[clinton/guile-figl.git] / upstream-doc / man4 / glMultiDrawArraysIndirect.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="glMultiDrawArraysIndirect">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2012</year>\r
                <holder>Khronos Group.</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>glMultiDrawArraysIndirect</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>glMultiDrawArraysIndirect</refname>\r
        <refpurpose>render multiple sets of primitives from array data, taking parameters from memory</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>C Specification</title>\r
        <funcsynopsis>\r
            <funcprototype>\r
                <funcdef>void <function>glMultiDrawArraysIndirect</function></funcdef>\r
                <paramdef>GLenum <parameter>mode</parameter></paramdef>\r
                <paramdef>const void *<parameter>indirect</parameter></paramdef>\r
                <paramdef>GLsizei <parameter>drawcount</parameter></paramdef>\r
                <paramdef>GLsizei <parameter>stride</parameter></paramdef>\r
            </funcprototype>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <!-- eqn: ignoring delim $$ -->\r
    <refsect1 id="parameters"><title>Parameters</title>\r
        <variablelist>\r
        <varlistentry>\r
            <term><parameter>mode</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies what kind of primitives to render.\r
                    Symbolic constants\r
                    <constant>GL_POINTS</constant>,\r
                    <constant>GL_LINE_STRIP</constant>,\r
                    <constant>GL_LINE_LOOP</constant>,\r
                    <constant>GL_LINES</constant>,\r
                    <constant>GL_LINE_STRIP_ADJACENCY</constant>,\r
                    <constant>GL_LINES_ADJACENCY</constant>,\r
                    <constant>GL_TRIANGLE_STRIP</constant>,\r
                    <constant>GL_TRIANGLE_FAN</constant>,\r
                    <constant>GL_TRIANGLES</constant>,\r
                    <constant>GL_TRIANGLE_STRIP_ADJACENCY</constant>,\r
                    <constant>GL_TRIANGLES_ADJACENCY</constant>, and\r
                    <constant>GL_PATCHES</constant>\r
                    are accepted.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>indirect</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the address of an array of structures containing the draw parameters.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>drawcount</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the the number of elements in the array of draw parameter structures.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>stride</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the distance in basic machine units between elements of the draw parameter array.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        </variablelist>\r
    </refsect1>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            <function>glMultiDrawArraysIndirect</function> specifies multiple geometric primitives\r
            with very few subroutine calls. <function>glMultiDrawArraysIndirect</function> behaves\r
            similarly to a multitude of calls to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>,\r
            execept that the parameters to each call to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>\r
            are stored in an array in memory at the address given by <parameter>indirect</parameter>, separated\r
            by the stride, in basic machine units, specified by <parameter>stride</parameter>. If <parameter>stride</parameter>\r
            is zero, then the array is assumed to be tightly packed in memory.\r
        </para>\r
        <para>\r
            The parameters addressed by <parameter>indirect</parameter> are packed into an array of structures,\r
            each element of which takes the form (in C):\r
            <programlisting><![CDATA[    typedef  struct {\r
        uint  count;\r
        uint  primCount;\r
        uint  first;\r
