1/*
2 * Copyright (C) 2011 LunarG, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24/**
25 * \file texcompress_etc.c
26 * GL_OES_compressed_ETC1_RGB8_texture support.
27 * Supported ETC2 texture formats are:
28 * GL_COMPRESSED_RGB8_ETC2
29 * GL_COMPRESSED_SRGB8_ETC2
30 * GL_COMPRESSED_RGBA8_ETC2_EAC
31 * GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
32 * GL_COMPRESSED_R11_EAC
33 * GL_COMPRESSED_RG11_EAC
34 * GL_COMPRESSED_SIGNED_R11_EAC
35 * GL_COMPRESSED_SIGNED_RG11_EAC
36 * MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1
37 * MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1
38 */
39
40#include <stdbool.h>
41#include "texcompress.h"
42#include "texcompress_etc.h"
43#include "texstore.h"
44#include "config.h"
45#include "macros.h"
46#include "format_unpack.h"
47#include "util/format_srgb.h"
48
49
50struct etc2_block {
51   int distance;
52   uint64_t pixel_indices[2];
53   const int *modifier_tables[2];
54   bool flipped;
55   bool opaque;
56   bool is_ind_mode;
57   bool is_diff_mode;
58   bool is_t_mode;
59   bool is_h_mode;
60   bool is_planar_mode;
61   uint8_t base_colors[3][3];
62   uint8_t paint_colors[4][3];
63   uint8_t base_codeword;
64   uint8_t multiplier;
65   uint8_t table_index;
66};
67
68static const int etc2_distance_table[8] = {
69   3, 6, 11, 16, 23, 32, 41, 64 };
70
71static const int etc2_modifier_tables[16][8] = {
72   {  -3,   -6,   -9,  -15,   2,   5,   8,   14},
73   {  -3,   -7,  -10,  -13,   2,   6,   9,   12},
74   {  -2,   -5,   -8,  -13,   1,   4,   7,   12},
75   {  -2,   -4,   -6,  -13,   1,   3,   5,   12},
76   {  -3,   -6,   -8,  -12,   2,   5,   7,   11},
77   {  -3,   -7,   -9,  -11,   2,   6,   8,   10},
78   {  -4,   -7,   -8,  -11,   3,   6,   7,   10},
79   {  -3,   -5,   -8,  -11,   2,   4,   7,   10},
80   {  -2,   -6,   -8,  -10,   1,   5,   7,    9},
81   {  -2,   -5,   -8,  -10,   1,   4,   7,    9},
82   {  -2,   -4,   -8,  -10,   1,   3,   7,    9},
83   {  -2,   -5,   -7,  -10,   1,   4,   6,    9},
84   {  -3,   -4,   -7,  -10,   2,   3,   6,    9},
85   {  -1,   -2,   -3,  -10,   0,   1,   2,    9},
86   {  -4,   -6,   -8,   -9,   3,   5,   7,    8},
87   {  -3,   -5,   -7,   -9,   2,   4,   6,    8},
88};
89
90static const int etc2_modifier_tables_non_opaque[8][4] = {
91   { 0,   8,   0,    -8},
92   { 0,   17,  0,   -17},
93   { 0,   29,  0,   -29},
94   { 0,   42,  0,   -42},
95   { 0,   60,  0,   -60},
96   { 0,   80,  0,   -80},
97   { 0,   106, 0,  -106},
98   { 0,   183, 0,  -183}
99};
100
101/* define etc1_parse_block and etc. */
102#define UINT8_TYPE GLubyte
103#define TAG(x) x
104#include "texcompress_etc_tmp.h"
105#undef TAG
106#undef UINT8_TYPE
107
108GLboolean
109_mesa_texstore_etc1_rgb8(UNUSED_TEXSTORE_PARAMS)
110{
111   /* GL_ETC1_RGB8_OES is only valid in glCompressedTexImage2D */
112   assert(0);
113
114   return GL_FALSE;
115}
116
117
118/**
119 * Decode texture data in format `MESA_FORMAT_ETC1_RGB8` to
120 * `MESA_FORMAT_ABGR8888`.
121 *
122 * The size of the source data must be a multiple of the ETC1 block size,
123 * which is 8, even if the texture image's dimensions are not aligned to 4.
124 * From the GL_OES_compressed_ETC1_RGB8_texture spec:
125 *   The texture is described as a number of 4x4 pixel blocks. If the
126 *   texture (or a particular mip-level) is smaller than 4 pixels in
127 *   any dimension (such as a 2x2 or a 8x1 texture), the texture is
128 *   found in the upper left part of the block(s), and the rest of the
129 *   pixels are not used. For instance, a texture of size 4x2 will be
130 *   placed in the upper half of a 4x4 block, and the lower half of the
131 *   pixels in the block will not be accessed.
