-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathdither.c
1146 lines (991 loc) · 26.8 KB
/
dither.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* dither.c
* Dithering
* (c) 2000-2002 Karel 'Clock' Kulhavy
* This file is a part of the Links program, released under GPL.
*/
#include "cfg.h"
#ifdef G
#include "links.h"
#include "bits.h"
#ifdef HAVE_MATH_H
#include <math.h>
#endif
/* The input of dithering function is 3 times 16-bit value. The value is
* proportional to light that will go out of the monitor. Only in this space it
* is possible to dither accurately because distributing the error means maintaining
* the photon count (blurring caused by human eye from big distance preservers photon
* count, just spreads the photons a little around)
* The 8-bit dithering functions are to be used only for dithering text.
*/
/* This source does dithering and rounding of images (in photon space) into
* struct bitmap. It also computes colors given r,g,b.
*/
/* No dither function destroys the passed bitmap */
/* All dither functions take format in booklike order without inter-line gaps.
* red, green, blue order. Input bytes=3*y*x. Takes x and y from bitmap.
*/
/* The input of dithering function is 3 times 8-bit value. The value is
* proportional to desired input into graphics driver (which is in fact
* proportional to monitor's input voltage for graphic drivers that do not
* pollute the picture with gamma correction)
*/
/* Dithering algorithm: Floyd-Steinberg error distribution. The used
* coefficients are depicted in the following table. The empty box denotes the
* originator pixel that generated the error.
*
* +----+----+
* | |7/16|
* +----+----+----+
* |3/16|5/16|1/16|
* +----+----+----+
*/
/* We assume here int holds at least 32 bits */
static int *red_table = DUMMY, *green_table = DUMMY, *blue_table = DUMMY;
static int table_16 = 1;
static unsigned short *
#if defined(__GNUC__) && __GNUC__ == 3
volatile
#endif
real_colors_table = NULL;
/* If we want to represent some 16-bit from-screen-light, it would require certain display input
* value (0-255 red, 0-255 green, 0-255 blue), possibly not a whole number. [red|green|blue]_table
* translares 16-bit light to the nearest index (that should be fed into the
* display). Nearest is meant in realm of numbers that are proportional to
* display input. The table also says what will be the real value this rounded
* display input yields. index is in
* bits 16-31, real light value is in bits 0-15. real light value is 0 (no
* photons) to 65535 (maximum photon flux). This is subtracted from wanted
* value and error remains which is the distributed into some neighboring
* pixels.
*
* Index memory organization
* -------------------------
* 1 byte per pixel: obvious. The output byte is OR of all three LSB's from red_table,
* green_table, blue_table
* 2 bytes per pixel: cast all three values to unsigned short, OR them together
* and dump the short into the memory
* 3 and 4 bytes per pixel: LSB's contain the red, green, and blue bytes.
*/
/* These tables allow the most precise dithering possible:
* a) Rouding is performed always to perceptually nearest value, not to
* nearest light flux
* b) error addition is performed in photon space to maintain fiedlity
* c) photon space addition from b) is performed with 16 bits thus not
* degrading 24-bit images
*/
/* We assume here unsigned short holds at least 16 bits */
static unsigned short round_red_table[256];
static unsigned short round_green_table[256];
static unsigned short round_blue_table[256];
/* Transforms sRGB red, green, blue (0-255) to light of nearest voltage to
* voltage appropriate to given sRGB coordinate.
