rename upstream-man-pages to upstream-doc

[clinton/guile-figl.git] / upstream-doc / man4 / glDispatchComputeIndirect.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="glDispatchComputeIndirect">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2012</year>\r
                <holder>Khronos Group</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>glDispatchComputeIndirect</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>glDispatchComputeIndirect</refname>\r
        <refpurpose>launch one or more compute work groups using parameters stored in a buffer</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>C Specification</title>\r
        <funcsynopsis>\r
            <funcprototype>\r
                <funcdef>void <function>glDispatchComputeIndirect</function></funcdef>\r
                <paramdef>GLintptr <parameter>indirect</parameter></paramdef>\r
            </funcprototype>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <refsect1 id="parameters"><title>Parameters</title>\r
        <variablelist>\r
        <varlistentry>\r
            <term><parameter>indirect</parameter></term>\r
            <listitem>\r
                <para>\r
                    The offset into the buffer object currently bound to the\r
                    <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> buffer target at\r
                    which the dispatch parameters are stored.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        </variablelist>\r
    </refsect1>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            <function>glDispatchComputeIndirect</function> launches one or more compute\r
            work groups using parameters stored in the buffer object currently bound\r
            to the <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> target.\r
            Each work group is processed by the active program object for the compute\r
            shader stage. While the individual shader invocations within a work group are\r
            executed as a unit, work groups are executed completely independently and in\r
            unspecified order. <parameter>indirect</parameter> contains the offset\r
            into the data store of the buffer object bound to the <constant>GL_DISPATCH_INDIRECT_BUFFER</constant>\r
            target at which the parameters are stored.\r
        </para>\r
        <para>\r
            The parameters addressed by <parameter>indirect</parameter> are packed a structure,\r
            which takes the form (in C):\r
            <programlisting><![CDATA[    typedef  struct {\r
        uint  num_groups_x;\r
        uint  num_groups_y;\r
        uint  num_groups_z;\r
    } DispatchIndirectCommand;]]></programlisting>\r
        </para>\r
        <para>\r
            A call to <function>glDispatchComputeIndirect</function> is equivalent, assuming no\r
            errors are generated, to:\r
            <programlisting><![CDATA[    cmd = (const DispatchIndirectCommand  *)indirect;\r
    glDispatchComputeIndirect(cmd->num_groups_x, cmd->num_groups_y, cmd->num_groups_z);\r
    }]]></programlisting>\r
        </para>\r
        <para>\r
            Unlike <citerefentry><refentrytitle>glDispatchCompute</refentrytitle></citerefentry>,\r
            no error is generated if any of the <code>num_groups_x</code>,\r
            <code>num_groups_y</code> or <code>num_groups_z</code> members\r
            of the <code>DispatchIndirectCommand</code> is larger than the\r
            value of <constant>GL_MAX_COMPUTE_WORK_GROUP_COUNT</constant> for the\r
            corresponding dimension. In such circumstances, behavior is undefined and\r
            may lead to application termination.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="errors"><title>Errors</title>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated if there is no active program\r
            for the compute shader stage.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>indirect</parameter> is\r
            less than zero or not a multiple of four.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated if no buffer is bound to the\r
            <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> target or if the command would\r
            source data beyond the end of the buffer object's data store.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="associatedgets"><title>Associated Gets</title>\r
        <para>\r
            <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_COMPUTE_WORK_GROUP_COUNT</constant>\r
        </para>\r
    </refsect1>\r
    <refsect1 id="seealso"><title>See Also</title>\r
        <para>\r
            <citerefentry><refentrytitle>glDispatchCompute</refentrytitle></citerefentry>.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="Copyright"><title>Copyright</title>\r
        <para>\r
            Copyright <trademark class="copyright"></trademark> 2012 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