rename upstream-man-pages to upstream-doc

[clinton/guile-figl.git] / upstream-doc / manglsl / gl_FragDepth.xml

<?xml version="1.0" encoding="UTF-8"?>\r
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r
              "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r
<refentry id="gl_FragDepth">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2011</year>\r
                <holder>Khronos Group</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>gl_FragDepth</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>gl_FragDepth</refname>\r
        <refpurpose>establishes a depth value for the current fragment</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>Declaration</title>\r
        <funcsynopsis>\r
            <function>out float gl_FragDepth;</function>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            Available only in the fragment language, <function>gl_FragDepth</function> is an output variable\r
            that is used to establish the depth value for the current fragment. If depth buffering is enabled\r
            and no shader writes to <function>gl_FragDepth</function>, then the fixed function value for\r
            depth will be used (this value is contained in the z component of <citerefentry><refentrytitle>gl_FragCoord</refentrytitle></citerefentry>)\r
            otherwise, the value written to <function>gl_FragDepth</function> is used.\r
            If a shader statically assigns to <function>gl_FragDepth</function>, then the value of the fragment's depth\r
            may be undefined for executions of the shader that take that path. That is, if the set of linked fragment\r
            shaders statically contain a write to <function>gl_FragDepth</function>, then it is responsible for always\r
            writing it.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="versions"><title>Version Support</title>\r
        <informaltable frame="topbot">\r
            #VARTABLECOLS#\r
                <thead>\r
                    #VARTABLEHEADER#\r
                    <row>\r
                        <entry>gl_FragDepth</entry>#newin11#\r
                    </row>\r
                </thead>\r
            </tgroup>\r
        </informaltable>\r
    </refsect1>\r
    <refsect1 id="seealso"><title>See Also</title>\r
        <para>\r
            <citerefentry><refentrytitle>gl_FragCoord</refentrytitle></citerefentry>\r
        </para>\r
    </refsect1>\r
    <refsect1 id="Copyright"><title>Copyright</title>\r
        <para>\r
            Copyright <trademark class="copyright"></trademark> 2011 Khronos Group. \r
            This material may be distributed subject to the terms and conditions set forth in \r
            the Open Publication License, v 1.0, 8 June 1999.\r
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
        </para>\r
    </refsect1>\r
</refentry>\r