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1 | <?xml version="1.0" encoding="UTF-8"?> |
2 | <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN" | |
3 | "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd"> | |
4 | <refentry id="glCompressedTexSubImage2D"> | |
5 | <refmeta> | |
6 | <refmetainfo> | |
7 | <copyright> | |
8 | <year>1991-2006</year> | |
9 | <holder>Silicon Graphics, Inc.</holder> | |
10 | </copyright> | |
11 | </refmetainfo> | |
12 | <refentrytitle>glCompressedTexSubImage2D</refentrytitle> | |
13 | <manvolnum>3G</manvolnum> | |
14 | </refmeta> | |
15 | <refnamediv> | |
16 | <refname>glCompressedTexSubImage2D</refname> | |
17 | <refpurpose>specify a two-dimensional texture subimage in a compressed format</refpurpose> | |
18 | </refnamediv> | |
19 | <refsynopsisdiv><title>C Specification</title> | |
20 | <funcsynopsis> | |
21 | <funcprototype> | |
22 | <funcdef>void <function>glCompressedTexSubImage2D</function></funcdef> | |
23 | <paramdef>GLenum <parameter>target</parameter></paramdef> | |
24 | <paramdef>GLint <parameter>level</parameter></paramdef> | |
25 | <paramdef>GLint <parameter>xoffset</parameter></paramdef> | |
26 | <paramdef>GLint <parameter>yoffset</parameter></paramdef> | |
27 | <paramdef>GLsizei <parameter>width</parameter></paramdef> | |
28 | <paramdef>GLsizei <parameter>height</parameter></paramdef> | |
29 | <paramdef>GLenum <parameter>format</parameter></paramdef> | |
30 | <paramdef>GLsizei <parameter>imageSize</parameter></paramdef> | |
31 | <paramdef>const GLvoid * <parameter>data</parameter></paramdef> | |
32 | </funcprototype> | |
33 | </funcsynopsis> | |
34 | </refsynopsisdiv> | |
35 | <!-- eqn: ignoring delim $$ --> | |
36 | <refsect1 id="parameters"><title>Parameters</title> | |
37 | <variablelist> | |
38 | <varlistentry> | |
39 | <term><parameter>target</parameter></term> | |
40 | <listitem> | |
41 | <para> | |
42 | Specifies the target texture. | |
43 | Must be <constant>GL_TEXTURE_2D</constant>, | |
44 | <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_X</constant>, | |
45 | <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_X</constant>, | |
46 | <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Y</constant>, | |
47 | <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Y</constant>, | |
48 | <constant>GL_TEXTURE_CUBE_MAP_POSITIVE_Z</constant>, or | |
49 | <constant>GL_TEXTURE_CUBE_MAP_NEGATIVE_Z</constant>. | |
50 | </para> | |
51 | </listitem> | |
52 | </varlistentry> | |
53 | <varlistentry> | |
54 | <term><parameter>level</parameter></term> | |
55 | <listitem> | |
56 | <para> | |
57 | Specifies the level-of-detail number. | |
58 | Level 0 is the base image level. | |
59 | Level <emphasis>n</emphasis> is the <emphasis>n</emphasis>th mipmap reduction image. | |
60 | </para> | |
61 | </listitem> | |
62 | </varlistentry> | |
63 | <varlistentry> | |
64 | <term><parameter>xoffset</parameter></term> | |
65 | <listitem> | |
66 | <para> | |
67 | Specifies a texel offset in the x direction within the texture array. | |
68 | </para> | |
69 | </listitem> | |
70 | </varlistentry> | |
71 | <varlistentry> | |
72 | <term><parameter>yoffset</parameter></term> | |
73 | <listitem> | |
74 | <para> | |
75 | Specifies a texel offset in the y direction within the texture array. | |
76 | </para> | |
77 | </listitem> | |
78 | </varlistentry> | |
79 | <varlistentry> | |
80 | <term><parameter>width</parameter></term> | |
81 | <listitem> | |
82 | <para> | |
83 | Specifies the width of the texture subimage. | |
84 | </para> | |
85 | </listitem> | |
86 | </varlistentry> | |
87 | <varlistentry> | |
88 | <term><parameter>height</parameter></term> | |
89 | <listitem> | |
90 | <para> | |
91 | Specifies the height of the texture subimage. | |
92 | </para> | |
93 | </listitem> | |
94 | </varlistentry> | |
95 | <varlistentry> | |
96 | <term><parameter>format</parameter></term> | |
97 | <listitem> | |
