summaryrefslogtreecommitdiff
path: root/spritecache.c
blob: fa94baf2bc1c04802493ba448677827b84457700 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
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
#include "stdafx.h"
#include "ttd.h"
#include "gfx.h"
#include "fileio.h"
#include <ctype.h>

#define SPRITECACHE_ID 0xF00F0006
#define SPRITE_CACHE_SIZE 1024*1024


//#define WANT_SPRITESIZES
#define WANT_NEW_LRU
//#define WANT_LOCKED


/* These are used in grfspecial.c: */

int _skip_sprites = 0;
int _replace_sprites_count[16];
int _replace_sprites_offset[16];

static const char *_cur_grffile;
static int _loading_stage;
static int _skip_specials;
uint16 _custom_sprites_base;
static SpriteHdr _cur_sprite;


static byte *_sprite_ptr[NUM_SPRITES];
static uint16 _sprite_size[NUM_SPRITES];
static uint32 _sprite_file_pos[NUM_SPRITES];

// This one is probably not needed.
#if defined(WANT_LOCKED)
static bool _sprite_locked[NUM_SPRITES];
#endif

#if defined(WANT_NEW_LRU)
static int16 _sprite_lru_new[NUM_SPRITES];
#else
static uint16 _sprite_lru[NUM_SPRITES];
static uint16 _sprite_lru_cur[NUM_SPRITES];
#endif

#ifdef WANT_SPRITESIZES
static int8 _sprite_xoffs[NUM_SPRITES];
static int8 _sprite_yoffs[NUM_SPRITES];
static uint16 _sprite_xsize[NUM_SPRITES];
static uint8 _sprite_ysize[NUM_SPRITES];
#endif

static uint _sprite_lru_counter;
static byte *_spritecache_ptr;
static uint32 _spritecache_size;
static int _compact_cache_counter;


static const char * const _filename_list[] = {
	"TRG1R.GRF",
	"TRGIR.GRF",
	"signalsw.grf", //0x1320 - 0x1405 inclusive
//	"openttd.grf",	//0x1406 -
	NULL
};

static const char * const _landscape_filenames[] = {
	"TRGCR.GRF",
	"TRGHR.GRF",
	"TRGTR.GRF"
};


#include "table/landscape_sprite.h"

static const uint16 * const _landscape_spriteindexes[] = {
	_landscape_spriteindexes_1,
	_landscape_spriteindexes_2,
	_landscape_spriteindexes_3,
};

static const uint16 * const _slopes_spriteindexes[] = {
	_slopes_spriteindexes_0,
	_slopes_spriteindexes_1,
	_slopes_spriteindexes_2,
	_slopes_spriteindexes_3,
};

static void CompactSpriteCache();

void InitNewGRFFile(const char *filename, int sprite_offset);
void DecodeSpecialSprite(const char *filename, int num, int load_index, int stage);

static void ReadSpriteHeaderSkipData(int num, int load_index)
{
	byte type;
	int8 i;
	int deaf = 0;

	if (_skip_sprites) {
		if (_skip_sprites > 0)
			_skip_sprites--;
		deaf = 1;
	}

	type = FioReadByte();
	_cur_sprite.info = type;
	if (type == 0xFF) {
		/* We need to really skip only special sprites in the deaf
		 * mode.  It won't hurt to proceed regular sprites as usual
		 * because if no special sprite referencing to them is
		 * processed, they themselves are never referenced and loaded
		 * on their own. */
		if (_skip_specials || deaf) {
			FioSkipBytes(num);
		} else {
			DecodeSpecialSprite(_cur_grffile, num, load_index, _loading_stage);
		}
		return;
	}