132 *
133 * \param src_width in pixels
134 * \param src_height in pixels
135 * \param dst_stride in bytes
136 */
137void
138_mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
139                           unsigned dst_stride,
140                           const uint8_t *src_row,
141                           unsigned src_stride,
142                           unsigned src_width,
143                           unsigned src_height)
144{
145   etc1_unpack_rgba8888(dst_row, dst_stride,
146                        src_row, src_stride,
147                        src_width, src_height);
148}
149
150static uint8_t
151etc2_base_color1_t_mode(const uint8_t *in, GLuint index)
152{
153   uint8_t R1a = 0, x = 0;
154   /* base col 1 = extend_4to8bits( (R1a << 2) | R1b, G1, B1) */
155   switch(index) {
156   case 0:
157      R1a = (in[0] >> 3) & 0x3;
158      x = ((R1a << 2) | (in[0] & 0x3));
159      break;
160   case 1:
161      x = ((in[1] >> 4) & 0xf);
162      break;
163   case 2:
164      x = (in[1] & 0xf);
165      break;
166   default:
167      /* invalid index */
168      break;
169   }
170   return ((x << 4) | (x & 0xf));
171}
172
173static uint8_t
174etc2_base_color2_t_mode(const uint8_t *in, GLuint index)
175{
176   uint8_t x = 0;
177   /*extend 4to8bits(R2, G2, B2)*/
178   switch(index) {
179   case 0:
180      x = ((in[2] >> 4) & 0xf );
181      break;
182   case 1:
183      x = (in[2] & 0xf);
184      break;
185   case 2:
186      x = ((in[3] >> 4) & 0xf);
187      break;
188   default:
189      /* invalid index */
190      break;
191   }
192   return ((x << 4) | (x & 0xf));
193}
194
195static uint8_t
196etc2_base_color1_h_mode(const uint8_t *in, GLuint index)
197{
198   uint8_t x = 0;
199   /* base col 1 = extend 4to8bits(R1, (G1a << 1) | G1b, (B1a << 3) | B1b) */
200   switch(index) {
201   case 0:
202      x = ((in[0] >> 3) & 0xf);
203      break;
204   case 1:
205      x = (((in[0] & 0x7) << 1) | ((in[1] >> 4) & 0x1));
206      break;
207   case 2:
208      x = ((in[1] & 0x8) |
209           (((in[1] & 0x3) << 1) | ((in[2] >> 7) & 0x1)));
210      break;
211   default:
212      /* invalid index */
213      break;
214   }
215   return ((x << 4) | (x & 0xf));
216}
217
218static uint8_t
219etc2_base_color2_h_mode(const uint8_t *in, GLuint index)
220{
221   uint8_t x = 0;
222   /* base col 2 = extend 4to8bits(R2, G2, B2) */
223   switch(index) {
224   case 0:
225      x = ((in[2] >> 3) & 0xf );
226      break;
227   case 1:
228      x = (((in[2] & 0x7) << 1) | ((in[3] >> 7) & 0x1));
229      break;
230   case 2:
231      x = ((in[3] >> 3) & 0xf);
232      break;
233   default:
234      /* invalid index */
235      break;
236   }
237   return ((x << 4) | (x & 0xf));
238}
239
240static uint8_t
241etc2_base_color_o_planar(const uint8_t *in, GLuint index)
242{
243   GLuint tmp;
244   switch(index) {
245   case 0:
246      tmp = ((in[0] >> 1) & 0x3f); /* RO */
247      return ((tmp << 2) | (tmp >> 4));
248   case 1:
249      tmp = (((in[0] & 0x1) << 6) | /* GO1 */
250             ((in[1] >> 1) & 0x3f)); /* GO2 */
251      return ((tmp << 1) | (tmp >> 6));
252   case 2:
253      tmp = (((in[1] & 0x1) << 5) | /* BO1 */
254             (in[2] & 0x18) | /* BO2 */
255             (((in[2] & 0x3) << 1) | ((in[3] >> 7) & 0x1))); /* BO3 */
256      return ((tmp << 2) | (tmp >> 4));
257    default:
258      /* invalid index */
259      return 0;
260   }
261}
262
263static uint8_t
264etc2_base_color_h_planar(const uint8_t *in, GLuint index)
265{
266   GLuint tmp;
267   switch(index) {
268   case 0:
269      tmp = (((in[3] & 0x7c) >> 1) | /* RH1 */
270             (in[3] & 0x1));         /* RH2 */
271      return ((tmp << 2) | (tmp >> 4));
272   case 1:
273      tmp = (in[4] >> 1) & 0x7f; /* GH */
274      return ((tmp << 1) | (tmp >> 6));
275   case 2:
276      tmp = (((in[4] & 0x1) << 5) |
277             ((in[5] >> 3) & 0x1f)); /* BH */
278      return ((tmp << 2) | (tmp >> 4));
279   default:
280      /* invalid index */
281      return 0;
282   }
283}
284
285static uint8_t
286etc2_base_color_v_planar(const uint8_t *in, GLuint index)
287{
288   GLuint tmp;
289   switch(index) {
290   case 0:
291      tmp = (((in[5] & 0x7) << 0x3) |
292             ((in[6] >> 5) & 0x7)); /* RV */
293      return ((tmp << 2) | (tmp >> 4));
294   case 1:
295      tmp = (((in[6] & 0x1f) << 2) |
296             ((in[7] >> 6) & 0x3)); /* GV */
297      return ((tmp << 1) | (tmp >> 6));
298   case 2:
299      tmp = in[7] & 0x3f; /* BV */
300      return ((tmp << 2) | (tmp >> 4));
301   default:
302      /* invalid index */
303      return 0;
304   }
305}
306
307static GLint
308etc2_get_pixel_index(const struct etc2_block *block, int x, int y)
309{
310   int bit = ((3 - y) + (3 - x) * 4) * 3;
311   int idx = (block->pixel_indices[1] >> bit) & 0x7;
312   return idx;
313}
314
315static uint8_t
316etc2_clamp(int color)
317{
318   /* CLAMP(color, 0, 255) */
319   return (uint8_t) CLAMP(color, 0, 255);
320}
321
322static GLushort
323etc2_clamp2(int color)
324{
325   /* CLAMP(color, 0, 2047) */
326   return (GLushort) CLAMP(color, 0, 2047);
327}
328
329static GLshort
330etc2_clamp3(int color)
331{
332   /* CLAMP(color, -1023, 1023) */
333   return (GLshort) CLAMP(color, -1023, 1023);
334}
335
336static void
337etc2_rgb8_parse_block(struct etc2_block *block,
338                      const uint8_t *src,
339                      GLboolean punchthrough_alpha)
340{
341   unsigned i;
342   GLboolean diffbit = false;
343   static const int lookup[8] = { 0, 1, 2, 3, -4, -3, -2, -1 };
344
345   const int R_plus_dR = (src[0] >> 3) + lookup[src[0] & 0x7];
346   const int G_plus_dG = (src[1] >> 3) + lookup[src[1] & 0x7];
347   const int B_plus_dB = (src[2] >> 3) + lookup[src[2] & 0x7];
348
349   /* Reset the mode flags */
350   block->is_ind_mode = false;
351   block->is_diff_mode = false;
352   block->is_t_mode = false;
353   block->is_h_mode = false;
354   block->is_planar_mode = false;
355
356   if (punchthrough_alpha)
357      block->opaque = src[3] & 0x2;
358   else
359      diffbit = src[3] & 0x2;
360
361   if (!diffbit && !punchthrough_alpha) {
362      /* individual mode */
363      block->is_ind_mode = true;
364
365      for (i = 0; i < 3; i++) {
366         /* Texture decode algorithm is same for individual mode in etc1
367          * & etc2.
