[clinton/guile-figl.git] / upstream-doc / man3 / glMapBufferRange.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="glMapBufferRange">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2010</year>\r
                <holder>Khronos Group</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>glMapBufferRange</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>glMapBufferRange</refname>\r
        <refpurpose>map a section of a buffer object's data store</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>C Specification</title>\r
        <funcsynopsis>\r
            <funcprototype>\r
                <funcdef>void *<function>glMapBufferRange</function></funcdef>\r
                <paramdef>GLenum <parameter>target</parameter></paramdef>\r
                <paramdef>GLintptr <parameter>offset</parameter></paramdef>\r
                <paramdef>GLsizeiptr <parameter>length</parameter></paramdef>\r
                <paramdef>GLbitfield <parameter>access</parameter></paramdef>\r
            </funcprototype>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <refsect1 id="parameters"><title>Parameters</title>\r
        <variablelist>\r
        <varlistentry>\r
            <term><parameter>target</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies a binding to which the target buffer is bound.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>offset</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies a the starting offset within the buffer of the range to be mapped.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>length</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies a length of the range to be mapped.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>access</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies a combination of access flags indicating the desired access to the range.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        </variablelist>\r
    </refsect1>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            <function>glMapBufferRange</function> maps all or part of the data store of a buffer object into the client's address\r
            space. <parameter>target</parameter> specifies the target to which the buffer is bound and must be one of <constant>GL_ARRAY_BUFFER</constant>,\r
            <constant>GL_COPY_READ_BUFFER</constant>, <constant>GL_COPY_WRITE_BUFFER</constant>, <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,\r
            <constant>GL_PIXEL_PACK_BUFFER</constant>, <constant>GL_PIXEL_UNPACK_BUFFER</constant>, <constant>GL_TEXTURE_BUFFER</constant>,\r
            <constant>GL_TRANSFORM_FEEDBACK_BUFFER</constant>, or <constant>GL_UNIFORM_BUFFER</constant>. <parameter>offset</parameter> and\r
            <parameter>length</parameter> indicate the range of data in the buffer object htat is to be mapped, in terms of basic machine units.\r
            <parameter>access</parameter> is a bitfield containing flags which describe the requested mapping. These flags are described below.\r
        </para>\r
        <para>\r
            If no error occurs, a pointer to the beginning of the mapped range is returned once all pending operations on that buffer have\r
            completed, and may be used to modify and/or query the corresponding range of the buffer, according to the following flag bits set\r
            in <parameter>access</parameter>:\r
            <itemizedlist>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_READ_BIT</constant> indicates that the returned pointer may be used to read\r
                        buffer object data. No GL error is generated if the pointer is used to query\r
                        a mapping which excludes this flag, but the result is undefined and system\r
                        errors (possibly including program termination) may occur.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_WRITE_BIT</constant> indicates that the returned pointer may be used to modify\r
                        buffer object data. No GL error is generated if the pointer is used to modify\r
                        a mapping which excludes this flag, but the result is undefined and system\r
                        errors (possibly including program termination) may occur.\r
                    </para>\r
                </listitem>\r
            </itemizedlist>\r
        </para>\r
        <para>\r
            Furthermore, the following <emphasis>optional</emphasis> flag bits in <parameter>access</parameter> may be used to modify the mapping:\r
            <itemizedlist>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_INVALIDATE_RANGE_BIT</constant> indicates that the previous contents of the\r
                        specified range may be discarded. Data within this range are undefined with\r
                        the exception of subsequently written data. No GL error is generated if sub-\r