#ifdef WANT_SPRITESIZES
	_cur_sprite.height = FioReadByte();
	_cur_sprite.width = FioReadWord();
	_cur_sprite.x_offs = FioReadWord();
	_cur_sprite.y_offs = FioReadWord();
#else
	FioSkipBytes(7);
#endif
	num -= 8;
	if (num == 0)
		return;

	if (type & 2) {
		FioSkipBytes(num);
		return;
	}

	while (num) {
		i = FioReadByte();
		if (i>=0) {
			num -= i;
			FioSkipBytes(i);
		} else {
			i = -(i >> 3);
			num -= i;
			FioReadByte();
		}
	}
}

static void ReadSprite(int num, byte *dest)
{
	byte type;
	byte *rel;
	int8 i;
	int j, dist;

	type = FioReadByte();
	/* We've decoded special sprites when reading headers. */
	if (type != 0xFF) {
		/* read sprite hdr */
		*dest++ = type;
		for(j=0; j!=7; j++)
			*dest++ = FioReadByte();
		num -= 8;
	}

	if (type & 2) {
		while (num--)
			*dest++ = FioReadByte();
		return;
	}

	while (num) {
		i = FioReadByte();
		if (i>=0) {
			num -= i;
			while (i--)
				*dest++ = FioReadByte();
		} else {
			dist = -(((i&7)<<8)|FioReadByte());
			i = -(i >> 3);
			num -= i;

			rel = &dest[dist];
			while (i--)
				*dest++ = *rel++;
		}
	}
}


static bool LoadNextSprite(int load_index, byte file_index)
{
	uint16 size;
	uint32 file_pos;

	if ((size = FioReadWord()) == 0)
		return false;

	file_pos = FioGetPos() | (file_index << 24);

	ReadSpriteHeaderSkipData(size, load_index);

	if ((_replace_sprites_count[0] > 0) && (_cur_sprite.info != 0xFF)) {
		int count = _replace_sprites_count[0];
		int offset = _replace_sprites_offset[0];

		_replace_sprites_offset[0]++;
		_replace_sprites_count[0]--;
		
		if ((offset + count) <= NUM_SPRITES) {
			load_index = offset;
		} else {
			DEBUG(spritecache, 1) ("Sprites to be replaced are out of range: %x+%x",
					count, offset);
			_replace_sprites_offset[0] = 0;
			_replace_sprites_count[0] = 0;
		}

		if (_replace_sprites_count[0] == 0) {
			int i;

			for (i = 0; i < 15; i++) {
				_replace_sprites_count[i] = _replace_sprites_count[i + 1];
				_replace_sprites_offset[i] = _replace_sprites_offset[i + 1];
			}
			_replace_sprites_count[i] = 0;
			_replace_sprites_offset[i] = 0;
		}
	}

	_sprite_size[load_index] = size;
	_sprite_file_pos[load_index] = file_pos;

#ifdef WANT_SPRITESIZES
	_sprite_xsize[load_index] = _cur_sprite.width;
	_sprite_ysize[load_index] = _cur_sprite.height;

	_sprite_xoffs[load_index] = _cur_sprite.x_offs;
	_sprite_yoffs[load_index] = _cur_sprite.y_offs;
#endif

	_sprite_ptr[load_index] = NULL;
#if defined(WANT_LOCKED)
	_sprite_locked[load_index] = false;
#endif

#if defined(WANT_NEW_LRU)
	_sprite_lru_new[load_index] = 0;
#else
	_sprite_lru[load_index] = 0xFFFF;
	_sprite_lru_cur[load_index] = 0;
#endif

	return true;
}

static void SkipSprites(int count)
{
	while(count>0)
	{
		uint16 size;
		if ( (size = FioReadWord()) == 0)
			return;

		ReadSpriteHeaderSkipData(size, NUM_SPRITES-1);
		count--;
	}
}

// Checks, if trg1r.grf is the Windows version
static bool CheckGrfFile()
{
	byte check;
	FioSeekToFile(38); // Byte 38 has the value 0x21 in Windows version, 0x07 in DOS
	check = FioReadWord();
	FioSeekToFile(0);
	return (check==0x21);
}

static int LoadGrfFile(const char *filename, int load_index, int file_index)
{
	int load_index_org = load_index;

	FioOpenFile(file_index, filename);

	/* Thou shalt use LoadNewGrfFile() if thou loadeth a GRF file that
	 * might contain some special sprites. */
	_skip_specials = 1;
	_skip_sprites = 0;

