summaryrefslogtreecommitdiffstatshomepage
path: root/src/mame/video/neogeo.c
blob: 8a1f82fe6257b28edb87edd3255720dfea4fe778 (plain) (blame)
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
/***************************************************************************

    Neo-Geo hardware

****************************************************************************/

#include "driver.h"
#include "neogeo.h"
#include "video/resnet.h"


#define NUM_PENS	(0x1000)

#define VERBOSE 	(0)

static UINT8 *sprite_gfx;
static UINT32 sprite_gfx_address_mask;
static UINT16 *neogeo_videoram;
static UINT16 *palettes[2]; /* 0x100*16 2 byte palette entries */
static pen_t *pens;
static UINT8 palette_bank;
static UINT8 screen_dark;
static UINT16 videoram_read_buffer;
static UINT16 videoram_modulo;
static UINT16 videoram_offset;

static UINT8 fixed_layer_source;
int neogeo_fixed_layer_bank_type;		/* no need to state save */

static UINT8 auto_animation_speed;
static UINT8 auto_animation_disabled;
static UINT8 auto_animation_counter;
static UINT8 auto_animation_frame_counter;
static emu_timer *auto_animation_timer;

static emu_timer *sprite_line_timer;

static const UINT8 *region_zoomy;


/*************************************
 *
 *  Video RAM access
 *
 *************************************/

static void set_videoram_offset(UINT16 data)
{
	videoram_offset = data;

	/* the read happens right away */
	videoram_read_buffer = neogeo_videoram[videoram_offset];
}


static UINT16 get_videoram_data(void)
{
	return videoram_read_buffer;
}


static void set_videoram_data(UINT16 data)
{
	neogeo_videoram[videoram_offset] = data;

	/* auto increment/decrement the current offset - A15 is NOT effected */
	videoram_offset = (videoram_offset & 0x8000) | ((videoram_offset + videoram_modulo) & 0x7fff);

	/* read next value right away */
	videoram_read_buffer = neogeo_videoram[videoram_offset];
}


static void set_videoram_modulo(UINT16 data)
{
	videoram_modulo = data;
}


static UINT16 get_videoram_modulo(void)
{
	return videoram_modulo;
}



/*************************************
 *
 *  Palette handling
 *
 *************************************/

static double rgb_weights_normal[5];
static double rgb_weights_normal_bit15[5];
static double rgb_weights_dark[5];
static double rgb_weights_dark_bit15[5];

static void compute_rgb_weights(void)
{
	static const int resistances[] = { 220, 470, 1000, 2200, 3900 };

	/* compute four sets of weights - with or without the pulldowns -
       ensuring that we use the same scaler for all */

	double scaler = compute_resistor_weights(0, 0xff, -1,
							 5, resistances, rgb_weights_normal, 0, 0,
							 0, 0, 0, 0, 0,
							 0, 0, 0, 0, 0);

	compute_resistor_weights(0, 0xff, scaler,
							 5, resistances, rgb_weights_normal_bit15, 8200, 0,
							 0, 0, 0, 0, 0,
							 0, 0, 0, 0, 0);

	compute_resistor_weights(0, 0xff, scaler,
							 5, resistances, rgb_weights_dark, 150, 0,
							 0, 0, 0, 0, 0,
							 0, 0, 0, 0, 0);

	compute_resistor_weights(0, 0xff, scaler,
							 5, resistances, rgb_weights_dark_bit15, 1 / ((1.0 / 8200) + (1.0 / 150)), 0,
							 0, 0, 0, 0, 0,
							 0, 0, 0, 0, 0);
}


static pen_t get_pen(UINT16 data)
{
	double *weights;
	UINT8 r, g, b;

	if (screen_dark)
	{
		if (data & 0x8000)
			weights = rgb_weights_dark_bit15;
		else
			weights = rgb_weights_dark;
	}
	else
	{
		if (data & 0x8000)
			weights = rgb_weights_normal_bit15;
		else
			weights = rgb_weights_normal;
	}

