2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
6 * Copyright (c) 2008 VMware, Inc.
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 * Helper functions for texture compression.
37 #include "mfeatures.h"
39 #include "texcompress.h"
40 #include "texcompress_fxt1.h"
41 #include "texcompress_rgtc.h"
42 #include "texcompress_s3tc.h"
43 #include "swrast/s_context.h"
47 * Get the GL base format of a specified GL compressed texture format
49 * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec:
51 * "Compressed Internal Format Base Internal Format Type
52 * --------------------------- -------------------- ---------
53 * COMPRESSED_ALPHA ALPHA Generic
54 * COMPRESSED_LUMINANCE LUMINANCE Generic
55 * COMPRESSED_LUMINANCE_ALPHA LUMINANCE_ALPHA Generic
56 * COMPRESSED_INTENSITY INTENSITY Generic
57 * COMPRESSED_RED RED Generic
58 * COMPRESSED_RG RG Generic
59 * COMPRESSED_RGB RGB Generic
60 * COMPRESSED_RGBA RGBA Generic
61 * COMPRESSED_SRGB RGB Generic
62 * COMPRESSED_SRGB_ALPHA RGBA Generic
63 * COMPRESSED_SLUMINANCE LUMINANCE Generic
64 * COMPRESSED_SLUMINANCE_ALPHA LUMINANCE_ALPHA Generic
65 * COMPRESSED_RED_RGTC1 RED Specific
66 * COMPRESSED_SIGNED_RED_RGTC1 RED Specific
67 * COMPRESSED_RG_RGTC2 RG Specific
68 * COMPRESSED_SIGNED_RG_RGTC2 RG Specific"
71 * The base format of \c format if \c format is a compressed format (either
72 * generic or specific. Otherwise 0 is returned.
75 _mesa_gl_compressed_format_base_format(GLenum format
)
78 case GL_COMPRESSED_RED
:
79 case GL_COMPRESSED_RED_RGTC1
:
80 case GL_COMPRESSED_SIGNED_RED_RGTC1
:
83 case GL_COMPRESSED_RG
:
84 case GL_COMPRESSED_RG_RGTC2
:
85 case GL_COMPRESSED_SIGNED_RG_RGTC2
:
88 case GL_COMPRESSED_RGB
:
89 case GL_COMPRESSED_SRGB
:
90 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
91 case GL_COMPRESSED_RGB_FXT1_3DFX
:
92 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
95 case GL_COMPRESSED_RGBA
:
96 case GL_COMPRESSED_SRGB_ALPHA
:
97 case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB
:
98 case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB
:
99 case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB
:
100 case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB
:
101 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
102 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
103 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
104 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
105 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
106 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
107 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
110 case GL_COMPRESSED_ALPHA
:
113 case GL_COMPRESSED_LUMINANCE
:
114 case GL_COMPRESSED_SLUMINANCE
:
115 case GL_COMPRESSED_LUMINANCE_LATC1_EXT
:
116 case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
:
119 case GL_COMPRESSED_LUMINANCE_ALPHA
:
120 case GL_COMPRESSED_SLUMINANCE_ALPHA
:
121 case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
:
122 case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
:
123 case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI
:
124 return GL_LUMINANCE_ALPHA
;
126 case GL_COMPRESSED_INTENSITY
:
135 * Return list of (and count of) all specific texture compression
136 * formats that are supported.
138 * Some formats are \b not returned by this function. The
139 * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
140 * "suitable for general-purpose usage." All texture compression extensions
141 * have taken this to mean either linear RGB or linear RGBA.
143 * The GL_ARB_texture_compress_rgtc spec says:
145 * "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
146 * GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
150 * The OpenGL 2.1 specification says "The only values returned
151 * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
152 * corresponding to formats suitable for general-purpose usage.
153 * The renderer will not enumerate formats with restrictions that
154 * need to be specifically understood prior to use."
156 * Compressed textures with just red or red-green components are
157 * not general-purpose so should not be returned by these queries
158 * because they have restrictions.
