cog/Frameworks/GME/gme/Ym2203_Emu.cpp

156 lines
3.1 KiB
C++

// Game_Music_Emu $vers. http://www.slack.net/~ant/
#include "Ym2203_Emu.h"
#include "fm.h"
#include <string.h>
static void psg_set_clock(void *param, int clock)
{
Ym2203_Emu *info = (Ym2203_Emu *)param;
info->psg_set_clock( clock );
}
static void psg_write(void *param, int address, int data)
{
Ym2203_Emu *info = (Ym2203_Emu *)param;
info->psg_write( address, data );
}
static int psg_read(void *param)
{
Ym2203_Emu *info = (Ym2203_Emu *)param;
return info->psg_read();
}
static void psg_reset(void *param)
{
Ym2203_Emu *info = (Ym2203_Emu *)param;
info->psg_reset();
}
static const ssg_callbacks psgintf =
{
psg_set_clock,
psg_write,
psg_read,
psg_reset
};
Ym2203_Emu::Ym2203_Emu() { opn = 0; psg.set_type( Ay_Apu::Ym2203 ); }
Ym2203_Emu::~Ym2203_Emu()
{
if ( opn ) ym2203_shutdown( opn );
}
int Ym2203_Emu::set_rate( int sample_rate, int clock_rate )
{
if ( opn )
{
ym2203_shutdown( opn );
opn = 0;
}
opn = ym2203_init( this, clock_rate, sample_rate, &psgintf );
if ( !opn )
return 1;
this->sample_rate = sample_rate;
psg_clock = clock_rate * 2;
buffer.set_sample_rate( sample_rate );
buffer.clock_rate( psg_clock );
psg.volume( 1.0 );
reset();
return 0;
}
void Ym2203_Emu::reset()
{
psg.reset();
ym2203_reset_chip( opn );
mute_voices( 0 );
}
static stream_sample_t* DUMMYBUF[0x02] = {(stream_sample_t*)NULL, (stream_sample_t*)NULL};
void Ym2203_Emu::write( int addr, int data )
{
ym2203_update_one( opn, DUMMYBUF, 0 );
ym2203_write( opn, 0, addr );
ym2203_write( opn, 1, data );
}
void Ym2203_Emu::mute_voices( int mask )
{
ym2203_set_mutemask( opn, mask );
for ( unsigned i = 0, j = 1 << 3; i < 3; i++, j <<= 1)
{
Blip_Buffer * buf = ( mask & j ) ? NULL : &buffer;
psg.set_output( i, buf );
}
}
void Ym2203_Emu::run( int pair_count, sample_t* out )
{
blip_sample_t buf[ 1024 ];
FMSAMPLE bufL[ 1024 ];
FMSAMPLE bufR[ 1024 ];
FMSAMPLE * buffers[2] = { bufL, bufR };
blip_time_t psg_end_time = pair_count * psg_clock / sample_rate;
psg.end_frame( psg_end_time );
buffer.end_frame( psg_end_time );
while (pair_count > 0)
{
int todo = pair_count;
if (todo > 1024) todo = 1024;
ym2203_update_one( opn, buffers, todo );
int sample_count = buffer.read_samples( buf, todo );
memset( buf + sample_count, 0, ( todo - sample_count ) * sizeof( blip_sample_t ) );
for (int i = 0; i < todo; i++)
{
int output_l, output_r;
int output = buf [i];
output_l = output + bufL [i];
output_r = output + bufR [i];
output_l += out [0];
output_r += out [1];
if ( (short)output_l != output_l ) output_l = 0x7FFF ^ ( output_l >> 31 );
if ( (short)output_r != output_r ) output_r = 0x7FFF ^ ( output_r >> 31 );
out [0] = output_l;
out [1] = output_r;
out += 2;
}
pair_count -= todo;
}
}
void Ym2203_Emu::psg_set_clock( int clock )
{
psg_clock = clock * 2;
buffer.clock_rate( psg_clock );
}
void Ym2203_Emu::psg_write( int addr, int data )
{
if ( !(addr & 1) ) psg.write_addr( data );
else psg.write_data( 0, data );
}
int Ym2203_Emu::psg_read()
{
return psg.read();
}
void Ym2203_Emu::psg_reset()
{
psg.reset();
}