                        sequent GL operations access unwritten data, but the result is undefined and\r
                        system errors (possibly including program termination) may occur. This flag\r
                        may not be used in combination with <constant>GL_MAP_READ_BIT</constant>.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_INVALIDATE_BUFFER_BIT</constant> indicates that the previous contents of the\r
                        entire buffer may be discarded. Data within the entire buffer are undefined\r
                        with the exception of subsequently written data. No GL error is generated if\r
                        subsequent GL operations access unwritten data, but the result is undefined\r
                        and system errors (possibly including program termination) may occur. This\r
                        flag may not be used in combination with <constant>GL_MAP_READ_BIT</constant>.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_FLUSH_EXPLICIT_BIT</constant> indicates that one or more discrete subranges\r
                        of the mapping may be modified.  When this flag is set, modifications to\r
                        each subrange must be explicitly flushed by calling <citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>.\r
                        No GL error is set if a subrange of the mapping is modified and\r
                        not flushed, but data within the corresponding subrange of the buffer are undefined.\r
                        This flag may only be used in conjunction with <constant>GL_MAP_WRITE_BIT</constant>.\r
                        When this option is selected, flushing is strictly limited to regions that are\r
                        explicitly indicated with calls to <citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>\r
                        prior to unmap; if this option is not selected <citerefentry><refentrytitle>glUnmapBuffer</refentrytitle></citerefentry>\r
                        will automatically flush the entire mapped range when called.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_UNSYNCHRONIZED_BIT</constant> indicates that the GL should not attempt to\r
                        synchronize pending operations on the buffer prior to returning from <function>glMapBufferRange</function>.\r
                        No GL error is generated if pending operations which source or modify the buffer overlap the mapped region,\r
                        but the result of such previous and any subsequent operations is undefined.\r
                    </para>\r
                </listitem>\r
            </itemizedlist>\r
        </para>\r
        <para>\r
            If an error occurs, <function>glMapBufferRange</function> returns a <code>NULL</code> pointer.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="errors"><title>Errors</title>\r
        <para>\r
            <constant>GL_INVALID_VALUE</constant> is generated if either of <parameter>offset</parameter> or <parameter>length</parameter> is negative,\r
            or if <parameter>offset</parameter> + <parameter>length</parameter> is greater than the value of <constant>GL_BUFFER_SIZE</constant>.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_VALUE</constant> is generated if <parameter>access</parameter> has any bits set other than those defined above.\r
        </para>\r
        <para>\r
            <constant>GL_INVALID_OPERATION</constant> is generated for any of the following conditions:\r
            <itemizedlist>\r
                <listitem>\r
                    <para>\r
                        The buffer is already in a mapped state.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        Neither <constant>GL_MAP_READ_BIT</constant> or <constant>GL_MAP_WRITE_BIT</constant> is set.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_READ_BIT</constant> is set and any of <constant>GL_MAP_INVALIDATE_RANGE_BIT</constant>,\r
                        <constant>GL_MAP_INVALIDATE_BUFFER_BIT</constant>, or <constant>GL_MAP_UNSYNCHRONIZED_BIT</constant> is set.\r
                    </para>\r
                </listitem>\r
                <listitem>\r
                    <para>\r
                        <constant>GL_MAP_FLUSH_EXPLICIT_BIT</constant> is set and <constant>GL_MAP_WRITE_BIT</constant> is not set.\r
                    </para>\r
                </listitem>\r
            </itemizedlist>\r
        </para>\r
        <para>\r
            <constant>GL_OUT_OF_MEMORY</constant> is generated if <function>glMapBufferRange</function> fails because memory for the\r
            mapping could not be obtained.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="seealso"><title>See Also</title>\r
        <para>\r
            <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>,\r
