namcos1.c

这个是延伸mame的在wince平台下的游戏模拟器的代码

#include "driver.h"

/* note: we work with signed samples here, unlike other drivers */
#ifdef SIGNED_SAMPLES
	#define AUDIO_CONV(A) (A)
	#define AUDIO_CONV16(A) (A)
#else
	#define AUDIO_CONV(A) (A+0x80)
	#define AUDIO_CONV16(A) (A+0x8000)
#endif

#define MAX_VOICES 8 /* 8 voices max */

static unsigned char default_prom[] ={
	0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,0x0e,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x03,0x05,0x03,0x09,0x0b,0x04,0x06,0x02,0x09,0x09,0x07,0x0a,0x05,0x08,0x06,
	0x0a,0x06,0x07,0x0c,0x05,0x08,0x04,0x08,0x06,0x07,0x02,0x07,0x05,0x0b,0x07,0x08,
	0xf7,0xfa,0xfc,0xfc,0xfe,0xfe,0xfc,0xfc,0xfe,0xfe,0xfc,0xf9,0xf7,0xf7,0xf5,0xf5,
	0xf7,0xf9,0xf9,0xf7,0xf7,0xf5,0xf2,0xf0,0xf0,0xf2,0xf2,0xf0,0xf0,0xf2,0xf2,0xf3,
	0xf1,0xf1,0xf2,0xf3,0xf3,0xf3,0xf3,0xf4,0xf5,0xf4,0xf3,0xf2,0xf0,0xf0,0xf2,0xf4,
	0xf5,0xf5,0xf4,0xf3,0xf3,0xfb,0xfb,0xfa,0xf9,0xfa,0xfb,0xfc,0xfe,0xfe,0xfc,0xfa,
	0xf0,0xf7,0xfe,0xf7,0xf3,0xf1,0xf0,0xf1,0xf3,0xf7,0xfb,0xfd,0xfe,0xfd,0xfb,0xf7,
	0xf4,0xf2,0xf1,0xf0,0xf1,0xf2,0xf4,0xf7,0xfa,0xfc,0xfd,0xfe,0xfd,0xfc,0xfa,0xf7,
	0xfa,0xfc,0xfc,0xfa,0xf7,0xf7,0xf8,0xfb,0xfd,0xfe,0xfd,0xfa,0xf6,0xf5,0xf5,0xf7,
	0xf9,0xf9,0xf8,0xf4,0xf1,0xf0,0xf1,0xf3,0xf6,0xf7,0xf7,0xf4,0xf2,0xf2,0xf4,0xf7,
	0xf9,0xfa,0xfb,0xfc,0xfd,0xfd,0xfe,0xfe,0xfe,0xfd,0xfd,0xfc,0xfb,0xfa,0xf9,0xf7,
	0xf5,0xf4,0xf3,0xf2,0xf1,0xf1,0xf0,0xf0,0xf0,0xf1,0xf1,0xf2,0xf3,0xf4,0xf5,0xf7,
	0xf0,0xf0,0xf1,0xf1,0xf0,0xf7,0xf8,0xf8,0xf0,0xf0,0xf1,0xf1,0xf0,0xf9,0xfa,0xfa,
	0xf0,0xf0,0xf1,0xf1,0xf0,0xfb,0xfc,0xfc,0xf0,0xf0,0xf1,0xf1,0xf0,0xfe,0xff,0xff,
	0x08,0x0a,0x0e,0x0a,0x0a,0x0a,0x0a,0x09,0x09,0x09,0x0a,0x0a,0x09,0x09,0x09,0x09,
	0x03,0x03,0x03,0x03,0x02,0x02,0x03,0x03,0x03,0x02,0x02,0x02,0x02,0x01,0x04,0x06,
	0x00,0x01,0x01,0x06,0x08,0x08,0x06,0x06,0x0c,0x0c,0x0b,0x06,0x08,0x08,0x0a,0x0b,
	0x0b,0x0b,0x0b,0x0e,0x0f,0x0f,0x08,0x08,0x0e,0x0e,0x0d,0x0a,0x0b,0x0b,0x0f,0x0f,
	0x0f,0x0f,0x0e,0x0e,0x0d,0x0d,0x0c,0x0c,0x0b,0x0b,0x0a,0x0a,0x09,0x09,0x08,0x08,
	0x07,0x07,0x06,0x06,0x05,0x05,0x04,0x04,0x03,0x03,0x02,0x02,0x01,0x01,0x00,0x00,
	0x00,0x02,0x09,0x0a,0x0a,0x0a,0x05,0x09,0x00,0x00,0x00,0x00,0x02,0x05,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x04,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x04,
	0x09,0x01,0x00,0x00,0x00,0x00,0x00,0x04,0x0b,0x07,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x02,0x06,0x0b,0x0e,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x00,0x00,0x00,0x06,
	0x00,0x00,0x00,0x00,0x02,0x02,0x0b,0x0d,0x0f,0x0b,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x0c,0x0c,0x0a,0x00,0x01,0x01,0x00,0x00,0x0a,0x0a,0x09,0x00,0x0a,0x0a,
	0x00,0x00,0x08,0x08,0x07,0x00,0x01,0x01,0x00,0x00,0x0f,0x0f,0x0e,0x00,0x01,0x01,
	0x00,0x02,0x04,0x06,0x08,0x0a,0x0c,0x0e,0x0e,0x0d,0x0c,0x0b,0x0a,0x09,0x08,0x07,
	0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00,0x00,0x02,0x04,0x06,0x08,0x0a,0x0c,0x0e,
	0x00,0x02,0x03,0x03,0x03,0x04,0x04,0x05,0x04,0x04,0x04,0x03,0x02,0x05,0x09,0x0c,
	0x0f,0x0e,0x0c,0x0c,0x0c,0x0a,0x0a,0x0a,0x0b,0x0b,0x0b,0x0c,0x0c,0x0a,0x07,0x03
};

static unsigned char *sound_prom;

static struct namcos1_interface *intf;
static int channel;

