forked from nejidev/arm-NES-linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathInfoNES.cpp
executable file
·1188 lines (986 loc) · 34.7 KB
/
InfoNES.cpp
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
/*===================================================================*/
/* */
/* InfoNES.cpp : NES Emulator for Win32, Linux(x86), Linux(PS2) */
/* */
/* 2000/05/18 InfoNES Project ( based on pNesX ) */
/* */
/*===================================================================*/
/*-------------------------------------------------------------------
* File List :
*
* [NES Hardware]
* InfoNES.cpp
* InfoNES.h
* K6502_rw.h
*
* [Mapper function]
* InfoNES_Mapper.cpp
* InfoNES_Mapper.h
*
* [The function which depends on a system]
* InfoNES_System_ooo.cpp (ooo is a system name. win, ...)
* InfoNES_System.h
*
* [CPU]
* K6502.cpp
* K6502.h
*
* [Others]
* InfoNES_Types.h
*
--------------------------------------------------------------------*/
/*-------------------------------------------------------------------*/
/* Include files */
/*-------------------------------------------------------------------*/
#include "InfoNES.h"
#include "InfoNES_System.h"
#include "InfoNES_Mapper.h"
#include "InfoNES_pAPU.h"
#include "K6502.h"
/*-------------------------------------------------------------------*/
/* NES resources */
/*-------------------------------------------------------------------*/
/* RAM */
BYTE RAM[ RAM_SIZE ];
/* SRAM */
BYTE SRAM[ SRAM_SIZE ];
/* ROM */
BYTE *ROM;
/* SRAM BANK ( 8Kb ) */
BYTE *SRAMBANK;
/* ROM BANK ( 8Kb * 4 ) */
BYTE *ROMBANK0;
BYTE *ROMBANK1;
BYTE *ROMBANK2;
BYTE *ROMBANK3;
/*-------------------------------------------------------------------*/
/* PPU resources */
/*-------------------------------------------------------------------*/
/* PPU RAM */
BYTE PPURAM[ PPURAM_SIZE ];
/* VROM */
BYTE *VROM;
/* PPU BANK ( 1Kb * 16 ) */
BYTE *PPUBANK[ 16 ];
/* Sprite RAM */
BYTE SPRRAM[ SPRRAM_SIZE ];
/* PPU Register */
BYTE PPU_R0;
BYTE PPU_R1;
BYTE PPU_R2;
BYTE PPU_R3;
BYTE PPU_R7;
/* Vertical scroll value */
BYTE PPU_Scr_V;
BYTE PPU_Scr_V_Next;
BYTE PPU_Scr_V_Byte;
BYTE PPU_Scr_V_Byte_Next;
BYTE PPU_Scr_V_Bit;
BYTE PPU_Scr_V_Bit_Next;
/* Horizontal scroll value */
BYTE PPU_Scr_H;
BYTE PPU_Scr_H_Next;
BYTE PPU_Scr_H_Byte;
BYTE PPU_Scr_H_Byte_Next;
BYTE PPU_Scr_H_Bit;
BYTE PPU_Scr_H_Bit_Next;
/* PPU Address */
WORD PPU_Addr;
/* PPU Address */
WORD PPU_Temp;
/* The increase value of the PPU Address */
WORD PPU_Increment;
/* Current Scanline */
WORD PPU_Scanline;
/* Scanline Table */
BYTE PPU_ScanTable[ 263 ];
/* Name Table Bank */
BYTE PPU_NameTableBank;
/* BG Base Address */
BYTE *PPU_BG_Base;
/* Sprite Base Address */
BYTE *PPU_SP_Base;
/* Sprite Height */
WORD PPU_SP_Height;
/* Sprite #0 Scanline Hit Position */
int SpriteJustHit;
/* VRAM Write Enable ( 0: Disable, 1: Enable ) */
BYTE byVramWriteEnable;
/* PPU Address and Scroll Latch Flag*/
BYTE PPU_Latch_Flag;
