rename upstream-man-pages to upstream-doc

[clinton/guile-figl.git] / upstream-doc / manglsl / dFdx.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="dFdx">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2011</year>\r
                <holder>Khronos Group</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>dFdx, dFdy</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>dFdx, dFdy</refname>\r
        <refpurpose>return the partial derivative of an argument with respect to x or y</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>Declaration</title>\r
        <funcsynopsis>\r
            <funcprototype>\r
                <funcdef>genType <function>dFdx</function></funcdef>\r
                <paramdef>genType <parameter>p</parameter></paramdef>\r
            </funcprototype>\r
            <funcprototype>\r
                <funcdef>genType <function>dFdy</function></funcdef>\r
                <paramdef>genType <parameter>p</parameter></paramdef>\r
            </funcprototype>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <refsect1 id="parameters"><title>Parameters</title>\r
        <variablelist>\r
        <varlistentry>\r
            <term><parameter>p</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the expression of which to take the partial derivative.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        </variablelist>\r
    </refsect1>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            <emphasis>Available only in the fragment shader</emphasis>, <function>dFdx</function> and <function>dFdy</function>\r
            return the partial derivative of expression <parameter>p</parameter> in x and y, respectively. Deviatives are calculated\r
            using local differencing. Expressions that imply higher order derivatives such as <code>dFdx(dFdx(n))</code> have undefined\r
            results, as do mixed-order derivatives such as <code>dFdx(dFdy(n))</code>.\r
            It is assumed that the expression <parameter>p</parameter> is continuous and therefore, expressions evaluated\r
            via non-uniform control flow may be undefined.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="versions"><title>Version Support</title>\r
        <informaltable frame="topbot">\r
            #VARTABLECOLS#\r
                <thead>\r
                    #FUNCTABLEHEADER#\r
                    <row>\r
                        <entry>dFdx</entry>#newin11#\r
                    </row>\r
                    <row>\r
                        <entry>dFdy</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>fwidth</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