aboutsummaryrefslogtreecommitdiff
path: root/engines/tinsel/graphics.cpp
blob: 4f3cc36994436e73803532531e30beb91d60964a (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
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Low level graphics interface.
 */

#include "tinsel/graphics.h"
#include "tinsel/handle.h"	// LockMem()
#include "tinsel/object.h"
#include "tinsel/palette.h"
#include "tinsel/scene.h"
#include "tinsel/tinsel.h"
#include "tinsel/scn.h"

#include "common/textconsole.h"

namespace Tinsel {

//----------------- LOCAL DEFINES --------------------

// Defines used in graphic drawing
#define CHARPTR_OFFSET 16
#define CHAR_WIDTH 4
#define CHAR_HEIGHT 4

extern uint8 transPalette[MAX_COLORS];

//----------------- SUPPORT FUNCTIONS ---------------------

/**
 * PSX Block list unwinder.
 * Chunk type 0x0003 (CHUNK_CHARPTR) in PSX version of DW 1 & 2 is compressed (original code
 * calls the compression PJCRLE), thus we need to decompress it before passing data to drawing functions
 */
uint8* psxPJCRLEUnwinder(uint16 imageWidth, uint16 imageHeight, uint8 *srcIdx) {
	uint32 remainingBlocks = 0;

	uint16 compressionType = 0; // Kind of decompression to apply
	uint16 controlBits = 0; // Control bits used to calculate the number of decompressed indexes
	uint16 baseIndex = 0; // Base index to be repeated / incremented.

	uint16 controlData;

	uint8* dstIdx = NULL;
	uint8* destinationBuffer = NULL;

	if (!imageWidth || !imageHeight)
		return NULL;

	// Calculate needed index numbers, align width and height not next multiple of four
	imageWidth = (imageWidth % 4) ? ((imageWidth / 4) + 1) * 4 : imageWidth;
	imageHeight = (imageHeight % 4) ? ((imageHeight / 4) + 1) * 4 : imageHeight;
	destinationBuffer = (uint8 *)malloc((imageWidth * imageHeight) / 8);
	dstIdx = destinationBuffer;
	remainingBlocks = (imageWidth * imageHeight) / 16;

	while (remainingBlocks) { // Repeat until all blocks are decompressed
		if (!controlBits) {
			controlData = READ_LE_UINT16(srcIdx);
			srcIdx += 2;

			// If bit 15 of controlData is enabled, compression data is type 1.
			// else if controlData has bit 16 enabled, compression type is 2,
			// else there is no compression.
			if (controlData & 0x4000)
				compressionType = 2;
			else if (controlData & 0x8000)
				compressionType = 1;
			else
				compressionType = 0;

			// Fetch control bits from controlData
			controlBits = controlData & 0x3FFF;

			// If there is compression, we need to fetch an index
			// to be treated as "base" for compression.
			if (compressionType != 0) {
				controlData = READ_LE_UINT16(srcIdx);
				srcIdx += 2;
				baseIndex = controlData;
			}
		}

		uint32 decremTiles; // Number of blocks that will be decompressed
		if (remainingBlocks < controlBits) {
			controlBits = controlBits - remainingBlocks;
			decremTiles = remainingBlocks;
		} else {
			decremTiles = controlBits;
			controlBits = 0;
		}

		// Decrement remaining blocks
		remainingBlocks -= decremTiles;

		// Manage different compressions
		switch (compressionType) {
			case 0: // No compression, plain copy of indexes
				while (decremTiles) {
					WRITE_LE_UINT16(dstIdx, READ_LE_UINT16(srcIdx));
					srcIdx += 2;
					dstIdx += 2;
					decremTiles--;
				}
				break;
			case 1: // Compression type 1, repeat a base index
				while (decremTiles) {
					WRITE_LE_UINT16(dstIdx, baseIndex);
					dstIdx += 2;
					decremTiles--;
				}
				break;
			case 2: // Compression type 2, increment a base index
				while (decremTiles) {
					WRITE_LE_UINT16(dstIdx, baseIndex);
					baseIndex++;
					dstIdx += 2;
					decremTiles--;
				}
				break;
		}
	}

