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}
552
553static void
554etc2_alpha8_fetch_texel(const struct etc2_block *block,
555      int x, int y, uint8_t *dst)
556{
557   int modifier, alpha, idx;
558   /* get pixel index */
559   idx = etc2_get_pixel_index(block, x, y);
560   modifier = etc2_modifier_tables[block->table_index][idx];
561   alpha = block->base_codeword + modifier * block->multiplier;
562   dst[3] = etc2_clamp(alpha);
563}
564
565static void
566etc2_r11_fetch_texel(const struct etc2_block *block,
567                     int x, int y, uint8_t *dst)
568{
569   GLint modifier, idx;
570   GLshort color;
571   /* Get pixel index */
572   idx = etc2_get_pixel_index(block, x, y);
573   modifier = etc2_modifier_tables[block->table_index][idx];
574
575   if (block->multiplier != 0)
576      /* clamp2(base codeword × 8 + 4 + modifier × multiplier × 8) */
577      color = etc2_clamp2(((block->base_codeword << 3) | 0x4)  +
578                          ((modifier * block->multiplier) << 3));
579   else
580      color = etc2_clamp2(((block->base_codeword << 3) | 0x4)  + modifier);
581
582   /* Extend 11 bits color value to 16 bits. OpenGL ES 3.0 specification
583    * allows extending the color value to any number of bits. But, an
584    * implementation is not allowed to truncate the 11-bit value to less than
585    * 11 bits."
586    */
587   color = (color << 5) | (color >> 6);
588   ((GLushort *)dst)[0] = color;
589}
590
591static void
592etc2_signed_r11_fetch_texel(const struct etc2_block *block,
593                            int x, int y, uint8_t *dst)
594{
595   GLint modifier, idx;
596   GLshort color;
597   GLbyte base_codeword = (GLbyte) block->base_codeword;
598
599   if (base_codeword == -128)
600      base_codeword = -127;
601
602   /* Get pixel index */
603   idx = etc2_get_pixel_index(block, x, y);
604   modifier = etc2_modifier_tables[block->table_index][idx];
605
606   if (block->multiplier != 0)
607      /* clamp3(base codeword × 8 + modifier × multiplier × 8) */
608      color = etc2_clamp3((base_codeword << 3)  +
609                         ((modifier * block->multiplier) << 3));
610   else
611      color = etc2_clamp3((base_codeword << 3)  + modifier);
612
613   /* Extend 11 bits color value to 16 bits. OpenGL ES 3.0 specification
614    * allows extending the color value to any number of bits. But, an
615    * implementation is not allowed to truncate the 11-bit value to less than
616    * 11 bits. A negative 11-bit value must first be made positive before bit
617    * replication, and then made negative again
618    */
619   if (color >= 0)
620      color = (color << 5) | (color >> 5);
621   else {
622      color = -color;
623      color = (color << 5) | (color >> 5);
624      color = -color;
625   }
626   ((GLshort *)dst)[0] = color;
627}
628
629static void
630etc2_alpha8_parse_block(struct etc2_block *block, const uint8_t *src)
631{
632   block->base_codeword = src[0];
633   block->multiplier = (src[1] >> 4) & 0xf;
634   block->table_index = src[1] & 0xf;
635   block->pixel_indices[1] = (((uint64_t)src[2] << 40) |
636                              ((uint64_t)src[3] << 32) |
637                              ((uint64_t)src[4] << 24) |
638                              ((uint64_t)src[5] << 16) |
639                              ((uint64_t)src[6] << 8)  |
640                              ((uint64_t)src[7]));
641}
642
643static void
644etc2_r11_parse_block(struct etc2_block *block, const uint8_t *src)
645{
646   /* Parsing logic remains same as for etc2_alpha8_parse_block */
647    etc2_alpha8_parse_block(block, src);
648}
649
650static void
651etc2_rgba8_parse_block(struct etc2_block *block, const uint8_t *src)
652{
653   /* RGB component is parsed the same way as for MESA_FORMAT_ETC2_RGB8 */
654   etc2_rgb8_parse_block(block, src + 8,
655                         false /* punchthrough_alpha */);
656   /* Parse Alpha component */
657   etc2_alpha8_parse_block(block, src);
658}
659
660static void
661etc2_rgba8_fetch_texel(const struct etc2_block *block,
662      int x, int y, uint8_t *dst)
663{
664   etc2_rgb8_fetch_texel(block, x, y, dst,
665                         false /* punchthrough_alpha */);
666   etc2_alpha8_fetch_texel(block, x, y, dst);
667}
668
669static void
670etc2_unpack_rgb8(uint8_t *dst_row,
671                 unsigned dst_stride,
672                 const uint8_t *src_row,
673                 unsigned src_stride,
674                 unsigned width,
675                 unsigned height)
676{
677   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
678   struct etc2_block block;
679   unsigned x, y, i, j;
680
681   for (y = 0; y < height; y += bh) {
682      const uint8_t *src = src_row;
683      /*
684       * Destination texture may not be a multiple of four texels in
685       * height. Compute a safe height to avoid writing outside the texture.
