2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
5 * Copyright (c) 2008 VMware, Inc.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
29 * Helper functions for texture compression.
40 #include "texcompress.h"
41 #include "texcompress_fxt1.h"
42 #include "texcompress_rgtc.h"
43 #include "texcompress_s3tc.h"
44 #include "texcompress_etc.h"
48 * Get the GL base format of a specified GL compressed texture format
50 * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec:
52 * "Compressed Internal Format Base Internal Format Type
53 * --------------------------- -------------------- ---------
54 * COMPRESSED_ALPHA ALPHA Generic
55 * COMPRESSED_LUMINANCE LUMINANCE Generic
56 * COMPRESSED_LUMINANCE_ALPHA LUMINANCE_ALPHA Generic
57 * COMPRESSED_INTENSITY INTENSITY Generic
58 * COMPRESSED_RED RED Generic
59 * COMPRESSED_RG RG Generic
60 * COMPRESSED_RGB RGB Generic
61 * COMPRESSED_RGBA RGBA Generic
62 * COMPRESSED_SRGB RGB Generic
63 * COMPRESSED_SRGB_ALPHA RGBA Generic
64 * COMPRESSED_SLUMINANCE LUMINANCE Generic
65 * COMPRESSED_SLUMINANCE_ALPHA LUMINANCE_ALPHA Generic
66 * COMPRESSED_RED_RGTC1 RED Specific
67 * COMPRESSED_SIGNED_RED_RGTC1 RED Specific
68 * COMPRESSED_RG_RGTC2 RG Specific
69 * COMPRESSED_SIGNED_RG_RGTC2 RG Specific"
72 * The base format of \c format if \c format is a compressed format (either
73 * generic or specific. Otherwise 0 is returned.
76 _mesa_gl_compressed_format_base_format(GLenum format
)
79 case GL_COMPRESSED_RED
:
80 case GL_COMPRESSED_R11_EAC
:
81 case GL_COMPRESSED_RED_RGTC1
:
82 case GL_COMPRESSED_SIGNED_R11_EAC
:
83 case GL_COMPRESSED_SIGNED_RED_RGTC1
:
86 case GL_COMPRESSED_RG
:
87 case GL_COMPRESSED_RG11_EAC
:
88 case GL_COMPRESSED_RG_RGTC2
:
89 case GL_COMPRESSED_SIGNED_RG11_EAC
:
90 case GL_COMPRESSED_SIGNED_RG_RGTC2
:
93 case GL_COMPRESSED_RGB
:
94 case GL_COMPRESSED_SRGB
:
95 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
96 case GL_COMPRESSED_RGB_FXT1_3DFX
:
97 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
98 case GL_ETC1_RGB8_OES
:
99 case GL_COMPRESSED_RGB8_ETC2
:
100 case GL_COMPRESSED_SRGB8_ETC2
:
103 case GL_COMPRESSED_RGBA
:
104 case GL_COMPRESSED_SRGB_ALPHA
:
105 case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB
:
106 case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB
:
107 case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB
:
108 case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB
:
109 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
110 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
111 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
112 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
113 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
114 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
115 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
116 case GL_COMPRESSED_RGBA8_ETC2_EAC
:
117 case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
:
118 case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
119 case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
122 case GL_COMPRESSED_ALPHA
:
125 case GL_COMPRESSED_LUMINANCE
:
126 case GL_COMPRESSED_SLUMINANCE
:
127 case GL_COMPRESSED_LUMINANCE_LATC1_EXT
:
128 case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
:
131 case GL_COMPRESSED_LUMINANCE_ALPHA
:
132 case GL_COMPRESSED_SLUMINANCE_ALPHA
:
133 case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
:
134 case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
:
135 case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI
:
136 return GL_LUMINANCE_ALPHA
;
138 case GL_COMPRESSED_INTENSITY
:
147 * Return list of (and count of) all specific texture compression
148 * formats that are supported.
150 * Some formats are \b not returned by this function. The
151 * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
152 * "suitable for general-purpose usage." All texture compression extensions
153 * have taken this to mean either linear RGB or linear RGBA.