	// End.
	return destinationBuffer;
}

/**
 * Straight rendering of uncompressed data
 */
static void t0WrtNonZero(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP, bool applyClipping) {
	int yClip = 0;

	if (applyClipping) {
		// Adjust the height down to skip any bottom clipping
		pObj->height -= pObj->botClip;
		yClip = pObj->topClip;
	}

	// Vertical loop
	for (int y = 0; y < pObj->height; ++y) {
		// Get the start of the next line output
		uint8 *tempDest = destP;

		int leftClip = applyClipping ? pObj->leftClip : 0;
		int rightClip = applyClipping ? pObj->rightClip : 0;

		// Horizontal loop
		for (int x = 0; x < pObj->width; ) {
			uint32 numBytes = READ_UINT32(srcP);
			srcP += sizeof(uint32);
			bool repeatFlag = (numBytes & 0x80000000L) != 0;
			numBytes &= 0x7fffffff;

			uint clipAmount = MIN((int)numBytes & 0xff, leftClip);
			leftClip -= clipAmount;
			x += clipAmount;

			if (repeatFlag) {
				// Repeat of a given color
				uint8 color = (numBytes >> 8) & 0xff;
				int runLength = (numBytes & 0xff) - clipAmount;

				int rptLength = MAX(MIN(runLength, pObj->width - rightClip - x), 0);
				if (yClip == 0) {
					if (color != 0)
						memset(tempDest, color, rptLength);
					tempDest += rptLength;
				}

				x += runLength;
			} else {
				// Copy a specified sequence length of pixels
				srcP += clipAmount;

				int runLength = numBytes - clipAmount;
				int rptLength = MAX(MIN(runLength, pObj->width - rightClip - x), 0);
				if (yClip == 0) {
					memmove(tempDest, srcP, rptLength);
					tempDest += rptLength;
				}

				int overflow = (numBytes % 4) == 0 ? 0 : 4 - (numBytes % 4);
				x += runLength;
				srcP += runLength + overflow;
			}
		}

		// Move to next line
		if (yClip > 0)
			--yClip;
		else
			destP += SCREEN_WIDTH;
	}
}

/**
 * Straight rendering with transparency support, PSX variant supporting also 4-BIT clut data
 */
static void PsxDrawTiles(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP, bool applyClipping, bool fourBitClut, uint32 psxSkipBytes, byte *psxMapperTable, bool transparency) {
	// Set up the offset between destination blocks
	int rightClip = applyClipping ? pObj->rightClip : 0;
	Common::Rect boxBounds;

	if (applyClipping) {
		// Adjust the height down to skip any bottom clipping
		pObj->height -= pObj->botClip;

		// Make adjustment for the top clipping row
		srcP += sizeof(uint16) * ((pObj->width + 3) >> 2) * (pObj->topClip >> 2);
		pObj->height -= pObj->topClip;
		pObj->topClip %= 4;
	}

	// Vertical loop
	while (pObj->height > 0) {
		// Get the start of the next line output
		uint8 *tempDest = destP;

		// Get the line width, and figure out which row range within the 4 row high blocks
		// will be displayed if clipping is to be taken into account
		int width = pObj->width;

		if (!applyClipping) {
			// No clipping, so so set box bounding area for drawing full 4x4 pixel blocks
			boxBounds.top = 0;
			boxBounds.bottom = 3;
			boxBounds.left = 0;
		} else {
			// Handle any possible clipping at the top of the char block.
			// We already handled topClip partially at the beginning of this function.
			// Hence the only non-zero values it can assume at this point are 1,2,3,
			// and that only during the very first iteration (i.e. when the top char
			// block is drawn only partially). In particular, we set topClip to zero,
			// as all following blocks are not to be top clipped.
			boxBounds.top = pObj->topClip;
			pObj->topClip = 0;

			boxBounds.bottom = MIN(boxBounds.top + pObj->height - 1, 3);