686       */
687      const unsigned h = MIN2(bh, height - y);
688
689      for (x = 0; x < width; x+= bw) {
690         /*
691          * Destination texture may not be a multiple of four texels in
692          * width. Compute a safe width to avoid writing outside the texture.
693          */
694         const unsigned w = MIN2(bw, width - x);
695
696         etc2_rgb8_parse_block(&block, src,
697                               false /* punchthrough_alpha */);
698
699         for (j = 0; j < h; j++) {
700            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
701            for (i = 0; i < w; i++) {
702               etc2_rgb8_fetch_texel(&block, i, j, dst,
703                                     false /* punchthrough_alpha */);
704               dst[3] = 255;
705               dst += comps;
706            }
707         }
708
709         src += bs;
710      }
711
712      src_row += src_stride;
713   }
714}
715
716static void
717etc2_unpack_srgb8(uint8_t *dst_row,
718                  unsigned dst_stride,
719                  const uint8_t *src_row,
720                  unsigned src_stride,
721                  unsigned width,
722		  unsigned height,
723		  bool bgra)
724{
725   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
726   struct etc2_block block;
727   unsigned x, y, i, j;
728   uint8_t tmp;
729
730   for (y = 0; y < height; y += bh) {
731      const uint8_t *src = src_row;
732      const unsigned h = MIN2(bh, height - y);
733
734      for (x = 0; x < width; x+= bw) {
735         const unsigned w = MIN2(bw, width - x);
736         etc2_rgb8_parse_block(&block, src,
737                               false /* punchthrough_alpha */);
738
739
740         for (j = 0; j < h; j++) {
741            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
742            for (i = 0; i < w; i++) {
743               etc2_rgb8_fetch_texel(&block, i, j, dst,
744                                     false /* punchthrough_alpha */);
745
746	       if (bgra) {
747		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
748		  tmp = dst[0];
749		  dst[0] = dst[2];
750		  dst[2] = tmp;
751		  dst[3] = 255;
752	       }
753
754               dst += comps;
755            }
756         }
757         src += bs;
758      }
759
760      src_row += src_stride;
761   }
762}
763
764static void
765etc2_unpack_rgba8(uint8_t *dst_row,
766                  unsigned dst_stride,
767                  const uint8_t *src_row,
768                  unsigned src_stride,
769                  unsigned width,
770                  unsigned height)
771{
772   /* If internalformat is COMPRESSED_RGBA8_ETC2_EAC, each 4 × 4 block of
773    * RGBA8888 information is compressed to 128 bits. To decode a block, the
774    * two 64-bit integers int64bitAlpha and int64bitColor are calculated.