160 * Applications that seek to use the RGTC formats should do so
161 * by looking for this extension's name in the string returned by
162 * glGetString(GL_EXTENSIONS) rather than
163 * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
164 * GL_COMPRESSED_TEXTURE_FORMATS return."
166 * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
169 * The GL_EXT_texture_rRGB spec says:
171 * "22) Should the new COMPRESSED_SRGB_* formats be listed in an
172 * implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
174 * RESOLVED: No. Section 3.8.1 says formats listed by
175 * GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
176 * usage." The non-linear distribution of red, green, and
177 * blue for these sRGB compressed formats makes them not really
180 * The GL_EXT_texture_compression_latc spec says:
182 * "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
183 * GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
187 * The OpenGL 2.1 specification says "The only values returned
188 * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
189 * corresponding to formats suitable for general-purpose usage.
190 * The renderer will not enumerate formats with restrictions that
191 * need to be specifically understood prior to use."
193 * Historically, OpenGL implementation have advertised the RGB and
194 * RGBA versions of the S3TC extensions compressed format tokens
195 * through this mechanism.
197 * The specification is not sufficiently clear about what "suitable
198 * for general-purpose usage" means. Historically that seems to mean
199 * unsigned RGB or unsigned RGBA. The DXT1 format supporting alpha
200 * (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
201 * least for NVIDIA drivers) because the alpha is always 1.0 expect
202 * when it is 0.0 when RGB is required to be black. NVIDIA's even
203 * limits itself to true linear RGB or RGBA formats, specifically
204 * not including EXT_texture_sRGB's sRGB S3TC compressed formats.
206 * Adding luminance and luminance-alpha texture formats (and
207 * certainly signed versions of luminance and luminance-alpha
208 * formats!) invites potential comptaibility problems with old
209 * applications using this mechanism since old applications are
210 * unlikely to expect non-RGB or non-RGBA formats to be advertised
211 * through this mechanism. However no specific misinteractions
212 * with old applications is known.
214 * Applications that seek to use the LATC formats should do so
215 * by looking for this extension's name in the string returned by
216 * glGetString(GL_EXTENSIONS) rather than
217 * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
218 * GL_COMPRESSED_TEXTURE_FORMATS return."
220 * There is no formal spec for GL_ATI_texture_compression_3dc. Since the
221 * formats added by this extension are luminance-alpha formats, it is
222 * reasonable to expect them to follow the same rules as
223 * GL_EXT_texture_compression_latc. At the very least, Catalyst 11.6 does not
224 * expose the 3dc formats through this mechanism.
226 * \param ctx the GL context
227 * \param formats the resulting format list (may be NULL).
229 * \return number of formats.
232 _mesa_get_compressed_formats(struct gl_context
*ctx
, GLint
*formats
)
235 if (ctx
->Extensions
.TDFX_texture_compression_FXT1
) {
237 formats
[n
++] = GL_COMPRESSED_RGB_FXT1_3DFX
;
238 formats
[n
++] = GL_COMPRESSED_RGBA_FXT1_3DFX
;
245 if (ctx
->Extensions
.EXT_texture_compression_s3tc
) {
247 formats
[n
++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
248 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
249 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
255 if (ctx
->Extensions
.S3_s3tc
) {
257 formats
[n
++] = GL_RGB_S3TC
;
258 formats
[n
++] = GL_RGB4_S3TC
;
259 formats
[n
++] = GL_RGBA_S3TC
;
260 formats
[n
++] = GL_RGBA4_S3TC
;
272 * Convert a compressed MESA_FORMAT_x to a GLenum.