            <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>\r
        </para>\r
    </refsect1>\r
    <refsect1 id="Copyright"><title>Copyright</title>\r
        <para>\r
            Copyright <trademark class="copyright"></trademark> 2010 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="glMapBufferRange">\r
	5	<refmeta>\r
	6	<refmetainfo>\r
	7	<copyright>\r
	8	<year>2010</year>\r
	9	<holder>Khronos Group</holder>\r
	10	</copyright>\r
	11	</refmetainfo>\r
	12	<refentrytitle>glMapBufferRange</refentrytitle>\r
	13	<manvolnum>3G</manvolnum>\r
	14	</refmeta>\r
	15	<refnamediv>\r
	16	<refname>glMapBufferRange</refname>\r
	17	<refpurpose>map a section of a buffer object's data store</refpurpose>\r
	18	</refnamediv>\r
	19	<refsynopsisdiv><title>C Specification</title>\r
	20	<funcsynopsis>\r
	21	<funcprototype>\r
	22	<funcdef>void *<function>glMapBufferRange</function></funcdef>\r
	23	<paramdef>GLenum <parameter>target</parameter></paramdef>\r
	24	<paramdef>GLintptr <parameter>offset</parameter></paramdef>\r
	25	<paramdef>GLsizeiptr <parameter>length</parameter></paramdef>\r
	26	<paramdef>GLbitfield <parameter>access</parameter></paramdef>\r
	27	</funcprototype>\r
	28	</funcsynopsis>\r
	29	</refsynopsisdiv>\r
	30	<refsect1 id="parameters"><title>Parameters</title>\r
	31	<variablelist>\r
	32	<varlistentry>\r
	33	<term><parameter>target</parameter></term>\r
	34	<listitem>\r
	35	<para>\r
	36	Specifies a binding to which the target buffer is bound.\r
	37	</para>\r
	38	</listitem>\r
	39	</varlistentry>\r
	40	<varlistentry>\r
	41	<term><parameter>offset</parameter></term>\r
	42	<listitem>\r
	43	<para>\r
	44	Specifies a the starting offset within the buffer of the range to be mapped.\r
	45	</para>\r
	46	</listitem>\r
	47	</varlistentry>\r
	48	<varlistentry>\r
	49	<term><parameter>length</parameter></term>\r
	50	<listitem>\r
	51	<para>\r
	52	Specifies a length of the range to be mapped.\r
	53	</para>\r
	54	</listitem>\r
	55	</varlistentry>\r
	56	<varlistentry>\r
	57	<term><parameter>access</parameter></term>\r
	58	<listitem>\r
	59	<para>\r
	60	Specifies a combination of access flags indicating the desired access to the range.\r
	61	</para>\r
	62	</listitem>\r
	63	</varlistentry>\r
	64	</variablelist>\r
65	</refsect1>\r
66	<refsect1 id="description"><title>Description</title>\r
67	<para>\r
68	<function>glMapBufferRange</function> maps all or part of the data store of a buffer object into the client's address\r
69	space. <parameter>target</parameter> specifies the target to which the buffer is bound and must be one of <constant>GL_ARRAY_BUFFER</constant>,\r
70	<constant>GL_COPY_READ_BUFFER</constant>, <constant>GL_COPY_WRITE_BUFFER</constant>, <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,\r
71	<constant>GL_PIXEL_PACK_BUFFER</constant>, <constant>GL_PIXEL_UNPACK_BUFFER</constant>, <constant>GL_TEXTURE_BUFFER</constant>,\r
72	<constant>GL_TRANSFORM_FEEDBACK_BUFFER</constant>, or <constant>GL_UNIFORM_BUFFER</constant>. <parameter>offset</parameter> and\r
73	<parameter>length</parameter> indicate the range of data in the buffer object htat is to be mapped, in terms of basic machine units.\r
74	<parameter>access</parameter> is a bitfield containing flags which describe the requested mapping. These flags are described below.\r
75	</para>\r
76	<para>\r
77	If no error occurs, a pointer to the beginning of the mapped range is returned once all pending operations on that buffer have\r
78	completed, and may be used to modify and/or query the corresponding range of the buffer, according to the following flag bits set\r
79	in <parameter>access</parameter>:\r
80	<itemizedlist>\r
81	<listitem>\r
82	<para>\r
83	<constant>GL_MAP_READ_BIT</constant> indicates that the returned pointer may be used to read\r
84	buffer object data. No GL error is generated if the pointer is used to query\r
85	a mapping which excludes this flag, but the result is undefined and system\r
86	errors (possibly including program termination) may occur.\r
87	</para>\r
88	</listitem>\r
89	<listitem>\r
90	<para>\r
91	<constant>GL_MAP_WRITE_BIT</constant> indicates that the returned pointer may be used to modify\r
92	buffer object data. No GL error is generated if the pointer is used to modify\r
93	a mapping which excludes this flag, but the result is undefined and system\r
94	errors (possibly including program termination) may occur.\r
95	</para>\r
96	</listitem>\r
97	</itemizedlist>\r
98	</para>\r
99	<para>\r
100	Furthermore, the following <emphasis>optional</emphasis> flag bits in <parameter>access</parameter> may be used to modify the mapping:\r
101	<itemizedlist>\r
102	<listitem>\r
103	<para>\r
104	<constant>GL_MAP_INVALIDATE_RANGE_BIT</constant> indicates that the previous contents of the\r
105	specified range may be discarded. Data within this range are undefined with\r
106	the exception of subsequently written data. No GL error is generated if sub-\r