775   */
776   const unsigned bw = 4, bh = 4, bs = 16, comps = 4;
777   struct etc2_block block;
778   unsigned x, y, i, j;
779
780   for (y = 0; y < height; y += bh) {
781      const uint8_t *src = src_row;
782      const unsigned h = MIN2(bh, height - y);
783
784      for (x = 0; x < width; x+= bw) {
785         const unsigned w = MIN2(bw, width - x);
786         etc2_rgba8_parse_block(&block, src);
787
788         for (j = 0; j < h; j++) {
789            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
790            for (i = 0; i < w; i++) {
791               etc2_rgba8_fetch_texel(&block, i, j, dst);
792               dst += comps;
793            }
794         }
795         src += bs;
796      }
797
798      src_row += src_stride;
799   }
800}
801
802static void
803etc2_unpack_srgb8_alpha8(uint8_t *dst_row,
804                         unsigned dst_stride,
805                         const uint8_t *src_row,
806                         unsigned src_stride,
807                         unsigned width,
808			 unsigned height,
809			 bool bgra)
810{
811   /* If internalformat is COMPRESSED_SRGB8_ALPHA8_ETC2_EAC, each 4 × 4 block
812    * of RGBA8888 information is compressed to 128 bits. To decode a block, the
813    * two 64-bit integers int64bitAlpha and int64bitColor are calculated.
814    */
815   const unsigned bw = 4, bh = 4, bs = 16, comps = 4;
816   struct etc2_block block;
817   unsigned x, y, i, j;
818   uint8_t tmp;
819
820   for (y = 0; y < height; y += bh) {
821      const unsigned h = MIN2(bh, height - y);
822      const uint8_t *src = src_row;
823
824      for (x = 0; x < width; x+= bw) {
825         const unsigned w = MIN2(bw, width - x);
826         etc2_rgba8_parse_block(&block, src);
827
828         for (j = 0; j < h; j++) {
829            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
830            for (i = 0; i < w; i++) {
831               etc2_rgba8_fetch_texel(&block, i, j, dst);
832
833	       if (bgra) {
834		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
835		  tmp = dst[0];
836		  dst[0] = dst[2];
837		  dst[2] = tmp;
838		  dst[3] = dst[3];
839	       }
840
841               dst += comps;
842            }
843         }
844         src += bs;
845      }
846
847      src_row += src_stride;
848   }
849}
850
851static void
852etc2_unpack_r11(uint8_t *dst_row,
853                unsigned dst_stride,
854                const uint8_t *src_row,
855                unsigned src_stride,
856                unsigned width,
857                unsigned height)
858{
859   /* If internalformat is COMPRESSED_R11_EAC, each 4 × 4 block of
860      color information is compressed to 64 bits.
861   */
862   const unsigned bw = 4, bh = 4, bs = 8, comps = 1, comp_size = 2;
863   struct etc2_block block;
864   unsigned x, y, i, j;
865
866   for (y = 0; y < height; y += bh) {
867      const unsigned h = MIN2(bh, height - y);
868      const uint8_t *src = src_row;
869
870      for (x = 0; x < width; x+= bw) {
871         const unsigned w = MIN2(bw, width - x);
872         etc2_r11_parse_block(&block, src);
873
874         for (j = 0; j < h; j++) {
875            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps * comp_size;
876            for (i = 0; i < w; i++) {
877               etc2_r11_fetch_texel(&block, i, j, dst);
878               dst += comps * comp_size;
879            }
880         }
881         src += bs;
882      }
883
884      src_row += src_stride;
885   }
886}
887
888static void
889etc2_unpack_rg11(uint8_t *dst_row,
890                 unsigned dst_stride,
891                 const uint8_t *src_row,
892                 unsigned src_stride,
893                 unsigned width,
894                 unsigned height)