*/
void (*round_fn)(unsigned short *my_restrict in, struct bitmap *out);
/* When you finish the stuff with dither_start, dither_restart, just do "if (dregs) mem_free(dregs);" */
static void (*dither_fn_internal)(unsigned short *my_restrict in, struct bitmap *out, int *dregs);
int slow_fpu = -1;
/* EMPIRE IMAGINE FEAR */
#define LTABLES \
ir = in[0];\
ig = in[1];\
ib = in[2];\
r+=(int)ir;\
g+=(int)ig;\
b+=(int)ib;\
in+=3;\
{\
int rc=r,gc=g,bc=b;\
if ((unsigned)rc>65535) rc=rc<0?0:65535;\
if ((unsigned)gc>65535) gc=gc<0?0:65535;\
if ((unsigned)bc>65535) bc=bc<0?0:65535;\
rt=red_table[rc >> shift];\
gt=green_table[gc >> shift];\
bt=blue_table[bc >> shift];\
}\
SAVE_CODE\
rt=r-(rt&65535);\
gt=g-(gt&65535);\
bt=b-(bt&65535);\
#define BODY \
LTABLES\
r=bptr[3];\
g=bptr[4];\
b=bptr[5];\
r+=rt;\
g+=gt;\
b+=bt;\
rt+=8;\
gt+=8;\
bt+=8;\
rt>>=4;\
gt>>=4;\
bt>>=4;\
r-=9*rt;\
g-=9*gt;\
b-=9*bt;\
bptr[3]=rt;\
bptr[4]=gt;\
bptr[5]=bt;
#define BODYR \
LTABLES\
rt+=8;\
gt+=8;\
bt+=8;\
rt>>=4;\
gt>>=4;\
bt>>=4;\
bptr[-3]+=3*rt;\
bptr[-2]+=3*gt;\
bptr[-1]+=3*bt;\
bptr[0]+=5*rt;\
bptr[1]+=5*gt;\
bptr[2]+=5*bt;
#define BODYC \
LTABLES\
r=rt;\
g=gt;\
b=bt;
#define BODYL \
bptr=dregs;\
r=bptr[0];\
g=bptr[1];\
b=bptr[2];\
BODY\
bptr[0]=5*rt;\
bptr[1]=5*gt;\
bptr[2]=5*bt;\
bptr+=3;
#define BODYI \
BODY\
bptr[0]+=5*rt;\
bptr[1]+=5*gt;\
bptr[2]+=5*bt;\
bptr[-3]+=3*rt;\
bptr[-2]+=3*gt;\
bptr[-1]+=3*bt;\
bptr+=3;
#define DITHER_TEMPLATE(template_name, sh) \
static void template_name(unsigned short *my_restrict in, struct bitmap *out, int *dregs)\
{\
const int shift = sh;\
unsigned short ir, ig, ib;\
int r,g,b,o,rt,gt,bt,y,x;\
unsigned char *my_restrict outp=out->data;\
int *my_restrict bptr;\
ssize_t skip = out->skip - SKIP_CODE;\
\
o=0;o=o; /*warning go away */\
switch(out->x){\
\
case 0:\
return;\
\
case 1:\
r=g=b=0;\
for (y=out->y;y;y--){\
BODYC\
outp+=skip;\
}\
break;\
\
default:\
for (y=out->y;y;y--){\
BODYL\
for (x=out->x-2;x;x--){\
BODYI\
}\
BODYR\
outp+=skip;\
}\
break;\
}\
}
#define ROUND_TEMPLATE(template_name, sh)\
static void template_name(unsigned short *my_restrict in, struct bitmap *out)\
{\
const int shift = sh;\
unsigned short ir, ig, ib;\
int rt,gt,bt,o,x,y;\
unsigned char *my_restrict outp=out->data;\
ssize_t skip = out->skip - SKIP_CODE;\
\
o=0;o=o; /*warning go away */\
for (y=out->y;y;y--){\
for (x=out->x;x;x--){\
ir = in[0];\
ig = in[1];\
ib = in[2];\
rt=red_table[limit_16(ir) >> shift];\
gt=green_table[limit_16(ig) >> shift];\
bt=blue_table[limit_16(ib) >> shift];\
in+=3;\
SAVE_CODE\
}\
outp+=skip;\
}\
}
/* Expression determining line length in bytes */
#define SKIP_CODE out->x
/* Code with input in rt, gt, bt (values from red_table, green_table, blue_table)
* that saves appropriate code on *outp (unsigned char *outp). We can use int o;
* as a scratchpad.