	r = combine_5_weights(weights,
						  (data >> 11) & 0x01,
						  (data >> 10) & 0x01,
						  (data >>  9) & 0x01,
						  (data >>  8) & 0x01,
						  (data >> 14) & 0x01);

	g = combine_5_weights(weights,
						  (data >>  7) & 0x01,
						  (data >>  6) & 0x01,
						  (data >>  5) & 0x01,
						  (data >>  4) & 0x01,
						  (data >> 13) & 0x01);

	b = combine_5_weights(weights,
						  (data >>  3) & 0x01,
						  (data >>  2) & 0x01,
						  (data >>  1) & 0x01,
						  (data >>  0) & 0x01,
						  (data >> 12) & 0x01);

	return MAKE_RGB(r, g, b);
}


static STATE_POSTLOAD( regenerate_pens )
{
	int i;

	for (i = 0; i < NUM_PENS; i++)
		pens[i] = get_pen(palettes[palette_bank][i]);
}


void neogeo_set_palette_bank(running_machine *machine, UINT8 data)
{
	if (data != palette_bank)
	{
		palette_bank = data;

		regenerate_pens(machine, NULL);
	}
}


void neogeo_set_screen_dark(running_machine *machine, UINT8 data)
{
	if (data != screen_dark)
	{
		screen_dark = data;

		regenerate_pens(machine, NULL);
	}
}


READ16_HANDLER( neogeo_paletteram_r )
{
	return palettes[palette_bank][offset];
}


WRITE16_HANDLER( neogeo_paletteram_w )
{
	UINT16 *addr = &palettes[palette_bank][offset];

	COMBINE_DATA(addr);

	pens[offset] = get_pen(*addr);
}



/*************************************
 *
 *  Auto animation
 *
 *************************************/

static void set_auto_animation_speed(UINT8 data)
{
	auto_animation_speed = data;
}


static void set_auto_animation_disabled(UINT8 data)
{
	auto_animation_disabled = data;
}


UINT8 neogeo_get_auto_animation_counter(void)
{
	return auto_animation_counter;
}


static TIMER_CALLBACK( auto_animation_timer_callback )
{
	if (auto_animation_frame_counter == 0)
	{
		auto_animation_frame_counter = auto_animation_speed;
		auto_animation_counter = auto_animation_counter + 1;
	}
	else
		auto_animation_frame_counter = auto_animation_frame_counter - 1;

	timer_adjust_oneshot(auto_animation_timer, video_screen_get_time_until_pos(machine->primary_screen, NEOGEO_VSSTART, 0), 0);
}


static void create_auto_animation_timer(void)
{
	auto_animation_timer = timer_alloc(auto_animation_timer_callback, NULL);
}


static void start_auto_animation_timer(running_machine *machine)
{
	timer_adjust_oneshot(auto_animation_timer, video_screen_get_time_until_pos(machine->primary_screen, NEOGEO_VSSTART, 0), 0);
}



/*************************************
 *
 *  Fixed layer
 *
 *************************************/

void neogeo_set_fixed_layer_source(UINT8 data)
{
	fixed_layer_source = data;
}


static void draw_fixed_layer(running_machine *machine, bitmap_t *bitmap, int scanline)
{
	int x;

	UINT8* gfx_base = memory_region(machine, fixed_layer_source ? "fixed" : "fixedbios");
	UINT32 addr_mask = memory_region_length(machine, fixed_layer_source ? "fixed" : "fixedbios") - 1;
	UINT16 *video_data = &neogeo_videoram[0x7000 | (scanline >> 3)];
	UINT32 *pixel_addr = BITMAP_ADDR32(bitmap, scanline, NEOGEO_HBEND);