895{
896   /* If internalformat is COMPRESSED_RG11_EAC, each 4 × 4 block of
897      RG color information is compressed to 128 bits.
898   */
899   const unsigned bw = 4, bh = 4, bs = 16, comps = 2, comp_size = 2;
900   struct etc2_block block;
901   unsigned x, y, i, j;
902
903   for (y = 0; y < height; y += bh) {
904      const unsigned h = MIN2(bh, height - y);
905      const uint8_t *src = src_row;
906
907      for (x = 0; x < width; x+= bw) {
908         const unsigned w = MIN2(bw, width - x);
909         /* red component */
910         etc2_r11_parse_block(&block, src);
911
912         for (j = 0; j < h; j++) {
913            uint8_t *dst = dst_row + (y + j) * dst_stride +
914                           x * comps * comp_size;
915            for (i = 0; i < w; i++) {
916               etc2_r11_fetch_texel(&block, i, j, dst);
917               dst += comps * comp_size;
918            }
919         }
920         /* green component */
921         etc2_r11_parse_block(&block, src + 8);
922
923         for (j = 0; j < h; j++) {
924            uint8_t *dst = dst_row + (y + j) * dst_stride +
925                           x * comps * comp_size;
926            for (i = 0; i < w; i++) {
927               etc2_r11_fetch_texel(&block, i, j, dst + comp_size);
928               dst += comps * comp_size;
929            }
930         }
931         src += bs;
932      }
933
934      src_row += src_stride;
935   }
936}
937
938static void
939etc2_unpack_signed_r11(uint8_t *dst_row,
940                       unsigned dst_stride,
941                       const uint8_t *src_row,
942                       unsigned src_stride,
943                       unsigned width,
944                       unsigned height)
945{
946   /* If internalformat is COMPRESSED_SIGNED_R11_EAC, each 4 × 4 block of
947      red color information is compressed to 64 bits.
948   */
949   const unsigned bw = 4, bh = 4, bs = 8, comps = 1, comp_size = 2;
950   struct etc2_block block;
951   unsigned x, y, i, j;
952
953   for (y = 0; y < height; y += bh) {
954      const unsigned h = MIN2(bh, height - y);
955      const uint8_t *src = src_row;
956
957      for (x = 0; x < width; x+= bw) {
958         const unsigned w = MIN2(bw, width - x);
959         etc2_r11_parse_block(&block, src);
960
961         for (j = 0; j < h; j++) {
962            uint8_t *dst = dst_row + (y + j) * dst_stride +
963                           x * comps * comp_size;
964            for (i = 0; i < w; i++) {
965               etc2_signed_r11_fetch_texel(&block, i, j, dst);
966               dst += comps * comp_size;
967            }
968         }
969         src += bs;
970      }
971
972      src_row += src_stride;
973   }
974}
975
976static void
977etc2_unpack_signed_rg11(uint8_t *dst_row,
978                        unsigned dst_stride,
979                        const uint8_t *src_row,
980                        unsigned src_stride,
981                        unsigned width,
982                        unsigned height)
983{
984   /* If internalformat is COMPRESSED_SIGNED_RG11_EAC, each 4 × 4 block of
985      RG color information is compressed to 128 bits.
986   */
987   const unsigned bw = 4, bh = 4, bs = 16, comps = 2, comp_size = 2;
988   struct etc2_block block;
989   unsigned x, y, i, j;
990
991   for (y = 0; y < height; y += bh) {
992      const unsigned h = MIN2(bh, height - y);
993      const uint8_t *src = src_row;
994
995      for (x = 0; x < width; x+= bw) {
996         const unsigned w = MIN2(bw, width - x);
997         /* red component */
998         etc2_r11_parse_block(&block, src);
999
1000         for (j = 0; j < h; j++) {
1001            uint8_t *dst = dst_row + (y + j) * dst_stride +
1002                          x * comps * comp_size;
1003            for (i = 0; i < w; i++) {
1004               etc2_signed_r11_fetch_texel(&block, i, j, dst);
1005               dst += comps * comp_size;
1006            }
1007         }
1008         /* green component */
1009         etc2_r11_parse_block(&block, src + 8);
1010
1011         for (j = 0; j < h; j++) {
1012            uint8_t *dst = dst_row + (y + j) * dst_stride +
1013                           x * comps * comp_size;
1014            for (i = 0; i < w; i++) {
