rename upstream-man-pages to upstream-doc

[clinton/guile-figl.git] / upstream-doc / man4 / glMinSampleShading.xml

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<refentry id="glMinSampleShading">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2010</year>
                <holder>Khronos Group.</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glMinSampleShading</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glMinSampleShading</refname>
        <refpurpose>specifies minimum rate at which sample shaing takes place</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glMinSampleShading</function></funcdef>
                <paramdef>GLfloat <parameter>value</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <!-- eqn: ignoring delim $$ -->
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>value</parameter></term>
            <listitem>
                <para>
                    Specifies the rate at which samples are shaded within each covered pixel.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glMinSampleShading</function> specifies the rate at which samples are shaded within
            a covered pixel. Sample-rate shading is enabled by calling <citerefentry><refentrytitle>glEnable</refentrytitle></citerefentry>
            with the parameter <constant>GL_SAMPLE_SHADING</constant>. If <constant>GL_MULTISAMPLE</constant>
            or <constant>GL_SAMPLE_SHADING</constant> is disabled, sample shading has no effect.
            Otherwise, an implementation must provide at least as many unique color values for
            each covered fragment as specified by <parameter>value</parameter> times <parameter>samples</parameter> where
            <parameter>samples</parameter> is the value of <constant>GL_SAMPLES</constant> for the current
            framebuffer. At least 1 sample for each covered fragment is generated.
        </para>
        <para>
            A <parameter>value</parameter> of 1.0 indicates that each sample in the framebuffer should be
            indpendently shaded. A <parameter>value</parameter> of 0.0 effectively allows the GL to ignore
            sample rate shading. Any value between 0.0 and 1.0 allows the GL to shade only a subset
            of the total samples within each covered fragment. Which samples are shaded and the algorithm
            used to select that subset of the fragment's samples is implementation dependent.
        </para>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            The type of the <parameter>value</parameter> parameter was
            changed from GLclampf to GLfloat. This change is transparent
            to user code and is described in detail on the
            <citerefentry><refentrytitle>removedTypes</refentrytitle></citerefentry>
            page.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            None.
        </para>
    </refsect1>
    <refsect1 id="associatedgets"><title>Associated Gets</title>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MIN_SAMPLE_SHADING</constant>.
        </para>
        <para>
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_SAMPLES</constant>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>removedTypes</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2011 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.
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
        </para>
    </refsect1>
</refentry>