155 * The GL_ARB_texture_compress_rgtc spec says:
157 * "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
158 * GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
162 * The OpenGL 2.1 specification says "The only values returned
163 * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
164 * corresponding to formats suitable for general-purpose usage.
165 * The renderer will not enumerate formats with restrictions that
166 * need to be specifically understood prior to use."
168 * Compressed textures with just red or red-green components are
169 * not general-purpose so should not be returned by these queries
170 * because they have restrictions.
172 * Applications that seek to use the RGTC formats should do so
173 * by looking for this extension's name in the string returned by
174 * glGetString(GL_EXTENSIONS) rather than
175 * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
176 * GL_COMPRESSED_TEXTURE_FORMATS return."
178 * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
181 * The GL_EXT_texture_rRGB spec says:
183 * "22) Should the new COMPRESSED_SRGB_* formats be listed in an
184 * implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
186 * RESOLVED: No. Section 3.8.1 says formats listed by
187 * GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
188 * usage." The non-linear distribution of red, green, and
189 * blue for these sRGB compressed formats makes them not really
192 * The GL_EXT_texture_compression_latc spec says:
194 * "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
195 * GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
199 * The OpenGL 2.1 specification says "The only values returned
200 * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
201 * corresponding to formats suitable for general-purpose usage.
202 * The renderer will not enumerate formats with restrictions that
203 * need to be specifically understood prior to use."
205 * Historically, OpenGL implementation have advertised the RGB and
206 * RGBA versions of the S3TC extensions compressed format tokens
207 * through this mechanism.
209 * The specification is not sufficiently clear about what "suitable
210 * for general-purpose usage" means. Historically that seems to mean
211 * unsigned RGB or unsigned RGBA. The DXT1 format supporting alpha
212 * (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
213 * least for NVIDIA drivers) because the alpha is always 1.0 expect
214 * when it is 0.0 when RGB is required to be black. NVIDIA's even
215 * limits itself to true linear RGB or RGBA formats, specifically
216 * not including EXT_texture_sRGB's sRGB S3TC compressed formats.
218 * Adding luminance and luminance-alpha texture formats (and
219 * certainly signed versions of luminance and luminance-alpha
220 * formats!) invites potential comptaibility problems with old
221 * applications using this mechanism since old applications are
222 * unlikely to expect non-RGB or non-RGBA formats to be advertised
223 * through this mechanism. However no specific misinteractions
224 * with old applications is known.
226 * Applications that seek to use the LATC formats should do so
227 * by looking for this extension's name in the string returned by
228 * glGetString(GL_EXTENSIONS) rather than
229 * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
230 * GL_COMPRESSED_TEXTURE_FORMATS return."
232 * There is no formal spec for GL_ATI_texture_compression_3dc. Since the
233 * formats added by this extension are luminance-alpha formats, it is
234 * reasonable to expect them to follow the same rules as
235 * GL_EXT_texture_compression_latc. At the very least, Catalyst 11.6 does not
236 * expose the 3dc formats through this mechanism.
238 * \param ctx the GL context
239 * \param formats the resulting format list (may be NULL).
241 * \return number of formats.
244 _mesa_get_compressed_formats(struct gl_context
*ctx
, GLint
*formats
)
247 if (ctx
->Extensions
.TDFX_texture_compression_FXT1
) {
249 formats
[n
++] = GL_COMPRESSED_RGB_FXT1_3DFX
;
250 formats
[n
++] = GL_COMPRESSED_RGBA_FXT1_3DFX
;
257 if (ctx
->Extensions
.EXT_texture_compression_s3tc
) {
259 formats
[n
++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
260 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
261 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
267 if (_mesa_is_desktop_gl(ctx
)
268 && ctx
->Extensions
.ANGLE_texture_compression_dxt
) {
270 formats
[n
++] = GL_RGB_S3TC
;
271 formats
[n
++] = GL_RGB4_S3TC
;
272 formats
[n
++] = GL_RGBA_S3TC
;
273 formats
[n
++] = GL_RGBA4_S3TC
;
280 /* The GL_OES_compressed_ETC1_RGB8_texture spec says:
284 * The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
285 * COMPRESSED_TEXTURE_FORMATS include ETC1_RGB8_OES."