			// Handle any possible clipping at the start of the line
			boxBounds.left = pObj->leftClip;
			if (boxBounds.left >= 4) {
				srcP += sizeof(uint16) * (boxBounds.left >> 2);
				width -= boxBounds.left & 0xfffc;
				boxBounds.left %= 4;
			}

			width -= boxBounds.left;
		}

		// Horizontal loop
		while (width > rightClip) {
			boxBounds.right = MIN(boxBounds.left + width - rightClip - 1, 3);
			assert(boxBounds.bottom >= boxBounds.top);
			assert(boxBounds.right >= boxBounds.left);

			int16 indexVal = READ_LE_UINT16(srcP);
			srcP += sizeof(uint16);

			// Draw a 4x4 block based on the opcode as in index into the block list
			// In case we have a 4-bit CLUT image, blocks are 2x4 bytes, then expanded into 4x4
			const uint8 *p;
			if (fourBitClut)
				p = (uint8 *)pObj->charBase + psxSkipBytes + (indexVal << 3);
			else
				p = (uint8 *)pObj->charBase + psxSkipBytes + (indexVal << 4);

			p += boxBounds.top * (fourBitClut ? sizeof(uint16) : sizeof(uint32));
			for (int yp = boxBounds.top; yp <= boxBounds.bottom; ++yp, p += (fourBitClut ? sizeof(uint16) : sizeof(uint32))) {
				if (!fourBitClut) {
					if (!transparency)
						Common::copy(p + boxBounds.left, p + boxBounds.right + 1, tempDest + (SCREEN_WIDTH * (yp - boxBounds.top)));
					else
						for (int xp = boxBounds.left; xp <= boxBounds.right; ++xp) {
							if (*(p + xp))
								*(tempDest + SCREEN_WIDTH * (yp - boxBounds.top) + (xp - boxBounds.left)) = *(p + xp);
						}
				} else {
					for (int xp = boxBounds.left; xp <= boxBounds.right; ++xp) {
						// Extract pixel value from byte
						byte pixValue =  (*(p + (xp / 2)) & ((xp % 2) ? 0xf0 : 0x0f)) >> ((xp % 2) ? 4 : 0);
						if (pixValue || !transparency)
							*(tempDest + SCREEN_WIDTH * (yp - boxBounds.top) + (xp - boxBounds.left)) = psxMapperTable[pixValue];
					}
				}
			}

			tempDest += boxBounds.right - boxBounds.left + 1;
			width -= 3 - boxBounds.left + 1;

			// None of the remaining horizontal blocks should be left clipped
			boxBounds.left = 0;
		}

		// If there is any width remaining, there must be a right edge clipping
		if (width >= 0)
			srcP += sizeof(uint16) * ((width + 3) >> 2);

		// Move to next line line
		pObj->height -= boxBounds.bottom - boxBounds.top + 1;
		destP += (boxBounds.bottom - boxBounds.top + 1) * SCREEN_WIDTH;
	}
}

/**
 * Straight rendering with transparency support
 */
static void WrtNonZero(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP, bool applyClipping) {
	// Set up the offset between destination blocks
	int rightClip = applyClipping ? pObj->rightClip : 0;
	Common::Rect boxBounds;

	if (applyClipping) {
		// Adjust the height down to skip any bottom clipping
		pObj->height -= pObj->botClip;

		// Make adjustment for the top clipping row
		srcP += sizeof(uint16) * ((pObj->width + 3) >> 2) * (pObj->topClip >> 2);
		pObj->height -= pObj->topClip;
		pObj->topClip %= 4;
	}

	// Vertical loop
	while (pObj->height > 0) {
		// Get the start of the next line output
		uint8 *tempDest = destP;

		// Get the line width, and figure out which row range within the 4 row high blocks
		// will be displayed if clipping is to be taken into account
		int width = pObj->width;

		if (!applyClipping) {
			// No clipping, so so set box bounding area for drawing full 4x4 pixel blocks
			boxBounds.top = 0;
			boxBounds.bottom = 3;
			boxBounds.left = 0;
		} else {
			// Handle any possible clipping at the top of the char block.
			// We already handled topClip partially at the beginning of this function.
			// Hence the only non-zero values it can assume at this point are 1,2,3,
			// and that only during the very first iteration (i.e. when the top char
			// block is drawn only partially). In particular, we set topClip to zero,
			// as all following blocks are not to be top clipped.
			boxBounds.top = pObj->topClip;
			pObj->topClip = 0;

			boxBounds.bottom = MIN(boxBounds.top + pObj->height - 1, 3);