*/
#define SAVE_CODE \
o = (rt >> 16) + (gt >> 16) + (bt >> 16); \
*outp++ = (unsigned char)o;
DITHER_TEMPLATE(dither_1byte, 0)
ROUND_TEMPLATE(round_1byte, 0)
DITHER_TEMPLATE(dither_1byte_8, 8)
ROUND_TEMPLATE(round_1byte_8, 8)
#undef SKIP_CODE
#undef SAVE_CODE
#define SKIP_CODE out->x
#define SAVE_CODE \
{ \
int rr, gr, br, or; \
o = (rt >> 16) + (gt >> 16) + (bt >> 16); \
rr = red_table[limit_16(ir) >> shift]; \
gr = green_table[limit_16(ig) >> shift]; \
br = blue_table[limit_16(ib) >> shift]; \
or = (rr >> 16) + (gr >> 16) + (br >> 16); \
if (!((real_colors_table[or * 3 + 0] - ir) | \
(real_colors_table[or * 3 + 1] - ig) | \
(real_colors_table[or * 3 + 2] - ib))) { \
o = or; \
} \
rt = real_colors_table[o * 3 + 0]; \
gt = real_colors_table[o * 3 + 1]; \
bt = real_colors_table[o * 3 + 2]; \
*outp++ = (unsigned char)o; \
} \
DITHER_TEMPLATE(dither_1byte_real_colors, 0)
DITHER_TEMPLATE(dither_1byte_real_colors_8, 8)
#undef SKIP_CODE
#undef SAVE_CODE
#define SKIP_CODE out->x*2
#if defined(t2c) && defined(C_LITTLE_ENDIAN)
#define SAVE_CODE \
o=rt|gt|bt;\
*(t2c *)outp=(o>>16);\
outp+=2;
#else
#define SAVE_CODE \
o=rt|gt|bt;\
o>>=16;\
outp[0]=o;\
outp[1]=o>>8;\
outp+=2;
#endif /* #ifdef t2c */
DITHER_TEMPLATE(dither_2byte, 0)
ROUND_TEMPLATE(round_2byte, 0)
DITHER_TEMPLATE(dither_2byte_8, 8)
ROUND_TEMPLATE(round_2byte_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* B G R */
#define SKIP_CODE out->x*3
#define SAVE_CODE \
outp[0]=bt>>16;\
outp[1]=gt>>16;\
outp[2]=rt>>16;\
outp+=3;
DITHER_TEMPLATE(dither_195, 0)
ROUND_TEMPLATE(round_195, 0)
DITHER_TEMPLATE(dither_195_8, 8)
ROUND_TEMPLATE(round_195_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* R G B */
#define SKIP_CODE out->x*3
#define SAVE_CODE \
outp[0]=rt>>16;\
outp[1]=gt>>16;\
outp[2]=bt>>16;\
outp+=3;
DITHER_TEMPLATE(dither_451, 0)
ROUND_TEMPLATE(round_451, 0)
DITHER_TEMPLATE(dither_451_8, 8)
ROUND_TEMPLATE(round_451_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* B G R 0 */
#define SKIP_CODE out->x*4
#define SAVE_CODE \
outp[0]=bt>>16;\
outp[1]=gt>>16;\
outp[2]=rt>>16;\
outp[3]=0;\
outp+=4;
DITHER_TEMPLATE(dither_196, 0)
ROUND_TEMPLATE(round_196, 0)
DITHER_TEMPLATE(dither_196_8, 8)
ROUND_TEMPLATE(round_196_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* 0 B G R */
#define SKIP_CODE out->x*4
#define SAVE_CODE \
outp[0]=0;\
outp[1]=bt>>16;\
outp[2]=gt>>16;\
outp[3]=rt>>16;\
outp+=4;
DITHER_TEMPLATE(dither_452, 0)
ROUND_TEMPLATE(round_452, 0)
DITHER_TEMPLATE(dither_452_8, 8)
ROUND_TEMPLATE(round_452_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* 0 R G B */
#define SKIP_CODE out->x*4
#define SAVE_CODE \
outp[0]=0;\
outp[1]=rt>>16;\
outp[2]=gt>>16;\
outp[3]=bt>>16;\
outp+=4;
DITHER_TEMPLATE(dither_708, 0)
ROUND_TEMPLATE(round_708, 0)
DITHER_TEMPLATE(dither_708_8, 8)
ROUND_TEMPLATE(round_708_8, 8)
#undef SAVE_CODE
#undef SKIP_CODE
/* For 256-color cube */
static long color_332(int rgb)
{
int r,g,b;
long ret = 0;
r=(rgb>>16)&255;
g=(rgb>>8)&255;
b=rgb&255;
r=(r*7+127)/255;
g=(g*7+127)/255;
b=(b*3+127)/255;
*(unsigned char *)&ret=(r<<5)|(g<<2)|b;
return ret;
}
/* For 216-color cube */
static long color_666(int rgb)
