bsnes/higan/md/psg/psg.cpp

57 lines
1.1 KiB
C++

#include <md/md.hpp>
namespace MegaDrive {
PSG psg;
#include "io.cpp"
#include "tone.cpp"
#include "noise.cpp"
auto PSG::Enter() -> void {
while(true) scheduler.synchronize(), psg.main();
}
auto PSG::main() -> void {
tone0.run();
tone1.run();
tone2.run();
noise.run();
int output = 0;
if(tone0.output) output += levels[tone0.volume];
if(tone1.output) output += levels[tone1.volume];
if(tone2.output) output += levels[tone2.volume];
if(noise.output) output += levels[noise.volume];
lowpass += (output - lowpass) * 20.0 / 256.0;
output = output * 2.0 / 6.0 + lowpass * 3.0 / 4.0;
output = sclamp<16>(output - 32768);
stream->sample(output / 32768.0);
step(1);
}
auto PSG::step(uint clocks) -> void {
Thread::step(clocks);
synchronize(cpu);
}
auto PSG::power() -> void {
create(PSG::Enter, system.colorburst() / 16.0);
stream = Emulator::audio.createStream(1, frequency());
select = 0;
lowpass = 0;
for(auto n : range(15)) {
levels[n] = 0x3fff * pow(2, n * -2.0 / 6.0) + 0.5;
}
levels[15] = 0;
tone0.power();
tone1.power();
tone2.power();
noise.power();
}
}