2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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
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14 * The above copyright notice and this permission notice shall be included
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22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
28 * Helper functions for texture compression.
38 #include "texcompress.h"
39 #include "texformat.h"
44 * Return list of (and count of) all specific texture compression
45 * formats that are supported.
47 * \param ctx the GL context
48 * \param formats the resulting format list (may be NULL).
49 * \param all if true return all formats, even those with some kind
50 * of restrictions/limitations (See GL_ARB_texture_compression
51 * spec for more info).
53 * \return number of formats.
56 _mesa_get_compressed_formats(GLcontext
*ctx
, GLint
*formats
, GLboolean all
)
59 if (ctx
->Extensions
.ARB_texture_compression
) {
60 if (ctx
->Extensions
.TDFX_texture_compression_FXT1
) {
62 formats
[n
++] = GL_COMPRESSED_RGB_FXT1_3DFX
;
63 formats
[n
++] = GL_COMPRESSED_RGBA_FXT1_3DFX
;
69 if (ctx
->Extensions
.EXT_texture_compression_s3tc
) {
71 formats
[n
++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
72 /* This format has some restrictions/limitations and so should
73 * not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
74 * Specifically, all transparent pixels become black. NVIDIA
75 * omits this format too.
78 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
79 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
80 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
88 if (ctx
->Extensions
.S3_s3tc
) {
90 formats
[n
++] = GL_RGB_S3TC
;
91 formats
[n
++] = GL_RGB4_S3TC
;
92 formats
[n
++] = GL_RGBA_S3TC
;
93 formats
[n
++] = GL_RGBA4_S3TC
;
99 #if FEATURE_EXT_texture_sRGB
100 if (ctx
->Extensions
.EXT_texture_sRGB
) {
102 formats
[n
++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
103 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
104 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
105 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
111 #endif /* FEATURE_EXT_texture_sRGB */
119 * Return number of bytes needed to store a texture of the given size
120 * using the specified compressed format.
121 * This is called via the ctx->Driver.CompressedTextureSize function,
122 * unless a device driver overrides it.
124 * \param width texture width in texels.
125 * \param height texture height in texels.
126 * \param depth texture depth in texels.
127 * \param mesaFormat one of the MESA_FORMAT_* compressed formats
129 * \return size in bytes, or zero if bad format
132 _mesa_compressed_texture_size( GLcontext
*ctx
,
133 GLsizei width
, GLsizei height
, GLsizei depth
,
141 switch (mesaFormat
) {
142 case MESA_FORMAT_RGB_FXT1
:
143 case MESA_FORMAT_RGBA_FXT1
:
144 /* round up width to next multiple of 8, height to next multiple of 4 */
145 width
= (width
+ 7) & ~7;
146 height
= (height
+ 3) & ~3;
147 /* 16 bytes per 8x4 tile of RGB[A] texels */
148 size
= width
* height
/ 2;
149 /* Textures smaller than 8x4 will effectively be made into 8x4 and
153 case MESA_FORMAT_RGB_DXT1
:
154 case MESA_FORMAT_RGBA_DXT1
:
155 /* round up width, height to next multiple of 4 */
156 width
= (width
+ 3) & ~3;
157 height
= (height
+ 3) & ~3;
158 /* 8 bytes per 4x4 tile of RGB[A] texels */
159 size
= width
* height
/ 2;
160 /* Textures smaller than 4x4 will effectively be made into 4x4 and
164 case MESA_FORMAT_RGBA_DXT3
:
165 case MESA_FORMAT_RGBA_DXT5
:
166 /* round up width, height to next multiple of 4 */
167 width
= (width
+ 3) & ~3;
168 height
= (height
+ 3) & ~3;
169 /* 16 bytes per 4x4 tile of RGBA texels */
170 size
= width
* height
; /* simple! */
171 /* Textures smaller than 4x4 will effectively be made into 4x4 and
176 _mesa_problem(ctx
, "bad mesaFormat in _mesa_compressed_texture_size");
183 * As above, but format is specified by a GLenum (GL_COMPRESSED_*) token.