{
int r, g, b;
unsigned char i;
long ret = 0;
r = (rgb >> 16) & 255;
g = (rgb >> 8) & 255;
b = rgb & 255;
r = (r * 5 + 127) / 255;
g = (g * 5 + 127) / 255;
b = (b * 5 + 127) / 255;
i = (unsigned char)r;
i *= 6;
i += g;
i *= 6;
i += b;
*(unsigned char *)&ret = i;
return ret;
}
static long color_121(int rgb)
{
int r, g, b;
long ret = 0;
r = (rgb >> 16) & 255;
g = (rgb >> 8) & 255;
b = rgb & 255;
r = (r + 127) / 255;
g = (3 * g + 127) / 255;
b = (b + 127) / 255;
*(unsigned char *)&ret = (r << 3) | (g << 1) | b;
return ret;
}
static long color_111(int rgb)
{
int r, g, b;
long ret = 0;
r = (rgb >> 16) & 255;
g = (rgb >> 8) & 255;
b = rgb & 255;
r = (r + 127) / 255;
g = (g + 127) / 255;
b = (b + 127) / 255;
*(unsigned char *)&ret = (r << 2) | (g << 1) | b;
return ret;
}
static long color_888_rgb(int rgb)
{
long ret = 0;
((unsigned char *)&ret)[0]=rgb>>16;
((unsigned char *)&ret)[1]=rgb>>8;
((unsigned char *)&ret)[2]=(unsigned char)rgb;
return ret;
}
static long color_888_bgr(int rgb)
{
long ret = 0;
((unsigned char *)&ret)[0]=(unsigned char)rgb;
((unsigned char *)&ret)[1]=rgb>>8;
((unsigned char *)&ret)[2]=rgb>>16;
return ret;
}
static long color_8888_bgr0(int rgb)
{
long ret = 0;
((unsigned char *)&ret)[0]=(unsigned char)rgb;
((unsigned char *)&ret)[1]=rgb>>8;
((unsigned char *)&ret)[2]=rgb>>16;
((unsigned char *)&ret)[3]=0;
return ret;
}
/* Long live the sigma-delta modulator! */
static long color_8888_0bgr(int rgb)
{
long ret = 0;
/* Atmospheric lightwave communication rulez */
((unsigned char *)&ret)[0]=0;
((unsigned char *)&ret)[1]=(unsigned char)rgb;
((unsigned char *)&ret)[2]=rgb>>8;
((unsigned char *)&ret)[3]=rgb>>16;
return ret;
}
/* Long live His Holiness The 14. Dalai Lama Taendzin Gjamccho! */
/* The above line will probably cause a ban of this browser in China under
* the capital punishment ;-) */
static long color_8888_0rgb(int rgb)
{
long ret = 0;
/* Chokpori Dharamsala Lhasa Laddakh */
((unsigned char *)&ret)[0]=0;
((unsigned char *)&ret)[1]=rgb>>16;
((unsigned char *)&ret)[2]=rgb>>8;
((unsigned char *)&ret)[3]=(unsigned char)rgb;
return ret;
}
/* We assume long holds at least 32 bits */
static long color_555be(int rgb)
{
int r=(rgb>>16)&255;
int g=(rgb>>8)&255;
int b=(rgb)&255;
int i;
long ret = 0;
r=(r*31+127)/255;
g=(g*31+127)/255;
b=(b*31+127)/255;
i=(r<<10)|(g<<5)|b;
((unsigned char *)&ret)[0]=i>>8;
((unsigned char *)&ret)[1]=(unsigned char)i;
return ret;
}
/* We assume long holds at least 32 bits */
static long color_555(int rgb)
{
int r=(rgb>>16)&255;
int g=(rgb>>8)&255;
int b=(rgb)&255;
int i;
long ret = 0;
r=(r*31+127)/255;
g=(g*31+127)/255;
b=(b*31+127)/255;
i=(r<<10)|(g<<5)|b;
((unsigned char *)&ret)[0]=(unsigned char)i;
((unsigned char *)&ret)[1]=i>>8;
return ret;
}
static long color_565be(int rgb)
{
int r,g,b;
long ret = 0;
int i;
r=(rgb>>16)&255;
g=(rgb>>8)&255;
/* Long live the PIN photodiode */
b=rgb&255;
r=(r*31+127)/255;
g=(g*63+127)/255;
b=(b*31+127)/255;
i = (r<<11)|(g<<5)|b;
((unsigned char *)&ret)[0]=i>>8;
((unsigned char *)&ret)[1]=(unsigned char)i;
return ret;
}
static long color_565(int rgb)
{
int r,g,b;
long ret = 0;
int i;
r=(rgb>>16)&255;
