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 /* The ES and desktop GL specs diverge here.
269 * In desktop OpenGL, the driver can perform online compression of
270 * uncompressed texture data. GL_NUM_COMPRESSED_TEXTURE_FORMATS and
271 * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
272 * formats that it could ask the driver to compress with some
273 * expectation of quality. The GL_ARB_texture_compression spec
274 * calls this "suitable for general-purpose usage." As noted
275 * above, this means GL_COMPRESSED_RGBA_S3TC_DXT1_EXT is not
276 * included in the list.
278 * In OpenGL ES, the driver never performs compression.
279 * GL_NUM_COMPRESSED_TEXTURE_FORMATS and
280 * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
281 * formats that the driver can receive from the application. It
282 * is the *complete* list of formats. The
283 * GL_EXT_texture_compression_s3tc spec says:
285 * "New State for OpenGL ES 2.0.25 and 3.0.2 Specifications
287 * The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
288 * COMPRESSED_TEXTURE_FORMATS include
289 * COMPRESSED_RGB_S3TC_DXT1_EXT,
290 * COMPRESSED_RGBA_S3TC_DXT1_EXT,
291 * COMPRESSED_RGBA_S3TC_DXT3_EXT, and
292 * COMPRESSED_RGBA_S3TC_DXT5_EXT."
294 * Note that the addition is only to the OpenGL ES specification!
296 if (_mesa_is_gles(ctx
)) {
298 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
305 /* The GL_OES_compressed_ETC1_RGB8_texture spec says:
309 * The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
310 * COMPRESSED_TEXTURE_FORMATS include ETC1_RGB8_OES."
312 if (_mesa_is_gles(ctx
)
313 && ctx
->Extensions
.OES_compressed_ETC1_RGB8_texture
) {
315 formats
[n
++] = GL_ETC1_RGB8_OES
;
322 if (ctx
->API
== API_OPENGLES
) {
324 formats
[n
++] = GL_PALETTE4_RGB8_OES
;
325 formats
[n
++] = GL_PALETTE4_RGBA8_OES
;
326 formats
[n
++] = GL_PALETTE4_R5_G6_B5_OES
;
327 formats
[n
++] = GL_PALETTE4_RGBA4_OES
;
328 formats
[n
++] = GL_PALETTE4_RGB5_A1_OES
;
329 formats
[n
++] = GL_PALETTE8_RGB8_OES
;
330 formats
[n
++] = GL_PALETTE8_RGBA8_OES
;
331 formats
[n
++] = GL_PALETTE8_R5_G6_B5_OES
;
332 formats
[n
++] = GL_PALETTE8_RGBA4_OES
;
333 formats
[n
++] = GL_PALETTE8_RGB5_A1_OES
;
340 if (_mesa_is_gles3(ctx
)) {
342 formats
[n
++] = GL_COMPRESSED_RGB8_ETC2
;
343 formats
[n
++] = GL_COMPRESSED_SRGB8_ETC2
;
344 formats
[n
++] = GL_COMPRESSED_RGBA8_ETC2_EAC
;
345 formats
[n
++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
;
346 formats
[n
++] = GL_COMPRESSED_R11_EAC
;
347 formats
[n
++] = GL_COMPRESSED_RG11_EAC
;
348 formats
[n
++] = GL_COMPRESSED_SIGNED_R11_EAC
;
349 formats
[n
++] = GL_COMPRESSED_SIGNED_RG11_EAC
;
350 formats
[n
++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
351 formats
[n
++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
362 * Convert a compressed MESA_FORMAT_x to a GLenum.
