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
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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
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29 * Helper functions for texture compression.
40 #include "texcompress.h"
45 * Return list of (and count of) all specific texture compression
46 * formats that are supported.
48 * \param ctx the GL context
49 * \param formats the resulting format list (may be NULL).
50 * \param all if true return all formats, even those with some kind
51 * of restrictions/limitations (See GL_ARB_texture_compression
52 * spec for more info).
54 * \return number of formats.
57 _mesa_get_compressed_formats(GLcontext *ctx, GLint *formats, GLboolean all)
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 */
117 * Convert a compressed MESA_FORMAT_x to a GLenum.
120 _mesa_glenum_to_compressed_format(GLenum format)
123 case GL_COMPRESSED_RGB_FXT1_3DFX:
124 return MESA_FORMAT_RGB_FXT1;
125 case GL_COMPRESSED_RGBA_FXT1_3DFX:
126 return MESA_FORMAT_RGBA_FXT1;
128 case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
130 return MESA_FORMAT_RGB_DXT1;
131 case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
133 return MESA_FORMAT_RGBA_DXT1;
134 case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
136 return MESA_FORMAT_RGBA_DXT3;
137 case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
139 return MESA_FORMAT_RGBA_DXT5;
141 case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
142 return MESA_FORMAT_SRGB_DXT1;
143 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
144 return MESA_FORMAT_SRGBA_DXT1;
145 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
146 return MESA_FORMAT_SRGBA_DXT3;
147 case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
148 return MESA_FORMAT_SRGBA_DXT5;
151 return MESA_FORMAT_NONE;
157 * Given a compressed MESA_FORMAT_x value, return the corresponding
158 * GLenum for that format.
159 * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
160 * which must return the specific texture format used when the user might
161 * have originally specified a generic compressed format in their
162 * glTexImage2D() call.
163 * For non-compressed textures, we always return the user-specified
164 * internal format unchanged.
167 _mesa_compressed_format_to_glenum(GLcontext *ctx, GLuint mesaFormat)
169 switch (mesaFormat) {
170 #if FEATURE_texture_fxt1
171 case MESA_FORMAT_RGB_FXT1:
172 return GL_COMPRESSED_RGB_FXT1_3DFX;
173 case MESA_FORMAT_RGBA_FXT1:
174 return GL_COMPRESSED_RGBA_FXT1_3DFX;
176 #if FEATURE_texture_s3tc
177 case MESA_FORMAT_RGB_DXT1:
178 return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
179 case MESA_FORMAT_RGBA_DXT1:
180 return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
181 case MESA_FORMAT_RGBA_DXT3:
182 return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
183 case MESA_FORMAT_RGBA_DXT5:
184 return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
185 #if FEATURE_EXT_texture_sRGB
186 case MESA_FORMAT_SRGB_DXT1:
187 return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
188 case MESA_FORMAT_SRGBA_DXT1:
189 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
190 case MESA_FORMAT_SRGBA_DXT3:
191 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
192 case MESA_FORMAT_SRGBA_DXT5:
193 return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
197 _mesa_problem(ctx, "Unexpected mesa texture format in"
198 " _mesa_compressed_format_to_glenum()");
205 * Return the address of the pixel at (col, row, img) in a
206 * compressed texture image.
207 * \param col, row, img - image position (3D), should be a multiple of the
208 * format's block size.
209 * \param format - compressed image format
210 * \param width - image width (stride) in pixels
211 * \param image - the image address
212 * \return address of pixel at (row, col, img)
215 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
216 gl_format mesaFormat,
217 GLsizei width, const GLubyte *image)
219 /* XXX only 2D images implemented, not 3D */
220 const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
224 _mesa_get_format_block_size(mesaFormat, &bw, &bh);
226 ASSERT(col % bw == 0);
227 ASSERT(row % bh == 0);
229 offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
232 return (GLubyte *) image + offset;