summaryrefslogtreecommitdiff
path: root/src/mesa/main/texcompress.c
blob: 4c6eaae4cf324272f5ab63e05788d500b6636480 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/**
 * \file texcompress.c
 * Compressed textures functions.
 */

/*
 * Mesa 3-D graphics library
 * Version:  5.1
 *
 * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


#include "glheader.h"
#include "imports.h"
#include "context.h"
#include "image.h"
#include "texcompress.h"
#include "texformat.h"


/**
 * Get the list of supported internal compression formats.
 * 
 * \param ctx GL context.
 * \param formats the resulting format list (may be NULL).
 *
 * \return number of formats.
 */
GLuint
_mesa_get_compressed_formats( GLcontext *ctx, GLint *formats )
{
   GLuint n = 0;
   if (ctx->Extensions.ARB_texture_compression) {
      if (ctx->Extensions.TDFX_texture_compression_FXT1) {
         if (formats) {
            formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
            formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
         }
         else {
            n += 2;
         }
      }
      if (ctx->Extensions.EXT_texture_compression_s3tc) {
         if (formats) {
            formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
            /* Skip this one because it has a restriction (all transparent
             * pixels become black).  See the texture compressions spec for
             * a detailed explanation.  This is what NVIDIA does.
            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
            */
            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
         }
         else {
            n += 3;
         }
      }
      if (ctx->Extensions.S3_s3tc) {
         if (formats) {
            formats[n++] = GL_RGB_S3TC;
            formats[n++] = GL_RGB4_S3TC;
            formats[n++] = GL_RGBA_S3TC;
            formats[n++] = GL_RGBA4_S3TC;
         }
         else {
            n += 4;
         }
      }
   }
   return n;
}


/**
 * Return bytes of storage needed for the given texture size and
 * compressed format.
 * 
 * \param width texture width in texels.
 * \param height texture height in texels.
 * \param depth texture depth in texels.
 * \param texFormat one of the compressed format enums
 * 
 * \return size in bytes, or zero if bad \p texFormat.
 */
GLuint
_mesa_compressed_texture_size( GLcontext *ctx,
                               GLsizei width, GLsizei height, GLsizei depth,
                               GLenum format )
{
   GLuint size;

   if (ctx->Driver.CompressedTextureSize) {
      return ctx->Driver.CompressedTextureSize(ctx, width, height, depth, format);
   }

   ASSERT(depth == 1);

   switch (format) {
   case GL_COMPRESSED_RGB_FXT1_3DFX:
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      /* round up width to next multiple of 8, height to next multiple of 4 */
      width = (width + 7) & ~7;
      height = (height + 3) & ~3;
      /* 16 bytes per 8x4 tile of RGB[A] texels */
      size = width * height / 2;
      /* Textures smaller than 8x4 will effectively be made into 8x4 and
       * take 16 bytes.
       */
      if (size < 16)
         size = 16;
      return size;
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
      /* round up width, height to next multiple of 4 */
      width = (width + 3) & ~3;
      height = (height + 3) & ~3;
      /* 8 bytes per 4x4 tile of RGB[A] texels */
      size = width * height / 2;
      /* Textures smaller than 4x4 will effectively be made into 4x4 and
       * take 8 bytes.
       */
      if (size < 8)
         size = 8;
      return size;
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
      /* round up width, height to next multiple of 4 */
      width = (width + 3) & ~3;
      height = (height + 3) & ~3;
      /* 16 bytes per 4x4 tile of RGBA texels */
      size = width * height; /* simple! */
      /* Textures smaller than 4x4 will effectively be made into 4x4 and
       * take 16 bytes.
       */
      if (size < 16)
         size = 16;
      return size;
   default:
      _mesa_problem(ctx, "bad texformat in compressed_texture_size");
      return 0;
   }
}


/**
 * Compute the bytes per row in a compressed texture image.
 * We use this for computing the destination address for sub-texture updates.
 * \param format  one of the specific texture compression formats
 * \param width  image width in pixels
 * \return stride, in bytes, between rows for compressed image
 */
GLint
_mesa_compressed_row_stride(GLenum format, GLsizei width)
{
   GLint stride;

   switch (format) {
   case GL_COMPRESSED_RGB_FXT1_3DFX:
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      stride = ((width + 7) / 8) * 16; /* 16 bytes per 8x4 tile */
      break;
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
      stride = ((width + 3) / 4) * 8; /* 8 bytes per 4x4 tile */
      break;
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
      stride = ((width + 3) / 4) * 16; /* 16 bytes per 4x4 tile */
      break;
   default:
      return 0;
   }

   return stride;
}


/**
 * Return the address of the pixel at (col, row, img) in a
 * compressed texture image.
 * 
 * \param col image position.
 * \param row image position.
 * \param img image position.
 * \param format compressed image format.
 * \param width image width.
 * \param image the image address.
 * 
 * \return address of pixel at (row, col).
 */
GLubyte *
_mesa_compressed_image_address(GLint col, GLint row, GLint img,
                               GLenum format,
                               GLsizei width, const GLubyte *image)
{
   GLubyte *addr;

   (void) img;

   /* We try to spot a "complete" subtexture "above" ROW, COL;
    * this texture is given by appropriate rounding of WIDTH x ROW.
    * Then we just add the amount left (usually on the left).
    *
    * Example for X*Y microtiles (Z bytes each)
    * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
    */

   switch (format) {
   case GL_COMPRESSED_RGB_FXT1_3DFX:
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      addr = (GLubyte *) image + 16 * (((width + 7) / 8) * (row / 4) + col / 8);
      break;
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
      addr = (GLubyte *) image + 8 * (((width + 3) / 4) * (row / 4) + col / 4);
      break;
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
      addr = (GLubyte *) image + 16 * (((width + 3) / 4) * (row / 4) + col / 4);
      break;
   default:
      return 0;
   }

   return addr;
}


/**
 * \param srcRowStride source stride, in pixels
 */
void
_mesa_compress_teximage( GLcontext *ctx, GLsizei width, GLsizei height,
                         GLenum srcFormat, const GLchan *source,
                         GLint srcRowStride,
                         const struct gl_texture_format *dstFormat,
                         GLubyte *dest, GLint dstRowStride )
{
   switch (dstFormat->MesaFormat) {
   default:
      _mesa_problem(ctx, "Bad dstFormat in _mesa_compress_teximage()");
      return;
   }
}