/* Up and Down Clipping Flag ( 0: non-clip, 1: clip ) */
BYTE PPU_UpDown_Clip;
/* Frame IRQ ( 0: Disabled, 1: Enabled )*/
BYTE FrameIRQ_Enable;
WORD FrameStep;
/*-------------------------------------------------------------------*/
/* Display and Others resouces */
/*-------------------------------------------------------------------*/
/* Frame Skip */
WORD FrameSkip;
WORD FrameCnt;
/* Display Buffer */
#if 0
WORD DoubleFrame[ 2 ][ NES_DISP_WIDTH * NES_DISP_HEIGHT ];
WORD *WorkFrame;
WORD WorkFrameIdx;
#else
WORD WorkFrame[ NES_DISP_WIDTH * NES_DISP_HEIGHT ];
#endif
/* Character Buffer */
BYTE ChrBuf[ 256 * 2 * 8 * 8 ];
/* Update flag for ChrBuf */
BYTE ChrBufUpdate;
/* Palette Table */
WORD PalTable[ 32 ];
/* Table for Mirroring */
BYTE PPU_MirrorTable[][ 4 ] =
{
{ NAME_TABLE0, NAME_TABLE0, NAME_TABLE1, NAME_TABLE1 },
{ NAME_TABLE0, NAME_TABLE1, NAME_TABLE0, NAME_TABLE1 },
{ NAME_TABLE1, NAME_TABLE1, NAME_TABLE1, NAME_TABLE1 },
{ NAME_TABLE0, NAME_TABLE0, NAME_TABLE0, NAME_TABLE0 },
{ NAME_TABLE0, NAME_TABLE1, NAME_TABLE2, NAME_TABLE3 },
{ NAME_TABLE0, NAME_TABLE0, NAME_TABLE0, NAME_TABLE1 }
};
/*-------------------------------------------------------------------*/
/* APU and Pad resources */
/*-------------------------------------------------------------------*/
/* APU Register */
BYTE APU_Reg[ 0x18 ];
/* APU Mute ( 0:OFF, 1:ON ) */
int APU_Mute = 0;
/* Pad data */
DWORD PAD1_Latch;
DWORD PAD2_Latch;
DWORD PAD_System;
DWORD PAD1_Bit;
DWORD PAD2_Bit;
/*-------------------------------------------------------------------*/
/* Mapper Function */
/*-------------------------------------------------------------------*/
/* Initialize Mapper */
void (*MapperInit)();
/* Write to Mapper */
void (*MapperWrite)( WORD wAddr, BYTE byData );
/* Write to SRAM */
void (*MapperSram)( WORD wAddr, BYTE byData );
/* Write to Apu */
void (*MapperApu)( WORD wAddr, BYTE byData );
/* Read from Apu */
BYTE (*MapperReadApu)( WORD wAddr );
/* Callback at VSync */
void (*MapperVSync)();
/* Callback at HSync */
void (*MapperHSync)();
/* Callback at PPU read/write */
void (*MapperPPU)( WORD wAddr );
/* Callback at Rendering Screen 1:BG, 0:Sprite */
void (*MapperRenderScreen)( BYTE byMode );
/*-------------------------------------------------------------------*/
/* ROM information */
/*-------------------------------------------------------------------*/
/* .nes File Header */
struct NesHeader_tag NesHeader;
/* Mapper Number */
BYTE MapperNo;
/* Mirroring 0:Horizontal 1:Vertical */
BYTE ROM_Mirroring;
/* It has SRAM */
BYTE ROM_SRAM;
/* It has Trainer */
BYTE ROM_Trainer;
/* Four screen VRAM */
BYTE ROM_FourScr;
/*===================================================================*/
/* */
/* InfoNES_Init() : Initialize InfoNES */
/* */
/*===================================================================*/
void InfoNES_Init()
{
/*
* Initialize InfoNES
*
* Remarks
* Initialize K6502 and Scanline Table.