368          */
369         block->base_colors[0][i] = etc1_base_color_ind_hi(src[i]);
370         block->base_colors[1][i] = etc1_base_color_ind_lo(src[i]);
371      }
372   }
373   else if (R_plus_dR < 0 || R_plus_dR > 31){
374      /* T mode */
375      block->is_t_mode = true;
376
377      for(i = 0; i < 3; i++) {
378         block->base_colors[0][i] = etc2_base_color1_t_mode(src, i);
379         block->base_colors[1][i] = etc2_base_color2_t_mode(src, i);
380      }
381      /* pick distance */
382      block->distance =
383         etc2_distance_table[(((src[3] >> 2) & 0x3) << 1) |
384                             (src[3] & 0x1)];
385
386      for (i = 0; i < 3; i++) {
387         block->paint_colors[0][i] = etc2_clamp(block->base_colors[0][i]);
388         block->paint_colors[1][i] = etc2_clamp(block->base_colors[1][i] +
389                                                block->distance);
390         block->paint_colors[2][i] = etc2_clamp(block->base_colors[1][i]);
391         block->paint_colors[3][i] = etc2_clamp(block->base_colors[1][i] -
392                                                block->distance);
393      }
394   }
395   else if (G_plus_dG < 0 || G_plus_dG > 31){
396      int base_color_1_value, base_color_2_value;
397
398      /* H mode */
399      block->is_h_mode = true;
400
401      for(i = 0; i < 3; i++) {
402         block->base_colors[0][i] = etc2_base_color1_h_mode(src, i);
403         block->base_colors[1][i] = etc2_base_color2_h_mode(src, i);
404      }
405
406      base_color_1_value = (block->base_colors[0][0] << 16) +
407                           (block->base_colors[0][1] << 8) +
408                           block->base_colors[0][2];
409      base_color_2_value = (block->base_colors[1][0] << 16) +
410                           (block->base_colors[1][1] << 8) +
411                           block->base_colors[1][2];
412      /* pick distance */
413      block->distance =
414         etc2_distance_table[(src[3] & 0x4) |
415                             ((src[3] & 0x1) << 1) |
416                             (base_color_1_value >= base_color_2_value)];
417
418      for (i = 0; i < 3; i++) {
419         block->paint_colors[0][i] = etc2_clamp(block->base_colors[0][i] +
420                                                block->distance);
421         block->paint_colors[1][i] = etc2_clamp(block->base_colors[0][i] -
422                                                block->distance);
423         block->paint_colors[2][i] = etc2_clamp(block->base_colors[1][i] +
424                                                block->distance);
425         block->paint_colors[3][i] = etc2_clamp(block->base_colors[1][i] -
426                                                block->distance);
427      }
428   }
429   else if (B_plus_dB < 0 || B_plus_dB > 31) {
430      /* Planar mode */
431      block->is_planar_mode = true;
432
433      /* opaque bit must be set in planar mode */
434      block->opaque = true;
435
436      for (i = 0; i < 3; i++) {
437         block->base_colors[0][i] = etc2_base_color_o_planar(src, i);
438         block->base_colors[1][i] = etc2_base_color_h_planar(src, i);
439         block->base_colors[2][i] = etc2_base_color_v_planar(src, i);
440      }
441   }
442   else if (diffbit || punchthrough_alpha) {
443      /* differential mode */
444      block->is_diff_mode = true;
445
446      for (i = 0; i < 3; i++) {
447         /* Texture decode algorithm is same for differential mode in etc1
448          * & etc2.
449          */
450         block->base_colors[0][i] = etc1_base_color_diff_hi(src[i]);
451         block->base_colors[1][i] = etc1_base_color_diff_lo(src[i]);
452      }
453   }
454
455   if (block->is_ind_mode || block->is_diff_mode) {
456      int table1_idx = (src[3] >> 5) & 0x7;
457      int table2_idx = (src[3] >> 2) & 0x7;
458
459      /* Use same modifier tables as for etc1 textures if opaque bit is set
460       * or if non punchthrough texture format
461       */
462      block->modifier_tables[0] = (!punchthrough_alpha || block->opaque) ?
463                                  etc1_modifier_tables[table1_idx] :
464                                  etc2_modifier_tables_non_opaque[table1_idx];
465      block->modifier_tables[1] = (!punchthrough_alpha || block->opaque) ?
466                                  etc1_modifier_tables[table2_idx] :
467                                  etc2_modifier_tables_non_opaque[table2_idx];
468
469      block->flipped = (src[3] & 0x1);
470   }
471
472   block->pixel_indices[0] =
473      (src[4] << 24) | (src[5] << 16) | (src[6] << 8) | src[7];
474}
475
476static void
477etc2_rgb8_fetch_texel(const struct etc2_block *block,
478                      int x, int y, uint8_t *dst,
479                      GLboolean punchthrough_alpha)
480{
481   const uint8_t *base_color;
482   int modifier, bit, idx, blk;
483
484   /* get pixel index */
485   bit = y + x * 4;
486   idx = ((block->pixel_indices[0] >> (15 + bit)) & 0x2) |
487         ((block->pixel_indices[0] >>      (bit)) & 0x1);
488
489   if (block->is_ind_mode || block->is_diff_mode) {
490      /* check for punchthrough_alpha format */
491      if (punchthrough_alpha) {
492         if (!block->opaque && idx == 2) {
493            dst[0] = dst[1] = dst[2] = dst[3] = 0;
494            return;
495         }
496         else
497            dst[3] = 255;
498      }
499
500      /* Use pixel index and subblock to get the modifier */
501      blk = (block->flipped) ? (y >= 2) : (x >= 2);
502      base_color = block->base_colors[blk];
503      modifier = block->modifier_tables[blk][idx];
504
505      dst[0] = etc2_clamp(base_color[0] + modifier);
506      dst[1] = etc2_clamp(base_color[1] + modifier);
507      dst[2] = etc2_clamp(base_color[2] + modifier);
508   }
509   else if (block->is_t_mode || block->is_h_mode) {
510      /* check for punchthrough_alpha format */
511      if (punchthrough_alpha) {
512         if (!block->opaque && idx == 2) {
513            dst[0] = dst[1] = dst[2] = dst[3] = 0;
514            return;
515         }
516         else
517            dst[3] = 255;
518      }
519
520      /* Use pixel index to pick one of the paint colors */
521      dst[0] = block->paint_colors[idx][0];
522      dst[1] = block->paint_colors[idx][1];
523      dst[2] = block->paint_colors[idx][2];
524   }
525   else if (block->is_planar_mode) {