/* Registers definition */
#define	LEFT_VOLUME		0x00
#define	WAVEFORM		0x01
#define	PITCH_MSB		0x02
#define	PITCH_LSB		0x03
#define	RIGHT_VOLUME	0x04

/* Our voice structure */
static struct namcos1_voice {
	int pitch;
	int lvol;
	int rvol;
	int step;
	unsigned char *wave;
} voice[MAX_VOICES];

#define MAXOUT_MASK 0x0f
#define MAXOUT_BITS 0x04

static unsigned char local_regs[64];

static void namcos1_update8( int num,void *buffer,int length ) {
	int		i,j, delta, step, data;
	unsigned char *rom_ptr;
	signed char *buf;

	if ( Machine->sample_rate == 0 )
		return;

	memset( buffer, AUDIO_CONV( 0 ), length );

	buf = buffer;
	for( i = 0; i < MAX_VOICES; i++ ) {
		if ( voice[i].pitch > 0 ) {
			delta = voice[i].pitch;
			rom_ptr = voice[i].wave;
			step = voice[i].step;
			for( j = 0; j < length; j++ ) {
				data = ( ( rom_ptr[( step >> 0x0f ) & 0x1f] & 0x0f ) - 8 );
				data *= ( voice[i].lvol + voice[i].rvol );
				data = ( data < 0 ) ? -( ( data >> MAXOUT_BITS ) & MAXOUT_MASK ) : ( ( data >> MAXOUT_BITS ) & MAXOUT_MASK );
				buf[j] += AUDIO_CONV( data );
				step += delta;
			}
			voice[i].step = step;
		}
	}
}
#undef MAXOUT_MASK
#undef MAXOUT_BITS

#define MAXOUT_MASK 0x0fff
#define MAXOUT_BITS 0x04

static void namcos1_update16( int num,void *buffer,int length ) {
	int		i,j, delta, step, data;
	unsigned char *rom_ptr;
	signed short *buf;

	if ( Machine->sample_rate == 0 )
		return;

	memset( buffer, AUDIO_CONV16( 0 ), length * sizeof( unsigned short ) );

	buf = buffer;
	for( i = 0; i < MAX_VOICES; i++ ) {
		if ( voice[i].pitch > 0 ) {
			delta = voice[i].pitch;
			rom_ptr = voice[i].wave;
			step = voice[i].step;
			for( j = 0; j < length; j++ ) {
				data = ( ( rom_ptr[( step >> 0x0f ) & 0x1f] & 0x0f ) - 8 );
				data *= ( voice[i].lvol + voice[i].rvol );
				data = ( data < 0 ) ? -( ( data << MAXOUT_BITS ) & MAXOUT_MASK ) : ( ( data << MAXOUT_BITS ) & MAXOUT_MASK );
				buf[j] += AUDIO_CONV16( data );
				step += delta;
			}
			voice[i].step = step;
		}
	}
}
#undef MAXOUT_MASK
#undef MAXOUT_BITS

int namcos1_sh_start( struct namcos1_interface *interface ) {
	int i;

	if ( Machine->sample_rate == 0 )
		return 0;

	channel = stream_init( "Namco PSG", interface->clock, Machine->sample_bits, 0, ( Machine->sample_bits == 16 ) ? namcos1_update16 : namcos1_update8 );

	if ( channel == -1 )
		return 1;

	intf = interface;

	if ( intf->region == -1 )
		sound_prom = default_prom;
	else
		sound_prom = Machine->memory_region[intf->region];

	stream_set_volume( channel,interface->volume & 0xff );

	/* Init voices */
	for ( i = 0; i < MAX_VOICES; i++ ) {
		voice[i].pitch = 0;
		voice[i].lvol = 0;
		voice[i].rvol = 0;
		voice[i].wave = &sound_prom[0];
		voice[i].step = 0;
	}

	return 0;
}

void namcos1_sh_stop( void ) {
}

void namcos1_sh_update( void ) {
}

int namcos1_sound_r( int offs ) {
	return local_regs[offs];
}

void namcos1_sound_w( int offs, int data ) {
	int	voicenum, r, base;

	if ( offs > 63 ) {
		return;
	}

	local_regs[offs] = data;

	if ( Machine->sample_rate == 0 )
		return;

	voicenum = offs / 8;
	base = voicenum * 8;
	r = offs % 8;

	switch( r ) {
		case LEFT_VOLUME:
			voice[voicenum].lvol = data & 0x0f;
		break;

		case WAVEFORM:
			voice[voicenum].wave = &sound_prom[32 * ( ( data >> 4 ) & 0x0f )];
		break;

		case PITCH_MSB:
			voice[voicenum].pitch &= 0x00ff;
			voice[voicenum].pitch |= ( data << 8 );
		break;

		case PITCH_LSB:
			voice[voicenum].pitch &= 0xff00;
			voice[voicenum].pitch |= data;
		break;

		case RIGHT_VOLUME:
			voice[voicenum].rvol = data & 0x0f;
		break;
	}
}