275 _mesa_glenum_to_compressed_format(GLenum format
)
278 case GL_COMPRESSED_RGB_FXT1_3DFX
:
279 return MESA_FORMAT_RGB_FXT1
;
280 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
281 return MESA_FORMAT_RGBA_FXT1
;
283 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
285 return MESA_FORMAT_RGB_DXT1
;
286 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
288 return MESA_FORMAT_RGBA_DXT1
;
289 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
291 return MESA_FORMAT_RGBA_DXT3
;
292 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
294 return MESA_FORMAT_RGBA_DXT5
;
296 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
297 return MESA_FORMAT_SRGB_DXT1
;
298 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
299 return MESA_FORMAT_SRGBA_DXT1
;
300 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
301 return MESA_FORMAT_SRGBA_DXT3
;
302 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
303 return MESA_FORMAT_SRGBA_DXT5
;
305 case GL_COMPRESSED_RED_RGTC1
:
306 return MESA_FORMAT_RED_RGTC1
;
307 case GL_COMPRESSED_SIGNED_RED_RGTC1
:
308 return MESA_FORMAT_SIGNED_RED_RGTC1
;
309 case GL_COMPRESSED_RG_RGTC2
:
310 return MESA_FORMAT_RG_RGTC2
;
311 case GL_COMPRESSED_SIGNED_RG_RGTC2
:
312 return MESA_FORMAT_SIGNED_RG_RGTC2
;
314 case GL_COMPRESSED_LUMINANCE_LATC1_EXT
:
315 return MESA_FORMAT_L_LATC1
;
316 case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
:
317 return MESA_FORMAT_SIGNED_L_LATC1
;
318 case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
:
319 case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI
:
320 return MESA_FORMAT_LA_LATC2
;
321 case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
:
322 return MESA_FORMAT_SIGNED_LA_LATC2
;
325 return MESA_FORMAT_NONE
;
331 * Given a compressed MESA_FORMAT_x value, return the corresponding
332 * GLenum for that format.
333 * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
334 * which must return the specific texture format used when the user might
335 * have originally specified a generic compressed format in their
336 * glTexImage2D() call.
337 * For non-compressed textures, we always return the user-specified
338 * internal format unchanged.
341 _mesa_compressed_format_to_glenum(struct gl_context
*ctx
, GLuint mesaFormat
)
343 switch (mesaFormat
) {
344 #if FEATURE_texture_fxt1
345 case MESA_FORMAT_RGB_FXT1
:
346 return GL_COMPRESSED_RGB_FXT1_3DFX
;
347 case MESA_FORMAT_RGBA_FXT1
:
348 return GL_COMPRESSED_RGBA_FXT1_3DFX
;
350 #if FEATURE_texture_s3tc
351 case MESA_FORMAT_RGB_DXT1
:
352 return GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
353 case MESA_FORMAT_RGBA_DXT1
:
354 return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
355 case MESA_FORMAT_RGBA_DXT3
:
356 return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
357 case MESA_FORMAT_RGBA_DXT5
:
358 return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
359 #if FEATURE_EXT_texture_sRGB
360 case MESA_FORMAT_SRGB_DXT1
:
361 return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
362 case MESA_FORMAT_SRGBA_DXT1
:
363 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
364 case MESA_FORMAT_SRGBA_DXT3
:
365 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
366 case MESA_FORMAT_SRGBA_DXT5
:
367 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
371 case MESA_FORMAT_RED_RGTC1
:
372 return GL_COMPRESSED_RED_RGTC1
;
373 case MESA_FORMAT_SIGNED_RED_RGTC1
:
374 return GL_COMPRESSED_SIGNED_RED_RGTC1
;
375 case MESA_FORMAT_RG_RGTC2
:
376 return GL_COMPRESSED_RG_RGTC2
;
377 case MESA_FORMAT_SIGNED_RG_RGTC2
:
378 return GL_COMPRESSED_SIGNED_RG_RGTC2
;
380 case MESA_FORMAT_L_LATC1
:
381 return GL_COMPRESSED_LUMINANCE_LATC1_EXT
;
382 case MESA_FORMAT_SIGNED_L_LATC1
:
383 return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT
;
384 case MESA_FORMAT_LA_LATC2
:
385 return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT
;
386 case MESA_FORMAT_SIGNED_LA_LATC2
:
387 return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT
;
390 _mesa_problem(ctx
, "Unexpected mesa texture format in"
391 " _mesa_compressed_format_to_glenum()");
398 * Return the address of the pixel at (col, row, img) in a
399 * compressed texture image.