107	sequent GL operations access unwritten data, but the result is undefined and\r
108	system errors (possibly including program termination) may occur. This flag\r
109	may not be used in combination with <constant>GL_MAP_READ_BIT</constant>.\r
110	</para>\r
111	</listitem>\r
112	<listitem>\r
113	<para>\r
114	<constant>GL_MAP_INVALIDATE_BUFFER_BIT</constant> indicates that the previous contents of the\r
115	entire buffer may be discarded. Data within the entire buffer are undefined\r
116	with the exception of subsequently written data. No GL error is generated if\r
117	subsequent GL operations access unwritten data, but the result is undefined\r
118	and system errors (possibly including program termination) may occur. This\r
119	flag may not be used in combination with <constant>GL_MAP_READ_BIT</constant>.\r
120	</para>\r
121	</listitem>\r
122	<listitem>\r
123	<para>\r
124	<constant>GL_MAP_FLUSH_EXPLICIT_BIT</constant> indicates that one or more discrete subranges\r
125	of the mapping may be modified. When this flag is set, modifications to\r
126	each subrange must be explicitly flushed by calling <citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>.\r
127	No GL error is set if a subrange of the mapping is modified and\r
128	not flushed, but data within the corresponding subrange of the buffer are undefined.\r
129	This flag may only be used in conjunction with <constant>GL_MAP_WRITE_BIT</constant>.\r
130	When this option is selected, flushing is strictly limited to regions that are\r
131	explicitly indicated with calls to <citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>\r
132	prior to unmap; if this option is not selected <citerefentry><refentrytitle>glUnmapBuffer</refentrytitle></citerefentry>\r
133	will automatically flush the entire mapped range when called.\r
134	</para>\r
135	</listitem>\r
136	<listitem>\r
137	<para>\r
138	<constant>GL_MAP_UNSYNCHRONIZED_BIT</constant> indicates that the GL should not attempt to\r
139	synchronize pending operations on the buffer prior to returning from <function>glMapBufferRange</function>.\r
140	No GL error is generated if pending operations which source or modify the buffer overlap the mapped region,\r
141	but the result of such previous and any subsequent operations is undefined.\r
142	</para>\r
143	</listitem>\r
144	</itemizedlist>\r
145	</para>\r
146	<para>\r
147	If an error occurs, <function>glMapBufferRange</function> returns a <code>NULL</code> pointer.\r
148	</para>\r
149	</refsect1>\r
150	<refsect1 id="errors"><title>Errors</title>\r
151	<para>\r
152	<constant>GL_INVALID_VALUE</constant> is generated if either of <parameter>offset</parameter> or <parameter>length</parameter> is negative,\r
153	or if <parameter>offset</parameter> + <parameter>length</parameter> is greater than the value of <constant>GL_BUFFER_SIZE</constant>.\r
154	</para>\r
155	<para>\r
156	<constant>GL_INVALID_VALUE</constant> is generated if <parameter>access</parameter> has any bits set other than those defined above.\r
157	</para>\r
158	<para>\r
159	<constant>GL_INVALID_OPERATION</constant> is generated for any of the following conditions:\r
160	<itemizedlist>\r
161	<listitem>\r
162	<para>\r
163	The buffer is already in a mapped state.\r
164	</para>\r
165	</listitem>\r
166	<listitem>\r
167	<para>\r
168	Neither <constant>GL_MAP_READ_BIT</constant> or <constant>GL_MAP_WRITE_BIT</constant> is set.\r
169	</para>\r
170	</listitem>\r
171	<listitem>\r
172	<para>\r
173	<constant>GL_MAP_READ_BIT</constant> is set and any of <constant>GL_MAP_INVALIDATE_RANGE_BIT</constant>,\r
174	<constant>GL_MAP_INVALIDATE_BUFFER_BIT</constant>, or <constant>GL_MAP_UNSYNCHRONIZED_BIT</constant> is set.\r
175	</para>\r
176	</listitem>\r
177	<listitem>\r
178	<para>\r
179	<constant>GL_MAP_FLUSH_EXPLICIT_BIT</constant> is set and <constant>GL_MAP_WRITE_BIT</constant> is not set.\r
180	</para>\r
181	</listitem>\r
182	</itemizedlist>\r
183	</para>\r
184	<para>\r
185	<constant>GL_OUT_OF_MEMORY</constant> is generated if <function>glMapBufferRange</function> fails because memory for the\r
186	mapping could not be obtained.\r
187	</para>\r
188	</refsect1>\r
189	<refsect1 id="seealso"><title>See Also</title>\r
190	<para>\r
191	<citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>,\r
192	<citerefentry><refentrytitle>glFlushMappedBufferRange</refentrytitle></citerefentry>,\r
193	<citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>\r
194	</para>\r
195	</refsect1>\r
196	<refsect1 id="Copyright"><title>Copyright</title>\r
197	<para>\r
198	Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. \r
199	This material may be distributed subject to the terms and conditions set forth in \r
200	the Open Publication License, v 1.0, 8 June 1999.\r
201	<ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
202	</para>\r
203	</refsect1>\r
204	</refentry>\r