int garouoffsets[32];
int banked = fixed_layer_source && (addr_mask > 0x1ffff);
{
/* thanks to Mr K for the garou & kof2000 banking info */
/* Build line banking table for Garou & MS3 before starting render */
if (banked && neogeo_fixed_layer_bank_type == 1)
{
	int garoubank = 0;
	int k = 0;
	int y = 0;
	while (y < 32)
	{
		if (neogeo_videoram[0x7500+k] == 0x0200 && (neogeo_videoram[0x7580+k] & 0xff00) == 0xff00)
		{
			garoubank = neogeo_videoram[0x7580+k] & 3;
			garouoffsets[y++] = garoubank;
		}
		garouoffsets[y++] = garoubank;
		k += 2;
	}
}
}

	for (x = 0; x < 40; x++)
	{
		UINT16 code_and_palette = *video_data;

		UINT16 code = code_and_palette & 0x0fff;

if (banked)
{
	int y = scanline >> 3;
	switch (neogeo_fixed_layer_bank_type)
	{
	case 1:
		/* Garou, MSlug 3 */
		code += 0x1000 * (garouoffsets[(y-2)&31] ^ 3);
		break;
	case 2:
		code += 0x1000 * (((neogeo_videoram[0x7500 + ((y-1)&31) + 32 * (x/6)] >> (5-(x%6))*2) & 3) ^ 3);
		break;
	}
}

		{
			UINT8 data = 0;
			int i;

			UINT8 *gfx = &gfx_base[((code << 5) | (scanline & 0x07)) & addr_mask];
			pen_t *char_pens = &pens[code_and_palette >> 12 << 4];

			for (i = 0; i < 8; i++)
			{
				static const UINT32 pix_offsets[] = { 0x10, 0x18, 0x00, 0x08 };

				if (i & 0x01)
					data = data >> 4;
				else
					data = gfx[pix_offsets[i >> 1]];

				if (data & 0x0f)
					*pixel_addr = char_pens[data & 0x0f];

				pixel_addr++;
			}
		}

		video_data = video_data + 0x20;
	}
}



/*************************************
 *
 *  Sprite hardware
 *
 *************************************/

#define MAX_SPRITES_PER_SCREEN	(381)
#define MAX_SPRITES_PER_LINE	(96)


/* horizontal zoom table - verified on real hardware */
static const int zoom_x_tables[][16] =
{
	{ 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0 },
	{ 0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0 },
	{ 0,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0 },
	{ 0,0,1,0,1,0,0,0,1,0,0,0,1,0,0,0 },
	{ 0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0 },
	{ 0,0,1,0,1,0,1,0,1,0,0,0,1,0,1,0 },
	{ 0,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0 },
	{ 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0 },
	{ 1,0,1,0,1,0,1,0,1,1,1,0,1,0,1,0 },
	{ 1,0,1,1,1,0,1,0,1,1,1,0,1,0,1,0 },
	{ 1,0,1,1,1,0,1,0,1,1,1,0,1,0,1,1 },
	{ 1,0,1,1,1,0,1,1,1,1,1,0,1,0,1,1 },
	{ 1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1 },
	{ 1,1,1,1,1,0,1,1,1,1,1,0,1,1,1,1 },
	{ 1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1 },
	{ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 }
};


INLINE int rows_to_height(int rows)
{
	if ((rows == 0) || (rows > 0x20))
		rows = 0x20;

	return rows * 0x10;
}


INLINE int sprite_on_scanline(int scanline, int y, int rows)
{
	/* check if the current scanline falls inside this sprite,
       two possible scenerios, wrap around or not */
	int max_y = (y + rows_to_height(rows) - 1) & 0x1ff;

	return (((max_y >= y) &&  (scanline >= y) && (scanline <= max_y)) ||
			((max_y <  y) && ((scanline >= y) || (scanline <= max_y))));
}


static void draw_sprites(running_machine *machine, bitmap_t *bitmap, int scanline)
{
	int sprite_index;
	int max_sprite_index;

	int y = 0;
	int x = 0;
	int rows = 0;
	int zoom_y = 0;
	int zoom_x = 0;
	UINT16 *sprite_list;

