bsnes/gb/apu/master/master.cpp

117 lines
2.8 KiB
C++

#ifdef APU_CPP
void APU::Master::run() {
if(enable == false) {
center = 0;
left = 0;
right = 0;
center_bias = left_bias = right_bias = 0;
return;
}
signed sample = 0;
sample += apu.square1.output;
sample += apu.square2.output;
sample += apu.wave.output;
sample += apu.noise.output;
center = (sample * 512) - 16384;
sample = 0;
if(channel1_left_enable) sample += apu.square1.output;
if(channel2_left_enable) sample += apu.square2.output;
if(channel3_left_enable) sample += apu.wave.output;
if(channel4_left_enable) sample += apu.noise.output;
sample = (sample * 512) - 16384;
sample = (sample * (left_volume + 1)) / 8;
left = sample;
sample = 0;
if(channel1_right_enable) sample += apu.square1.output;
if(channel2_right_enable) sample += apu.square2.output;
if(channel3_right_enable) sample += apu.wave.output;
if(channel4_right_enable) sample += apu.noise.output;
sample = (sample * 512) - 16384;
sample = (sample * (right_volume + 1)) / 8;
right = sample;
//reduce audio volume
center >>= 1;
left >>= 1;
right >>= 1;
}
void APU::Master::write(unsigned r, uint8 data) {
if(r == 0) { //$ff24 NR50
left_in_enable = data & 0x80;
left_volume = (data >> 4) & 7;
right_in_enable = data & 0x08;
right_volume = (data >> 0) & 7;
}
if(r == 1) { //$ff25 NR51
channel4_left_enable = data & 0x80;
channel3_left_enable = data & 0x40;
channel2_left_enable = data & 0x20;
channel1_left_enable = data & 0x10;
channel4_right_enable = data & 0x08;
channel3_right_enable = data & 0x04;
channel2_right_enable = data & 0x02;
channel1_right_enable = data & 0x01;
}
if(r == 2) { //$ff26 NR52
enable = data & 0x80;
}
}
void APU::Master::power() {
left_in_enable = 0;
left_volume = 0;
right_in_enable = 0;
right_volume = 0;
channel4_left_enable = 0;
channel3_left_enable = 0;
channel2_left_enable = 0;
channel1_left_enable = 0;
channel4_right_enable = 0;
channel3_right_enable = 0;
channel2_right_enable = 0;
channel1_right_enable = 0;
enable = 0;
center = 0;
left = 0;
right = 0;
center_bias = 0;
left_bias = 0;
right_bias = 0;
}
void APU::Master::serialize(serializer& s) {
s.integer(left_in_enable);
s.integer(left_volume);
s.integer(right_in_enable);
s.integer(right_volume);
s.integer(channel4_left_enable);
s.integer(channel3_left_enable);
s.integer(channel2_left_enable);
s.integer(channel1_left_enable);
s.integer(channel4_right_enable);
s.integer(channel3_right_enable);
s.integer(channel2_right_enable);
s.integer(channel1_right_enable);
s.integer(enable);
s.integer(center);
s.integer(left);
s.integer(right);
s.integer(center_bias);
s.integer(left_bias);
s.integer(right_bias);
}
#endif