			// Handle any possible clipping at the start of the line
			boxBounds.left = pObj->leftClip;
			if (boxBounds.left >= 4) {
				srcP += sizeof(uint16) * (boxBounds.left >> 2);
				width -= boxBounds.left & 0xfffc;
				boxBounds.left %= 4;
			}

			width -= boxBounds.left;
		}

		// Horizontal loop
		while (width > rightClip) {
			boxBounds.right = MIN(boxBounds.left + width - rightClip - 1, 3);
			assert(boxBounds.bottom >= boxBounds.top);
			assert(boxBounds.right >= boxBounds.left);

			int16 indexVal = READ_LE_UINT16(srcP);
			srcP += sizeof(uint16);

			if (indexVal >= 0) {
				// Draw a 4x4 block based on the opcode as in index into the block list
				const uint8 *p = (uint8 *)pObj->charBase + (indexVal << 4);
				p += boxBounds.top * sizeof(uint32);
				for (int yp = boxBounds.top; yp <= boxBounds.bottom; ++yp, p += sizeof(uint32)) {
					Common::copy(p + boxBounds.left, p + boxBounds.right + 1, tempDest + (SCREEN_WIDTH * (yp - boxBounds.top)));
				}

			} else {
				// Draw a 4x4 block with transparency support
				indexVal &= 0x7fff;

				// If index is zero, then skip drawing the block completely
				if (indexVal > 0) {
					// Use the index along with the object's translation offset
					const uint8 *p = (uint8 *)pObj->charBase + ((pObj->transOffset + indexVal) << 4);

					// Loop through each pixel - only draw a pixel if it's non-zero
					p += boxBounds.top * sizeof(uint32);
					for (int yp = boxBounds.top; yp <= boxBounds.bottom; ++yp) {
						p += boxBounds.left;
						for (int xp = boxBounds.left; xp <= boxBounds.right; ++xp, ++p) {
							if (*p)
								*(tempDest + SCREEN_WIDTH * (yp - boxBounds.top) + (xp - boxBounds.left)) = *p;
						}
						p += 3 - boxBounds.right;
					}
				}
			}

			tempDest += boxBounds.right - boxBounds.left + 1;
			width -= 3 - boxBounds.left + 1;

			// None of the remaining horizontal blocks should be left clipped
			boxBounds.left = 0;
		}

		// If there is any width remaining, there must be a right edge clipping
		if (width >= 0)
			srcP += sizeof(uint16) * ((width + 3) >> 2);

		// Move to next line line
		pObj->height -= boxBounds.bottom - boxBounds.top + 1;
		destP += (boxBounds.bottom - boxBounds.top + 1) * SCREEN_WIDTH;
	}
}

/**
 * Tinsel 2 Straight rendering with transparency support
 */
static void t2WrtNonZero(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP, bool applyClipping, bool horizFlipped) {
	// Setup for correct clipping of object edges
	int yClip = applyClipping ? pObj->topClip : 0;
	if (applyClipping)
		pObj->height -= pObj->botClip;
	int numBytes;
	int clipAmount;

	// WORKAROUND: One of the mortician frames has several corrupt bytes in the Russian version
	if ((pObj->hBits == 2517583660UL) && (_vm->getLanguage() == Common::RU_RUS)) {
		uint8 correctBytes[5] = {0xA3, 0x00, 0x89, 0xC0, 0xA6};
		Common::copy(&correctBytes[0], &correctBytes[5], srcP);
	}

	for (int y = 0; y < pObj->height; ++y) {
		// Get the position to start writing out from
		uint8 *tempP = !horizFlipped ? destP :
			destP + (pObj->width - pObj->leftClip - pObj->rightClip) - 1;
		int leftClip = applyClipping ? pObj->leftClip : 0;
		int rightClip = applyClipping ? pObj->rightClip : 0;
		if (horizFlipped)
			SWAP(leftClip, rightClip);