98 | <para> | |
99 | Specifies the format of the compressed image data stored at address <parameter>data</parameter>. | |
100 | </para> | |
101 | </listitem> | |
102 | </varlistentry> | |
103 | <varlistentry> | |
104 | <term><parameter>imageSize</parameter></term> | |
105 | <listitem> | |
106 | <para> | |
107 | Specifies the number of unsigned bytes of image data starting at the | |
108 | address specified by <parameter>data</parameter>. | |
109 | </para> | |
110 | </listitem> | |
111 | </varlistentry> | |
112 | <varlistentry> | |
113 | <term><parameter>data</parameter></term> | |
114 | <listitem> | |
115 | <para> | |
116 | Specifies a pointer to the compressed image data in memory. | |
117 | </para> | |
118 | </listitem> | |
119 | </varlistentry> | |
120 | </variablelist> | |
121 | </refsect1> | |
122 | <refsect1 id="description"><title>Description</title> | |
123 | <para> | |
124 | Texturing allows elements of an image array to be read by shaders. | |
125 | </para> | |
126 | <para> | |
127 | <function>glCompressedTexSubImage2D</function> redefines a contiguous subregion of an existing two-dimensional | |
128 | texture image. The texels referenced by <parameter>data</parameter> replace the portion of the | |
129 | existing texture array with x indices <parameter>xoffset</parameter> and | |
130 | <inlineequation><mml:math> | |
131 | <!-- eqn: xoffset + width - 1: --> | |
132 | <mml:mrow> | |
133 | <mml:mi mathvariant="italic">xoffset</mml:mi> | |
134 | <mml:mo>+</mml:mo> | |
135 | <mml:mi mathvariant="italic">width</mml:mi> | |
136 | <mml:mo>-</mml:mo> | |
137 | <mml:mn>1</mml:mn> | |
138 | </mml:mrow> | |
139 | </mml:math></inlineequation>, | |
140 | and the y indices <parameter>yoffset</parameter> and | |
141 | <inlineequation><mml:math> | |
142 | <!-- eqn: yoffset + height - 1: --> | |
143 | <mml:mrow> | |
144 | <mml:mi mathvariant="italic">yoffset</mml:mi> | |
145 | <mml:mo>+</mml:mo> | |
146 | <mml:mi mathvariant="italic">height</mml:mi> | |
147 | <mml:mo>-</mml:mo> | |
148 | <mml:mn>1</mml:mn> | |
149 | </mml:mrow> | |
150 | </mml:math></inlineequation>, | |
151 | inclusive. | |
152 | This region may not include any texels | |
153 | outside the range of the texture array as it was originally specified. It | |
154 | is not an error to specify a subtexture with width of 0, but such a | |
155 | specification has no effect. | |
156 | </para> | |
157 | <para> | |
158 | <parameter>internalformat</parameter> must be a known compressed image format (such as <constant>GL_RGTC</constant>) | |
159 | or an extension-specified compressed-texture format. | |
160 | The <parameter>format</parameter> of the compressed texture | |
161 | image is selected by the GL implementation that compressed it (see | |
162 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>) and should be queried at the time the texture was | |
163 | compressed with <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry>. | |
164 | </para> | |
165 | <para> | |
166 | If a non-zero named buffer object is bound to the <constant>GL_PIXEL_UNPACK_BUFFER</constant> target | |
167 | (see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while a texture image is | |
168 | specified, <parameter>data</parameter> is treated as a byte offset into the buffer object's data store. | |
169 | </para> | |
170 | </refsect1> | |
171 | <refsect1 id="errors"><title>Errors</title> | |
172 | <para> | |
173 | <constant>GL_INVALID_ENUM</constant> is generated if <parameter>internalformat</parameter> is of the generic compressed internal formats: | |
174 | <constant>GL_COMPRESSED_RED</constant>, | |
175 | <constant>GL_COMPRESSED_RG</constant>, | |
176 | <constant>GL_COMPRESSED_RGB</constant>, | |
177 | <constant>GL_COMPRESSED_RGBA</constant>. | |
178 | <constant>GL_COMPRESSED_SRGB</constant>, or | |
179 | <constant>GL_COMPRESSED_SRGB_ALPHA</constant>. | |
180 | </para> | |
181 | <para> | |
