Nsf_Emu.cpp 12.8 KB
Newer Older
Libretro-Admin's avatar
Libretro-Admin committed
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
// Game_Music_Emu 0.6.0. http://www.slack.net/~ant/

#include "Nsf_Emu.h"

#include "blargg_endian.h"
#include <string.h>

#if !NSF_EMU_APU_ONLY
	#include "Nes_Namco_Apu.h"
	#include "Nes_Vrc6_Apu.h"
	#include "Nes_Fme7_Apu.h"
#endif

/* Copyright (C) 2003-2006 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module 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 Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */

#include "blargg_source.h"

int const vrc6_flag  = 0x01;
int const namco_flag = 0x10;
int const fme7_flag  = 0x20;

long const clock_divisor = 12;

Nsf_Emu::equalizer_t const Nsf_Emu::nes_eq     =
	Music_Emu::make_equalizer( -1.0, 80 );
Nsf_Emu::equalizer_t const Nsf_Emu::famicom_eq =
	Music_Emu::make_equalizer( -15.0, 80 );

int Nsf_Emu::pcm_read( void* emu, nes_addr_t addr )
{
	return *((Nsf_Emu*) emu)->cpu::get_code( addr );
}

Nsf_Emu::Nsf_Emu()
{
	vrc6  = 0;
	namco = 0;
	fme7  = 0;
	
	set_type( gme_nsf_type );
	set_silence_lookahead( 6 );
	apu.dmc_reader( pcm_read, this );
	Music_Emu::set_equalizer( nes_eq );
	set_gain( 1.4 );
	memset( unmapped_code, Nes_Cpu::bad_opcode, sizeof unmapped_code );
}

Nsf_Emu::~Nsf_Emu() { unload(); }

void Nsf_Emu::unload()
{
	#if !NSF_EMU_APU_ONLY
	{
		delete vrc6;
		vrc6  = 0;
		
		delete namco;
		namco = 0;
		
		delete fme7;
		fme7  = 0;
	}
	#endif
	
	rom.clear();
	Music_Emu::unload();
}

// Track info

static void copy_nsf_fields( Nsf_Emu::header_t const& h, track_info_t* out )
{
	GME_COPY_FIELD( h, out, game );
	GME_COPY_FIELD( h, out, author );
	GME_COPY_FIELD( h, out, copyright );
	if ( h.chip_flags )
		Gme_File::copy_field_( out->system, "Famicom" );
}

blargg_err_t Nsf_Emu::track_info_( track_info_t* out, int ) const
{
	copy_nsf_fields( header_, out );
	return 0;
}

static blargg_err_t check_nsf_header( void const* header )
{
	if ( memcmp( header, "NESM\x1A", 5 ) )
		return gme_wrong_file_type;
	return 0;
}

struct Nsf_File : Gme_Info_
{
	Nsf_Emu::header_t h;
	
	Nsf_File() { set_type( gme_nsf_type ); }
	
	blargg_err_t load_( Data_Reader& in )
	{
		blargg_err_t err = in.read( &h, Nsf_Emu::header_size );
		if ( err )
			return (err == in.eof_error ? gme_wrong_file_type : err);
		
		if ( h.chip_flags & ~(namco_flag | vrc6_flag | fme7_flag) )
			set_warning( "Uses unsupported audio expansion hardware" );
		
		set_track_count( h.track_count );
		return check_nsf_header( &h );
	}
	
	blargg_err_t track_info_( track_info_t* out, int ) const
	{
		copy_nsf_fields( h, out );
		return 0;
	}
};

static Music_Emu* new_nsf_emu () { return BLARGG_NEW Nsf_Emu ; }
static Music_Emu* new_nsf_file() { return BLARGG_NEW Nsf_File; }

static gme_type_t_ const gme_nsf_type_ = { "Nintendo NES", 0, &new_nsf_emu, &new_nsf_file, "NSF", 1 };
gme_type_t const gme_nsf_type = &gme_nsf_type_;