287 if (_mesa_is_gles(ctx
)
288 && ctx
->Extensions
.OES_compressed_ETC1_RGB8_texture
) {
290 formats
[n
++] = GL_ETC1_RGB8_OES
;
297 if (ctx
->API
== API_OPENGLES
) {
299 formats
[n
++] = GL_PALETTE4_RGB8_OES
;
300 formats
[n
++] = GL_PALETTE4_RGBA8_OES
;
301 formats
[n
++] = GL_PALETTE4_R5_G6_B5_OES
;
302 formats
[n
++] = GL_PALETTE4_RGBA4_OES
;
303 formats
[n
++] = GL_PALETTE4_RGB5_A1_OES
;
304 formats
[n
++] = GL_PALETTE8_RGB8_OES
;
305 formats
[n
++] = GL_PALETTE8_RGBA8_OES
;
306 formats
[n
++] = GL_PALETTE8_R5_G6_B5_OES
;
307 formats
[n
++] = GL_PALETTE8_RGBA4_OES
;
308 formats
[n
++] = GL_PALETTE8_RGB5_A1_OES
;
315 if (_mesa_is_gles3(ctx
)) {
317 formats
[n
++] = GL_COMPRESSED_RGB8_ETC2
;
318 formats
[n
++] = GL_COMPRESSED_SRGB8_ETC2
;
319 formats
[n
++] = GL_COMPRESSED_RGBA8_ETC2_EAC
;
320 formats
[n
++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
;
321 formats
[n
++] = GL_COMPRESSED_R11_EAC
;
322 formats
[n
++] = GL_COMPRESSED_RG11_EAC
;
323 formats
[n
++] = GL_COMPRESSED_SIGNED_R11_EAC
;
324 formats
[n
++] = GL_COMPRESSED_SIGNED_RG11_EAC
;
325 formats
[n
++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
326 formats
[n
++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
337 * Convert a compressed MESA_FORMAT_x to a GLenum.
340 _mesa_glenum_to_compressed_format(GLenum format
)
343 case GL_COMPRESSED_RGB_FXT1_3DFX
:
344 return MESA_FORMAT_RGB_FXT1
;
345 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
346 return MESA_FORMAT_RGBA_FXT1
;
348 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
350 return MESA_FORMAT_RGB_DXT1
;
351 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
353 return MESA_FORMAT_RGBA_DXT1
;
354 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
356 return MESA_FORMAT_RGBA_DXT3
;
357 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
359 return MESA_FORMAT_RGBA_DXT5
;
361 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
362 return MESA_FORMAT_SRGB_DXT1
;
363 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
364 return MESA_FORMAT_SRGBA_DXT1
;
365 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
366 return MESA_FORMAT_SRGBA_DXT3
;
367 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
368 return MESA_FORMAT_SRGBA_DXT5
;
370 case GL_COMPRESSED_RED_RGTC1
:
371 return MESA_FORMAT_RED_RGTC1
;
372 case GL_COMPRESSED_SIGNED_RED_RGTC1
:
373 return MESA_FORMAT_SIGNED_RED_RGTC1
;
374 case GL_COMPRESSED_RG_RGTC2
:
375 return MESA_FORMAT_RG_RGTC2
;
376 case GL_COMPRESSED_SIGNED_RG_RGTC2
:
377 return MESA_FORMAT_SIGNED_RG_RGTC2
;
379 case GL_COMPRESSED_LUMINANCE_LATC1_EXT
:
380 return MESA_FORMAT_L_LATC1
;
381 case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
:
382 return MESA_FORMAT_SIGNED_L_LATC1
;
383 case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
:
384 case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI
:
385 return MESA_FORMAT_LA_LATC2
;
386 case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
:
387 return MESA_FORMAT_SIGNED_LA_LATC2
;
389 case GL_ETC1_RGB8_OES
:
390 return MESA_FORMAT_ETC1_RGB8
;
391 case GL_COMPRESSED_RGB8_ETC2
:
392 return MESA_FORMAT_ETC2_RGB8
;
393 case GL_COMPRESSED_SRGB8_ETC2
:
394 return MESA_FORMAT_ETC2_SRGB8
;
395 case GL_COMPRESSED_RGBA8_ETC2_EAC
:
396 return MESA_FORMAT_ETC2_RGBA8_EAC
;
397 case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
:
398 return MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC
;
399 case GL_COMPRESSED_R11_EAC
:
400 return MESA_FORMAT_ETC2_R11_EAC
;
401 case GL_COMPRESSED_RG11_EAC
:
402 return MESA_FORMAT_ETC2_RG11_EAC
;
403 case GL_COMPRESSED_SIGNED_R11_EAC
:
404 return MESA_FORMAT_ETC2_SIGNED_R11_EAC
;
405 case GL_COMPRESSED_SIGNED_RG11_EAC
:
406 return MESA_FORMAT_ETC2_SIGNED_RG11_EAC
;
407 case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
408 return MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1
;
409 case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
410 return MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1
;
413 return MESA_FORMAT_NONE
;
419 * Given a compressed MESA_FORMAT_x value, return the corresponding
420 * GLenum for that format.