400 * \param col, row, img - image position (3D), should be a multiple of the
401 * format's block size.
402 * \param format - compressed image format
403 * \param width - image width (stride) in pixels
404 * \param image - the image address
405 * \return address of pixel at (row, col, img)
408 _mesa_compressed_image_address(GLint col
, GLint row
, GLint img
,
409 gl_format mesaFormat
,
410 GLsizei width
, const GLubyte
*image
)
412 /* XXX only 2D images implemented, not 3D */
413 const GLuint blockSize
= _mesa_get_format_bytes(mesaFormat
);
417 _mesa_get_format_block_size(mesaFormat
, &bw
, &bh
);
419 ASSERT(col
% bw
== 0);
420 ASSERT(row
% bh
== 0);
422 offset
= ((width
+ bw
- 1) / bw
) * (row
/ bh
) + col
/ bw
;
425 return (GLubyte
*) image
+ offset
;
430 * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
433 _mesa_decompress_image(gl_format format
, GLuint width
, GLuint height
,
434 const GLubyte
*src
, GLint srcRowStride
,
437 void (*fetch
)(const struct swrast_texture_image
*texImage
,
438 GLint i
, GLint j
, GLint k
, GLfloat
*texel
);
439 struct swrast_texture_image texImage
; /* dummy teximage */
442 /* setup dummy texture image info */
443 memset(&texImage
, 0, sizeof(texImage
));
444 texImage
.Map
= (void *) src
;
445 texImage
.RowStride
= srcRowStride
;
449 case MESA_FORMAT_RGB_DXT1
:
450 fetch
= _mesa_fetch_texel_2d_f_rgb_dxt1
;
452 case MESA_FORMAT_RGBA_DXT1
:
453 fetch
= _mesa_fetch_texel_2d_f_rgba_dxt1
;
455 case MESA_FORMAT_RGBA_DXT3
:
456 fetch
= _mesa_fetch_texel_2d_f_rgba_dxt3
;
458 case MESA_FORMAT_RGBA_DXT5
:
459 fetch
= _mesa_fetch_texel_2d_f_rgba_dxt5
;
463 case MESA_FORMAT_RGB_FXT1
:
464 fetch
= _mesa_fetch_texel_2d_f_rgb_fxt1
;
466 case MESA_FORMAT_RGBA_FXT1
:
467 fetch
= _mesa_fetch_texel_2d_f_rgba_fxt1
;
471 case MESA_FORMAT_RED_RGTC1
:
472 fetch
= _mesa_fetch_texel_2d_f_red_rgtc1
;
474 case MESA_FORMAT_SIGNED_RED_RGTC1
:
475 fetch
= _mesa_fetch_texel_2d_f_signed_red_rgtc1
;
477 case MESA_FORMAT_RG_RGTC2
:
478 fetch
= _mesa_fetch_texel_2d_f_rg_rgtc2
;
480 case MESA_FORMAT_SIGNED_RG_RGTC2
:
481 fetch
= _mesa_fetch_texel_2d_f_signed_rg_rgtc2
;
485 case MESA_FORMAT_L_LATC1
:
486 fetch
= _mesa_fetch_texel_2d_f_l_latc1
;
488 case MESA_FORMAT_SIGNED_L_LATC1
:
489 fetch
= _mesa_fetch_texel_2d_f_signed_l_latc1
;
491 case MESA_FORMAT_LA_LATC2
:
492 fetch
= _mesa_fetch_texel_2d_f_la_latc2
;
494 case MESA_FORMAT_SIGNED_LA_LATC2
:
495 fetch
= _mesa_fetch_texel_2d_f_signed_la_latc2
;
499 _mesa_problem(NULL
, "Unexpected format in _mesa_decompress_image()");
503 for (j
= 0; j
< height
; j
++) {
504 for (i
= 0; i
< width
; i
++) {
505 fetch(&texImage
, i
, j
, 0, dest
);