cog/Frameworks/GME/gme/Sms_Fm_Apu.cpp

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2013-09-28 03:24:46 +00:00
#include "Sms_Fm_Apu.h"
#include "blargg_source.h"
Sms_Fm_Apu::Sms_Fm_Apu()
{ }
Sms_Fm_Apu::~Sms_Fm_Apu()
{ }
blargg_err_t Sms_Fm_Apu::init( double clock_rate, double sample_rate )
{
period_ = clock_rate / sample_rate + 0.5;
CHECK_ALLOC( !apu.set_rate( sample_rate, clock_rate ) );
set_output( 0 );
volume( 1.0 );
reset();
return blargg_ok;
}
void Sms_Fm_Apu::reset()
{
addr = 0;
next_time = 0;
last_amp = 0;
apu.reset();
}
void Sms_Fm_Apu::write_data( blip_time_t time, int data )
{
if ( time > next_time )
run_until( time );
apu.write( addr, data );
}
void Sms_Fm_Apu::run_until( blip_time_t end_time )
{
assert( end_time > next_time );
Blip_Buffer* const output = this->output_;
if ( !output )
{
next_time = end_time;
return;
}
blip_time_t time = next_time;
do
{
Ym2413_Emu::sample_t samples [2] = {0};
apu.run( 1, samples );
int amp = (samples [0] + samples [1]) >> 1;
int delta = amp - last_amp;
if ( delta )
{
last_amp = amp;
synth.offset_inline( time, delta, output );
}
time += period_;
}
while ( time < end_time );
next_time = time;
}
void Sms_Fm_Apu::end_frame( blip_time_t time )
{
if ( time > next_time )
run_until( time );
next_time -= time;
assert( next_time >= 0 );
if ( output_ )
output_->set_modified();
}