421 * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
422 * which must return the specific texture format used when the user might
423 * have originally specified a generic compressed format in their
424 * glTexImage2D() call.
425 * For non-compressed textures, we always return the user-specified
426 * internal format unchanged.
429 _mesa_compressed_format_to_glenum(struct gl_context
*ctx
, gl_format mesaFormat
)
431 switch (mesaFormat
) {
432 case MESA_FORMAT_RGB_FXT1
:
433 return GL_COMPRESSED_RGB_FXT1_3DFX
;
434 case MESA_FORMAT_RGBA_FXT1
:
435 return GL_COMPRESSED_RGBA_FXT1_3DFX
;
436 case MESA_FORMAT_RGB_DXT1
:
437 return GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
438 case MESA_FORMAT_RGBA_DXT1
:
439 return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
440 case MESA_FORMAT_RGBA_DXT3
:
441 return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
442 case MESA_FORMAT_RGBA_DXT5
:
443 return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
444 case MESA_FORMAT_SRGB_DXT1
:
445 return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
446 case MESA_FORMAT_SRGBA_DXT1
:
447 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
448 case MESA_FORMAT_SRGBA_DXT3
:
449 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
450 case MESA_FORMAT_SRGBA_DXT5
:
451 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
452 case MESA_FORMAT_RED_RGTC1
:
453 return GL_COMPRESSED_RED_RGTC1
;
454 case MESA_FORMAT_SIGNED_RED_RGTC1
:
455 return GL_COMPRESSED_SIGNED_RED_RGTC1
;
456 case MESA_FORMAT_RG_RGTC2
:
457 return GL_COMPRESSED_RG_RGTC2
;
458 case MESA_FORMAT_SIGNED_RG_RGTC2
:
459 return GL_COMPRESSED_SIGNED_RG_RGTC2
;
461 case MESA_FORMAT_L_LATC1
:
462 return GL_COMPRESSED_LUMINANCE_LATC1_EXT
;
463 case MESA_FORMAT_SIGNED_L_LATC1
:
464 return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
;
465 case MESA_FORMAT_LA_LATC2
:
466 return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
;
467 case MESA_FORMAT_SIGNED_LA_LATC2
:
468 return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
;
470 case MESA_FORMAT_ETC1_RGB8
:
471 return GL_ETC1_RGB8_OES
;
472 case MESA_FORMAT_ETC2_RGB8
:
473 return GL_COMPRESSED_RGB8_ETC2
;
474 case MESA_FORMAT_ETC2_SRGB8
:
475 return GL_COMPRESSED_SRGB8_ETC2
;
476 case MESA_FORMAT_ETC2_RGBA8_EAC
:
477 return GL_COMPRESSED_RGBA8_ETC2_EAC
;
478 case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC
:
479 return GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
;
480 case MESA_FORMAT_ETC2_R11_EAC
:
481 return GL_COMPRESSED_R11_EAC
;
482 case MESA_FORMAT_ETC2_RG11_EAC
:
483 return GL_COMPRESSED_RG11_EAC
;
484 case MESA_FORMAT_ETC2_SIGNED_R11_EAC
:
485 return GL_COMPRESSED_SIGNED_R11_EAC
;
486 case MESA_FORMAT_ETC2_SIGNED_RG11_EAC
:
487 return GL_COMPRESSED_SIGNED_RG11_EAC
;
488 case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1
:
489 return GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
490 case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1
:
491 return GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
494 _mesa_problem(ctx
, "Unexpected mesa texture format in"
495 " _mesa_compressed_format_to_glenum()");
502 * Return the address of the pixel at (col, row, img) in a
503 * compressed texture image.