// Setup

void Nsf_Emu::set_tempo_( double t )
{
	unsigned playback_rate = get_le16( header_.ntsc_speed );
	unsigned standard_rate = 0x411A;
	clock_rate_ = 1789772.72727;
	play_period = 262 * 341L * 4 - 2; // two fewer PPU clocks every four frames
	
	if ( pal_only )
	{
		play_period   = 33247 * clock_divisor;
		clock_rate_   = 1662607.125;
		standard_rate = 0x4E20;
		playback_rate = get_le16( header_.pal_speed );
	}
	
	if ( !playback_rate )
		playback_rate = standard_rate;
	
	if ( playback_rate != standard_rate || t != 1.0 )
		play_period = long (playback_rate * clock_rate_ / (1000000.0 / clock_divisor * t));

	apu.set_tempo( t );
}

blargg_err_t Nsf_Emu::init_sound()
{
	if ( header_.chip_flags & ~(namco_flag | vrc6_flag | fme7_flag) )
		set_warning( "Uses unsupported audio expansion hardware" );
	
	{
		#define APU_NAMES "Square 1", "Square 2", "Triangle", "Noise", "DMC"
		
		int const count = Nes_Apu::osc_count;
		static const char* const apu_names [count] = { APU_NAMES };
		set_voice_count( count );
		set_voice_names( apu_names );
		
	}
	
	static int const types [] = {
		wave_type  | 1, wave_type  | 2, wave_type | 0,
		noise_type | 0, mixed_type | 1,
		wave_type  | 3, wave_type  | 4, wave_type | 5,
		wave_type  | 6, wave_type  | 7, wave_type | 8, wave_type | 9,
		wave_type  |10, wave_type  |11, wave_type |12, wave_type |13
	};
	set_voice_types( types ); // common to all sound chip configurations
	
	double adjusted_gain = gain();
	
	#if NSF_EMU_APU_ONLY
	{
		if ( header_.chip_flags )
			set_warning( "Uses unsupported audio expansion hardware" );
	}
	#else
	{
		if ( header_.chip_flags & (namco_flag | vrc6_flag | fme7_flag) )
			set_voice_count( Nes_Apu::osc_count + 3 );
		
		if ( header_.chip_flags & namco_flag )
		{
			namco = BLARGG_NEW Nes_Namco_Apu;
			CHECK_ALLOC( namco );
			adjusted_gain *= 0.75;
			
			int const count = Nes_Apu::osc_count + Nes_Namco_Apu::osc_count;
			static const char* const names [count] = {
				APU_NAMES,
				"Wave 1", "Wave 2", "Wave 3", "Wave 4",
				"Wave 5", "Wave 6", "Wave 7", "Wave 8"
			};
			set_voice_count( count );
			set_voice_names( names );
		}
		
		if ( header_.chip_flags & vrc6_flag )
		{
			vrc6 = BLARGG_NEW Nes_Vrc6_Apu;
			CHECK_ALLOC( vrc6 );
			adjusted_gain *= 0.75;
			
			{
				int const count = Nes_Apu::osc_count + Nes_Vrc6_Apu::osc_count;
				static const char* const names [count] = {
					APU_NAMES,
					"Saw Wave", "Square 3", "Square 4"
				};
				set_voice_count( count );
				set_voice_names( names );
			}
			
			if ( header_.chip_flags & namco_flag )
			{
				int const count = Nes_Apu::osc_count + Nes_Vrc6_Apu::osc_count +
						Nes_Namco_Apu::osc_count;
				static const char* const names [count] = {
					APU_NAMES,
					"Saw Wave", "Square 3", "Square 4",
					"Wave 1", "Wave 2", "Wave 3", "Wave 4",
					"Wave 5", "Wave 6", "Wave 7", "Wave 8"
				};
				set_voice_count( count );
				set_voice_names( names );
			}
		}
		
		if ( header_.chip_flags & fme7_flag )
		{
			fme7 = BLARGG_NEW Nes_Fme7_Apu;
			CHECK_ALLOC( fme7 );
			adjusted_gain *= 0.75;
			
			int const count = Nes_Apu::osc_count + Nes_Fme7_Apu::osc_count;
			static const char* const names [count] = {
				APU_NAMES,
				"Square 3", "Square 4", "Square 5"
			};
			set_voice_count( count );
			set_voice_names( names );
		}
		
		if ( namco ) namco->volume( adjusted_gain );
		if ( vrc6  ) vrc6 ->volume( adjusted_gain );
		if ( fme7  ) fme7 ->volume( adjusted_gain );
	}
	#endif
	
	apu.volume( adjusted_gain );
	
	return 0;
}

blargg_err_t Nsf_Emu::load_( Data_Reader& in )
{
	assert( offsetof (header_t,unused [4]) == header_size );
	RETURN_ERR( rom.load( in, header_size, &header_, 0 ) );
	
	set_track_count( header_.track_count );
	RETURN_ERR( check_nsf_header( &header_ ) );
	
	if ( header_.vers != 1 )
		set_warning( "Unknown file version" );
	