1015               etc2_signed_r11_fetch_texel(&block, i, j, dst + comp_size);
1016               dst += comps * comp_size;
1017            }
1018         }
1019         src += bs;
1020      }
1021
1022      src_row += src_stride;
1023   }
1024}
1025
1026static void
1027etc2_unpack_rgb8_punchthrough_alpha1(uint8_t *dst_row,
1028                                     unsigned dst_stride,
1029                                     const uint8_t *src_row,
1030                                     unsigned src_stride,
1031                                     unsigned width,
1032                                     unsigned height)
1033{
1034   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
1035   struct etc2_block block;
1036   unsigned x, y, i, j;
1037
1038   for (y = 0; y < height; y += bh) {
1039      const unsigned h = MIN2(bh, height - y);
1040      const uint8_t *src = src_row;
1041
1042      for (x = 0; x < width; x+= bw) {
1043         const unsigned w = MIN2(bw, width - x);
1044         etc2_rgb8_parse_block(&block, src,
1045                               true /* punchthrough_alpha */);
1046         for (j = 0; j < h; j++) {
1047            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
1048            for (i = 0; i < w; i++) {
1049               etc2_rgb8_fetch_texel(&block, i, j, dst,
1050                                     true /* punchthrough_alpha */);
1051               dst += comps;
1052            }
1053         }
1054
1055         src += bs;
1056      }
1057
1058      src_row += src_stride;
1059   }
1060}
1061
1062static void
1063etc2_unpack_srgb8_punchthrough_alpha1(uint8_t *dst_row,
1064                                     unsigned dst_stride,
1065                                     const uint8_t *src_row,
1066                                     unsigned src_stride,
1067                                     unsigned width,
1068				     unsigned height,
1069				     bool bgra)
1070{
1071   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
1072   struct etc2_block block;
1073   unsigned x, y, i, j;
1074   uint8_t tmp;
1075
1076   for (y = 0; y < height; y += bh) {
1077      const unsigned h = MIN2(bh, height - y);
1078      const uint8_t *src = src_row;
1079
1080      for (x = 0; x < width; x+= bw) {
1081         const unsigned w = MIN2(bw, width - x);
1082         etc2_rgb8_parse_block(&block, src,
1083                               true /* punchthrough_alpha */);
1084         for (j = 0; j < h; j++) {
1085            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
1086            for (i = 0; i < w; i++) {
1087               etc2_rgb8_fetch_texel(&block, i, j, dst,
1088                                     true /* punchthrough_alpha */);
1089
1090	       if (bgra) {
1091		  /* Convert to MESA_FORMAT_B8G8R8A8_SRGB */
1092		  tmp = dst[0];
1093		  dst[0] = dst[2];
1094		  dst[2] = tmp;
1095		  dst[3] = dst[3];
1096	       }
1097
1098               dst += comps;
1099            }
1100         }
1101
1102         src += bs;
1103      }
1104
1105      src_row += src_stride;
1106   }
1107}
1108
1109/* ETC2 texture formats are valid in glCompressedTexImage2D and
1110 * glCompressedTexSubImage2D functions */
1111GLboolean
1112_mesa_texstore_etc2_rgb8(UNUSED_TEXSTORE_PARAMS)
1113{
1114   assert(0);
1115
1116   return GL_FALSE;
1117}
1118
1119GLboolean
1120_mesa_texstore_etc2_srgb8(UNUSED_TEXSTORE_PARAMS)
1121{
1122   assert(0);
1123
1124   return GL_FALSE;
1125}
1126
1127GLboolean
1128_mesa_texstore_etc2_rgba8_eac(UNUSED_TEXSTORE_PARAMS)
1129{
1130   assert(0);
1131
1132   return GL_FALSE;
1133}
1134
1135GLboolean
1136_mesa_texstore_etc2_srgb8_alpha8_eac(UNUSED_TEXSTORE_PARAMS)
1137{
1138   assert(0);
1139
1140   return GL_FALSE;
1141}
1142
1143GLboolean
1144_mesa_texstore_etc2_r11_eac(UNUSED_TEXSTORE_PARAMS)
1145{
1146   assert(0);
1147
1148   return GL_FALSE;
1149}
1150
1151GLboolean
1152_mesa_texstore_etc2_signed_r11_eac(UNUSED_TEXSTORE_PARAMS)
1153{
1154   assert(0);
1155
1156   return GL_FALSE;
1157}
1158
1159GLboolean
1160_mesa_texstore_etc2_rg11_eac(UNUSED_TEXSTORE_PARAMS)
1161{
1162   assert(0);
1163
1164   return GL_FALSE;
1165}
1166
1167GLboolean
1168_mesa_texstore_etc2_signed_rg11_eac(UNUSED_TEXSTORE_PARAMS)