*/
int nIdx;
// Initialize 6502
K6502_Init();
// Initialize Scanline Table
for ( nIdx = 0; nIdx < 263; ++nIdx )
{
if ( nIdx < SCAN_ON_SCREEN_START )
PPU_ScanTable[ nIdx ] = SCAN_ON_SCREEN;
else
if ( nIdx < SCAN_BOTTOM_OFF_SCREEN_START )
PPU_ScanTable[ nIdx ] = SCAN_ON_SCREEN;
else
if ( nIdx < SCAN_UNKNOWN_START )
PPU_ScanTable[ nIdx ] = SCAN_ON_SCREEN;
else
if ( nIdx < SCAN_VBLANK_START )
PPU_ScanTable[ nIdx ] = SCAN_UNKNOWN;
else
PPU_ScanTable[ nIdx ] = SCAN_VBLANK;
}
}
/*===================================================================*/
/* */
/* InfoNES_Fin() : Completion treatment */
/* */
/*===================================================================*/
void InfoNES_Fin()
{
/*
* Completion treatment
*
* Remarks
* Release resources
*/
// Finalize pAPU
InfoNES_pAPUDone();
// Release a memory for ROM
InfoNES_ReleaseRom();
}
/*===================================================================*/
/* */
/* InfoNES_Load() : Load a cassette */
/* */
/*===================================================================*/
int InfoNES_Load( const char *pszFileName )
{
/*
* Load a cassette
*
* Parameters
* const char *pszFileName (Read)
* File name of ROM image
*
* Return values
* 0 : It was finished normally.
* -1 : An error occurred.
*
* Remarks
* Read a ROM image in the memory.
* Reset InfoNES.
*/
// Release a memory for ROM
InfoNES_ReleaseRom();
// Read a ROM image in the memory
if ( InfoNES_ReadRom( pszFileName ) < 0 )
return -1;
// Reset InfoNES
if ( InfoNES_Reset() < 0 )
return -1;
// Successful
return 0;
}
/*===================================================================*/
/* */
/* InfoNES_Reset() : Reset InfoNES */
/* */
/*===================================================================*/
int InfoNES_Reset()
{
/*
* Reset InfoNES
*
* Return values
* 0 : Normally
* -1 : Non support mapper
*
* Remarks
* Initialize Resources, PPU and Mapper.
* Reset CPU.
*/
int nIdx;
/*-------------------------------------------------------------------*/
/* Get information on the cassette */
/*-------------------------------------------------------------------*/
// Get Mapper Number
MapperNo = NesHeader.byInfo1 >> 4;
// Check bit counts of Mapper No.
for ( nIdx = 4; nIdx < 8 && NesHeader.byReserve[ nIdx ] == 0; ++nIdx )
;
if ( nIdx == 8 )
{
// Mapper Number is 8bits
MapperNo |= ( NesHeader.byInfo2 & 0xf0 );
}
// Get information on the ROM
ROM_Mirroring = NesHeader.byInfo1 & 1;
ROM_SRAM = NesHeader.byInfo1 & 2;
ROM_Trainer = NesHeader.byInfo1 & 4;
ROM_FourScr = NesHeader.byInfo1 & 8;
/*-------------------------------------------------------------------*/
/* Initialize resources */
/*-------------------------------------------------------------------*/
// Clear RAM
InfoNES_MemorySet( RAM, 0, sizeof RAM );
// Reset frame skip and frame count
FrameSkip = 0;
FrameCnt = 0;
#if 0
// Reset work frame
WorkFrame = DoubleFrame[ 0 ];
WorkFrameIdx = 0;
#endif
// Reset update flag of ChrBuf
ChrBufUpdate = 0xff;