	DEBUG(spritecache, 2) ("Reading grf-file ``%s''", filename);

 	if(file_index==0 && !_ignore_wrong_grf)
 		if(!CheckGrfFile())
 			error("Wrong version of grf files!\nThe Windows 95 edition of Transport Tycoon Deluxe is required to play OTTD!\n(you can disable this message by starting with the \"-i\" switch.");

	while (LoadNextSprite(load_index, file_index)) {
		load_index++;
		if (load_index >= NUM_SPRITES) {
			error("Too many sprites. Recompile with higher NUM_SPRITES value or remove some custom GRF files.");
		}
	}

	return load_index - load_index_org;
}

static int LoadNewGrfFile(const char *filename, int load_index, int file_index)
{
	/* XXX: Is it better to fervently follow the num_sprites information or
	 * be tolerant and comply with more/less sprites too? --pasky */
	int num_sprites = 0;
	int i;
	
	FioOpenFile(file_index, filename);
	_cur_grffile = filename;
	_skip_specials = 0;
	_skip_sprites = 0;

	DEBUG(spritecache, 2) ("Reading newgrf-file ``%s'' [offset: %u]",
			filename, load_index);

	{
		int length;
		byte type;

		length = FioReadWord();
		type = FioReadByte();

		if ((length == 4) && (type == 0xFF)) {
			num_sprites = FioReadDword();
		} else {
			error("Custom .grf has invalid format.");
		}

		/* Ignore last sprite, it's only used to mark end-of-file */
		num_sprites--;
		load_index++;
	}

	if ((load_index + num_sprites) > NUM_SPRITES)
		error("Too many sprites (%x). Recompile with higher NUM_SPRITES value or remove some custom GRF files.",
		      load_index + num_sprites);

	for (i = 0; i < num_sprites; i++) {
		if (!LoadNextSprite(load_index + i, file_index))
			error("NEWGRF: Header was talking abount %d sprites, but only %d found..",
			      num_sprites, i);
	}

	/* Clean up. */
	_skip_sprites = 0;
	memset(_replace_sprites_count, 0, 16 * sizeof(*_replace_sprites_count));
	memset(_replace_sprites_offset, 0, 16 * sizeof(*_replace_sprites_offset));

	return num_sprites;
}

static void LoadGrfIndexed(const char *filename, const uint16 *index_tbl, int file_index)
{
	int start;

	FioOpenFile(file_index, filename);
	_skip_specials = 1;
	_skip_sprites = 0;

	DEBUG(spritecache, 2) ("Reading indexed grf-file ``%s''", filename);

	for(;(start=*index_tbl++) != 0xffff;) {
		int end = *index_tbl++;
		if(start==0xfffe) { // skip sprites (amount in second var)
			SkipSprites(end);
		} else { // load sprites and use indexes from start to end
			do {
				bool b = LoadNextSprite(start, file_index);
				assert(b);
			} while (++start <= end);
		}
	}
}

typedef size_t CDECL fread_t(void*,size_t,size_t,FILE*);

static bool HandleCachedSpriteHeaders(const char *filename, bool read)
{
	FILE *f;
	fread_t *proc;
	uint32 hdr;

	if (!_cache_sprites)
		return false;

	if (read) {
		f = fopen(filename, "rb");
		proc = fread;

		if (f == NULL)
			return false;

		proc(&hdr, sizeof(hdr), 1, f);
		if (hdr != SPRITECACHE_ID) {
			fclose(f);
			return false;
		}
	} else {
		f = fopen(filename, "wb");
		proc = (fread_t*) fwrite;

		if (f == NULL)
			return false;

		hdr = SPRITECACHE_ID;
		proc(&hdr, sizeof(hdr), 1, f);
	}

	proc(_sprite_size, 1, sizeof(_sprite_size), f);
	proc(_sprite_file_pos, 1, sizeof(_sprite_file_pos), f);

#if 0
	proc(_sprite_xsize, 1, sizeof(_sprite_xsize), f);
	proc(_sprite_ysize, 1, sizeof(_sprite_ysize), f);
	proc(_sprite_xoffs, 1, sizeof(_sprite_xoffs), f);
	proc(_sprite_yoffs, 1, sizeof(_sprite_yoffs), f);
#endif