526      /* {R(x, y) = clamp255((x × (RH − RO) + y × (RV − RO) + 4 × RO + 2) >> 2)
527       * {G(x, y) = clamp255((x × (GH − GO) + y × (GV − GO) + 4 × GO + 2) >> 2)
528       * {B(x, y) = clamp255((x × (BH − BO) + y × (BV − BO) + 4 × BO + 2) >> 2)
529       */
530      int red, green, blue;
531      red = (x * (block->base_colors[1][0] - block->base_colors[0][0]) +
532             y * (block->base_colors[2][0] - block->base_colors[0][0]) +
533             4 * block->base_colors[0][0] + 2) >> 2;
534
535      green = (x * (block->base_colors[1][1] - block->base_colors[0][1]) +
536               y * (block->base_colors[2][1] - block->base_colors[0][1]) +
537               4 * block->base_colors[0][1] + 2) >> 2;
538
539      blue = (x * (block->base_colors[1][2] - block->base_colors[0][2]) +
540              y * (block->base_colors[2][2] - block->base_colors[0][2]) +
541              4 * block->base_colors[0][2] + 2) >> 2;
542
543      dst[0] = etc2_clamp(red);
544      dst[1] = etc2_clamp(green);
545      dst[2] = etc2_clamp(blue);
546
547      /* check for punchthrough_alpha format */
548      if (punchthrough_alpha)
549         dst[3] = 255;
550   }
551   else
552      unreachable("unhandled block mode");
553}
554
555static void
556etc2_alpha8_fetch_texel(const struct etc2_block *block,
557      int x, int y, uint8_t *dst)
558{
559   int modifier, alpha, idx;
560   /* get pixel index */
561   idx = etc2_get_pixel_index(block, x, y);
562   modifier = etc2_modifier_tables[block->table_index][idx];
563   alpha = block->base_codeword + modifier * block->multiplier;
564   dst[3] = etc2_clamp(alpha);
565}
566
567static void
568etc2_r11_fetch_texel(const struct etc2_block *block,
569                     int x, int y, uint8_t *dst)
570{
571   GLint modifier, idx;
572   GLshort color;
573   /* Get pixel index */
574   idx = etc2_get_pixel_index(block, x, y);
575   modifier = etc2_modifier_tables[block->table_index][idx];
576
577   if (block->multiplier != 0)
578      /* clamp2(base codeword × 8 + 4 + modifier × multiplier × 8) */
579      color = etc2_clamp2(((block->base_codeword << 3) | 0x4)  +
580                          ((modifier * block->multiplier) << 3));
581   else
582      color = etc2_clamp2(((block->base_codeword << 3) | 0x4)  + modifier);
583
584   /* Extend 11 bits color value to 16 bits. OpenGL ES 3.0 specification
585    * allows extending the color value to any number of bits. But, an
586    * implementation is not allowed to truncate the 11-bit value to less than
587    * 11 bits."
588    */
589   color = (color << 5) | (color >> 6);
590   ((GLushort *)dst)[0] = color;
591}
592
593static void
594etc2_signed_r11_fetch_texel(const struct etc2_block *block,
595                            int x, int y, uint8_t *dst)
596{
597   GLint modifier, idx;
598   GLshort color;
599   GLbyte base_codeword = (GLbyte) block->base_codeword;
600
601   if (base_codeword == -128)
602      base_codeword = -127;
603
604   /* Get pixel index */
605   idx = etc2_get_pixel_index(block, x, y);
606   modifier = etc2_modifier_tables[block->table_index][idx];
607
608   if (block->multiplier != 0)
609      /* clamp3(base codeword × 8 + modifier × multiplier × 8) */
610      color = etc2_clamp3((base_codeword << 3)  +
611                         ((modifier * block->multiplier) << 3));
612   else
613      color = etc2_clamp3((base_codeword << 3)  + modifier);
614
615   /* Extend 11 bits color value to 16 bits. OpenGL ES 3.0 specification
616    * allows extending the color value to any number of bits. But, an
617    * implementation is not allowed to truncate the 11-bit value to less than
618    * 11 bits. A negative 11-bit value must first be made positive before bit
619    * replication, and then made negative again
620    */
621   if (color >= 0)
622      color = (color << 5) | (color >> 5);
623   else {
624      color = -color;
625      color = (color << 5) | (color >> 5);
626      color = -color;
627   }
628   ((GLshort *)dst)[0] = color;
629}
630
631static void
632etc2_alpha8_parse_block(struct etc2_block *block, const uint8_t *src)
633{
634   block->base_codeword = src[0];
635   block->multiplier = (src[1] >> 4) & 0xf;
636   block->table_index = src[1] & 0xf;
637   block->pixel_indices[1] = (((uint64_t)src[2] << 40) |
638                              ((uint64_t)src[3] << 32) |
639                              ((uint64_t)src[4] << 24) |
640                              ((uint64_t)src[5] << 16) |
641                              ((uint64_t)src[6] << 8)  |
642                              ((uint64_t)src[7]));
643}
644
645static void
646etc2_r11_parse_block(struct etc2_block *block, const uint8_t *src)
647{
648   /* Parsing logic remains same as for etc2_alpha8_parse_block */
649    etc2_alpha8_parse_block(block, src);
650}
651
652static void
653etc2_rgba8_parse_block(struct etc2_block *block, const uint8_t *src)
654{
655   /* RGB component is parsed the same way as for MESA_FORMAT_ETC2_RGB8 */
656   etc2_rgb8_parse_block(block, src + 8,
657                         false /* punchthrough_alpha */);
658   /* Parse Alpha component */
659   etc2_alpha8_parse_block(block, src);
660}
661
662static void
663etc2_rgba8_fetch_texel(const struct etc2_block *block,
664      int x, int y, uint8_t *dst)
665{
666   etc2_rgb8_fetch_texel(block, x, y, dst,
667                         false /* punchthrough_alpha */);
668   etc2_alpha8_fetch_texel(block, x, y, dst);
669}
670
671static void
672etc2_unpack_rgb8(uint8_t *dst_row,
673                 unsigned dst_stride,
674                 const uint8_t *src_row,
675                 unsigned src_stride,
676                 unsigned width,
677                 unsigned height)
678{
679   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
680   struct etc2_block block;
681   unsigned x, y, i, j;
682
683   for (y = 0; y < height; y += bh) {
684      const uint8_t *src = src_row;
685      /*
686       * Destination texture may not be a multiple of four texels in
687       * height. Compute a safe height to avoid writing outside the texture.
688       */
689      const unsigned h = MIN2(bh, height - y);
690
691      for (x = 0; x < width; x+= bw) {
692         /*
693          * Destination texture may not be a multiple of four texels in
694          * width. Compute a safe width to avoid writing outside the texture.