        uint  baseInstance;\r
    } DrawArraysIndirectCommand;]]></programlisting>\r
        </para>\r
        <para>\r
            A single call to <function>glMultiDrawArraysIndirect</function> is equivalent, assuming no errors\r
            are generated to:\r
            <programlisting><![CDATA[    GLsizei n;\r
    for (n = 0; n < drawcount; n++)\r
    {\r
        const DrawArraysIndirectCommand  *cmd;\r
        if (stride != 0)\r
        {\r
            cmd = (const DrawArraysIndirectCommand  *)((uintptr)indirect + n * stride);\r
        }\r
        else\r
        {\r
            cmd = (const DrawArraysIndirectCommand  *)indirect + n;\r
        }\r
\r
        glDrawArraysInstancedBaseInstance(mode,  cmd->first,  cmd->count,  cmd->primCount, cmd->baseInstance);\r
    }]]></programlisting>\r
        </para>\r
        <para>\r
            If a buffer is bound to the <constant>GL_DRAW_INDIRECT_BUFFER</constant> binding at the time\r
            of a call to <function>glMultiDrawArraysIndirect</function>, <parameter>indirect</parameter>\r
            is interpreted as an offset, in basic machine units, into that buffer and the parameter\r
            data is read from the buffer rather than from client memory.\r
        </para>\r
        <para>\r
            In contrast to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>,\r
            the <code>first</code> member of the parameter structure is unsigned, and out-of-range indices\r
            do not generate an error.\r
        </para>\r
        <para>\r
            Vertex attributes that are modified by <function>glMultiDrawArraysIndirect</function> have an\r
            unspecified value after <function>glMultiDrawArraysIndirect</function> returns. Attributes that aren't\r
            modified remain well defined.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="notes"><title>Notes</title>\r
        <para>\r
            The <parameter>baseInstance</parameter> member of the <parameter>DrawArraysIndirectCommand</parameter>\r
            structure is defined only if the GL version is 4.2 or greater. For versions of the GL less than 4.2,\r
            this parameter is present but is reserved and should be set to zero. On earlier versions of the GL,\r
            behavior is undefined if it is non-zero.\r
        </para>\r
        <para>\r
            <function>glMultiDrawArraysIndirect</function> is available only if the GL version is 4.3 or greater.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="errors"><title>Errors</title>\r
        <para>\r
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>stride</parameter> is not a multiple\r
            of four.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>drawcount</parameter> is negative.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an\r
            enabled array or to the <constant>GL_DRAW_INDIRECT_BUFFER</constant> binding and the buffer object's data store is currently mapped.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated if a geometry shader is active and <parameter>mode</parameter>\r
            is incompatible with the input primitive type of the geometry shader in the currently installed program object.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>mode</parameter> is <constant>GL_PATCHES</constant>\r
            and no tessellation control shader is active.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="seealso"><title>See Also</title>\r
        <para>\r
            <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glDrawArraysInstanced</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glDrawArraysIndirect</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glMultiDrawElementsIndirect</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
Commit	Line	Data
7faf1d71 AW	1	<?xml version="1.0" encoding="UTF-8"?>\r
	2	<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r
	3	"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r
	4	<refentry id="glMultiDrawArraysIndirect">\r