#if !defined(WANT_NEW_LRU)
	if (read)
		memset(_sprite_lru, 0xFF, sizeof(_sprite_lru));
#endif

	fclose(f);
	return true;
}

#define S_DATA(x) (*(uint32*)(x))
#define S_FREE_MASK 1
#define S_HDRSIZE sizeof(uint32)

static uint32 GetSpriteCacheUsage()
{
	byte *s = _spritecache_ptr;
	size_t cur_size, tot_size = 0;
	for(; (cur_size=S_DATA(s)) != 0; s+=cur_size) {
		if ( cur_size & S_FREE_MASK ) {
			cur_size--;
		} else {
			tot_size += cur_size;
		}
	}

	return tot_size;
}


void IncreaseSpriteLRU()
{
	int i;

	// Increase all LRU values
#if defined(WANT_NEW_LRU)
	if (_sprite_lru_counter > 16384) {
		DEBUG(spritecache, 2) ("fixing lru %d, inuse=%d", _sprite_lru_counter, GetSpriteCacheUsage());

		for(i=0; i!=NUM_SPRITES; i++)
			if (_sprite_ptr[i] != NULL) {
				if (_sprite_lru_new[i] >= 0) {
					_sprite_lru_new[i] = -1;
				} else if (_sprite_lru_new[i] != -32768) {
					_sprite_lru_new[i]--;
				}
			}
		_sprite_lru_counter = 0;
	}
#else
	for(i=0; i!=NUM_SPRITES; i++)
		if (_sprite_ptr[i] != NULL && _sprite_lru[i] != 65535)
			_sprite_lru[i]++;
	// Reset the lru counter.
	_sprite_lru_counter = 0;
#endif

	// Compact sprite cache every now and then.
	if (++_compact_cache_counter >= 740) {
		CompactSpriteCache();
		_compact_cache_counter = 0;
	}
}

// Called when holes in the sprite cache should be removed.
// That is accomplished by moving the cached data.
static void CompactSpriteCache()
{
	byte *s, *t;
	size_t size, sizeb, cur_size;
	int i;

	DEBUG(spritecache, 2) ("compacting sprite cache, inuse=%d", GetSpriteCacheUsage());

	s = _spritecache_ptr;

	while (true) {
		size = S_DATA(s);

		// Only look for free blocks.
		if (size & S_FREE_MASK) {
			size -= S_FREE_MASK;
			// Since free blocks are automatically coalesced, this should hold true.
			assert(!(S_DATA(s+size) & S_FREE_MASK));

			// If the next block is the sentinel block, we can safely return
			if ( (sizeb=S_DATA(s + size)) == 0)
				break;

			// Locate the sprite number belonging to the next pointer.
			for(i=0,t=s+size+S_HDRSIZE; _sprite_ptr[i] != t; i++) {assert(i < NUM_SPRITES);}

			// If it's locked, we must not move it.
#if defined(WANT_LOCKED)
			if (!_sprite_locked[i]) {
#endif

				// Offset the sprite pointer by the size of the free block
				_sprite_ptr[i] -= size;

				// Move the memory
				memcpy_overlapping(s+S_HDRSIZE, s+S_HDRSIZE+size, sizeb - S_HDRSIZE );

				// What we just did had the effect of swapping the allocated block with the free block, so we need to update
				//  the block pointers. First update the allocated one. It is in use.
				S_DATA(s) = sizeb;

				// Then coalesce the free ones that follow.
				s += sizeb;
				while ((cur_size = S_DATA(s+size)) & S_FREE_MASK)
					size += cur_size - S_FREE_MASK;
				S_DATA(s) = size + S_FREE_MASK;
				continue;
#if defined(WANT_LOCKED)
			}
#endif
		}
		// Continue with next block until the sentinel is reached.
		s += size;
		if (size == 0)
			break;
	}
}

static void DeleteEntryFromSpriteCache()
{
	int i;
	int best = -1;
	byte *s;
	size_t cur_size, cur;
	int cur_lru;

	DEBUG(spritecache, 2) ("DeleteEntryFromSpriteCache, inuse=%d", GetSpriteCacheUsage());