695          */
696         const unsigned w = MIN2(bw, width - x);
697
698         etc2_rgb8_parse_block(&block, src,
699                               false /* punchthrough_alpha */);
700
701         for (j = 0; j < h; j++) {
702            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
703            for (i = 0; i < w; i++) {
704               etc2_rgb8_fetch_texel(&block, i, j, dst,
705                                     false /* punchthrough_alpha */);
706               dst[3] = 255;
707               dst += comps;
708            }
709         }
710
711         src += bs;
712      }
713
714      src_row += src_stride;
715   }
716}
717
718static void
719etc2_unpack_srgb8(uint8_t *dst_row,
720                  unsigned dst_stride,
721                  const uint8_t *src_row,
722                  unsigned src_stride,
723                  unsigned width,
724		  unsigned height,
725		  bool bgra)
726{
727   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
728   struct etc2_block block;
729   unsigned x, y, i, j;
730   uint8_t tmp;
731
732   for (y = 0; y < height; y += bh) {
733      const uint8_t *src = src_row;
734      const unsigned h = MIN2(bh, height - y);
735
736      for (x = 0; x < width; x+= bw) {
737         const unsigned w = MIN2(bw, width - x);
738         etc2_rgb8_parse_block(&block, src,
739                               false /* punchthrough_alpha */);
740
741
742         for (j = 0; j < h; j++) {
743            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
744            for (i = 0; i < w; i++) {
745               etc2_rgb8_fetch_texel(&block, i, j, dst,
746                                     false /* punchthrough_alpha */);
747
748	       if (bgra) {
749		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
750		  tmp = dst[0];
751		  dst[0] = dst[2];
752		  dst[2] = tmp;
753	       }
754               dst[3] = 255;
755
756               dst += comps;
757            }
758         }
759         src += bs;
760      }
761
762      src_row += src_stride;
763   }
764}
765
766static void
767etc2_unpack_rgba8(uint8_t *dst_row,
768                  unsigned dst_stride,
769                  const uint8_t *src_row,
770                  unsigned src_stride,
771                  unsigned width,
772                  unsigned height)
773{
774   /* If internalformat is COMPRESSED_RGBA8_ETC2_EAC, each 4 × 4 block of
775    * RGBA8888 information is compressed to 128 bits. To decode a block, the
776    * two 64-bit integers int64bitAlpha and int64bitColor are calculated.
777   */
778   const unsigned bw = 4, bh = 4, bs = 16, comps = 4;
779   struct etc2_block block;
780   unsigned x, y, i, j;
781
782   for (y = 0; y < height; y += bh) {
783      const uint8_t *src = src_row;
784      const unsigned h = MIN2(bh, height - y);
785
786      for (x = 0; x < width; x+= bw) {
787         const unsigned w = MIN2(bw, width - x);
788         etc2_rgba8_parse_block(&block, src);
789
790         for (j = 0; j < h; j++) {
791            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
792            for (i = 0; i < w; i++) {
793               etc2_rgba8_fetch_texel(&block, i, j, dst);
794               dst += comps;
795            }
796         }
797         src += bs;
798      }
799
800      src_row += src_stride;
801   }
802}
803
804static void
805etc2_unpack_srgb8_alpha8(uint8_t *dst_row,
806                         unsigned dst_stride,
807                         const uint8_t *src_row,
808                         unsigned src_stride,
809                         unsigned width,
810			 unsigned height,
811			 bool bgra)
812{
813   /* If internalformat is COMPRESSED_SRGB8_ALPHA8_ETC2_EAC, each 4 × 4 block
814    * of RGBA8888 information is compressed to 128 bits. To decode a block, the
815    * two 64-bit integers int64bitAlpha and int64bitColor are calculated.
816    */
817   const unsigned bw = 4, bh = 4, bs = 16, comps = 4;
818   struct etc2_block block;
819   unsigned x, y, i, j;
820   uint8_t tmp;
821
822   for (y = 0; y < height; y += bh) {
823      const unsigned h = MIN2(bh, height - y);
824      const uint8_t *src = src_row;
825
826      for (x = 0; x < width; x+= bw) {
827         const unsigned w = MIN2(bw, width - x);
828         etc2_rgba8_parse_block(&block, src);
829
830         for (j = 0; j < h; j++) {
831            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
832            for (i = 0; i < w; i++) {
833               etc2_rgba8_fetch_texel(&block, i, j, dst);
834
835	       if (bgra) {
836		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
837		  tmp = dst[0];
838		  dst[0] = dst[2];
839		  dst[2] = tmp;
840		  dst[3] = dst[3];
841	       }
842
843               dst += comps;
844            }
845         }
846         src += bs;
847      }
848
849      src_row += src_stride;
850   }
851}
852
853static void
854etc2_unpack_r11(uint8_t *dst_row,
855                unsigned dst_stride,
856                const uint8_t *src_row,
857                unsigned src_stride,
858                unsigned width,
859                unsigned height)
860{
861   /* If internalformat is COMPRESSED_R11_EAC, each 4 × 4 block of
862      color information is compressed to 64 bits.
863   */
864   const unsigned bw = 4, bh = 4, bs = 8, comps = 1, comp_size = 2;
865   struct etc2_block block;
866   unsigned x, y, i, j;
867
868   for (y = 0; y < height; y += bh) {
869      const unsigned h = MIN2(bh, height - y);
870      const uint8_t *src = src_row;
871
872      for (x = 0; x < width; x+= bw) {
873         const unsigned w = MIN2(bw, width - x);
874         etc2_r11_parse_block(&block, src);
875
876         for (j = 0; j < h; j++) {
877            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps * comp_size;
878            for (i = 0; i < w; i++) {
879               etc2_r11_fetch_texel(&block, i, j, dst);
880               dst += comps * comp_size;
881            }
882         }
883         src += bs;
884      }
885
886      src_row += src_stride;
887   }
888}
889
890static void
891etc2_unpack_rg11(uint8_t *dst_row,
892                 unsigned dst_stride,
893                 const uint8_t *src_row,
894                 unsigned src_stride,
895                 unsigned width,
896                 unsigned height)
897{
898   /* If internalformat is COMPRESSED_RG11_EAC, each 4 × 4 block of
899      RG color information is compressed to 128 bits.
900   */
901   const unsigned bw = 4, bh = 4, bs = 16, comps = 2, comp_size = 2;
902   struct etc2_block block;
903   unsigned x, y, i, j;
904
905   for (y = 0; y < height; y += bh) {
906      const unsigned h = MIN2(bh, height - y);
907      const uint8_t *src = src_row;
908
909      for (x = 0; x < width; x+= bw) {
910         const unsigned w = MIN2(bw, width - x);
911         /* red component */
912         etc2_r11_parse_block(&block, src);
913
914         for (j = 0; j < h; j++) {
915            uint8_t *dst = dst_row + (y + j) * dst_stride +
916                           x * comps * comp_size;
917            for (i = 0; i < w; i++) {
918               etc2_r11_fetch_texel(&block, i, j, dst);
919               dst += comps * comp_size;
920            }
921         }
922         /* green component */
923         etc2_r11_parse_block(&block, src + 8);
924
925         for (j = 0; j < h; j++) {
926            uint8_t *dst = dst_row + (y + j) * dst_stride +
927                           x * comps * comp_size;
928            for (i = 0; i < w; i++) {
929               etc2_r11_fetch_texel(&block, i, j, dst + comp_size);
930               dst += comps * comp_size;
931            }
932         }
933         src += bs;
934      }
935
936      src_row += src_stride;
937   }
938}
939
940static void
941etc2_unpack_signed_r11(uint8_t *dst_row,
942                       unsigned dst_stride,
943                       const uint8_t *src_row,
944                       unsigned src_stride,
945                       unsigned width,
946                       unsigned height)
947{
948   /* If internalformat is COMPRESSED_SIGNED_R11_EAC, each 4 × 4 block of
949      red color information is compressed to 64 bits.