	// sound and memory
	blargg_err_t err = init_sound();
	if ( err )
		return err;
	
	// set up data
	nes_addr_t load_addr = get_le16( header_.load_addr );
	init_addr = get_le16( header_.init_addr );
	play_addr = get_le16( header_.play_addr );
	if ( !load_addr ) load_addr = rom_begin;
	if ( !init_addr ) init_addr = rom_begin;
	if ( !play_addr ) play_addr = rom_begin;
	if ( load_addr < rom_begin || init_addr < rom_begin )
	{
		const char* w = warning();
		if ( !w )
			w = "Corrupt file (invalid load/init/play address)";
		return w;
	}
	
	rom.set_addr( load_addr % bank_size );
	int total_banks = rom.size() / bank_size;
	
	// bank switching
	int first_bank = (load_addr - rom_begin) / bank_size;
	for ( int i = 0; i < bank_count; i++ )
	{
		unsigned bank = i - first_bank;
		if ( bank >= (unsigned) total_banks )
			bank = 0;
		initial_banks [i] = bank;
		
		if ( header_.banks [i] )
		{
			// bank-switched
			memcpy( initial_banks, header_.banks, sizeof initial_banks );
			break;
		}
	}
	
	pal_only = (header_.speed_flags & 3) == 1;
	
	#if !NSF_EMU_EXTRA_FLAGS
		header_.speed_flags = 0;
	#endif
	
	set_tempo( tempo() );
	
	return setup_buffer( (long) (clock_rate_ + 0.5) );
}

void Nsf_Emu::update_eq( blip_eq_t const& eq )
{
	apu.treble_eq( eq );
	
	#if !NSF_EMU_APU_ONLY
	{
		if ( namco ) namco->treble_eq( eq );
		if ( vrc6  ) vrc6 ->treble_eq( eq );
		if ( fme7  ) fme7 ->treble_eq( eq );
	}
	#endif
}

void Nsf_Emu::set_voice( int i, Blip_Buffer* buf, Blip_Buffer*, Blip_Buffer* )
{
	if ( i < Nes_Apu::osc_count )
	{
		apu.osc_output( i, buf );
		return;
	}
	i -= Nes_Apu::osc_count;
	
	#if !NSF_EMU_APU_ONLY
	{
		if ( fme7 && i < Nes_Fme7_Apu::osc_count )
		{
			fme7->osc_output( i, buf );
			return;
		}
		
		if ( vrc6 )
		{
			if ( i < Nes_Vrc6_Apu::osc_count )
			{
				// put saw first
				if ( --i < 0 )
					i = 2;
				vrc6->osc_output( i, buf );
				return;
			}
			i -= Nes_Vrc6_Apu::osc_count;
		}
		
		if ( namco && i < Nes_Namco_Apu::osc_count )
		{
			namco->osc_output( i, buf );
			return;
		}
	}
	#endif
}

// Emulation

// see nes_cpu_io.h for read/write functions

void Nsf_Emu::cpu_write_misc( nes_addr_t addr, int data )
{
	#if !NSF_EMU_APU_ONLY
	{
		if ( namco )
		{
			switch ( addr )
			{
			case Nes_Namco_Apu::data_reg_addr:
				namco->write_data( time(), data );
				return;
			
			case Nes_Namco_Apu::addr_reg_addr:
				namco->write_addr( data );
				return;
			}
		}
		
		if ( addr >= Nes_Fme7_Apu::latch_addr && fme7 )
		{
			switch ( addr & Nes_Fme7_Apu::addr_mask )
			{
			case Nes_Fme7_Apu::latch_addr:
				fme7->write_latch( data );
				return;
			
			case Nes_Fme7_Apu::data_addr:
				fme7->write_data( time(), data );
				return;
			}
		}
		
		if ( vrc6 )
		{
			unsigned reg = addr & (Nes_Vrc6_Apu::addr_step - 1);
			unsigned osc = unsigned (addr - Nes_Vrc6_Apu::base_addr) / Nes_Vrc6_Apu::addr_step;
			if ( osc < Nes_Vrc6_Apu::osc_count && reg < Nes_Vrc6_Apu::reg_count )
			{
				vrc6->write_osc( time(), osc, reg, data );
				return;
			}
		}
	}
	#endif
	