#if defined(WANT_NEW_LRU)
	cur_lru = 0xffff;
	for(i=0; i!=NUM_SPRITES; i++) {
		if (_sprite_ptr[i] != 0 &&
				_sprite_lru_new[i] < cur_lru
#if defined(WANT_LOCKED)
				 && !_sprite_locked[i]) {
#else
				) {
#endif
			cur_lru = _sprite_lru_new[i];
			best = i;
		}
	}
#else
	{
	uint16 cur_lru = 0, cur_lru_cur = 0xffff;
	for(i=0; i!=NUM_SPRITES; i++) {
		if (_sprite_ptr[i] == 0 ||
#if defined(WANT_LOCKED)
				_sprite_locked[i] ||
#endif
				_sprite_lru[i] < cur_lru)
					continue;

		// Found a sprite with a higher LRU value, then remember it.
		if (_sprite_lru[i] != cur_lru) {
			cur_lru = _sprite_lru[i];
			best = i;

		// Else if both sprites were very recently referenced, compare by the cur value instead.
		} else if (cur_lru == 0 && _sprite_lru_cur[i] <= cur_lru_cur) {
			cur_lru_cur = _sprite_lru_cur[i];
			cur_lru = _sprite_lru[i];
			best = i;
		}
	}
	}
#endif

	// Display an error message and die, in case we found no sprite at all.
	// This shouldn't really happen, unless all sprites are locked.
	if (best == -1)
		error("Out of sprite memory");

	// Mark the block as free (the block must be in use)
	s = _sprite_ptr[best];
	assert(!(S_DATA(s - S_HDRSIZE) & S_FREE_MASK));
	S_DATA(s - S_HDRSIZE) += S_FREE_MASK;
	_sprite_ptr[best] = NULL;

	// And coalesce adjacent free blocks
	s = _spritecache_ptr;
	for(; (cur_size=S_DATA(s)) != 0; s+=cur_size) {
		if ( cur_size & S_FREE_MASK ) {
			while ((cur=S_DATA(s+cur_size-S_FREE_MASK)) & S_FREE_MASK) {
				cur_size += cur - S_FREE_MASK;
				S_DATA(s) = cur_size;
			}
			cur_size--;
		}
	}
}

static byte *LoadSpriteToMem(int sprite)
{
	byte *s;
	size_t mem_req, cur_size;

	DEBUG(spritecache, 9) ("load sprite %d", sprite);

restart:
	// Number of needed bytes
	mem_req = _sprite_size[sprite] + S_HDRSIZE;

	// Align this to an uint32 boundary. This also makes sure that the 2 least bit are not used,
	//  so we could use those for other things.
	mem_req = (mem_req + sizeof(uint32) - 1) & ~(sizeof(uint32) - 1);

	s = _spritecache_ptr;
	for(;;) {
		for(;;) {
			cur_size = S_DATA(s);
			if (! (cur_size & S_FREE_MASK) ) break;

			cur_size -= S_FREE_MASK;

			// Now s points at a free block.
			// The block is exactly the size we need?
			if (cur_size != mem_req) {

				// No.. is it too small?
				if (cur_size < mem_req + S_HDRSIZE)
					break;

				// Block was big enough, and we need to inject a free block too.
				S_DATA(s + mem_req) = cur_size - mem_req + S_FREE_MASK;

			}
			// Set size and in use
			S_DATA(s) = mem_req;

			_sprite_ptr[sprite] = (s += S_HDRSIZE);

			FioSeekToFile(_sprite_file_pos[sprite]);
			ReadSprite(_sprite_size[sprite], s);

			// Patch the height to compensate for a TTD bug?
			if (sprite == 142) { s[1] = 10; }

			// Return sprite ptr
			return s;
		}

		// Reached sentinel, but no block found yet. Need to delete some old entries.
		if (cur_size == 0) {
			DeleteEntryFromSpriteCache();
			goto restart;
		}

		s += cur_size;
	}
}

#if defined(NEW_ROTATION)
#define X15(x) else if (s >= x && s < (x+15)) { s = _rotate_tile_sprite[s - x] + x; }
#define X19(x) else if (s >= x && s < (x+19)) { s = _rotate_tile_sprite[s - x] + x; }
#define MAP(from,to,map) else if (s >= from && s <= to) { s = map[s - from] + from; }


uint RotateSprite(uint s)
{
	static const byte _rotate_tile_sprite[19] = { 0,2,4,6,8,10,12,14,1,3,5,7,9,11,13,17,18,16,15 };
	static const byte _coast_map[9] = {0, 4, 3, 1, 2, 6, 8, 5, 7};
	static const byte _fence_map[6] = {1, 0, 5, 4, 3, 2};