365 _mesa_glenum_to_compressed_format(GLenum format
)
368 case GL_COMPRESSED_RGB_FXT1_3DFX
:
369 return MESA_FORMAT_RGB_FXT1
;
370 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
371 return MESA_FORMAT_RGBA_FXT1
;
373 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
375 return MESA_FORMAT_RGB_DXT1
;
376 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
378 return MESA_FORMAT_RGBA_DXT1
;
379 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
381 return MESA_FORMAT_RGBA_DXT3
;
382 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
384 return MESA_FORMAT_RGBA_DXT5
;
386 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
387 return MESA_FORMAT_SRGB_DXT1
;
388 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
389 return MESA_FORMAT_SRGBA_DXT1
;
390 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
391 return MESA_FORMAT_SRGBA_DXT3
;
392 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
393 return MESA_FORMAT_SRGBA_DXT5
;
395 case GL_COMPRESSED_RED_RGTC1
:
396 return MESA_FORMAT_R_RGTC1_UNORM
;
397 case GL_COMPRESSED_SIGNED_RED_RGTC1
:
398 return MESA_FORMAT_R_RGTC1_SNORM
;
399 case GL_COMPRESSED_RG_RGTC2
:
400 return MESA_FORMAT_RG_RGTC2_UNORM
;
401 case GL_COMPRESSED_SIGNED_RG_RGTC2
:
402 return MESA_FORMAT_RG_RGTC2_SNORM
;
404 case GL_COMPRESSED_LUMINANCE_LATC1_EXT
:
405 return MESA_FORMAT_L_LATC1_UNORM
;
406 case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
:
407 return MESA_FORMAT_L_LATC1_SNORM
;
408 case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
:
409 case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI
:
410 return MESA_FORMAT_LA_LATC2_UNORM
;
411 case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
:
412 return MESA_FORMAT_LA_LATC2_SNORM
;
414 case GL_ETC1_RGB8_OES
:
415 return MESA_FORMAT_ETC1_RGB8
;
416 case GL_COMPRESSED_RGB8_ETC2
:
417 return MESA_FORMAT_ETC2_RGB8
;
418 case GL_COMPRESSED_SRGB8_ETC2
:
419 return MESA_FORMAT_ETC2_SRGB8
;
420 case GL_COMPRESSED_RGBA8_ETC2_EAC
:
421 return MESA_FORMAT_ETC2_RGBA8_EAC
;
422 case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
:
423 return MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC
;
424 case GL_COMPRESSED_R11_EAC
:
425 return MESA_FORMAT_ETC2_R11_EAC
;
426 case GL_COMPRESSED_RG11_EAC
:
427 return MESA_FORMAT_ETC2_RG11_EAC
;
428 case GL_COMPRESSED_SIGNED_R11_EAC
:
429 return MESA_FORMAT_ETC2_SIGNED_R11_EAC
;
430 case GL_COMPRESSED_SIGNED_RG11_EAC
:
431 return MESA_FORMAT_ETC2_SIGNED_RG11_EAC
;
432 case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
433 return MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1
;
434 case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
:
435 return MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1
;
438 return MESA_FORMAT_NONE
;
444 * Given a compressed MESA_FORMAT_x value, return the corresponding
445 * GLenum for that format.
446 * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
447 * which must return the specific texture format used when the user might
448 * have originally specified a generic compressed format in their
449 * glTexImage2D() call.
450 * For non-compressed textures, we always return the user-specified
451 * internal format unchanged.
454 _mesa_compressed_format_to_glenum(struct gl_context
*ctx
, mesa_format mesaFormat
)
456 switch (mesaFormat
) {
457 case MESA_FORMAT_RGB_FXT1
:
458 return GL_COMPRESSED_RGB_FXT1_3DFX
;
459 case MESA_FORMAT_RGBA_FXT1
:
460 return GL_COMPRESSED_RGBA_FXT1_3DFX
;
461 case MESA_FORMAT_RGB_DXT1
:
462 return GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
463 case MESA_FORMAT_RGBA_DXT1
:
464 return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
465 case MESA_FORMAT_RGBA_DXT3
:
466 return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
467 case MESA_FORMAT_RGBA_DXT5
:
468 return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
469 case MESA_FORMAT_SRGB_DXT1
:
470 return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
471 case MESA_FORMAT_SRGBA_DXT1
:
472 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
473 case MESA_FORMAT_SRGBA_DXT3
:
474 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
475 case MESA_FORMAT_SRGBA_DXT5
:
476 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
477 case MESA_FORMAT_R_RGTC1_UNORM
:
478 return GL_COMPRESSED_RED_RGTC1
;
479 case MESA_FORMAT_R_RGTC1_SNORM
:
480 return GL_COMPRESSED_SIGNED_RED_RGTC1
;
481 case MESA_FORMAT_RG_RGTC2_UNORM
:
482 return GL_COMPRESSED_RG_RGTC2
;
483 case MESA_FORMAT_RG_RGTC2_SNORM
:
484 return GL_COMPRESSED_SIGNED_RG_RGTC2
;
486 case MESA_FORMAT_L_LATC1_UNORM
:
487 return GL_COMPRESSED_LUMINANCE_LATC1_EXT
;
488 case MESA_FORMAT_L_LATC1_SNORM
:
489 return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
;
490 case MESA_FORMAT_LA_LATC2_UNORM
:
491 return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
;
492 case MESA_FORMAT_LA_LATC2_SNORM
:
493 return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
;
495 case MESA_FORMAT_ETC1_RGB8
:
496 return GL_ETC1_RGB8_OES
;
497 case MESA_FORMAT_ETC2_RGB8
:
498 return GL_COMPRESSED_RGB8_ETC2
;
499 case MESA_FORMAT_ETC2_SRGB8
:
500 return GL_COMPRESSED_SRGB8_ETC2
;
501 case MESA_FORMAT_ETC2_RGBA8_EAC
:
502 return GL_COMPRESSED_RGBA8_ETC2_EAC
;
503 case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC
:
504 return GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
;
505 case MESA_FORMAT_ETC2_R11_EAC
:
506 return GL_COMPRESSED_R11_EAC
;
507 case MESA_FORMAT_ETC2_RG11_EAC
:
508 return GL_COMPRESSED_RG11_EAC
;
509 case MESA_FORMAT_ETC2_SIGNED_R11_EAC
:
510 return GL_COMPRESSED_SIGNED_R11_EAC
;
511 case MESA_FORMAT_ETC2_SIGNED_RG11_EAC
:
512 return GL_COMPRESSED_SIGNED_RG11_EAC
;
513 case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1
:
514 return GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
515 case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1
:
516 return GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
;
519 _mesa_problem(ctx
, "Unexpected mesa texture format in"
520 " _mesa_compressed_format_to_glenum()");
527 * Return the address of the pixel at (col, row, img) in a
528 * compressed texture image.