		int x = 0;
		while (x < pObj->width) {
			// Get the next opcode
			numBytes = *srcP++;
			if (numBytes & 0x80) {
				// Run length following
				numBytes &= 0x7f;
				clipAmount = MIN(numBytes, leftClip);
				leftClip -= clipAmount;
				x+= clipAmount;

				int runLength = numBytes - clipAmount;
				uint8 color = *srcP++;

				if ((yClip == 0) && (runLength > 0) && (color != 0)) {
					runLength = MIN(runLength, pObj->width - rightClip - x);

					if (runLength > 0) {
						// Non-transparent run length
						color += pObj->constant;
						if (horizFlipped)
							Common::fill(tempP - runLength + 1, tempP + 1, color);
						else
							Common::fill(tempP, tempP + runLength, color);
					}
				}

				if (horizFlipped)
					tempP -= runLength;
				else
					tempP += runLength;

				x += numBytes - clipAmount;

			} else {
				// Dump a length of pixels
				clipAmount = MIN(numBytes, leftClip);
				leftClip -= clipAmount;
				srcP += clipAmount;
				int runLength = numBytes - clipAmount;
				x += numBytes - runLength;

				for (int xp = 0; xp < runLength; ++xp) {
					if ((yClip > 0) || (x >= (pObj->width - rightClip)))
						++srcP;
					else if (horizFlipped)
						*tempP-- = pObj->constant + *srcP++;
					else
						*tempP++ = pObj->constant + *srcP++;
					++x;
				}
			}
		}
		assert(x == pObj->width);

		if (yClip > 0)
			--yClip;
		else
			destP += SCREEN_WIDTH;
	}
}

/**
 * Fill the destination area with a constant color
 */
static void WrtConst(DRAWOBJECT *pObj, uint8 *destP, bool applyClipping) {
	if (applyClipping) {
		pObj->height -= pObj->topClip + pObj->botClip;
		pObj->width -= pObj->leftClip + pObj->rightClip;

		if (pObj->width <= 0)
			return;
	}

	// Loop through any remaining lines
	while (pObj->height > 0) {
		Common::fill(destP, destP + pObj->width, pObj->constant);

		--pObj->height;
		destP += SCREEN_WIDTH;
	}
}

/**
 * Translates the destination surface within the object's bounds using the transparency
 * lookup table from transpal.cpp (the contents of which have been moved into palette.cpp)
 */
static void WrtTrans(DRAWOBJECT *pObj, uint8 *destP, bool applyClipping) {
	if (applyClipping) {
		pObj->height -= pObj->topClip + pObj->botClip;
		pObj->width -= pObj->leftClip + pObj->rightClip;

		if (pObj->width <= 0)
			return;
	}

	// Set up the offset between destination lines
	int lineOffset = SCREEN_WIDTH - pObj->width;

	// Loop through any remaining lines
	while (pObj->height > 0) {
		for (int i = 0; i < pObj->width; ++i, ++destP)
			*destP = transPalette[*destP];

		--pObj->height;
		destP += lineOffset;
	}
}

/**
 * Copies an uncompressed block of data straight to the screen
 */
static void WrtAll(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP, bool applyClipping) {
	int objWidth = pObj->width;

	if (applyClipping) {
		srcP += (pObj->topClip * pObj->width) + pObj->leftClip;

		pObj->height -= pObj->topClip + pObj->botClip;
		pObj->width -= pObj->leftClip + pObj->rightClip;

		if (pObj->width <= 0)
			return;
	}

	for (int y = 0; y < pObj->height; ++y) {
		Common::copy(srcP, srcP + pObj->width, destP);
		srcP += objWidth;
		destP += SCREEN_WIDTH;
	}
}