950   */
951   const unsigned bw = 4, bh = 4, bs = 8, comps = 1, comp_size = 2;
952   struct etc2_block block;
953   unsigned x, y, i, j;
954
955   for (y = 0; y < height; y += bh) {
956      const unsigned h = MIN2(bh, height - y);
957      const uint8_t *src = src_row;
958
959      for (x = 0; x < width; x+= bw) {
960         const unsigned w = MIN2(bw, width - x);
961         etc2_r11_parse_block(&block, src);
962
963         for (j = 0; j < h; j++) {
964            uint8_t *dst = dst_row + (y + j) * dst_stride +
965                           x * comps * comp_size;
966            for (i = 0; i < w; i++) {
967               etc2_signed_r11_fetch_texel(&block, i, j, dst);
968               dst += comps * comp_size;
969            }
970         }
971         src += bs;
972      }
973
974      src_row += src_stride;
975   }
976}
977
978static void
979etc2_unpack_signed_rg11(uint8_t *dst_row,
980                        unsigned dst_stride,
981                        const uint8_t *src_row,
982                        unsigned src_stride,
983                        unsigned width,
984                        unsigned height)
985{
986   /* If internalformat is COMPRESSED_SIGNED_RG11_EAC, each 4 × 4 block of
987      RG color information is compressed to 128 bits.
988   */
989   const unsigned bw = 4, bh = 4, bs = 16, comps = 2, comp_size = 2;
990   struct etc2_block block;
991   unsigned x, y, i, j;
992
993   for (y = 0; y < height; y += bh) {
994      const unsigned h = MIN2(bh, height - y);
995      const uint8_t *src = src_row;
996
997      for (x = 0; x < width; x+= bw) {
998         const unsigned w = MIN2(bw, width - x);
999         /* red component */
1000         etc2_r11_parse_block(&block, src);
1001
1002         for (j = 0; j < h; j++) {
1003            uint8_t *dst = dst_row + (y + j) * dst_stride +
1004                          x * comps * comp_size;
1005            for (i = 0; i < w; i++) {
1006               etc2_signed_r11_fetch_texel(&block, i, j, dst);
1007               dst += comps * comp_size;
1008            }
1009         }
1010         /* green component */
1011         etc2_r11_parse_block(&block, src + 8);
1012
1013         for (j = 0; j < h; j++) {
1014            uint8_t *dst = dst_row + (y + j) * dst_stride +
1015                           x * comps * comp_size;
1016            for (i = 0; i < w; i++) {
1017               etc2_signed_r11_fetch_texel(&block, i, j, dst + comp_size);
1018               dst += comps * comp_size;
1019            }
1020         }
1021         src += bs;
1022      }
1023
1024      src_row += src_stride;
1025   }
1026}
1027
1028static void
1029etc2_unpack_rgb8_punchthrough_alpha1(uint8_t *dst_row,
1030                                     unsigned dst_stride,
1031                                     const uint8_t *src_row,
1032                                     unsigned src_stride,
1033                                     unsigned width,
1034                                     unsigned height)
1035{
1036   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
1037   struct etc2_block block;
1038   unsigned x, y, i, j;
1039
1040   for (y = 0; y < height; y += bh) {
1041      const unsigned h = MIN2(bh, height - y);
1042      const uint8_t *src = src_row;
1043
1044      for (x = 0; x < width; x+= bw) {
1045         const unsigned w = MIN2(bw, width - x);
1046         etc2_rgb8_parse_block(&block, src,
1047                               true /* punchthrough_alpha */);
1048         for (j = 0; j < h; j++) {
1049            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
1050            for (i = 0; i < w; i++) {
1051               etc2_rgb8_fetch_texel(&block, i, j, dst,
1052                                     true /* punchthrough_alpha */);
1053               dst += comps;
1054            }
1055         }
1056
1057         src += bs;
1058      }
1059
1060      src_row += src_stride;
1061   }
1062}
1063
1064static void
1065etc2_unpack_srgb8_punchthrough_alpha1(uint8_t *dst_row,
1066                                     unsigned dst_stride,
1067                                     const uint8_t *src_row,
1068                                     unsigned src_stride,
1069                                     unsigned width,
1070				     unsigned height,
1071				     bool bgra)
1072{
1073   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
1074   struct etc2_block block;
1075   unsigned x, y, i, j;
1076   uint8_t tmp;
1077
1078   for (y = 0; y < height; y += bh) {
1079      const unsigned h = MIN2(bh, height - y);
1080      const uint8_t *src = src_row;
1081
1082      for (x = 0; x < width; x+= bw) {
1083         const unsigned w = MIN2(bw, width - x);
1084         etc2_rgb8_parse_block(&block, src,
1085                               true /* punchthrough_alpha */);
1086         for (j = 0; j < h; j++) {
1087            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
1088            for (i = 0; i < w; i++) {
1089               etc2_rgb8_fetch_texel(&block, i, j, dst,
1090                                     true /* punchthrough_alpha */);
1091
1092	       if (bgra) {
1093		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
1094		  tmp = dst[0];
1095		  dst[0] = dst[2];
1096		  dst[2] = tmp;
1097		  dst[3] = dst[3];
1098	       }
1099
1100               dst += comps;
1101            }
1102         }
1103
1104         src += bs;
1105      }
1106
1107      src_row += src_stride;
1108   }
1109}
1110
1111/* ETC2 texture formats are valid in glCompressedTexImage2D and
1112 * glCompressedTexSubImage2D functions */
1113GLboolean
1114_mesa_texstore_etc2_rgb8(UNUSED_TEXSTORE_PARAMS)
1115{
1116   assert(0);
1117
1118   return GL_FALSE;
1119}
1120
1121GLboolean
1122_mesa_texstore_etc2_srgb8(UNUSED_TEXSTORE_PARAMS)
1123{
1124   assert(0);
1125
1126   return GL_FALSE;
1127}
1128
1129GLboolean
1130_mesa_texstore_etc2_rgba8_eac(UNUSED_TEXSTORE_PARAMS)
1131{
1132   assert(0);
1133
1134   return GL_FALSE;
1135}
1136
1137GLboolean
1138_mesa_texstore_etc2_srgb8_alpha8_eac(UNUSED_TEXSTORE_PARAMS)
1139{
1140   assert(0);
1141
1142   return GL_FALSE;
1143}
1144
1145GLboolean
1146_mesa_texstore_etc2_r11_eac(UNUSED_TEXSTORE_PARAMS)
1147{
1148   assert(0);
1149
1150   return GL_FALSE;
1151}
1152
1153GLboolean
1154_mesa_texstore_etc2_signed_r11_eac(UNUSED_TEXSTORE_PARAMS)
1155{
1156   assert(0);
1157
1158   return GL_FALSE;
1159}
1160
1161GLboolean