g=(rgb>>8)&255;
/* Long live the PIN photodiode */
b=rgb&255;
r=(r*31+127)/255;
g=(g*63+127)/255;
b=(b*31+127)/255;
i=(r<<11)|(g<<5)|b;
((unsigned char *)&ret)[0]=(unsigned char)i;
((unsigned char *)&ret)[1]=i>>8;
return ret;
}
static long color_888_bgr_15bit(int rgb)
{
int r,g,b;
long ret = 0;
r=(rgb>>16)&255;
g=(rgb>>8)&255;
/* Long live the PIN photodiode */
b=rgb&255;
r=(r*31+127)/255;
g=(g*31+127)/255;
b=(b*31+127)/255;
((unsigned char *)&ret)[0]=(unsigned char)(r<<3);
((unsigned char *)&ret)[1]=(unsigned char)(g<<3);
((unsigned char *)&ret)[2]=(unsigned char)(b<<3);
return ret;
}
static long color_888_bgr_16bit(int rgb)
{
int r,g,b;
long ret = 0;
r=(rgb>>16)&255;
g=(rgb>>8)&255;
/* Long live the PIN photodiode */
b=rgb&255;
r=(r*31+127)/255;
g=(g*63+127)/255;
b=(b*31+127)/255;
((unsigned char *)&ret)[0]=(unsigned char)(r<<3);
((unsigned char *)&ret)[1]=(unsigned char)(g<<2);
((unsigned char *)&ret)[2]=(unsigned char)(b<<3);
return ret;
}
/* rgb = r*65536+g*256+b */
/* The selected color_fn returns a long.
* When we have for example 2 bytes per pixel, we make them in the memory,
* then copy them to the beginning of the memory occupied by the long
* variable, and return that long variable.
*/
long (*get_color_fn(int depth))(int rgb)
{
switch (depth) {
case 33:
return color_121;
break;
case 801:
return color_111;
break;
case 65:
return color_332;
break;
case 833:
return color_666;
case 122:
return color_555;
break;
case 378:
return color_555be;
break;
case 130:
return color_565;
break;
case 386:
return color_565be;
break;
case 451:
return color_888_rgb;
break;
case 195:
return color_888_bgr;
break;
case 452:
return color_8888_0bgr;
break;
case 196:
return color_8888_bgr0;
break;
case 708:
return color_8888_0rgb;
break;
case 15555:
return color_888_bgr_15bit;
break;
case 16579:
return color_888_bgr_16bit;
break;
default:
return NULL;
break;
}
}
/* Gamma says that light=electricity raised to gamma */
static void make_16_table(int *table, int values, int mult, float_double gamma, int bigendian)
{
int grades = values - 1;
int j, light_val, grade;
float_double voltage;
float_double rev_gamma = 1 / gamma;
const float_double inv_65535 = (float_double)(1 / 65535.);
int last_grade, last_content;
unsigned val;
uttime start_time = get_time();
int sample_state = 0;
int x_slow_fpu = slow_fpu;
if (gamma_bits != 2) x_slow_fpu = !gamma_bits;
repeat_loop:
last_grade = -1;
last_content = 0;
for (j=0;j<65536;j++){
if (x_slow_fpu) {
if (x_slow_fpu == 1) {
if (j & 255) {
table[j] = last_content;
continue;
}
} else {
if (!(j & (j - 1))) {
uttime now = get_time();
if (!sample_state) {
if (now != start_time) start_time = now, sample_state = 1;
} else {
if (now - start_time > SLOW_FPU_DETECT_THRESHOLD && (now - start_time) * 65536 / j > SLOW_FPU_MAX_STARTUP / 3) {
x_slow_fpu = 1;
goto repeat_loop;
}
}
}
}
}
voltage=fd_pow(j * inv_65535, rev_gamma);
/* Determine which monitor input voltage is equivalent
* to said photon flux level
*/
grade=(int)(voltage * grades + (float_double)0.5);
if (grade == last_grade){
table[j] = last_content;
continue;
}
last_grade = grade;
voltage = (float_double)grade / grades;