// Reset palette table
InfoNES_MemorySet( PalTable, 0, sizeof PalTable );
// Reset APU register
InfoNES_MemorySet( APU_Reg, 0, sizeof APU_Reg );
// Reset joypad
PAD1_Latch = PAD2_Latch = PAD_System = 0;
PAD1_Bit = PAD2_Bit = 0;
/*-------------------------------------------------------------------*/
/* Initialize PPU */
/*-------------------------------------------------------------------*/
InfoNES_SetupPPU();
/*-------------------------------------------------------------------*/
/* Initialize pAPU */
/*-------------------------------------------------------------------*/
InfoNES_pAPUInit();
/*-------------------------------------------------------------------*/
/* Initialize Mapper */
/*-------------------------------------------------------------------*/
// Get Mapper Table Index
for ( nIdx = 0; MapperTable[ nIdx ].nMapperNo != -1; ++nIdx )
{
if ( MapperTable[ nIdx ].nMapperNo == MapperNo )
break;
}
if ( MapperTable[ nIdx ].nMapperNo == -1 )
{
// Non support mapper
InfoNES_MessageBox( "Mapper #%d is unsupported.\n" );
return -1;
}
// Set up a mapper initialization function
MapperTable[ nIdx ].pMapperInit();
/*-------------------------------------------------------------------*/
/* Reset CPU */
/*-------------------------------------------------------------------*/
K6502_Reset();
// Successful
return 0;
}
/*===================================================================*/
/* */
/* InfoNES_SetupPPU() : Initialize PPU */
/* */
/*===================================================================*/
void InfoNES_SetupPPU()
{
/*
* Initialize PPU
*
*/
int nPage;
// Clear PPU and Sprite Memory
InfoNES_MemorySet( PPURAM, 0, sizeof PPURAM );
InfoNES_MemorySet( SPRRAM, 0, sizeof SPRRAM );
// Reset PPU Register
PPU_R0 = PPU_R1 = PPU_R2 = PPU_R3 = PPU_R7 = 0;
// Reset latch flag
PPU_Latch_Flag = 0;
// Reset up and down clipping flag
PPU_UpDown_Clip = 0;
FrameStep = 0;
FrameIRQ_Enable = 0;
// Reset Scroll values
PPU_Scr_V = PPU_Scr_V_Next = PPU_Scr_V_Byte = PPU_Scr_V_Byte_Next = PPU_Scr_V_Bit = PPU_Scr_V_Bit_Next = 0;
PPU_Scr_H = PPU_Scr_H_Next = PPU_Scr_H_Byte = PPU_Scr_H_Byte_Next = PPU_Scr_H_Bit = PPU_Scr_H_Bit_Next = 0;
// Reset PPU address
PPU_Addr = 0;
PPU_Temp = 0;
// Reset scanline
PPU_Scanline = 0;
// Reset hit position of sprite #0
SpriteJustHit = 0;
// Reset information on PPU_R0
PPU_Increment = 1;
PPU_NameTableBank = NAME_TABLE0;
PPU_BG_Base = ChrBuf;
PPU_SP_Base = ChrBuf + 256 * 64;
PPU_SP_Height = 8;
// Reset PPU banks
for ( nPage = 0; nPage < 16; ++nPage )
PPUBANK[ nPage ] = &PPURAM[ nPage * 0x400 ];
/* Mirroring of Name Table */
InfoNES_Mirroring( ROM_Mirroring );
/* Reset VRAM Write Enable */
byVramWriteEnable = ( NesHeader.byVRomSize == 0 ) ? 1 : 0;
}
/*===================================================================*/
/* */
/* InfoNES_Mirroring() : Set up a Mirroring of Name Table */
/* */
/*===================================================================*/
