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.
38 #include "texcompress.h"
42 * Return list of (and count of) all specific texture compression
43 * formats that are supported.
45 * \param ctx the GL context
46 * \param formats the resulting format list (may be NULL).
47 * \param all if true return all formats, even those with some kind
48 * of restrictions/limitations (See GL_ARB_texture_compression
49 * spec for more info).
51 * \return number of formats.
54 _mesa_get_compressed_formats(GLcontext
*ctx
, GLint
*formats
, GLboolean all
)
57 if (ctx
->Extensions
.TDFX_texture_compression_FXT1
) {
59 formats
[n
++] = GL_COMPRESSED_RGB_FXT1_3DFX
;
60 formats
[n
++] = GL_COMPRESSED_RGBA_FXT1_3DFX
;
66 if (ctx
->Extensions
.EXT_texture_compression_s3tc
) {
68 formats
[n
++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
69 /* This format has some restrictions/limitations and so should
70 * not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
71 * Specifically, all transparent pixels become black. NVIDIA
72 * omits this format too.
75 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
76 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
77 formats
[n
++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
85 if (ctx
->Extensions
.S3_s3tc
) {
87 formats
[n
++] = GL_RGB_S3TC
;
88 formats
[n
++] = GL_RGB4_S3TC
;
89 formats
[n
++] = GL_RGBA_S3TC
;
90 formats
[n
++] = GL_RGBA4_S3TC
;
96 #if FEATURE_EXT_texture_sRGB
97 if (ctx
->Extensions
.EXT_texture_sRGB
) {
99 formats
[n
++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
100 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
101 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
102 formats
[n
++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
108 #endif /* FEATURE_EXT_texture_sRGB */
114 * Convert a compressed MESA_FORMAT_x to a GLenum.
117 _mesa_glenum_to_compressed_format(GLenum format
)
120 case GL_COMPRESSED_RGB_FXT1_3DFX
:
121 return MESA_FORMAT_RGB_FXT1
;
122 case GL_COMPRESSED_RGBA_FXT1_3DFX
:
123 return MESA_FORMAT_RGBA_FXT1
;
125 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT
:
127 return MESA_FORMAT_RGB_DXT1
;
128 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
:
130 return MESA_FORMAT_RGBA_DXT1
;
131 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
:
133 return MESA_FORMAT_RGBA_DXT3
;
134 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
:
136 return MESA_FORMAT_RGBA_DXT5
;
138 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
:
139 return MESA_FORMAT_SRGB_DXT1
;
140 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
:
141 return MESA_FORMAT_SRGBA_DXT1
;
142 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
:
143 return MESA_FORMAT_SRGBA_DXT3
;
144 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
:
145 return MESA_FORMAT_SRGBA_DXT5
;
148 return MESA_FORMAT_NONE
;
154 * Given a compressed MESA_FORMAT_x value, return the corresponding
155 * GLenum for that format.
156 * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
157 * which must return the specific texture format used when the user might
158 * have originally specified a generic compressed format in their
159 * glTexImage2D() call.
160 * For non-compressed textures, we always return the user-specified
161 * internal format unchanged.
164 _mesa_compressed_format_to_glenum(GLcontext
*ctx
, GLuint mesaFormat
)
166 switch (mesaFormat
) {
167 #if FEATURE_texture_fxt1
168 case MESA_FORMAT_RGB_FXT1
:
169 return GL_COMPRESSED_RGB_FXT1_3DFX
;
170 case MESA_FORMAT_RGBA_FXT1
:
171 return GL_COMPRESSED_RGBA_FXT1_3DFX
;
173 #if FEATURE_texture_s3tc
174 case MESA_FORMAT_RGB_DXT1
:
175 return GL_COMPRESSED_RGB_S3TC_DXT1_EXT
;
176 case MESA_FORMAT_RGBA_DXT1
:
177 return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
;
178 case MESA_FORMAT_RGBA_DXT3
:
179 return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
;
180 case MESA_FORMAT_RGBA_DXT5
:
181 return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
;
182 #if FEATURE_EXT_texture_sRGB
183 case MESA_FORMAT_SRGB_DXT1
:
184 return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
;
185 case MESA_FORMAT_SRGBA_DXT1
:
186 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
;
187 case MESA_FORMAT_SRGBA_DXT3
:
188 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
;
189 case MESA_FORMAT_SRGBA_DXT5
:
190 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
;
194 _mesa_problem(ctx
, "Unexpected mesa texture format in"
195 " _mesa_compressed_format_to_glenum()");
202 * Return the address of the pixel at (col, row, img) in a
203 * compressed texture image.
204 * \param col, row, img - image position (3D), should be a multiple of the
205 * format's block size.
206 * \param format - compressed image format
207 * \param width - image width (stride) in pixels
208 * \param image - the image address
209 * \return address of pixel at (row, col, img)
212 _mesa_compressed_image_address(GLint col
, GLint row
, GLint img
,
213 gl_format mesaFormat
,
214 GLsizei width
, const GLubyte
*image
)
216 /* XXX only 2D images implemented, not 3D */
217 const GLuint blockSize
= _mesa_get_format_bytes(mesaFormat
);
221 _mesa_get_format_block_size(mesaFormat
, &bw
, &bh
);
223 ASSERT(col
% bw
== 0);
224 ASSERT(row
% bh
== 0);
226 offset
= ((width
+ bw
- 1) / bw
) * (row
/ bh
) + col
/ bw
;
229 return (GLubyte
*) image
+ offset
;