504 * \param col, row, img - image position (3D), should be a multiple of the
505 * format's block size.
506 * \param format - compressed image format
507 * \param width - image width (stride) in pixels
508 * \param image - the image address
509 * \return address of pixel at (row, col, img)
512 _mesa_compressed_image_address(GLint col
, GLint row
, GLint img
,
513 gl_format mesaFormat
,
514 GLsizei width
, const GLubyte
*image
)
516 /* XXX only 2D images implemented, not 3D */
517 const GLuint blockSize
= _mesa_get_format_bytes(mesaFormat
);
521 _mesa_get_format_block_size(mesaFormat
, &bw
, &bh
);
523 ASSERT(col
% bw
== 0);
524 ASSERT(row
% bh
== 0);
526 offset
= ((width
+ bw
- 1) / bw
) * (row
/ bh
) + col
/ bw
;
529 return (GLubyte
*) image
+ offset
;
534 * Return a texel-fetch function for the given format, or NULL if
537 compressed_fetch_func
538 _mesa_get_compressed_fetch_func(gl_format format
)
541 case MESA_FORMAT_RGB_DXT1
:
542 case MESA_FORMAT_RGBA_DXT1
:
543 case MESA_FORMAT_RGBA_DXT3
:
544 case MESA_FORMAT_RGBA_DXT5
:
545 case MESA_FORMAT_SRGB_DXT1
:
546 case MESA_FORMAT_SRGBA_DXT1
:
547 case MESA_FORMAT_SRGBA_DXT3
:
548 case MESA_FORMAT_SRGBA_DXT5
:
549 return _mesa_get_dxt_fetch_func(format
);
550 case MESA_FORMAT_RGB_FXT1
:
551 case MESA_FORMAT_RGBA_FXT1
:
552 return _mesa_get_fxt_fetch_func(format
);
553 case MESA_FORMAT_RED_RGTC1
:
554 case MESA_FORMAT_L_LATC1
:
555 case MESA_FORMAT_SIGNED_RED_RGTC1
:
556 case MESA_FORMAT_SIGNED_L_LATC1
:
557 case MESA_FORMAT_RG_RGTC2
:
558 case MESA_FORMAT_LA_LATC2
:
559 case MESA_FORMAT_SIGNED_RG_RGTC2
:
560 case MESA_FORMAT_SIGNED_LA_LATC2
:
561 return _mesa_get_compressed_rgtc_func(format
);
562 case MESA_FORMAT_ETC1_RGB8
:
563 return _mesa_get_etc_fetch_func(format
);
571 * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
572 * \param srcRowStride stride in bytes between rows of blocks in the
573 * compressed source image.
576 _mesa_decompress_image(gl_format format
, GLuint width
, GLuint height
,
577 const GLubyte
*src
, GLint srcRowStride
,
580 compressed_fetch_func fetch
;
582 GLuint bytes
, bw
, bh
;
585 bytes
= _mesa_get_format_bytes(format
);
586 _mesa_get_format_block_size(format
, &bw
, &bh
);
588 fetch
= _mesa_get_compressed_fetch_func(format
);
590 _mesa_problem(NULL
, "Unexpected format in _mesa_decompress_image()");
594 stride
= srcRowStride
* bh
/ bytes
;
596 for (j
= 0; j
< height
; j
++) {
597 for (i
= 0; i
< width
; i
++) {
598 fetch(src
, stride
, i
, j
, dest
);