/**
 * Renders a packed data stream with a variable sized palette
 */
static void PackedWrtNonZero(DRAWOBJECT *pObj, uint8 *srcP, uint8 *destP,
							 bool applyClipping, bool horizFlipped, int packingType) {
	uint8 numColors = 0;
	uint8 *colorTable = NULL;
	int topClip = 0;
	int xOffset = 0;
	int numBytes, color;
	int v;

	if (_vm->getLanguage() == Common::RU_RUS) {
		// WORKAROUND: One of the mortician frames has several corrupt bytes in the Russian version
		if (pObj->hBits == 2517583393UL) {
			uint8 correctBytes[5] = {0x00, 0x00, 0x17, 0x01, 0x00};
			Common::copy(&correctBytes[0], &correctBytes[5], srcP + 267);
		}
		// WORKAROUND: One of Dibbler's frames in the end sequence has corrupt bytes in the Russian version
		if (pObj->hBits == 33651742) {
			uint8 correctBytes[40] = {
				0x06, 0xc0, 0xd6, 0xc1, 0x09, 0xce, 0x0d, 0x24, 0x02, 0x12, 0x01, 0x00, 0x00, 0x23, 0x21, 0x32,
				0x12, 0x00, 0x00, 0x20, 0x01, 0x11, 0x32, 0x12, 0x01, 0x00, 0x00, 0x1b, 0x02, 0x11, 0x34, 0x11,
				0x00, 0x00, 0x18, 0x01, 0x11, 0x35, 0x21, 0x01
			};
			Common::copy(&correctBytes[0], &correctBytes[40], srcP);
		}
	}

	if (applyClipping) {
		pObj->height -= pObj->botClip;
		topClip = pObj->topClip;
	}

	if (packingType == 3) {
		// Variable colors
		numColors = *srcP++;
		colorTable = srcP;
		srcP += numColors;
	}

	for (int y = 0; y < pObj->height; ++y) {
		// Get the position to start writing out from
		uint8 *tempP = !horizFlipped ? destP :
			destP + (pObj->width - pObj->leftClip - pObj->rightClip) - 1;
		int leftClip = applyClipping ? pObj->leftClip : 0;
		int rightClip = applyClipping ? pObj->rightClip : 0;
		if (horizFlipped)
			SWAP(leftClip, rightClip);
		bool eolFlag = false;

		// Get offset for first pixels in next line
		xOffset = *srcP++;

		int x = 0;
		while (x < pObj->width) {
			// Get next run size and color to use
			for (;;) {
				if (xOffset > 0) {
					x += xOffset;

					// Reduce offset amount by any remaining left clipping
					v = MIN(xOffset, leftClip);
					xOffset -= v;
					leftClip -= v;

					if (horizFlipped) tempP -= xOffset; else tempP += xOffset;
					xOffset = 0;
				}

				v = *srcP++;
				numBytes = v & 0xf;	// No. bytes 1-15
				if (packingType == 3)
					color = colorTable[v >> 4];
				else
					color = pObj->baseCol + (v >> 4);

				if (numBytes != 0)
					break;

				numBytes = *srcP++;
				if (numBytes >= 16)
					break;

				xOffset = numBytes + v;
				if (xOffset == 0) {
					// End of line encountered
					eolFlag = true;
					break;
				}
			}

			if (eolFlag)
				break;

			// Apply clipping on byte sequence
			v = MIN(numBytes, leftClip);
			leftClip -= v;
			numBytes -= v;
			x += v;

			while (numBytes-- > 0) {
				if ((topClip == 0) && (x < (pObj->width - rightClip))) {
					*tempP = color;
					if (horizFlipped) --tempP; else ++tempP;
				}
				++x;
			}
		}
		assert(x <= pObj->width);

		if (!eolFlag) {
			// Assert that the next bytes signal a line end
			uint8 d = *srcP++;
			assert((d & 0xf) == 0);
			d = *srcP++;
			assert(d == 0);
		}

		if (topClip > 0)
			--topClip;
		else
			destP += SCREEN_WIDTH;
	}
}

//----------------- MAIN FUNCTIONS ---------------------

/**
 * Clears both the screen surface buffer and screen to the specified value
 */
void ClearScreen() {
	void *pDest = _vm->screen().getBasePtr(0, 0);
	memset(pDest, 0, SCREEN_WIDTH * SCREEN_HEIGHT);
	g_system->fillScreen(0);
	g_system->updateScreen();
}