	5	<refmeta>\r
	6	<refmetainfo>\r
	7	<copyright>\r
	8	<year>2012</year>\r
	9	<holder>Khronos Group.</holder>\r
	10	</copyright>\r
	11	</refmetainfo>\r
	12	<refentrytitle>glMultiDrawArraysIndirect</refentrytitle>\r
	13	<manvolnum>3G</manvolnum>\r
	14	</refmeta>\r
	15	<refnamediv>\r
	16	<refname>glMultiDrawArraysIndirect</refname>\r
	17	<refpurpose>render multiple sets of primitives from array data, taking parameters from memory</refpurpose>\r
	18	</refnamediv>\r
	19	<refsynopsisdiv><title>C Specification</title>\r
	20	<funcsynopsis>\r
	21	<funcprototype>\r
	22	<funcdef>void <function>glMultiDrawArraysIndirect</function></funcdef>\r
	23	<paramdef>GLenum <parameter>mode</parameter></paramdef>\r
	24	<paramdef>const void *<parameter>indirect</parameter></paramdef>\r
	25	<paramdef>GLsizei <parameter>drawcount</parameter></paramdef>\r
	26	<paramdef>GLsizei <parameter>stride</parameter></paramdef>\r
	27	</funcprototype>\r
	28	</funcsynopsis>\r
	29	</refsynopsisdiv>\r
	30	<!-- eqn: ignoring delim $$ -->\r
	31	<refsect1 id="parameters"><title>Parameters</title>\r
	32	<variablelist>\r
	33	<varlistentry>\r
	34	<term><parameter>mode</parameter></term>\r
	35	<listitem>\r
	36	<para>\r
	37	Specifies what kind of primitives to render.\r
	38	Symbolic constants\r
	39	<constant>GL_POINTS</constant>,\r
	40	<constant>GL_LINE_STRIP</constant>,\r
	41	<constant>GL_LINE_LOOP</constant>,\r
	42	<constant>GL_LINES</constant>,\r
	43	<constant>GL_LINE_STRIP_ADJACENCY</constant>,\r
	44	<constant>GL_LINES_ADJACENCY</constant>,\r
	45	<constant>GL_TRIANGLE_STRIP</constant>,\r
	46	<constant>GL_TRIANGLE_FAN</constant>,\r
	47	<constant>GL_TRIANGLES</constant>,\r
	48	<constant>GL_TRIANGLE_STRIP_ADJACENCY</constant>,\r
	49	<constant>GL_TRIANGLES_ADJACENCY</constant>, and\r
	50	<constant>GL_PATCHES</constant>\r
	51	are accepted.\r
	52	</para>\r
	53	</listitem>\r
	54	</varlistentry>\r
	55	<varlistentry>\r
	56	<term><parameter>indirect</parameter></term>\r
	57	<listitem>\r
	58	<para>\r
	59	Specifies the address of an array of structures containing the draw parameters.\r
	60	</para>\r
	61	</listitem>\r
	62	</varlistentry>\r
	63	<varlistentry>\r
	64	<term><parameter>drawcount</parameter></term>\r
65	<listitem>\r
66	<para>\r
67	Specifies the the number of elements in the array of draw parameter structures.\r
68	</para>\r
69	</listitem>\r
70	</varlistentry>\r
71	<varlistentry>\r
72	<term><parameter>stride</parameter></term>\r
73	<listitem>\r
74	<para>\r
75	Specifies the distance in basic machine units between elements of the draw parameter array.\r
76	</para>\r
77	</listitem>\r
78	</varlistentry>\r
79	</variablelist>\r
80	</refsect1>\r
81	<refsect1 id="description"><title>Description</title>\r
82	<para>\r
83	<function>glMultiDrawArraysIndirect</function> specifies multiple geometric primitives\r
84	with very few subroutine calls. <function>glMultiDrawArraysIndirect</function> behaves\r
85	similarly to a multitude of calls to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>,\r
86	execept that the parameters to each call to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>\r
87	are stored in an array in memory at the address given by <parameter>indirect</parameter>, separated\r
88	by the stride, in basic machine units, specified by <parameter>stride</parameter>. If <parameter>stride</parameter>\r
89	is zero, then the array is assumed to be tightly packed in memory.\r
90	</para>\r
91	<para>\r
92	The parameters addressed by <parameter>indirect</parameter> are packed into an array of structures,\r
93	each element of which takes the form (in C):\r
94	<programlisting><![CDATA[ typedef struct {\r
95	uint count;\r
96	uint primCount;\r
97	uint first;\r
98	uint baseInstance;\r
99	} DrawArraysIndirectCommand;]]></programlisting>\r
100	</para>\r
101	<para>\r
102	A single call to <function>glMultiDrawArraysIndirect</function> is equivalent, assuming no errors\r
103	are generated to:\r
104	<programlisting><![CDATA[ GLsizei n;\r
105	for (n = 0; n < drawcount; n++)\r
106	{\r
107	const DrawArraysIndirectCommand *cmd;\r
