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Further accuracy improvements to the audio envelope

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This commit is contained in:
Lior Halphon 2021-02-22 01:58:43 +02:00
parent 6d2d88648e
commit d50fdc52ea
1 changed files with 44 additions and 46 deletions
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90
Core/apu.c
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@ -333,30 +333,28 @@ static void tick_square_envelope(GB_gameboy_t *gb, enum GB_CHANNELS index)
{ {
uint8_t nrx2 = gb->io_registers[index == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22]; uint8_t nrx2 = gb->io_registers[index == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22];
if (!gb->apu.square_channels[index].volume_countdown || !--gb->apu.square_channels[index].volume_countdown) { gb->apu.square_channels[index].volume_countdown = nrx2 & 7;
gb->apu.square_channels[index].volume_countdown = nrx2 & 7; if (!(nrx2 & 7)) return;
if (!(nrx2 & 7)) return; if (gb->cgb_double_speed) {
if (gb->cgb_double_speed) { if (index == GB_SQUARE_1) {
if (index == GB_SQUARE_1) { gb->apu.pcm_mask[0] &= gb->apu.square_channels[GB_SQUARE_1].current_volume | 0xF1;
gb->apu.pcm_mask[0] &= gb->apu.square_channels[GB_SQUARE_1].current_volume | 0xF1;
}
else {
gb->apu.pcm_mask[0] &= (gb->apu.square_channels[GB_SQUARE_2].current_volume << 2) | 0x1F;
}
} }
else {
gb->apu.pcm_mask[0] &= (gb->apu.square_channels[GB_SQUARE_2].current_volume << 2) | 0x1F;
}
}
if ((nrx2 & 8) && gb->apu.square_channels[index].current_volume < 0xF) { if ((nrx2 & 8) && gb->apu.square_channels[index].current_volume < 0xF) {
gb->apu.square_channels[index].current_volume++; gb->apu.square_channels[index].current_volume++;
} }
else if (!(nrx2 & 8) && gb->apu.square_channels[index].current_volume > 0) { else if (!(nrx2 & 8) && gb->apu.square_channels[index].current_volume > 0) {
gb->apu.square_channels[index].current_volume--; gb->apu.square_channels[index].current_volume--;
} }
if (gb->apu.is_active[index]) { if (gb->apu.is_active[index]) {
update_square_sample(gb, index); update_square_sample(gb, index);
}
} }
} }
@ -364,28 +362,25 @@ static void tick_noise_envelope(GB_gameboy_t *gb)
{ {
uint8_t nr42 = gb->io_registers[GB_IO_NR42]; uint8_t nr42 = gb->io_registers[GB_IO_NR42];
if (!gb->apu.noise_channel.volume_countdown || !--gb->apu.noise_channel.volume_countdown) { if (!(nr42 & 7)) return;
gb->apu.noise_channel.volume_countdown = nr42 & 7;
if (!(nr42 & 7)) return;
if (gb->cgb_double_speed) { if (gb->cgb_double_speed) {
gb->apu.pcm_mask[0] &= (gb->apu.noise_channel.current_volume << 2) | 0x1F; gb->apu.pcm_mask[0] &= (gb->apu.noise_channel.current_volume << 2) | 0x1F;
} }
if ((nr42 & 8) && gb->apu.noise_channel.current_volume < 0xF) { if ((nr42 & 8) && gb->apu.noise_channel.current_volume < 0xF) {
gb->apu.noise_channel.current_volume++; gb->apu.noise_channel.current_volume++;
} }
else if (!(nr42 & 8) && gb->apu.noise_channel.current_volume > 0) { else if (!(nr42 & 8) && gb->apu.noise_channel.current_volume > 0) {
gb->apu.noise_channel.current_volume--; gb->apu.noise_channel.current_volume--;
} }
if (gb->apu.is_active[GB_NOISE]) { if (gb->apu.is_active[GB_NOISE]) {
update_sample(gb, GB_NOISE, update_sample(gb, GB_NOISE,
(gb->apu.noise_channel.lfsr & 1) ? (gb->apu.noise_channel.lfsr & 1) ?
gb->apu.noise_channel.current_volume : 0, gb->apu.noise_channel.current_volume : 0,
0); 0);
}
} }
} }
@ -428,28 +423,31 @@ void GB_apu_div_event(GB_gameboy_t *gb)
} }
if ((gb->apu.div_divider & 1) == 0) { if ((gb->apu.div_divider & 1) == 0) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) { UNROLL for (unsigned i = GB_SQUARE_2 + 1; i--;) {
uint8_t nrx2 = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22]; uint8_t nrx2 = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22];
if (gb->apu.is_active[i] && gb->apu.square_channels[i].volume_countdown == 0 && (nrx2 & 7)) { if (gb->apu.is_active[i] && gb->apu.square_channels[i].volume_countdown == 0) {
tick_square_envelope(gb, i); tick_square_envelope(gb, i);
gb->apu.square_channels[i].volume_countdown = nrx2 & 7;
} }
} }
if (gb->apu.is_active[GB_NOISE] && gb->apu.noise_channel.volume_countdown == 0 && (gb->io_registers[GB_IO_NR42] & 7)) { if (gb->apu.is_active[GB_NOISE] && gb->apu.noise_channel.volume_countdown == 0) {
tick_noise_envelope(gb); tick_noise_envelope(gb);
gb->apu.noise_channel.volume_countdown = gb->io_registers[GB_IO_NR42] & 7;
} }
} }
if ((gb->apu.div_divider & 7) == 0) { if ((gb->apu.div_divider & 7) == 7) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) { UNROLL for (unsigned i = GB_SQUARE_2 + 1; i--;) {
tick_square_envelope(gb, i); gb->apu.square_channels[i].volume_countdown--;
gb->apu.square_channels[i].volume_countdown &= 7;
} }
gb->apu.noise_channel.volume_countdown--;
tick_noise_envelope(gb); gb->apu.noise_channel.volume_countdown &= 7;
} }
if ((gb->apu.div_divider & 1) == 1) { if ((gb->apu.div_divider & 1) == 1) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) { UNROLL for (unsigned i = GB_SQUARE_2 + 1; i--;) {
if (gb->apu.square_channels[i].length_enabled) { if (gb->apu.square_channels[i].length_enabled) {
if (gb->apu.square_channels[i].pulse_length) { if (gb->apu.square_channels[i].pulse_length) {
if (!--gb->apu.square_channels[i].pulse_length) { if (!--gb->apu.square_channels[i].pulse_length) {