/**
 * Updates the screen surface within the following rectangle
 */
void UpdateScreenRect(const Common::Rect &pClip) {
	int yOffset = TinselV2 ? (g_system->getHeight() - SCREEN_HEIGHT) / 2 : 0;
	byte *pSrc = (byte *)_vm->screen().getBasePtr(pClip.left, pClip.top);
	g_system->copyRectToScreen(pSrc, _vm->screen().pitch, pClip.left, pClip.top + yOffset,
		pClip.width(), pClip.height());
}

/**
 * Draws the specified object onto the screen surface buffer
 */
void DrawObject(DRAWOBJECT *pObj) {
	uint8 *srcPtr = NULL;
	uint8 *destPtr;
	byte psxMapperTable[16];

	bool psxFourBitClut = false; // Used by Tinsel PSX, true if an image using a 4bit CLUT is rendered
	bool psxRLEindex = false; // Used by Tinsel PSX, true if an image is using PJCRLE compressed indexes
	uint32 psxSkipBytes = 0; // Used by Tinsel PSX, number of bytes to skip before counting indexes for image tiles

	if ((pObj->width <= 0) || (pObj->height <= 0))
		// Empty image, so return immediately
		return;

	// If writing constant data, don't bother locking the data pointer and reading src details
	if ((pObj->flags & DMA_CONST) == 0) {
		if (TinselV2) {
			srcPtr  = (byte *)LockMem(pObj->hBits);
			pObj->charBase = NULL;
			pObj->transOffset = 0;
		} else {
			byte *p = (byte *)LockMem(pObj->hBits & HANDLEMASK);

			srcPtr = p + (pObj->hBits & OFFSETMASK);
			pObj->charBase = (char *)p + READ_LE_UINT32(p + 0x10);
			pObj->transOffset = READ_LE_UINT32(p + 0x14);

			// Decompress block indexes for Discworld PSX
			if (TinselV1PSX) {
				uint8 paletteType = *(srcPtr); // if 0x88 we are using an 8bit palette type, if 0x44 we are using a 4 bit PSX CLUT
				uint8 indexType = *(srcPtr + 1); // if 0xCC indexes for this image are compressed with PCJRLE, if 0xDD indexes are not compressed

				switch (paletteType) {
					case 0x88: // Normal 8-bit palette
						psxFourBitClut = false;
						psxSkipBytes = 0;
						switch (indexType) {
							case 0xDD: // Normal uncompressed indexes
								psxRLEindex = false;
								srcPtr += sizeof(uint16); // Get to the beginning of index data
								break;
							case 0xCC: // PJCRLE compressed indexes
								psxRLEindex = true;
								srcPtr = psxPJCRLEUnwinder(pObj->width, pObj->height, srcPtr + sizeof(uint16));
								break;
							default:
								error("Unknown PSX index type 0x%.2X", indexType);
								break;
						}
						break;
					case 0x44: // PSX 4-bit CLUT
						psxPaletteMapper(pObj->pPal, srcPtr + sizeof(uint16), psxMapperTable);

						psxFourBitClut = true;
						psxSkipBytes = READ_LE_UINT32(p + sizeof(uint32) * 5) << 4; // Fetch number of bytes we have to skip
						switch (indexType) {
							case 0xDD: // Normal uncompressed indexes
								psxRLEindex = false;
								srcPtr += sizeof(uint16) * 17; // Skip image type and clut, and get to beginning of index data
								break;
							case 0xCC: // PJCRLE compressed indexes
								psxRLEindex = true;
								srcPtr = psxPJCRLEUnwinder(pObj->width, pObj->height, srcPtr + sizeof(uint16) * 17);
								break;
							default:
								error("Unknown PSX index type 0x%.2X", indexType);
								break;
						}
						break;
					default:
						error("Unknown PSX palette type 0x%.2X", paletteType);
						break;
				}
			}
		}

	}

	// Get destination starting point
	destPtr = (byte *)_vm->screen().getBasePtr(pObj->xPos, pObj->yPos);