	/* select the active list */
	if (scanline & 0x01)
		sprite_list = &neogeo_videoram[0x8680];
	else
		sprite_list = &neogeo_videoram[0x8600];

	/* optimization -- find last non-zero entry and only draw that many +1
       sprite.  This is not 100% correct as the hardware will keep drawing
       the #0 sprite over and over, but we need the speed */
    for (max_sprite_index = (MAX_SPRITES_PER_LINE - 1); max_sprite_index >= 0; max_sprite_index--)
    {
		if (sprite_list[max_sprite_index] != 0)
			break;
	}

	/* add the +1 now, just in case the 0 at the end is real sprite */
	if (max_sprite_index != (MAX_SPRITES_PER_LINE - 1))
		max_sprite_index = max_sprite_index + 1;

	for (sprite_index = 0; sprite_index <= max_sprite_index; sprite_index++)
	{
		UINT16 sprite_number = sprite_list[sprite_index] & 0x01ff;

		UINT16 y_control = neogeo_videoram[0x8200 | sprite_number];
		UINT16 zoom_control = neogeo_videoram[0x8000 | sprite_number];

		/* if chained, go to next X coordinate and get new X zoom */
		if (y_control & 0x40)
		{
			x = (x + zoom_x + 1) & 0x01ff;
			zoom_x = (zoom_control >> 8) & 0x0f;
		}
		/* new block */
		else
		{
			y = 0x200 - (y_control >> 7);
			x = neogeo_videoram[0x8400 | sprite_number] >> 7;
			zoom_y = zoom_control & 0xff;
			zoom_x = (zoom_control >> 8) & 0x0f;
			rows = y_control & 0x3f;
		}

		/* skip if falls completely outside the screen */
		if ((x >= 0x140) && (x <= 0x1f0))
			continue;

		/* double check the Y coordinate, in case somebody modified the sprite coordinate
           since we buffered it */
		if (sprite_on_scanline(scanline, y, rows))
		{
			int sprite_y;
			int tile;
			UINT8 sprite_y_and_tile;
			offs_t attr_and_code_offs;
			UINT16 attr;
			UINT32 code;
			const int *zoom_x_table;
			UINT8 *gfx;
			pen_t *line_pens;
			int x_inc;

			int sprite_line = (scanline - y) & 0x1ff;
			int zoom_line = sprite_line & 0xff;
			int invert = sprite_line & 0x100;

			if (invert)
				zoom_line ^= 0xff;

			if (rows > 0x20)
			{
				zoom_line = zoom_line % ((zoom_y + 1) << 1);

				if (zoom_line > zoom_y)
				{
					zoom_line = ((zoom_y + 1) << 1) - 1 - zoom_line;
					invert = !invert;
				}
			}

			sprite_y_and_tile = region_zoomy[(zoom_y << 8) | zoom_line];
			sprite_y = sprite_y_and_tile & 0x0f;
			tile = sprite_y_and_tile >> 4;

			if (invert)
			{
				sprite_y ^= 0x0f;
				tile ^= 0x1f;
			}

			attr_and_code_offs = (sprite_number << 6) | (tile << 1);
			attr = neogeo_videoram[attr_and_code_offs + 1];
			code = ((attr << 12) & 0x70000) | neogeo_videoram[attr_and_code_offs];

			/* substitute auto animation bits */
			if (!auto_animation_disabled)
			{
				if (attr & 0x0008)
					code = (code & ~0x07) | (auto_animation_counter & 0x07);
				else if (attr & 0x0004)
					code = (code & ~0x03) | (auto_animation_counter & 0x03);
			}

			/* vertical flip? */
			if (attr & 0x0002)
				sprite_y ^= 0x0f;

			zoom_x_table = zoom_x_tables[zoom_x];