void InfoNES_Mirroring( int nType )
{
/*
* Set up a Mirroring of Name Table
*
* Parameters
* int nType (Read)
* Mirroring Type
* 0 : Horizontal
* 1 : Vertical
* 2 : One Screen 0x2400
* 3 : One Screen 0x2000
* 4 : Four Screen
* 5 : Special for Mapper #233
*/
PPUBANK[ NAME_TABLE0 ] = &PPURAM[ PPU_MirrorTable[ nType ][ 0 ] * 0x400 ];
PPUBANK[ NAME_TABLE1 ] = &PPURAM[ PPU_MirrorTable[ nType ][ 1 ] * 0x400 ];
PPUBANK[ NAME_TABLE2 ] = &PPURAM[ PPU_MirrorTable[ nType ][ 2 ] * 0x400 ];
PPUBANK[ NAME_TABLE3 ] = &PPURAM[ PPU_MirrorTable[ nType ][ 3 ] * 0x400 ];
}
/*===================================================================*/
/* */
/* InfoNES_Main() : The main loop of InfoNES */
/* */
/*===================================================================*/
void InfoNES_Main()
{
/*
* The main loop of InfoNES
*
*/
// Initialize InfoNES
InfoNES_Init();
// Main loop
while ( 1 )
{
/*-------------------------------------------------------------------*/
/* To the menu screen */
/*-------------------------------------------------------------------*/
if ( InfoNES_Menu() == -1 )
break; // Quit
/*-------------------------------------------------------------------*/
/* Start a NES emulation */
/*-------------------------------------------------------------------*/
InfoNES_Cycle();
}
// Completion treatment
InfoNES_Fin();
}
/*===================================================================*/
/* */
/* InfoNES_Cycle() : The loop of emulation */
/* */
/*===================================================================*/
void InfoNES_Cycle()
{
/*
* The loop of emulation
*
*/
// Set the PPU adress to the buffered value
if ( ( PPU_R1 & R1_SHOW_SP ) || ( PPU_R1 & R1_SHOW_SCR ) )
PPU_Addr = PPU_Temp;
// Emulation loop
for (;;)
{
int nStep;
// Set a flag if a scanning line is a hit in the sprite #0
if ( SpriteJustHit == PPU_Scanline &&
PPU_ScanTable[ PPU_Scanline ] == SCAN_ON_SCREEN )
{
// # of Steps to execute before sprite #0 hit
nStep = SPRRAM[ SPR_X ] * STEP_PER_SCANLINE / NES_DISP_WIDTH;
// Execute instructions
K6502_Step( nStep );
// Set a sprite hit flag
if ( ( PPU_R1 & R1_SHOW_SP ) && ( PPU_R1 & R1_SHOW_SCR ) )
PPU_R2 |= R2_HIT_SP;
// NMI is required if there is necessity
if ( ( PPU_R0 & R0_NMI_SP ) && ( PPU_R1 & R1_SHOW_SP ) )
NMI_REQ;
// Execute instructions
K6502_Step( STEP_PER_SCANLINE - nStep );
}
else
{
// Execute instructions
K6502_Step( STEP_PER_SCANLINE );
}
// Frame IRQ in H-Sync
FrameStep += STEP_PER_SCANLINE;
if ( FrameStep > STEP_PER_FRAME && FrameIRQ_Enable )
{
FrameStep %= STEP_PER_FRAME;
IRQ_REQ;
APU_Reg[ 0x4015 ] |= 0x40;
}
// A mapper function in H-Sync
MapperHSync();
// A function in H-Sync
if ( InfoNES_HSync() == -1 )
return; // To the menu screen
// HSYNC Wait
InfoNES_Wait();
}
}
/*===================================================================*/
/* */
/* InfoNES_HSync() : A function in H-Sync */
/* */
/*===================================================================*/