	// Handle various draw types
	uint8 typeId = pObj->flags & 0xff;

	if (TinselV2) {
		// Tinsel v2 decoders
		// Initial switch statement for the different bit packing types
		int packType = pObj->flags >> 14;

		if (packType == 0) {
			// No color packing
			switch (typeId) {
			case 0x01:
			case 0x11:
			case 0x41:
			case 0x51:
			case 0x81:
			case 0xC1:
				t2WrtNonZero(pObj, srcPtr, destPtr, typeId >= 0x40, (typeId & 0x10) != 0);
				break;
			case 0x02:
			case 0x42:
				// This renderer called 'RlWrtAll', but is the same as t2WrtNonZero
				t2WrtNonZero(pObj, srcPtr, destPtr, typeId >= 0x40, false);
				break;
			case 0x04:
			case 0x44:
				// WrtConst with/without clipping
				WrtConst(pObj, destPtr, typeId == 0x44);
				break;
			case 0x08:
			case 0x48:
				WrtAll(pObj, srcPtr, destPtr, typeId >= 0x40);
				break;
			case 0x84:
			case 0xC4:
				// WrtTrans with/without clipping
				WrtTrans(pObj, destPtr, typeId == 0xC4);
				break;
			default:
				error("Unknown drawing type %d", typeId);
			}
		} else {
			// 1 = 16 from 240
			// 2 = 16 from 224
			// 3 = variable color
			if (packType == 1) pObj->baseCol = 0xF0;
			else if (packType == 2) pObj->baseCol = 0xE0;

			PackedWrtNonZero(pObj, srcPtr, destPtr, (pObj->flags & DMA_CLIP) != 0,
				(pObj->flags & DMA_FLIPH), packType);
		}

	} else if (TinselV1PSX) {
		// Tinsel v1 decoders, PSX specific variants
		switch (typeId) {
		case 0x01:
		case 0x41:
			PsxDrawTiles(pObj, srcPtr, destPtr, typeId >= 0x40, psxFourBitClut, psxSkipBytes, psxMapperTable, true);
			break;
		case 0x08:
		case 0x48:
			PsxDrawTiles(pObj, srcPtr, destPtr, typeId >= 0x40, psxFourBitClut, psxSkipBytes, psxMapperTable, false);
			break;
		case 0x84:
		case 0xC4:
			// WrtTrans with/without clipping
			WrtTrans(pObj, destPtr, typeId == 0xC4);
			break;
		case 0x04:
		case 0x44:
			// WrtConst with/without clipping
			WrtConst(pObj, destPtr, typeId == 0x44);
			break;
		default:
			error("Unknown drawing type %d", typeId);
		}
	} else if (TinselV1) {
		// Tinsel v1 decoders
		switch (typeId) {
		case 0x01:
		case 0x08:
		case 0x41:
		case 0x48:
			WrtNonZero(pObj, srcPtr, destPtr, typeId >= 0x40);
			break;

		case 0x04:
		case 0x44:
			// WrtConst with/without clipping
			WrtConst(pObj, destPtr, typeId == 0x44);
			break;

		case 0x84:
		case 0xC4:
			// WrtTrans with/without clipping
			WrtTrans(pObj, destPtr, typeId == 0xC4);
			break;

		default:
			error("Unknown drawing type %d", typeId);
		}
	} else {
		// Tinsel v0 decoders
		switch (typeId) {
		case 0x01:
		case 0x41:
			t0WrtNonZero(pObj, srcPtr, destPtr, typeId >= 0x40);
			break;
		case 0x08:
		case 0x48:
			WrtAll(pObj, srcPtr, destPtr, typeId >= 0x40);
			break;
		case 0x84:
		case 0xC4:
			WrtTrans(pObj, destPtr, (typeId & 0x40) != 0);
			break;
		default:
			error("Unknown drawing type %d", typeId);
		}
	}

	// If we were using Discworld PSX, free the memory allocated
	// for decompressed block indexes.
	if (TinselV1PSX && psxRLEindex)
		free(srcPtr);
}

} // End of namespace Tinsel