	if (0);
	X19(752)
	X15(990-1)
	X19(3924)
	X19(3943)
	X19(3962)
	X19(3981)
	X19(4000)
	X19(4023)
	X19(4042)
	MAP(4061,4069,_coast_map)
	X19(4126)
	X19(4145)
	X19(4164)
	X19(4183)
	X19(4202)
	X19(4221)
	X19(4240)
	X19(4259)
	X19(4259)
	X19(4278)
	MAP(4090, 4095, _fence_map)
	MAP(4096, 4101, _fence_map)
	MAP(4102, 4107, _fence_map)
	MAP(4108, 4113, _fence_map)
	MAP(4114, 4119, _fence_map)
	MAP(4120, 4125, _fence_map)
	return s;
}
#endif

byte *GetSpritePtr(uint sprite)
{
	byte *p;

	assert(sprite < NUM_SPRITES);

#if defined(NEW_ROTATION)
	sprite = RotateSprite(sprite);
#endif

	// Update LRU
#if defined(WANT_NEW_LRU)
	_sprite_lru_new[sprite] = ++_sprite_lru_counter;
#else
	_sprite_lru_cur[sprite]	= ++_sprite_lru_counter;
	_sprite_lru[sprite] = 0;
#endif

	// Check if the sprite is loaded already?
	p = _sprite_ptr[sprite];
	if (p == NULL)
		p = LoadSpriteToMem(sprite);  // No, need to load it.
	return p;
}

byte _sprite_page_to_load = 0xFF;

static const char * const _cached_filenames[4] = {
	"cached_sprites.xxx",
	"cached_sprites.xx1",
	"cached_sprites.xx2",
	"cached_sprites.xx3",
};

#define OPENTTD_SPRITES_COUNT 70
static const uint16 _openttd_grf_indexes[] = {
	SPR_OPENTTD_BASE+0,	SPR_OPENTTD_BASE+7, // icons etc
	98,98,     // euro symbol medium size
	546,546,   // euro symbol large size
	SPR_OPENTTD_BASE+10, SPR_OPENTTD_BASE+57, // more icons
	648, 648, // nordic char: æ
	616, 616, // nordic char: Æ
	666, 666, // nordic char: Ø
	634, 634, // nordic char: Ø
	SPR_OPENTTD_BASE+62, SPR_OPENTTD_BASE + OPENTTD_SPRITES_COUNT, // more icons
	0xffff,
};

static void LoadSpriteTables()
{
	int i,j;

	_loading_stage = 1;

	/*
	 * Note for developers:
	 *   Keep in mind that when you add a LoadGrfIndexed in the 'if'-section below
	 *   that you should also add the corresponding FioOpenFile to the 'else'-section
	 *   below.
	 *
	 * TODO:
	 *   I think we can live entirely without Indexed GRFs, but I have to
	 *   invest that further. --octo
	 */

	// Try to load the sprites from cache
	if (!HandleCachedSpriteHeaders(_cached_filenames[_opt.landscape], true)) {
		// We do not have the sprites in cache yet, or cache is disabled
		// So just load all files from disk..

		int load_index = 0;

		for(i=0; _filename_list[i] != NULL; i++) {
			load_index += LoadGrfFile(_filename_list[i], load_index, (byte)i);
		}

		LoadGrfIndexed("openttd.grf", _openttd_grf_indexes, i++);

		if (_sprite_page_to_load != 0)
			LoadGrfIndexed(_landscape_filenames[_sprite_page_to_load-1], _landscape_spriteindexes[_sprite_page_to_load-1], i++);

		LoadGrfIndexed("trkfoundw.grf", _slopes_spriteindexes[_opt.landscape], i++);

		load_index = SPR_CANALS_BASE;
		load_index += LoadGrfFile("canalsw.grf", load_index, i++);

		load_index = SPR_OPENTTD_BASE + OPENTTD_SPRITES_COUNT + 1;


		/* Load newgrf sprites */

		_custom_sprites_base = load_index;