108	if (stride != 0)\r
109	{\r
110	cmd = (const DrawArraysIndirectCommand )((uintptr)indirect + n stride);\r
111	}\r
112	else\r
113	{\r
114	cmd = (const DrawArraysIndirectCommand *)indirect + n;\r
115	}\r
116	\r
117	glDrawArraysInstancedBaseInstance(mode, cmd->first, cmd->count, cmd->primCount, cmd->baseInstance);\r
118	}]]></programlisting>\r
119	</para>\r
120	<para>\r
121	If a buffer is bound to the <constant>GL_DRAW_INDIRECT_BUFFER</constant> binding at the time\r
122	of a call to <function>glMultiDrawArraysIndirect</function>, <parameter>indirect</parameter>\r
123	is interpreted as an offset, in basic machine units, into that buffer and the parameter\r
124	data is read from the buffer rather than from client memory.\r
125	</para>\r
126	<para>\r
127	In contrast to <citerefentry><refentrytitle>glDrawArraysInstancedBaseInstance</refentrytitle></citerefentry>,\r
128	the <code>first</code> member of the parameter structure is unsigned, and out-of-range indices\r
129	do not generate an error.\r
130	</para>\r
131	<para>\r
132	Vertex attributes that are modified by <function>glMultiDrawArraysIndirect</function> have an\r
133	unspecified value after <function>glMultiDrawArraysIndirect</function> returns. Attributes that aren't\r
134	modified remain well defined.\r
135	</para>\r
136	</refsect1>\r
137	<refsect1 id="notes"><title>Notes</title>\r
138	<para>\r
139	The <parameter>baseInstance</parameter> member of the <parameter>DrawArraysIndirectCommand</parameter>\r
140	structure is defined only if the GL version is 4.2 or greater. For versions of the GL less than 4.2,\r
141	this parameter is present but is reserved and should be set to zero. On earlier versions of the GL,\r
142	behavior is undefined if it is non-zero.\r
143	</para>\r
144	<para>\r
145	<function>glMultiDrawArraysIndirect</function> is available only if the GL version is 4.3 or greater.\r
146	</para>\r
147	</refsect1>\r
148	<refsect1 id="errors"><title>Errors</title>\r
149	<para>\r
150	<constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.\r
151	</para>\r
152	<para>\r
153	<constant>GL_INVALID_VALUE</constant> is generated if <parameter>stride</parameter> is not a multiple\r
154	of four.\r
155	</para>\r
156	<para>\r
157	<constant>GL_INVALID_VALUE</constant> is generated if <parameter>drawcount</parameter> is negative.\r
158	</para>\r
159	<para>\r
160	<constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an\r
161	enabled array or to the <constant>GL_DRAW_INDIRECT_BUFFER</constant> binding and the buffer object's data store is currently mapped.\r
162	</para>\r
163	<para>\r
164	<constant>GL_INVALID_OPERATION</constant> is generated if a geometry shader is active and <parameter>mode</parameter>\r
165	is incompatible with the input primitive type of the geometry shader in the currently installed program object.\r
166	</para>\r
167	<para>\r
168	<constant>GL_INVALID_OPERATION</constant> is generated if <parameter>mode</parameter> is <constant>GL_PATCHES</constant>\r
169	and no tessellation control shader is active.\r
170	</para>\r
171	</refsect1>\r
172	<refsect1 id="seealso"><title>See Also</title>\r
173	<para>\r
174	<citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,\r
175	<citerefentry><refentrytitle>glDrawArraysInstanced</refentrytitle></citerefentry>,\r
176	<citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,\r
177	<citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,\r
178	<citerefentry><refentrytitle>glDrawArraysIndirect</refentrytitle></citerefentry>,\r
179	<citerefentry><refentrytitle>glMultiDrawElementsIndirect</refentrytitle></citerefentry>\r
180	</para>\r
181	</refsect1>\r
182	<refsect1 id="Copyright"><title>Copyright</title>\r
183	<para>\r
184	Copyright <trademark class="copyright"></trademark> 2012 Khronos Group.\r
185	This material may be distributed subject to the terms and conditions set forth in \r
186	the Open Publication License, v 1.0, 8 June 1999.\r
187	<ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
188	</para>\r
189	</refsect1>\r
190	</refentry>\r