/* Find nearest voltage to this voltage. Finding nearest voltage, not
* nearest photon flux ensures the dithered pixels will be perceived to be
* near. The voltage input into the monitor was intentionally chosen by
* generations of television engineers to roughly comply with eye's
* response, thus minimizing and unifying noise impact on transmitted
* signal. This is only marginal enhancement however it sounds
* kool ;-) (and is kool)
*/
light_val = (int)(fd_pow(voltage, gamma) * 65535 + (float_double)0.5);
/* Find out what photon flux this index represents */
if (light_val < 0) light_val = 0;
if (light_val > 65535) light_val = 65535;
/* Clip photon flux for safety */
val = grade * mult;
if (bigendian)
val = (val >> 8) | ((val & 0xff) << 8);
last_content = light_val | (val << 16);
table[j] = last_content;
/* Save index and photon flux. */
}
if (x_slow_fpu == -1) slow_fpu = 0; /* if loop passed once without
detecting slow fpu, always assume fast FPU */
if (gamma_bits == 2 && x_slow_fpu == 1) slow_fpu = 1;
}
static void make_red_table(int values, int mult, int be)
{
red_table = mem_realloc(red_table, 65536 * sizeof(*red_table));
make_16_table(red_table, values, mult, (float_double)(display_red_gamma tcc_hack), be);
}
static void make_green_table(int values, int mult, int be)
{
green_table = mem_realloc(green_table, 65536 * sizeof(*green_table));
make_16_table(green_table, values, mult, (float_double)(display_green_gamma tcc_hack), be);
}
static void make_blue_table(int values, int mult, int be)
{
blue_table = mem_realloc(blue_table, 65536 * sizeof(*blue_table));
make_16_table(blue_table, values, mult, (float_double)(display_blue_gamma tcc_hack), be);
}
void dither(unsigned short *in, struct bitmap *out)
{
int *dregs;
if ((unsigned)out->x > MAXINT / 3 / sizeof(*dregs)) overalloc();
dregs=mem_calloc(out->x*3*sizeof(*dregs));
(*dither_fn_internal)(in, out, dregs);
mem_free(dregs);
}
/* For functions that do dithering.
* Returns allocated dregs. */
int *dither_start(unsigned short *in, struct bitmap *out)
{
int *dregs;
if ((unsigned)out->x > MAXINT / 3 / sizeof(*dregs)) overalloc();
dregs=mem_calloc(out->x*3*sizeof(*dregs));
(*dither_fn_internal)(in, out, dregs);
return dregs;
}
void dither_restart(unsigned short *in, struct bitmap *out, int *dregs)
{
(*dither_fn_internal)(in, out, dregs);
}
static void make_round_tables(void)
{
int a;
/* ICC bug */
icc_volatile unsigned short v;
for (a = 0; a < 256; a++) {
/* a is sRGB coordinate */
v=ags_8_to_16((unsigned char)a, (float)(user_gamma / sRGB_gamma));
round_red_table[a] = red_table[v >> (8 - 8 * table_16)] & 0xffff;
round_green_table[a] = green_table[v >> (8 - 8 * table_16)] & 0xffff;
round_blue_table[a] = blue_table[v >> (8 - 8 * table_16)] & 0xffff;
}
}
static void compress_tables(void)
{
int i;
int *rt, *gt, *bt;
/*for (i = 0; i < 65536; i++) {
fprintf(stderr, "16: %03d: %08x %08x %08x\n", i, red_table[i], green_table[i], blue_table[i]);
}*/
for (i = 0; i < 65536; i++) {
if (red_table[i] != red_table[i & 0xff00] ||
green_table[i] != green_table[i & 0xff00] ||
blue_table[i] != blue_table[i & 0xff00])
return;
}
table_16 = 0;
rt = mem_alloc(256 * sizeof(*rt));