529 * \param col, row, img - image position (3D), should be a multiple of the
530 * format's block size.
531 * \param format - compressed image format
532 * \param width - image width (stride) in pixels
533 * \param image - the image address
534 * \return address of pixel at (row, col, img)
537 _mesa_compressed_image_address(GLint col
, GLint row
, GLint img
,
538 mesa_format mesaFormat
,
539 GLsizei width
, const GLubyte
*image
)
541 /* XXX only 2D images implemented, not 3D */
542 const GLuint blockSize
= _mesa_get_format_bytes(mesaFormat
);
546 _mesa_get_format_block_size(mesaFormat
, &bw
, &bh
);
548 ASSERT(col
% bw
== 0);
549 ASSERT(row
% bh
== 0);
551 offset
= ((width
+ bw
- 1) / bw
) * (row
/ bh
) + col
/ bw
;
554 return (GLubyte
*) image
+ offset
;
559 * Return a texel-fetch function for the given format, or NULL if
562 compressed_fetch_func
563 _mesa_get_compressed_fetch_func(mesa_format format
)
566 case MESA_FORMAT_RGB_DXT1
:
567 case MESA_FORMAT_RGBA_DXT1
:
568 case MESA_FORMAT_RGBA_DXT3
:
569 case MESA_FORMAT_RGBA_DXT5
:
570 case MESA_FORMAT_SRGB_DXT1
:
571 case MESA_FORMAT_SRGBA_DXT1
:
572 case MESA_FORMAT_SRGBA_DXT3
:
573 case MESA_FORMAT_SRGBA_DXT5
:
574 return _mesa_get_dxt_fetch_func(format
);
575 case MESA_FORMAT_RGB_FXT1
:
576 case MESA_FORMAT_RGBA_FXT1
:
577 return _mesa_get_fxt_fetch_func(format
);
578 case MESA_FORMAT_R_RGTC1_UNORM
:
579 case MESA_FORMAT_L_LATC1_UNORM
:
580 case MESA_FORMAT_R_RGTC1_SNORM
:
581 case MESA_FORMAT_L_LATC1_SNORM
:
582 case MESA_FORMAT_RG_RGTC2_UNORM
:
583 case MESA_FORMAT_LA_LATC2_UNORM
:
584 case MESA_FORMAT_RG_RGTC2_SNORM
:
585 case MESA_FORMAT_LA_LATC2_SNORM
:
586 return _mesa_get_compressed_rgtc_func(format
);
587 case MESA_FORMAT_ETC1_RGB8
:
588 return _mesa_get_etc_fetch_func(format
);
596 * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
597 * \param srcRowStride stride in bytes between rows of blocks in the
598 * compressed source image.
601 _mesa_decompress_image(mesa_format format
, GLuint width
, GLuint height
,
602 const GLubyte
*src
, GLint srcRowStride
,
605 compressed_fetch_func fetch
;
607 GLuint bytes
, bw
, bh
;
610 bytes
= _mesa_get_format_bytes(format
);
611 _mesa_get_format_block_size(format
, &bw
, &bh
);
613 fetch
= _mesa_get_compressed_fetch_func(format
);
615 _mesa_problem(NULL
, "Unexpected format in _mesa_decompress_image()");
619 stride
= srcRowStride
* bh
/ bytes
;
621 for (j
= 0; j
< height
; j
++) {
622 for (i
= 0; i
< width
; i
++) {
623 fetch(src
, stride
, i
, j
, dest
);