int InfoNES_HSync()
{
/*
* A function in H-Sync
*
* Return values
* 0 : Normally
* -1 : Exit an emulation
*/
/*-------------------------------------------------------------------*/
/* Render a scanline */
/*-------------------------------------------------------------------*/
if ( FrameCnt == 0 &&
PPU_ScanTable[ PPU_Scanline ] == SCAN_ON_SCREEN )
{
InfoNES_DrawLine();
}
/*-------------------------------------------------------------------*/
/* Set new scroll values */
/*-------------------------------------------------------------------*/
PPU_Scr_V = PPU_Scr_V_Next;
PPU_Scr_V_Byte = PPU_Scr_V_Byte_Next;
PPU_Scr_V_Bit = PPU_Scr_V_Bit_Next;
PPU_Scr_H = PPU_Scr_H_Next;
PPU_Scr_H_Byte = PPU_Scr_H_Byte_Next;
PPU_Scr_H_Bit = PPU_Scr_H_Bit_Next;
/*-------------------------------------------------------------------*/
/* Next Scanline */
/*-------------------------------------------------------------------*/
PPU_Scanline = ( PPU_Scanline == SCAN_VBLANK_END ) ? 0 : PPU_Scanline + 1;
/*-------------------------------------------------------------------*/
/* Operation in the specific scanning line */
/*-------------------------------------------------------------------*/
switch ( PPU_Scanline )
{
case SCAN_TOP_OFF_SCREEN:
// Reset a PPU status
PPU_R2 = 0;
// Set up a character data
if ( NesHeader.byVRomSize == 0 && FrameCnt == 0 )
InfoNES_SetupChr();
// Get position of sprite #0
InfoNES_GetSprHitY();
break;
case SCAN_UNKNOWN_START:
if ( FrameCnt == 0 )
{
// Transfer the contents of work frame on the screen
InfoNES_LoadFrame();
#if 0
// Switching of the double buffer
WorkFrameIdx = 1 - WorkFrameIdx;
WorkFrame = DoubleFrame[ WorkFrameIdx ];
#endif
}
break;
case SCAN_VBLANK_START:
// FrameCnt + 1
FrameCnt = ( FrameCnt >= FrameSkip ) ? 0 : FrameCnt + 1;
// Set a V-Blank flag
PPU_R2 = R2_IN_VBLANK;
// Reset latch flag
PPU_Latch_Flag = 0;
// pAPU Sound function in V-Sync
if ( !APU_Mute )
InfoNES_pAPUVsync();
// A mapper function in V-Sync
MapperVSync();
// Get the condition of the joypad
InfoNES_PadState( &PAD1_Latch, &PAD2_Latch, &PAD_System );
// NMI on V-Blank
if ( PPU_R0 & R0_NMI_VB )
NMI_REQ;
// Exit an emulation if a QUIT button is pushed
if ( PAD_PUSH( PAD_System, PAD_SYS_QUIT ) )
return -1; // Exit an emulation
break;
}
// Successful
return 0;
}
/*===================================================================*/
/* */
/* InfoNES_DrawLine() : Render a scanline */
/* */
/*===================================================================*/
void InfoNES_DrawLine()
{
/*
* Render a scanline
*
*/
int nX;
int nY;
int nY4;
int nYBit;
WORD *pPalTbl;
BYTE *pAttrBase;
WORD *pPoint;
int nNameTable;
BYTE *pbyNameTable;
BYTE *pbyChrData;
BYTE *pSPRRAM;
int nAttr;
int nSprCnt;
int nIdx;
int nSprData;
BYTE bySprCol;
BYTE pSprBuf[ NES_DISP_WIDTH + 7 ];
/*-------------------------------------------------------------------*/
/* Render Background */
/*-------------------------------------------------------------------*/