1169{
1170   assert(0);
1171
1172   return GL_FALSE;
1173}
1174
1175GLboolean
1176_mesa_texstore_etc2_rgb8_punchthrough_alpha1(UNUSED_TEXSTORE_PARAMS)
1177{
1178   assert(0);
1179
1180   return GL_FALSE;
1181}
1182
1183GLboolean
1184_mesa_texstore_etc2_srgb8_punchthrough_alpha1(UNUSED_TEXSTORE_PARAMS)
1185{
1186   assert(0);
1187
1188   return GL_FALSE;
1189}
1190
1191
1192/**
1193 * Decode texture data in any one of following formats:
1194 * `MESA_FORMAT_ETC2_RGB8`
1195 * `MESA_FORMAT_ETC2_SRGB8`
1196 * `MESA_FORMAT_ETC2_RGBA8_EAC`
1197 * `MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC`
1198 * `MESA_FORMAT_ETC2_R11_EAC`
1199 * `MESA_FORMAT_ETC2_RG11_EAC`
1200 * `MESA_FORMAT_ETC2_SIGNED_R11_EAC`
1201 * `MESA_FORMAT_ETC2_SIGNED_RG11_EAC`
1202 * `MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1`
1203 * `MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1`
1204 *
1205 * The size of the source data must be a multiple of the ETC2 block size
1206 * even if the texture image's dimensions are not aligned to 4.
1207 *
1208 * \param src_width in pixels
1209 * \param src_height in pixels
1210 * \param dst_stride in bytes
1211 */
1212
1213void
1214_mesa_unpack_etc2_format(uint8_t *dst_row,
1215                         unsigned dst_stride,
1216                         const uint8_t *src_row,
1217                         unsigned src_stride,
1218                         unsigned src_width,
1219                         unsigned src_height,
1220			 mesa_format format,
1221			 bool bgra)
1222{
1223   if (format == MESA_FORMAT_ETC2_RGB8)
1224      etc2_unpack_rgb8(dst_row, dst_stride,
1225                       src_row, src_stride,
1226                       src_width, src_height);
1227   else if (format == MESA_FORMAT_ETC2_SRGB8)
1228      etc2_unpack_srgb8(dst_row, dst_stride,
1229                        src_row, src_stride,
1230			src_width, src_height, bgra);
1231   else if (format == MESA_FORMAT_ETC2_RGBA8_EAC)
1232      etc2_unpack_rgba8(dst_row, dst_stride,
1233                        src_row, src_stride,
1234                        src_width, src_height);
1235   else if (format == MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC)
1236      etc2_unpack_srgb8_alpha8(dst_row, dst_stride,
1237                               src_row, src_stride,
1238			       src_width, src_height, bgra);
1239   else if (format == MESA_FORMAT_ETC2_R11_EAC)
1240      etc2_unpack_r11(dst_row, dst_stride,
1241                      src_row, src_stride,
1242                      src_width, src_height);
1243   else if (format == MESA_FORMAT_ETC2_RG11_EAC)
1244      etc2_unpack_rg11(dst_row, dst_stride,
1245                       src_row, src_stride,
1246                       src_width, src_height);
1247   else if (format == MESA_FORMAT_ETC2_SIGNED_R11_EAC)
1248      etc2_unpack_signed_r11(dst_row, dst_stride,
1249                             src_row, src_stride,
1250                             src_width, src_height);
1251   else if (format == MESA_FORMAT_ETC2_SIGNED_RG11_EAC)
1252      etc2_unpack_signed_rg11(dst_row, dst_stride,
1253                              src_row, src_stride,
1254                              src_width, src_height);
1255   else if (format == MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1)
1256      etc2_unpack_rgb8_punchthrough_alpha1(dst_row, dst_stride,
1257                                           src_row, src_stride,
1258                                           src_width, src_height);
1259   else if (format == MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1)
1260      etc2_unpack_srgb8_punchthrough_alpha1(dst_row, dst_stride,
1261                                            src_row, src_stride,
1262					    src_width, src_height, bgra);
1263}
1264
1265
1266
1267static void
1268fetch_etc1_rgb8(const GLubyte *map,
1269                GLint rowStride, GLint i, GLint j,
1270                GLfloat *texel)
1271{
1272   struct etc1_block block;
1273   GLubyte dst[3];
1274   const GLubyte *src;
1275
1276   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1277
1278   etc1_parse_block(&block, src);
1279   etc1_fetch_texel(&block, i % 4, j % 4, dst);
1280
