            and framebuffer objects:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_DOUBLEBUFFER</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns a boolean value
                        indicating whether double buffering is supported for
                        the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_IMPLEMENTATION_COLOR_READ_FORMAT</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns a GLenum value
                        indicating the preferred pixel data format for the
                        framebuffer object. See
                        <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_IMPLEMENTATION_COLOR_READ_TYPE</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns a GLenum value
                        indicating the implementation's preferred pixel data
                        type for the framebuffer object. See
                        <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_SAMPLES</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns an integer
                        value indicating the coverage mask size for the
                        framebuffer object. See
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_SAMPLE_BUFFERS</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns an integer
                        value indicating the number of sample buffers
                        associated with the framebuffer object. See
                        <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_STEREO</constant></term>
                <listitem>
                    <para>
                        <parameter>param</parameter> returns a boolean value
                        indicating whether stereo buffers (left and right)
                        are supported for the framebuffer object.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 xml:id="notes"><title>Notes</title>
        <para>
            Queries of default framebuffers are supported only if the GL
            version is 4.5 or higher. Otherwise, an
            <constant>GL_INVALID_OPERATION</constant> error is generated.
        </para> 
        <para>
            Queries of the framebuffer-dependent parameters
            <constant>GL_DOUBLEBUFFER</constant>,
            <constant>GL_IMPLEMENTATION_COLOR_READ_FORMAT</constant>,
            <constant>GL_IMPLEMENTATION_COLOR_READ_TYPE</constant>,
            <constant>GL_SAMPLES</constant>,
            <constant>GL_SAMPLE_BUFFERS</constant> and
            <constant>GL_STEREO</constant> are supported only if the GL
            version is 4.5 or higher.
        </para>
        <para>
            The framebuffer-dependent state
            <constant>GL_SAMPLE_POSITION</constant> cannot be queried
            with these commands.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated by
            <function>glGetFramebufferParameteriv</function> if
            <parameter>target</parameter> is not one of the accepted
            framebuffer targets.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated by
            <function>glGetNamedFramebufferAttachmentParameteriv</function>
            if <parameter>framebuffer</parameter> is not zero or the name of
            an existing framebuffer object.
        </para>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if
            <parameter>pname</parameter> is not one of the accepted
            parameter names.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if a
            default framebuffer is queried, and <parameter>pname</parameter>
            is not one of <constant>GL_DOUBLEBUFFER</constant>,
            <constant>GL_IMPLEMENTATION_COLOR_READ_FORMAT</constant>,
            <constant>GL_IMPLEMENTATION_COLOR_READ_TYPE</constant>,
            <constant>GL_SAMPLES</constant>,
            <constant>GL_SAMPLE_BUFFERS</constant> or
            <constant>GL_STEREO</constant>.
        </para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGetFramebufferAttachmentParameter</refentrytitle></citerefentry>
        </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>glGetFramebufferParameteriv</function></entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='43']/*)"/>
                    </row>
                    <row>
                        <entry><function>glGetNamedFramebufferParameteriv</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>glFramebufferParameteri</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glGetFramebufferAttachmentParameter</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>