/* MMC5 VROM switch */
MapperRenderScreen( 1 );
// Pointer to the render position
pPoint = &WorkFrame[ PPU_Scanline * NES_DISP_WIDTH ];
// Clear a scanline if screen is off
if ( !( PPU_R1 & R1_SHOW_SCR ) )
{
InfoNES_MemorySet( pPoint, 0, NES_DISP_WIDTH << 1 );
}
else
{
nNameTable = PPU_NameTableBank;
nY = PPU_Scr_V_Byte + ( PPU_Scanline >> 3 );
nYBit = PPU_Scr_V_Bit + ( PPU_Scanline & 7 );
if ( nYBit > 7 )
{
++nY;
nYBit &= 7;
}
nYBit <<= 3;
if ( nY > 29 )
{
// Next NameTable (An up-down direction)
nNameTable ^= NAME_TABLE_V_MASK;
nY -= 30;
}
nX = PPU_Scr_H_Byte;
nY4 = ( ( nY & 2 ) << 1 );
/*-------------------------------------------------------------------*/
/* Rendering of the block of the left end */
/*-------------------------------------------------------------------*/
pbyNameTable = PPUBANK[ nNameTable ] + nY * 32 + nX;
pbyChrData = PPU_BG_Base + ( *pbyNameTable << 6 ) + nYBit;
pAttrBase = PPUBANK[ nNameTable ] + 0x3c0 + ( nY / 4 ) * 8;
pPalTbl = &PalTable[ ( ( ( pAttrBase[ nX >> 2 ] >> ( ( nX & 2 ) + nY4 ) ) & 3 ) << 2 ) ];
for ( nIdx = PPU_Scr_H_Bit; nIdx < 8; ++nIdx )
{
*( pPoint++ ) = pPalTbl[ pbyChrData[ nIdx ] ];
}
// Callback at PPU read/write
MapperPPU( PATTBL( pbyChrData ) );
++nX;
++pbyNameTable;
/*-------------------------------------------------------------------*/
/* Rendering of the left table */
/*-------------------------------------------------------------------*/
for ( ; nX < 32; ++nX )
{
pbyChrData = PPU_BG_Base + ( *pbyNameTable << 6 ) + nYBit;
pPalTbl = &PalTable[ ( ( ( pAttrBase[ nX >> 2 ] >> ( ( nX & 2 ) + nY4 ) ) & 3 ) << 2 ) ];
pPoint[ 0 ] = pPalTbl[ pbyChrData[ 0 ] ];
pPoint[ 1 ] = pPalTbl[ pbyChrData[ 1 ] ];
pPoint[ 2 ] = pPalTbl[ pbyChrData[ 2 ] ];
pPoint[ 3 ] = pPalTbl[ pbyChrData[ 3 ] ];
pPoint[ 4 ] = pPalTbl[ pbyChrData[ 4 ] ];
pPoint[ 5 ] = pPalTbl[ pbyChrData[ 5 ] ];
pPoint[ 6 ] = pPalTbl[ pbyChrData[ 6 ] ];
pPoint[ 7 ] = pPalTbl[ pbyChrData[ 7 ] ];
pPoint += 8;
// Callback at PPU read/write
MapperPPU( PATTBL( pbyChrData ) );
++pbyNameTable;
}
// Holizontal Mirror
nNameTable ^= NAME_TABLE_H_MASK;
pbyNameTable = PPUBANK[ nNameTable ] + nY * 32;
pAttrBase = PPUBANK[ nNameTable ] + 0x3c0 + ( nY / 4 ) * 8;
/*-------------------------------------------------------------------*/
/* Rendering of the right table */
/*-------------------------------------------------------------------*/
for ( nX = 0; nX < PPU_Scr_H_Byte; ++nX )
{
pbyChrData = PPU_BG_Base + ( *pbyNameTable << 6 ) + nYBit;
pPalTbl = &PalTable[ ( ( ( pAttrBase[ nX >> 2 ] >> ( ( nX & 2 ) + nY4 ) ) & 3 ) << 2 ) ];
pPoint[ 0 ] = pPalTbl[ pbyChrData[ 0 ] ];
pPoint[ 1 ] = pPalTbl[ pbyChrData[ 1 ] ];
pPoint[ 2 ] = pPalTbl[ pbyChrData[ 2 ] ];
pPoint[ 3 ] = pPalTbl[ pbyChrData[ 3 ] ];
pPoint[ 4 ] = pPalTbl[ pbyChrData[ 4 ] ];
pPoint[ 5 ] = pPalTbl[ pbyChrData[ 5 ] ];
pPoint[ 6 ] = pPalTbl[ pbyChrData[ 6 ] ];
pPoint[ 7 ] = pPalTbl[ pbyChrData[ 7 ] ];
pPoint += 8;
// Callback at PPU read/write