gt = mem_alloc(256 * sizeof(*gt));
bt = mem_alloc(256 * sizeof(*bt));
for (i = 0; i < 256; i++) {
rt[i] = red_table[i << 8];
gt[i] = green_table[i << 8];
bt[i] = blue_table[i << 8];
/*fprintf(stderr, "8: %03d: %08x %08x %08x\n", i, rt[i], gt[i], bt[i]);*/
}
mem_free(red_table);
mem_free(green_table);
mem_free(blue_table);
red_table = rt;
green_table = gt;
blue_table = bt;
}
static void make_real_colors_table(void)
{
unsigned short *real_colors;
if (real_colors_table) mem_free(real_colors_table), real_colors_table = NULL;
if (round_fn != round_1byte && round_fn != round_1byte_8)
return;
if (!drv->get_real_colors)
return;
real_colors = drv->get_real_colors();
if (!real_colors)
return;
real_colors_table = mem_alloc(256 * 3 * sizeof(unsigned short));
agx_48_to_48(real_colors_table, real_colors, 256, (float)(display_red_gamma tcc_hack), (float)(display_green_gamma tcc_hack), (float)(display_blue_gamma tcc_hack));
mem_free(real_colors);
}
/* Also makes up the dithering tables.
* You may call it twice - it doesn't leak any memory.
*/
void init_dither(int depth)
{
table_16 = 1;
switch (depth) {
case 33:
/* 4bpp, 1Bpp */
make_red_table(1 << 1, 1 << 3, 0);
make_green_table(1 << 2, 1 << 1, 0);
make_blue_table(1 << 1, 1 << 0, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_1byte : dither_1byte_8;
round_fn = table_16 ? round_1byte : round_1byte_8;
break;
case 801:
/* 8bpp, 1Bpp, 1x1x1 */
make_red_table(1 << 1, 1 << 2, 0);
make_green_table(1 << 1, 1 << 1, 0);
make_blue_table(1 << 1, 1 << 0, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_1byte : dither_1byte_8;
round_fn = table_16 ? round_1byte : round_1byte_8;
break;
case 65:
/* 8 bpp, 1Bpp */
make_red_table(1 << 3, 1 << 5, 0);
make_green_table(1 << 3, 1 << 2, 0);
make_blue_table(1 << 2, 1 << 0, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_1byte : dither_1byte_8;
round_fn = table_16 ? round_1byte : round_1byte_8;
break;
case 833:
/* 8bpp, 1Bpp, 6x6x6 */
make_red_table(6, 36, 0);
make_green_table(6, 6, 0);
make_blue_table(6, 1, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_1byte : dither_1byte_8;
round_fn = table_16 ? round_1byte : round_1byte_8;
break;
case 122:
/* 15bpp, 2Bpp */
make_red_table(1 << 5, 1 << 10, 0);
make_green_table(1 << 5, 1 << 5, 0);
make_blue_table(1 << 5, 1 << 0, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_2byte : dither_2byte_8;
round_fn = table_16 ? round_2byte : round_2byte_8;
break;
case 378:
/* 15bpp, 2Bpp, disordered (1 << I have a mental disorder) */
make_red_table(1 << 5, 1 << 10, 1);
make_green_table(1 << 5, 1 << 5, 1);
make_blue_table(1 << 5, 1 << 0, 1);
compress_tables();
dither_fn_internal = table_16 ? dither_2byte : dither_2byte_8;
round_fn = table_16 ? round_2byte : round_2byte_8;
break;
case 130:
/* 16bpp, 2Bpp */
make_red_table(1 << 5, 1 << 11, 0);
make_green_table(1 << 6, 1 << 5, 0);
make_blue_table(1 << 5, 1 << 0, 0);
compress_tables();
dither_fn_internal = table_16 ? dither_2byte : dither_2byte_8;
round_fn = table_16 ? round_2byte : round_2byte_8;
break;
case 386:
/* 16bpp, 2Bpp, disordered */
make_red_table(1 << 5, 1 << 11, 1);
make_green_table(1 << 6, 1 << 5, 1);