	// unmapped write
	
	#ifndef NDEBUG
	{
		// some games write to $8000 and $8001 repeatedly
		if ( addr == 0x8000 || addr == 0x8001 ) return;
		
		// probably namco sound mistakenly turned on in mck
		if ( addr == 0x4800 || addr == 0xF800 ) return;
		
		// memory mapper?
		if ( addr == 0xFFF8 ) return;
		
		debug_printf( "write_unmapped( 0x%04X, 0x%02X )\n", (unsigned) addr, (unsigned) data );
	}
	#endif
}

blargg_err_t Nsf_Emu::start_track_( int track )
{
	RETURN_ERR( Classic_Emu::start_track_( track ) );
	
	memset( low_mem, 0, sizeof low_mem );
	memset( sram,    0, sizeof sram );
	
	cpu::reset( unmapped_code ); // also maps low_mem
	cpu::map_code( sram_addr, sizeof sram, sram );
	for ( int i = 0; i < bank_count; ++i )
		cpu_write( bank_select_addr + i, initial_banks [i] );
	
	apu.reset( pal_only, (header_.speed_flags & 0x20) ? 0x3F : 0 );
	apu.write_register( 0, 0x4015, 0x0F );
	apu.write_register( 0, 0x4017, (header_.speed_flags & 0x10) ? 0x80 : 0 );
	#if !NSF_EMU_APU_ONLY
	{
		if ( namco ) namco->reset();
		if ( vrc6  ) vrc6 ->reset();
		if ( fme7  ) fme7 ->reset();
	}
	#endif
	
	play_ready = 4;
	play_extra = 0;
	next_play = play_period / clock_divisor;
	
	saved_state.pc = badop_addr;
	low_mem [0x1FF] = (badop_addr - 1) >> 8;
	low_mem [0x1FE] = (badop_addr - 1) & 0xFF;
	r.sp = 0xFD;
	r.pc = init_addr;
	r.a  = track;
	r.x  = pal_only;
	
	return 0;
}

blargg_err_t Nsf_Emu::run_clocks( blip_time_t& duration, int )
{
	set_time( 0 );
	while ( time() < duration )
	{
		nes_time_t end = min( (blip_time_t) next_play, duration );
		end = min( end, time() + 32767 ); // allows CPU to use 16-bit time delta
		if ( cpu::run( end ) )
		{
			if ( r.pc != badop_addr )
			{
				set_warning( "Emulation error (illegal instruction)" );
				r.pc++;
			}
			else
			{
				play_ready = 1;
				if ( saved_state.pc != badop_addr )
				{
					cpu::r = saved_state;
					saved_state.pc = badop_addr;
				}
				else
				{
					set_time( end );
				}
			}
		}
		
		if ( time() >= next_play )
		{
			nes_time_t period = (play_period + play_extra) / clock_divisor;
			play_extra = play_period - period * clock_divisor;
			next_play += period;
			if ( play_ready && !--play_ready )
			{
				check( saved_state.pc == badop_addr );
				if ( r.pc != badop_addr )
					saved_state = cpu::r;
				
				r.pc = play_addr;
				low_mem [0x100 + r.sp--] = (badop_addr - 1) >> 8;
				low_mem [0x100 + r.sp--] = (badop_addr - 1) & 0xFF;
				GME_FRAME_HOOK( this );
			}
		}
	}
	
	if ( cpu::error_count() )
	{
		cpu::clear_error_count();
		set_warning( "Emulation error (illegal instruction)" );
	}
	
	duration = time();
	next_play -= duration;
	check( next_play >= 0 );
	if ( next_play < 0 )
		next_play = 0;
	
	apu.end_frame( duration );
	
	#if !NSF_EMU_APU_ONLY
	{
		if ( namco ) namco->end_frame( duration );
		if ( vrc6  ) vrc6 ->end_frame( duration );
		if ( fme7  ) fme7 ->end_frame( duration );
	}
	#endif
	
	return 0;
}