
<refentry id="glXGetVisualFromFBConfig">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>1991-2006</year>
                <holder>Silicon Graphics, Inc.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glXGetVisualFromFBConfig</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glXGetVisualFromFBConfig</refname>
        <refpurpose>return visual that is associated with the frame buffer configuration</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>XVisualInfo * <function>glXGetVisualFromFBConfig</function></funcdef>
                <paramdef>Display * <parameter>dpy</parameter></paramdef>
                <paramdef>GLXFBConfig <parameter>config</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>dpy</parameter></term>
            <listitem>
                <para>
                    Specifies the connection to the X server. 
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>config</parameter></term>
            <listitem>
                <para>
                    Specifies the GLX frame buffer configuration.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            If <parameter>config</parameter> is a valid GLX frame buffer configuration
            and it has an associated X Visual, then
            information describing that visual is returned; otherwise <constant>NULL</constant>
            is returned. Use <function>XFree</function> to free the data returned.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            <function>glXGetVisualFromFBConfig</function> is available only if the GLX version is 1.3 or greater.
        </para>
        <para>
            If the GLX version is 1.1 or 1.0, the GL version must be 1.0.
            If the GLX version is 1.2, then the GL version must be 1.1.
            If the GLX version is 1.3, then the GL version must be 1.2.
        </para>
        <para>
            <constant>XVisualInfo</constant> is defined in <emphasis>Xutil.h.</emphasis>
            It is a structure that includes <emphasis>visual</emphasis>, <emphasis>visualID</emphasis>, 
            <emphasis>screen</emphasis>, and <emphasis>depth</emphasis> elements.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            Returns <constant>NULL</constant> if <parameter>config</parameter> is not a valid GLXFBConfig.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glXGetFBConfigAttrib</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glXChooseFBConfig</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glXChooseVisual</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glXGetConfig</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 1991-2006
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
        </para>
    </refsect1>
</refentry>