1281   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1282   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1283   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1284   texel[ACOMP] = 1.0f;
1285}
1286
1287
1288static void
1289fetch_etc2_rgb8(const GLubyte *map,
1290                GLint rowStride, GLint i, GLint j, GLfloat *texel)
1291{
1292   struct etc2_block block;
1293   uint8_t dst[3];
1294   const uint8_t *src;
1295
1296   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1297
1298   etc2_rgb8_parse_block(&block, src,
1299                         false /* punchthrough_alpha */);
1300   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1301                         false /* punchthrough_alpha */);
1302
1303   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1304   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1305   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1306   texel[ACOMP] = 1.0f;
1307}
1308
1309static void
1310fetch_etc2_srgb8(const GLubyte *map,
1311                 GLint rowStride, GLint i, GLint j, GLfloat *texel)
1312{
1313   struct etc2_block block;
1314   uint8_t dst[3];
1315   const uint8_t *src;
1316
1317   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1318
1319   etc2_rgb8_parse_block(&block, src,
1320                         false /* punchthrough_alpha */);
1321   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1322                         false /* punchthrough_alpha */);
1323
1324   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1325   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1326   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1327   texel[ACOMP] = 1.0f;
1328}
1329
1330static void
1331fetch_etc2_rgba8_eac(const GLubyte *map,
1332                     GLint rowStride, GLint i, GLint j, GLfloat *texel)
1333{
1334   struct etc2_block block;
1335   uint8_t dst[4];
1336   const uint8_t *src;
1337
1338   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1339
1340   etc2_rgba8_parse_block(&block, src);
1341   etc2_rgba8_fetch_texel(&block, i % 4, j % 4, dst);
1342
1343   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1344   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1345   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1346   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1347}
1348
1349static void
1350fetch_etc2_srgb8_alpha8_eac(const GLubyte *map,
1351                            GLint rowStride, GLint i, GLint j, GLfloat *texel)
1352{
1353   struct etc2_block block;
1354   uint8_t dst[4];
1355   const uint8_t *src;
1356
1357   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1358
1359   etc2_rgba8_parse_block(&block, src);
1360   etc2_rgba8_fetch_texel(&block, i % 4, j % 4, dst);
1361
1362   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1363   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1364   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1365   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1366}
1367
1368static void
1369fetch_etc2_r11_eac(const GLubyte *map,
1370                   GLint rowStride, GLint i, GLint j, GLfloat *texel)
1371{
1372   struct etc2_block block;
1373   GLushort dst;
1374   const uint8_t *src;
1375
1376   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1377
1378   etc2_r11_parse_block(&block, src);
1379   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)&dst);
1380
1381   texel[RCOMP] = USHORT_TO_FLOAT(dst);
1382   texel[GCOMP] = 0.0f;
1383   texel[BCOMP] = 0.0f;
1384   texel[ACOMP] = 1.0f;
1385}
1386
1387static void
1388fetch_etc2_rg11_eac(const GLubyte *map,
1389                    GLint rowStride, GLint i, GLint j, GLfloat *texel)
1390{
1391   struct etc2_block block;
1392   GLushort dst[2];
1393   const uint8_t *src;
1394
1395   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1396
1397   /* red component */
1398   etc2_r11_parse_block(&block, src);
1399   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)dst);
1400
1401   /* green component */
1402   etc2_r11_parse_block(&block, src + 8);
1403   etc2_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)(dst + 1));
1404
1405   texel[RCOMP] = USHORT_TO_FLOAT(dst[0]);
1406   texel[GCOMP] = USHORT_TO_FLOAT(dst[1]);
1407   texel[BCOMP] = 0.0f;