		_loading_stage = 0;
		for (j = 0; j != lengthof(_newgrf_files) && _newgrf_files[j]; j++) {
			InitNewGRFFile(_newgrf_files[j], load_index);
			load_index += LoadNewGrfFile(_newgrf_files[j], load_index, i++);
		}

		_loading_stage = 1;
		load_index = _custom_sprites_base;
		for (j = 0; j != lengthof(_newgrf_files) && _newgrf_files[j]; j++)
			load_index += LoadNewGrfFile(_newgrf_files[j], load_index, i++);


		// If needed, save the cache to file
		HandleCachedSpriteHeaders(_cached_filenames[_opt.landscape], false);
	} else {
		// We have sprites cached. We just loaded the cached files
		//  now we only have to open a file-pointer to all the original grf-files
		// This is very important. Not all sprites are in the cache. So sometimes
		//  the game needs to load the sprite from disk. When the file is not
		//  open it can not read. So all files that are in the 'if'-section
		//  above should also be in this 'else'-section.
		//
		// NOTE: the order of the files must be identical as in the section above!!

		for(i = 0; _filename_list[i] != NULL; i++)
			FioOpenFile(i,_filename_list[i]);

		FioOpenFile(i++, "openttd.grf");

		if (_sprite_page_to_load != 0)
			FioOpenFile(i++, _landscape_filenames[_sprite_page_to_load-1]);

		FioOpenFile(i++, "trkfoundw.grf");
		FioOpenFile(i++, "canalsw.grf");

		// FIXME: if a user changes his newgrf's, the cached-sprites gets
		//  invalid. We should have some kind of check for this.
		// The best solution for this is to delete the cached-sprites.. but how
		//  do we detect it?
		for(j=0; j!=lengthof(_newgrf_files) && _newgrf_files[j]; j++)
			FioOpenFile(i++, _newgrf_files[j]);
	}

	_compact_cache_counter = 0;
}

void GfxInitSpriteMem(byte *ptr, uint32 size)
{
	// initialize sprite cache heap
	_spritecache_ptr = ptr;
	_spritecache_size = size;

	// Sentinel block (identified by size=0)
	S_DATA(ptr + size - S_HDRSIZE) = 0;
	// A big free block
	S_DATA(ptr) = size - S_HDRSIZE + S_FREE_MASK;

	memset(_sprite_ptr, 0, sizeof(_sprite_ptr));
}


void GfxLoadSprites() {
	static byte *_sprite_mem;

	// Need to reload the sprites only if the landscape changed
	if (_sprite_page_to_load != _opt.landscape) {
		_sprite_page_to_load = _opt.landscape;

		// Sprite cache
		DEBUG(spritecache, 1) ("Loading sprite set %d.", _sprite_page_to_load);

		// Reuse existing memory?
		if (_sprite_mem == NULL) _sprite_mem = malloc(SPRITE_CACHE_SIZE);
		GfxInitSpriteMem(_sprite_mem, SPRITE_CACHE_SIZE);
		LoadSpriteTables();
		GfxInitPalettes();
	}
}


const SpriteDimension *GetSpriteDimension(uint sprite)
{
	static SpriteDimension sd_static;
	SpriteDimension *sd;

#ifndef WANT_SPRITESIZES
	byte *p;

	p = _sprite_ptr[sprite];
	if (p == NULL)
		p = GetSpritePtr(sprite);

	/* decode sprite header */
	sd = &sd_static;
	sd->xoffs = (int16)READ_LE_UINT16(&((SpriteHdr*)p)->x_offs);
	sd->yoffs = (int16)READ_LE_UINT16(&((SpriteHdr*)p)->y_offs);
	sd->xsize = READ_LE_UINT16(&((SpriteHdr*)p)->width);
	sd->ysize = ((SpriteHdr*)p)->height;
#else
	sd = &sd_static;
	sd->xoffs = _sprite_xoffs[sprite];
	sd->yoffs = _sprite_yoffs[sprite];
	sd->xsize = _sprite_xsize[sprite];
	sd->ysize = _sprite_ysize[sprite];
#endif
/*	sd->xoffs = _sprite_xoffs[sprite];
	sd->yoffs = _sprite_yoffs[sprite];
	sd->xsize = _sprite_xsize[sprite];
	sd->ysize = _sprite_ysize[sprite];
*/
	return sd;
}