MapperPPU( PATTBL( pbyChrData ) );
++pbyNameTable;
}
/*-------------------------------------------------------------------*/
/* Rendering of the block of the right end */
/*-------------------------------------------------------------------*/
pbyChrData = PPU_BG_Base + ( *pbyNameTable << 6 ) + nYBit;
pPalTbl = &PalTable[ ( ( ( pAttrBase[ nX >> 2 ] >> ( ( nX & 2 ) + nY4 ) ) & 3 ) << 2 ) ];
for ( nIdx = 0; nIdx < PPU_Scr_H_Bit; ++nIdx )
{
pPoint[ nIdx ] = pPalTbl[ pbyChrData[ nIdx ] ];
}
// Callback at PPU read/write
MapperPPU( PATTBL( pbyChrData ) );
/*-------------------------------------------------------------------*/
/* Backgroud Clipping */
/*-------------------------------------------------------------------*/
if ( !( PPU_R1 & R1_CLIP_BG ) )
{
WORD *pPointTop;
pPointTop = &WorkFrame[ PPU_Scanline * NES_DISP_WIDTH ];
InfoNES_MemorySet( pPointTop, 0, 8 << 1 );
}
/*-------------------------------------------------------------------*/
/* Clear a scanline if up and down clipping flag is set */
/*-------------------------------------------------------------------*/
if ( PPU_UpDown_Clip &&
( SCAN_ON_SCREEN_START > PPU_Scanline || PPU_Scanline > SCAN_BOTTOM_OFF_SCREEN_START ) )
{
WORD *pPointTop;
pPointTop = &WorkFrame[ PPU_Scanline * NES_DISP_WIDTH ];
InfoNES_MemorySet( pPointTop, 0, NES_DISP_WIDTH << 1 );
}
}
/*-------------------------------------------------------------------*/
/* Render a sprite */
/*-------------------------------------------------------------------*/
/* MMC5 VROM switch */
MapperRenderScreen( 0 );
if ( PPU_R1 & R1_SHOW_SP )
{
// Reset Scanline Sprite Count
PPU_R2 &= ~R2_MAX_SP;
// Reset sprite buffer
InfoNES_MemorySet( pSprBuf, 0, sizeof pSprBuf );
// Render a sprite to the sprite buffer
nSprCnt = 0;
for ( pSPRRAM = SPRRAM + ( 63 << 2 ); pSPRRAM >= SPRRAM; pSPRRAM -= 4 )
{
nY = pSPRRAM[ SPR_Y ] + 1;
if ( nY > PPU_Scanline || nY + PPU_SP_Height <= PPU_Scanline )
continue; // Next sprite
/*-------------------------------------------------------------------*/
/* A sprite in scanning line */
/*-------------------------------------------------------------------*/
// Holizontal Sprite Count +1
++nSprCnt;
nAttr = pSPRRAM[ SPR_ATTR ];
nYBit = PPU_Scanline - nY;
nYBit = ( nAttr & SPR_ATTR_V_FLIP ) ? ( PPU_SP_Height - nYBit - 1 ) << 3 : nYBit << 3;
if ( PPU_R0 & R0_SP_SIZE )
{
// Sprite size 8x16
if ( pSPRRAM[ SPR_CHR ] & 1 )
{
pbyChrData = ChrBuf + 256 * 64 + ( ( pSPRRAM[ SPR_CHR ] & 0xfe ) << 6 ) + nYBit;
}
else
{
pbyChrData = ChrBuf + ( ( pSPRRAM[ SPR_CHR ] & 0xfe ) << 6 ) + nYBit;
}
}
else
{
// Sprite size 8x8
pbyChrData = PPU_SP_Base + ( pSPRRAM[ SPR_CHR ] << 6 ) + nYBit;
}
nAttr ^= SPR_ATTR_PRI;
bySprCol = ( nAttr & ( SPR_ATTR_COLOR | SPR_ATTR_PRI ) ) << 2;
nX = pSPRRAM[ SPR_X ];
if ( nAttr & SPR_ATTR_H_FLIP )
{
// Horizontal flip
if ( pbyChrData[ 7 ] )
pSprBuf[ nX ] = bySprCol | pbyChrData[ 7 ];
if ( pbyChrData[ 6 ] )
pSprBuf[ nX + 1 ] = bySprCol | pbyChrData[ 6 ];