			/* compute offset in gfx ROM and mask it to the number of bits available */
			gfx = &sprite_gfx[((code << 8) | (sprite_y << 4)) & sprite_gfx_address_mask];

			line_pens = &pens[attr >> 8 << 4];

			/* horizontal flip? */
			if (attr & 0x0001)
			{
				gfx = gfx + 0x0f;
				x_inc = -1;
			}
			else
				x_inc = 1;

			/* draw the line - no wrap-around */
			if (x <= 0x01f0)
			{
				int i;

				UINT32 *pixel_addr = BITMAP_ADDR32(bitmap, scanline, x + NEOGEO_HBEND);

				for (i = 0; i < 0x10; i++)
				{
					if (*zoom_x_table)
					{
						if (*gfx)
							*pixel_addr = line_pens[*gfx];

						pixel_addr++;
					}

					zoom_x_table++;
					gfx += x_inc;
				}
			}
			/* wrap-around */
			else
			{
				int i;

				int x_save = x;
				UINT32 *pixel_addr = BITMAP_ADDR32(bitmap, scanline, NEOGEO_HBEND);

				for (i = 0; i < 0x10; i++)
				{
					if (*zoom_x_table)
					{
						if (x >= 0x200)
						{
							if (*gfx)
								*pixel_addr = line_pens[*gfx];

							pixel_addr++;
						}

						x++;
					}

					zoom_x_table++;
					gfx += x_inc;
				}

				x = x_save;
			}
		}
	}
}


static void parse_sprites(int scanline)
{
	UINT16 sprite_number;
	int y = 0;
	int rows = 0;
	UINT16 *sprite_list;

	int active_sprite_count = 0;

	/* select the active list */
	if (scanline & 0x01)
		sprite_list = &neogeo_videoram[0x8680];
	else
		sprite_list = &neogeo_videoram[0x8600];

	/* scan all sprites */
	for (sprite_number = 0; sprite_number < MAX_SPRITES_PER_SCREEN; sprite_number++)
	{
		UINT16 y_control = neogeo_videoram[0x8200 | sprite_number];

		/* if not chained, get Y position and height, otherwise use previous values */
		if (~y_control & 0x40)
		{
			y = 0x200 - (y_control >> 7);
			rows = y_control & 0x3f;
		}

		/* skip sprites with 0 rows */
		if (rows == 0)
			continue;

		if (!sprite_on_scanline(scanline, y, rows))
			continue;

		/* sprite is on this scanline, add it to active list */
		*sprite_list = sprite_number;

		sprite_list++;

		/* increment sprite count, and if we reached the max, bail out */
		active_sprite_count++;

		if (active_sprite_count == MAX_SPRITES_PER_LINE)
			break;
	}

	/* fill the rest of the sprite list with 0, including one extra entry */
	for (; active_sprite_count <= MAX_SPRITES_PER_LINE ; active_sprite_count++)
	{
		*sprite_list = 0;

		sprite_list++;
	}
}


static TIMER_CALLBACK( sprite_line_timer_callback )
{
	int scanline = param;

	/* we are at the beginning of a scanline -
       we need to draw the previous scanline and parse the sprites on the current one */
    if (scanline != 0)
    	video_screen_update_partial(machine->primary_screen, scanline - 1);

	parse_sprites(scanline);

	/* let's come back at the beginning of the next line */
	scanline = (scanline + 1) % NEOGEO_VTOTAL;

	timer_adjust_oneshot(sprite_line_timer, video_screen_get_time_until_pos(machine->primary_screen, scanline, 0), scanline);
}


static void create_sprite_line_timer(void)
{
	sprite_line_timer = timer_alloc(sprite_line_timer_callback, NULL);
}


static void start_sprite_line_timer(running_machine *machine)
{
	timer_adjust_oneshot(sprite_line_timer, video_screen_get_time_until_pos(machine->primary_screen, 0, 0), 0);
}


static void optimize_sprite_data(running_machine *machine)
{
	/* convert the sprite graphics data into a format that
       allows faster blitting */
	int i;
	int len;
	UINT8 *src;
	UINT8 *dest;
	UINT32 bit;