185 * Note: This function CAN NOT return a padded hardware texture size.
186 * That's why we don't call the ctx->Driver.CompressedTextureSize() function.
188 * We use this function to validate the <imageSize> parameter
189 * of glCompressedTex[Sub]Image1/2/3D(), which must be an exact match.
192 _mesa_compressed_texture_size_glenum(GLcontext
*ctx
,
193 GLsizei width
, GLsizei height
,
194 GLsizei depth
, GLenum glformat
)
199 case GL_COMPRESSED_RGB_FXT1_3DFX
:
200 mesaFormat
= MESA_FORMAT_RGB_FXT1
;
202 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
203 mesaFormat
= MESA_FORMAT_RGBA_FXT1
;
205 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
207 mesaFormat
= MESA_FORMAT_RGB_DXT1
;
209 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
211 mesaFormat
= MESA_FORMAT_RGBA_DXT1
;
213 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
215 mesaFormat
= MESA_FORMAT_RGBA_DXT3
;
217 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
219 mesaFormat
= MESA_FORMAT_RGBA_DXT5
;
225 return _mesa_compressed_texture_size(ctx
, width
, height
, depth
, mesaFormat
);
230 * Compute the bytes per row in a compressed texture image.
231 * We use this for computing the destination address for sub-texture updates.
232 * \param mesaFormat one of the MESA_FORMAT_* compressed formats
233 * \param width image width in pixels
234 * \return stride, in bytes, between rows for compressed image
237 _mesa_compressed_row_stride(GLuint mesaFormat
, GLsizei width
)
241 switch (mesaFormat
) {
242 case MESA_FORMAT_RGB_FXT1
:
243 case MESA_FORMAT_RGBA_FXT1
:
244 stride
= ((width
+ 7) / 8) * 16; /* 16 bytes per 8x4 tile */
246 case MESA_FORMAT_RGB_DXT1
:
247 case MESA_FORMAT_RGBA_DXT1
:
248 stride
= ((width
+ 3) / 4) * 8; /* 8 bytes per 4x4 tile */
250 case MESA_FORMAT_RGBA_DXT3
:
251 case MESA_FORMAT_RGBA_DXT5
:
252 stride
= ((width
+ 3) / 4) * 16; /* 16 bytes per 4x4 tile */
255 _mesa_problem(NULL
, "bad mesaFormat in _mesa_compressed_row_stride");
264 * Return the address of the pixel at (col, row, img) in a
265 * compressed texture image.
266 * \param col, row, img - image position (3D)
267 * \param format - compressed image format
268 * \param width - image width
269 * \param image - the image address
270 * \return address of pixel at (row, col)
273 _mesa_compressed_image_address(GLint col
, GLint row
, GLint img
,
275 GLsizei width
, const GLubyte
*image
)
281 /* We try to spot a "complete" subtexture "above" ROW, COL;
282 * this texture is given by appropriate rounding of WIDTH x ROW.
283 * Then we just add the amount left (usually on the left).
285 * Example for X*Y microtiles (Z bytes each)
286 * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
289 switch (mesaFormat
) {
290 case MESA_FORMAT_RGB_FXT1
:
291 case MESA_FORMAT_RGBA_FXT1
:
292 addr
= (GLubyte
*) image
+ 16 * (((width
+ 7) / 8) * (row
/ 4) + col
/ 8);
294 case MESA_FORMAT_RGB_DXT1
:
295 case MESA_FORMAT_RGBA_DXT1
:
296 addr
= (GLubyte
*) image
+ 8 * (((width
+ 3) / 4) * (row
/ 4) + col
/ 4);
298 case MESA_FORMAT_RGBA_DXT3
:
299 case MESA_FORMAT_RGBA_DXT5
:
300 addr
= (GLubyte
*) image
+ 16 * (((width
+ 3) / 4) * (row
/ 4) + col
/ 4);
303 _mesa_problem(NULL
, "bad mesaFormat in _mesa_compressed_image_address");