1162_mesa_texstore_etc2_rg11_eac(UNUSED_TEXSTORE_PARAMS)
1163{
1164   assert(0);
1165
1166   return GL_FALSE;
1167}
1168
1169GLboolean
1170_mesa_texstore_etc2_signed_rg11_eac(UNUSED_TEXSTORE_PARAMS)
1171{
1172   assert(0);
1173
1174   return GL_FALSE;
1175}
1176
1177GLboolean
1178_mesa_texstore_etc2_rgb8_punchthrough_alpha1(UNUSED_TEXSTORE_PARAMS)
1179{
1180   assert(0);
1181
1182   return GL_FALSE;
1183}
1184
1185GLboolean
1186_mesa_texstore_etc2_srgb8_punchthrough_alpha1(UNUSED_TEXSTORE_PARAMS)
1187{
1188   assert(0);
1189
1190   return GL_FALSE;
1191}
1192
1193
1194/**
1195 * Decode texture data in any one of following formats:
1196 * `MESA_FORMAT_ETC2_RGB8`
1197 * `MESA_FORMAT_ETC2_SRGB8`
1198 * `MESA_FORMAT_ETC2_RGBA8_EAC`
1199 * `MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC`
1200 * `MESA_FORMAT_ETC2_R11_EAC`
1201 * `MESA_FORMAT_ETC2_RG11_EAC`
1202 * `MESA_FORMAT_ETC2_SIGNED_R11_EAC`
1203 * `MESA_FORMAT_ETC2_SIGNED_RG11_EAC`
1204 * `MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1`
1205 * `MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1`
1206 *
1207 * The size of the source data must be a multiple of the ETC2 block size
1208 * even if the texture image's dimensions are not aligned to 4.
1209 *
1210 * \param src_width in pixels
1211 * \param src_height in pixels
1212 * \param dst_stride in bytes
1213 */
1214
1215void
1216_mesa_unpack_etc2_format(uint8_t *dst_row,
1217                         unsigned dst_stride,
1218                         const uint8_t *src_row,
1219                         unsigned src_stride,
1220                         unsigned src_width,
1221                         unsigned src_height,
1222			 mesa_format format,
1223			 bool bgra)
1224{
1225   if (format == MESA_FORMAT_ETC2_RGB8)
1226      etc2_unpack_rgb8(dst_row, dst_stride,
1227                       src_row, src_stride,
1228                       src_width, src_height);
1229   else if (format == MESA_FORMAT_ETC2_SRGB8)
1230      etc2_unpack_srgb8(dst_row, dst_stride,
1231                        src_row, src_stride,
1232			src_width, src_height, bgra);
1233   else if (format == MESA_FORMAT_ETC2_RGBA8_EAC)
1234      etc2_unpack_rgba8(dst_row, dst_stride,
1235                        src_row, src_stride,
1236                        src_width, src_height);
1237   else if (format == MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC)
1238      etc2_unpack_srgb8_alpha8(dst_row, dst_stride,
1239                               src_row, src_stride,
1240			       src_width, src_height, bgra);
1241   else if (format == MESA_FORMAT_ETC2_R11_EAC)
1242      etc2_unpack_r11(dst_row, dst_stride,
1243                      src_row, src_stride,
1244                      src_width, src_height);
1245   else if (format == MESA_FORMAT_ETC2_RG11_EAC)
1246      etc2_unpack_rg11(dst_row, dst_stride,
1247                       src_row, src_stride,
1248                       src_width, src_height);
1249   else if (format == MESA_FORMAT_ETC2_SIGNED_R11_EAC)
1250      etc2_unpack_signed_r11(dst_row, dst_stride,
1251                             src_row, src_stride,
1252                             src_width, src_height);
1253   else if (format == MESA_FORMAT_ETC2_SIGNED_RG11_EAC)
1254      etc2_unpack_signed_rg11(dst_row, dst_stride,
1255                              src_row, src_stride,
1256                              src_width, src_height);
1257   else if (format == MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1)
1258      etc2_unpack_rgb8_punchthrough_alpha1(dst_row, dst_stride,
1259                                           src_row, src_stride,
1260                                           src_width, src_height);
1261   else if (format == MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1)
1262      etc2_unpack_srgb8_punchthrough_alpha1(dst_row, dst_stride,
1263                                            src_row, src_stride,
1264					    src_width, src_height, bgra);
1265}
1266
1267
1268
1269static void
1270fetch_etc1_rgb8(const GLubyte *map,
1271                GLint rowStride, GLint i, GLint j,
1272                GLfloat *texel)
1273{
1274   struct etc1_block block;
1275   GLubyte dst[3];
1276   const GLubyte *src;
1277
1278   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1279
1280   etc1_parse_block(&block, src);
1281   etc1_fetch_texel(&block, i % 4, j % 4, dst);
1282
1283   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1284   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1285   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1286   texel[ACOMP] = 1.0f;
1287}
1288
1289
1290static void
1291fetch_etc2_rgb8(const GLubyte *map,
1292                GLint rowStride, GLint i, GLint j, GLfloat *texel)
1293{
1294   struct etc2_block block;
1295   uint8_t dst[3];
1296   const uint8_t *src;
1297
1298   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1299
1300   etc2_rgb8_parse_block(&block, src,
1301                         false /* punchthrough_alpha */);
1302   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1303                         false /* punchthrough_alpha */);
1304
1305   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1306   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1307   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1308   texel[ACOMP] = 1.0f;
1309}
1310
1311static void
1312fetch_etc2_srgb8(const GLubyte *map,
1313                 GLint rowStride, GLint i, GLint j, GLfloat *texel)
1314{
1315   struct etc2_block block;
1316   uint8_t dst[3];
1317   const uint8_t *src;
1318
1319   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1320
1321   etc2_rgb8_parse_block(&block, src,
1322                         false /* punchthrough_alpha */);
1323   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1324                         false /* punchthrough_alpha */);
1325
1326   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1327   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1328   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1329   texel[ACOMP] = 1.0f;
1330}
1331
1332static void
1333fetch_etc2_rgba8_eac(const GLubyte *map,
1334                     GLint rowStride, GLint i, GLint j, GLfloat *texel)
1335{
1336   struct etc2_block block;
1337   uint8_t dst[4];
1338   const uint8_t *src;
1339
1340   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1341
1342   etc2_rgba8_parse_block(&block, src);