	/* get mask based on the length rounded up to the nearest
       power of 2 */
	sprite_gfx_address_mask = 0xffffffff;

	len = memory_region_length(machine, "sprites");
	for (bit = 0x80000000; bit != 0; bit >>= 1)
	{
		if (((len * 2) - 1) & bit)
			break;

		sprite_gfx_address_mask >>= 1;
	}

	sprite_gfx = auto_malloc(sprite_gfx_address_mask + 1);
	memset(sprite_gfx, 0, sprite_gfx_address_mask + 1);

	src = memory_region(machine, "sprites");
	dest = sprite_gfx;

	for (i = 0; i < len; i += 0x80, src += 0x80)
	{
		int y;

		for (y = 0; y < 0x10; y++)
		{
			int x;

			for (x = 0; x < 8; x++)
			{
				*(dest++) = (((src[0x43 | (y << 2)] >> x) & 0x01) << 3) |
						    (((src[0x41 | (y << 2)] >> x) & 0x01) << 2) |
							(((src[0x42 | (y << 2)] >> x) & 0x01) << 1) |
							(((src[0x40 | (y << 2)] >> x) & 0x01) << 0);
			}

			for (x = 0; x < 8; x++)
			{
				*(dest++) = (((src[0x03 | (y << 2)] >> x) & 0x01) << 3) |
						    (((src[0x01 | (y << 2)] >> x) & 0x01) << 2) |
							(((src[0x02 | (y << 2)] >> x) & 0x01) << 1) |
							(((src[0x00 | (y << 2)] >> x) & 0x01) << 0);
			}
		}
	}
}



/*************************************
 *
 *  Video control
 *
 *************************************/

static UINT16 get_video_control(running_machine *machine)
{
	UINT16 ret;
	UINT16 v_counter;

	/*
        The format of this very important location is:  AAAA AAAA A??? BCCC

        A is the raster line counter. mosyougi relies solely on this to do the
          raster effects on the title screen; sdodgeb loops waiting for the top
          bit to be 1; zedblade heavily depends on it to work correctly (it
          checks the top bit in the IRQ2 handler).
        B is definitely a PAL/NTSC flag. Evidence:
          1) trally changes the position of the speed indicator depending on
             it (0 = lower 1 = higher).
          2) samsho3 sets a variable to 60 when the bit is 0 and 50 when it's 1.
             This is obviously the video refresh rate in Hz.
          3) samsho3 sets another variable to 256 or 307. This could be the total
             screen height (including vblank), or close to that.
          Some games (e.g. lstbld2, samsho3) do this (or similar):
          bclr    #$0, $3c000e.l
          when the bit is set, so 3c000e (whose function is unknown) has to be
          related
        C animation counter lower 3 bits
    */

	/* the vertical counter chain goes from 0xf8 - 0x1ff */
	v_counter = video_screen_get_vpos(machine->primary_screen) + 0x100;

	if (v_counter >= 0x200)
		v_counter = v_counter - NEOGEO_VTOTAL;

	ret = (v_counter << 7) | (neogeo_get_auto_animation_counter() & 0x0007);

	if (VERBOSE) logerror("PC %06x: video_control read (%04x)\n", activecpu_get_pc(), ret);

	return ret;
}


static void set_video_control(UINT16 data)
{
	/* this does much more than this, but I'm not sure exactly what */
	if (VERBOSE) logerror("%06x: video control write %04x\n", activecpu_get_pc(), data);

	set_auto_animation_speed(data >> 8);
	set_auto_animation_disabled(data & 0x0008);

	neogeo_set_display_position_interrupt_control(data & 0x00f0);
}


READ16_HANDLER( neogeo_video_register_r )
{
	UINT16 ret;