1408   texel[ACOMP] = 1.0f;
1409}
1410
1411static void
1412fetch_etc2_signed_r11_eac(const GLubyte *map,
1413                          GLint rowStride, GLint i, GLint j, GLfloat *texel)
1414{
1415   struct etc2_block block;
1416   GLushort dst;
1417   const uint8_t *src;
1418
1419   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1420
1421   etc2_r11_parse_block(&block, src);
1422   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)&dst);
1423
1424   texel[RCOMP] = SHORT_TO_FLOAT(dst);
1425   texel[GCOMP] = 0.0f;
1426   texel[BCOMP] = 0.0f;
1427   texel[ACOMP] = 1.0f;
1428}
1429
1430static void
1431fetch_etc2_signed_rg11_eac(const GLubyte *map,
1432                           GLint rowStride, GLint i, GLint j, GLfloat *texel)
1433{
1434   struct etc2_block block;
1435   GLushort dst[2];
1436   const uint8_t *src;
1437
1438   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
1439
1440   /* red component */
1441   etc2_r11_parse_block(&block, src);
1442   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)dst);
1443
1444   /* green component */
1445   etc2_r11_parse_block(&block, src + 8);
1446   etc2_signed_r11_fetch_texel(&block, i % 4, j % 4, (uint8_t *)(dst + 1));
1447
1448   texel[RCOMP] = SHORT_TO_FLOAT(dst[0]);
1449   texel[GCOMP] = SHORT_TO_FLOAT(dst[1]);
1450   texel[BCOMP] = 0.0f;
1451   texel[ACOMP] = 1.0f;
1452}
1453
1454static void
1455fetch_etc2_rgb8_punchthrough_alpha1(const GLubyte *map,
1456                                    GLint rowStride, GLint i, GLint j,
1457                                    GLfloat *texel)
1458{
1459   struct etc2_block block;
1460   uint8_t dst[4];
1461   const uint8_t *src;
1462
1463   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1464
1465   etc2_rgb8_parse_block(&block, src,
1466                         true /* punchthrough alpha */);
1467   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1468                         true /* punchthrough alpha */);
1469   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
1470   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
1471   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
1472   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1473}
1474
1475static void
1476fetch_etc2_srgb8_punchthrough_alpha1(const GLubyte *map,
1477                                     GLint rowStride,
1478                                     GLint i, GLint j, GLfloat *texel)
1479{
1480   struct etc2_block block;
1481   uint8_t dst[4];
1482   const uint8_t *src;
1483
1484   src = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
1485
1486   etc2_rgb8_parse_block(&block, src,
1487                         true /* punchthrough alpha */);
1488   etc2_rgb8_fetch_texel(&block, i % 4, j % 4, dst,
1489                         true /* punchthrough alpha */);
1490   texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(dst[0]);
1491   texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(dst[1]);
1492   texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(dst[2]);
1493   texel[ACOMP] = UBYTE_TO_FLOAT(dst[3]);
1494}
1495
1496
1497compressed_fetch_func
1498_mesa_get_etc_fetch_func(mesa_format format)
1499{
1500   switch (format) {
1501   case MESA_FORMAT_ETC1_RGB8:
1502      return fetch_etc1_rgb8;
1503   case MESA_FORMAT_ETC2_RGB8:
1504      return fetch_etc2_rgb8;
1505   case MESA_FORMAT_ETC2_SRGB8:
1506      return fetch_etc2_srgb8;
1507   case MESA_FORMAT_ETC2_RGBA8_EAC:
1508      return fetch_etc2_rgba8_eac;
1509   case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC:
1510      return fetch_etc2_srgb8_alpha8_eac;
1511   case MESA_FORMAT_ETC2_R11_EAC:
1512      return fetch_etc2_r11_eac;
1513   case MESA_FORMAT_ETC2_RG11_EAC:
1514      return fetch_etc2_rg11_eac;
1515   case MESA_FORMAT_ETC2_SIGNED_R11_EAC:
1516      return fetch_etc2_signed_r11_eac;
1517   case MESA_FORMAT_ETC2_SIGNED_RG11_EAC:
1518      return fetch_etc2_signed_rg11_eac;
1519   case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1:
1520      return fetch_etc2_rgb8_punchthrough_alpha1;
1521   case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1:
1522      return fetch_etc2_srgb8_punchthrough_alpha1;
1523   default:
1524      return NULL;
1525   }
1526}
1527