1343   etc2_rgba8_fetch_texel(&block, i % 4, j % 4, dst);
1344
1345   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1346   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1347   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1348   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1349}
1350
1351static void
1352fetch_etc2_srgb8_alpha8_eac(const GLubyte *map,
1353                            GLint rowStride, GLint i, GLint j, GLfloat *texel)
1354{
1355   struct etc2_block block;
1356   uint8_t dst[4];
1357   const uint8_t *src;
1358
1359   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1360
1361   etc2_rgba8_parse_block(&block, src);
1362   etc2_rgba8_fetch_texel(&block, i % 4, j % 4, dst);
1363
1364   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1365   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1366   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1367   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1368}
1369
1370static void
1371fetch_etc2_r11_eac(const GLubyte *map,
1372                   GLint rowStride, GLint i, GLint j, GLfloat *texel)
1373{
1374   struct etc2_block block;
1375   GLushort dst;
1376   const uint8_t *src;
1377
1378   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1379
1380   etc2_r11_parse_block(&block, src);
1381   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)&dst);
1382
1383   texel[RCOMP] = USHORT_TO_FLOAT(dst);
1384   texel[GCOMP] = 0.0f;
1385   texel[BCOMP] = 0.0f;
1386   texel[ACOMP] = 1.0f;
1387}
1388
1389static void
1390fetch_etc2_rg11_eac(const GLubyte *map,
1391                    GLint rowStride, GLint i, GLint j, GLfloat *texel)
1392{
1393   struct etc2_block block;
1394   GLushort dst[2];
1395   const uint8_t *src;
1396
1397   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1398
1399   /* red component */
1400   etc2_r11_parse_block(&block, src);
1401   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)dst);
1402
1403   /* green component */
1404   etc2_r11_parse_block(&block, src + 8);
1405   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)(dst + 1));
1406
1407   texel[RCOMP] = USHORT_TO_FLOAT(dst[0]);
1408   texel[GCOMP] = USHORT_TO_FLOAT(dst[1]);
1409   texel[BCOMP] = 0.0f;
1410   texel[ACOMP] = 1.0f;
1411}
1412
1413static void
1414fetch_etc2_signed_r11_eac(const GLubyte *map,
1415                          GLint rowStride, GLint i, GLint j, GLfloat *texel)
1416{
1417   struct etc2_block block;
1418   GLushort dst;
1419   const uint8_t *src;
1420
1421   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1422
1423   etc2_r11_parse_block(&block, src);
1424   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)&dst);
1425
1426   texel[RCOMP] = SHORT_TO_FLOAT(dst);
1427   texel[GCOMP] = 0.0f;
1428   texel[BCOMP] = 0.0f;
1429   texel[ACOMP] = 1.0f;
1430}
1431
1432static void
1433fetch_etc2_signed_rg11_eac(const GLubyte *map,
1434                           GLint rowStride, GLint i, GLint j, GLfloat *texel)
1435{
1436   struct etc2_block block;
1437   GLushort dst[2];
1438   const uint8_t *src;
1439
1440   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1441
1442   /* red component */
1443   etc2_r11_parse_block(&block, src);
1444   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)dst);
1445
1446   /* green component */
1447   etc2_r11_parse_block(&block, src + 8);
1448   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)(dst + 1));
1449
1450   texel[RCOMP] = SHORT_TO_FLOAT(dst[0]);
1451   texel[GCOMP] = SHORT_TO_FLOAT(dst[1]);
1452   texel[BCOMP] = 0.0f;
1453   texel[ACOMP] = 1.0f;
1454}
1455
1456static void
1457fetch_etc2_rgb8_punchthrough_alpha1(const GLubyte *map,
1458                                    GLint rowStride, GLint i, GLint j,
1459                                    GLfloat *texel)
1460{
1461   struct etc2_block block;
1462   uint8_t dst[4];
1463   const uint8_t *src;
1464
1465   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1466
1467   etc2_rgb8_parse_block(&block, src,
1468                         true /* punchthrough alpha */);
1469   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1470                         true /* punchthrough alpha */);
1471   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1472   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1473   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1474   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1475}
1476
1477static void
1478fetch_etc2_srgb8_punchthrough_alpha1(const GLubyte *map,
1479                                     GLint rowStride,
1480                                     GLint i, GLint j, GLfloat *texel)
1481{
1482   struct etc2_block block;
1483   uint8_t dst[4];
1484   const uint8_t *src;
1485
1486   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1487
1488   etc2_rgb8_parse_block(&block, src,
1489                         true /* punchthrough alpha */);
1490   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1491                         true /* punchthrough alpha */);
1492   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1493   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1494   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1495   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1496}
1497
1498
1499compressed_fetch_func
1500_mesa_get_etc_fetch_func(mesa_format format)
1501{
1502   switch (format) {
1503   case MESA_FORMAT_ETC1_RGB8:
1504      return fetch_etc1_rgb8;
1505   case MESA_FORMAT_ETC2_RGB8:
1506      return fetch_etc2_rgb8;
1507   case MESA_FORMAT_ETC2_SRGB8:
1508      return fetch_etc2_srgb8;
1509   case MESA_FORMAT_ETC2_RGBA8_EAC:
1510      return fetch_etc2_rgba8_eac;
1511   case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC:
1512      return fetch_etc2_srgb8_alpha8_eac;
1513   case MESA_FORMAT_ETC2_R11_EAC:
1514      return fetch_etc2_r11_eac;
1515   case MESA_FORMAT_ETC2_RG11_EAC:
1516      return fetch_etc2_rg11_eac;
1517   case MESA_FORMAT_ETC2_SIGNED_R11_EAC:
1518      return fetch_etc2_signed_r11_eac;
1519   case MESA_FORMAT_ETC2_SIGNED_RG11_EAC:
1520      return fetch_etc2_signed_rg11_eac;
1521   case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1:
1522      return fetch_etc2_rgb8_punchthrough_alpha1;
1523   case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1:
1524      return fetch_etc2_srgb8_punchthrough_alpha1;
1525   default:
1526      return NULL;
1527   }
1528}
1529