	/* accessing the LSB only is not mapped */
	if (mem_mask == 0x00ff)
		ret = neogeo_unmapped_r(machine, 0, 0xffff) & 0x00ff;
	else
	{
		switch (offset)
		{
		default:
		case 0x00:
		case 0x01: ret = get_videoram_data(); break;
		case 0x02: ret = get_videoram_modulo(); break;
		case 0x03: ret = get_video_control(machine); break;
		}
	}

	return ret;
}


WRITE16_HANDLER( neogeo_video_register_w )
{
	/* accessing the LSB only is not mapped */
	if (mem_mask != 0x00ff)
	{
		/* accessing the MSB only stores same data in MSB and LSB */
		if (mem_mask == 0xff00)
			data = (data & 0xff00) | (data >> 8);

		switch (offset)
		{
		case 0x00: set_videoram_offset(data); break;
		case 0x01: set_videoram_data(data); break;
		case 0x02: set_videoram_modulo(data); break;
		case 0x03: set_video_control(data); break;
		case 0x04: neogeo_set_display_counter_msb(data); break;
		case 0x05: neogeo_set_display_counter_lsb(machine, data); break;
		case 0x06: neogeo_acknowledge_interrupt(machine, data); break;
		case 0x07: break; /* unknown, see get_video_control */
		}
	}
}



/*************************************
 *
 *  Video system start
 *
 *************************************/

VIDEO_START( neogeo )
{
	/* allocate memory not directly mapped */
	palettes[0] = auto_malloc(NUM_PENS * sizeof(UINT16));
	palettes[1] = auto_malloc(NUM_PENS * sizeof(UINT16));
	pens = auto_malloc(NUM_PENS * sizeof(pen_t));
	neogeo_videoram = auto_malloc(0x20000);

	/* clear allocated memory */
	memset(palettes[0],0x00, NUM_PENS * sizeof(UINT16));
	memset(palettes[1],0x00, NUM_PENS * sizeof(UINT16));
	memset(pens,0x00, NUM_PENS * sizeof(pen_t));
	memset(neogeo_videoram,0x00, 0x20000);

	compute_rgb_weights();
	create_sprite_line_timer();
	create_auto_animation_timer();
	optimize_sprite_data(machine);

	/* initialize values that are not modified on a reset */
	videoram_read_buffer = 0;
	videoram_offset = 0;
	videoram_modulo = 0;
	auto_animation_speed = 0;
	auto_animation_disabled = 0;
	auto_animation_counter = 0;
	auto_animation_frame_counter = 0;

	/* register for state saving */
	state_save_register_global_pointer(palettes[0], NUM_PENS);
	state_save_register_global_pointer(palettes[1], NUM_PENS);
	state_save_register_global_pointer(neogeo_videoram, 0x20000/2);
	state_save_register_global(videoram_read_buffer);
	state_save_register_global(videoram_modulo);
	state_save_register_global(videoram_offset);
	state_save_register_global(fixed_layer_source);
	state_save_register_global(screen_dark);
	state_save_register_global(palette_bank);
	state_save_register_global(auto_animation_speed);
	state_save_register_global(auto_animation_disabled);
	state_save_register_global(auto_animation_counter);
	state_save_register_global(auto_animation_frame_counter);

	state_save_register_postload(machine, regenerate_pens, NULL);
	
	region_zoomy = memory_region(machine, "zoomy");
}



/*************************************
 *
 *  Video system reset
 *
 *************************************/

VIDEO_RESET( neogeo )
{
	start_sprite_line_timer(machine);
	start_auto_animation_timer(machine);
}



/*************************************
 *
 *  Video update
 *
 *************************************/

VIDEO_UPDATE( neogeo )
{
	/* fill with background color first */
	fillbitmap(bitmap, pens[0x0fff], cliprect);

	draw_sprites(screen->machine, bitmap, cliprect->min_y);

	draw_fixed_layer(screen->machine, bitmap, cliprect->min_y);

	return 0;
}