182 | <constant>GL_INVALID_VALUE</constant> is generated if <parameter>imageSize</parameter> is not consistent with | |
183 | the format, dimensions, and contents of the specified compressed image | |
184 | data. | |
185 | </para> | |
186 | <para> | |
187 | <constant>GL_INVALID_OPERATION</constant> is generated if parameter combinations are not | |
188 | supported by the specific compressed internal format as specified in the | |
189 | specific texture compression extension. | |
190 | </para> | |
191 | <para> | |
192 | <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the | |
193 | <constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the buffer object's data store is currently mapped. | |
194 | </para> | |
195 | <para> | |
196 | <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the | |
197 | <constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the data would be unpacked from the buffer | |
198 | object such that the memory reads required would exceed the data store size. | |
199 | </para> | |
200 | <para> | |
201 | Undefined results, including abnormal program termination, are generated if | |
202 | <parameter>data</parameter> is not encoded in a manner consistent with the extension | |
203 | specification defining the internal compression format. | |
204 | </para> | |
205 | </refsect1> | |
206 | <refsect1 id="associatedgets"><title>Associated Gets</title> | |
207 | <para> | |
208 | <citerefentry><refentrytitle>glGetCompressedTexImage</refentrytitle></citerefentry> | |
209 | </para> | |
210 | <para> | |
211 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_TEXTURE_COMPRESSED</constant> | |
212 | </para> | |
213 | <para> | |
214 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_UNPACK_BUFFER_BINDING</constant> | |
215 | </para> | |
216 | <para> | |
217 | <citerefentry><refentrytitle>glGetTexLevelParameter</refentrytitle></citerefentry> with arguments <constant>GL_TEXTURE_INTERNAL_FORMAT</constant> | |
218 | and <constant>GL_TEXTURE_COMPRESSED_IMAGE_SIZE</constant> | |
219 | </para> | |
220 | </refsect1> | |
221 | <refsect1 id="seealso"><title>See Also</title> | |
222 | <para> | |
223 | <citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>, | |
224 | <citerefentry><refentrytitle>glCompressedTexImage1D</refentrytitle></citerefentry>, | |
225 | <citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>, | |
226 | <citerefentry><refentrytitle>glCompressedTexImage3D</refentrytitle></citerefentry>, | |
227 | <citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>, | |
228 | <citerefentry><refentrytitle>glCompressedTexSubImage3D</refentrytitle></citerefentry>, | |
229 | <citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>, | |
230 | <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>, | |
231 | <citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>, | |
232 | <citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>, | |
233 | <citerefentry><refentrytitle>glCopyTexSubImage3D</refentrytitle></citerefentry>, | |
234 | <citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>, | |
235 | <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, | |
236 | <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>, | |
237 | <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>, | |
238 | <citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>, | |
239 | <citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>, | |
240 | <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry> | |
241 | </para> | |
242 | </refsect1> | |
243 | <refsect1 id="Copyright"><title>Copyright</title> | |
244 | <para> | |
245 | Copyright <trademark class="copyright"></trademark> 1991-2006 | |
246 | Silicon Graphics, Inc. This document is licensed under the SGI | |
247 | Free Software B License. For details, see | |
248 | <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>. | |
249 | </para> | |
250 | </refsect1> | |
251 | </refentry> |