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Improved emulation of the volume envelope

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This commit is contained in:
Lior Halphon 2021-02-22 01:10:14 +02:00
parent e7a5be70c2
commit 6d2d88648e
1 changed files with 38 additions and 47 deletions
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83
Core/apu.c
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@ -318,7 +318,7 @@ static void _nrx2_glitch(uint8_t *volume, uint8_t value, uint8_t old_value)
(*volume) &= 0xF; (*volume) &= 0xF;
} }
static void nrx2_glitch(GB_gameboy_t *gb,uint8_t *volume, uint8_t value, uint8_t old_value) static void nrx2_glitch(GB_gameboy_t *gb, uint8_t *volume, uint8_t value, uint8_t old_value)
{ {
if (gb->model <= GB_MODEL_CGB_C) { if (gb->model <= GB_MODEL_CGB_C) {
_nrx2_glitch(volume, 0xFF, old_value); _nrx2_glitch(volume, 0xFF, old_value);
@ -333,30 +333,29 @@ 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 || (nrx2 & 7)) { if (!gb->apu.square_channels[index].volume_countdown || !--gb->apu.square_channels[index].volume_countdown) {
if (!gb->apu.square_channels[index].volume_countdown || !--gb->apu.square_channels[index].volume_countdown) { gb->apu.square_channels[index].volume_countdown = nrx2 & 7;
if (gb->cgb_double_speed) { if (!(nrx2 & 7)) return;
if (index == GB_SQUARE_1) { if (gb->cgb_double_speed) {
gb->apu.pcm_mask[0] &= gb->apu.square_channels[GB_SQUARE_1].current_volume | 0xF1; if (index == GB_SQUARE_1) {
} 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 {
if ((nrx2 & 8) && gb->apu.square_channels[index].current_volume < 0xF) { gb->apu.pcm_mask[0] &= (gb->apu.square_channels[GB_SQUARE_2].current_volume << 2) | 0x1F;
gb->apu.square_channels[index].current_volume++;
} }
}
else if (!(nrx2 & 8) && gb->apu.square_channels[index].current_volume > 0) { 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++;
} }
gb->apu.square_channels[index].volume_countdown = nrx2 & 7; else if (!(nrx2 & 8) && gb->apu.square_channels[index].current_volume > 0) {
gb->apu.square_channels[index].current_volume--;
}
if (gb->apu.is_active[index]) {
update_square_sample(gb, index); if (gb->apu.is_active[index]) {
} update_square_sample(gb, index);
} }
} }
} }
@ -365,27 +364,27 @@ 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 || (nr42 & 7)) { if (!gb->apu.noise_channel.volume_countdown || !--gb->apu.noise_channel.volume_countdown) {
if (!gb->apu.noise_channel.volume_countdown || !--gb->apu.noise_channel.volume_countdown) { gb->apu.noise_channel.volume_countdown = nr42 & 7;
if (gb->cgb_double_speed) { if (!(nr42 & 7)) return;
gb->apu.pcm_mask[0] &= (gb->apu.noise_channel.current_volume << 2) | 0x1F;
}
if ((nr42 & 8) && gb->apu.noise_channel.current_volume < 0xF) {
gb->apu.noise_channel.current_volume++;
}
else if (!(nr42 & 8) && gb->apu.noise_channel.current_volume > 0) { if (gb->cgb_double_speed) {
gb->apu.noise_channel.current_volume--; gb->apu.pcm_mask[0] &= (gb->apu.noise_channel.current_volume << 2) | 0x1F;
} }
if ((nr42 & 8) && gb->apu.noise_channel.current_volume < 0xF) {
gb->apu.noise_channel.current_volume++;
}
gb->apu.noise_channel.volume_countdown = nr42 & 7; else if (!(nr42 & 8) && gb->apu.noise_channel.current_volume > 0) {
gb->apu.noise_channel.current_volume--;
}
if (gb->apu.is_active[GB_NOISE]) {
update_sample(gb, GB_NOISE, if (gb->apu.is_active[GB_NOISE]) {
(gb->apu.noise_channel.lfsr & 1) ? update_sample(gb, GB_NOISE,
gb->apu.noise_channel.current_volume : 0, (gb->apu.noise_channel.lfsr & 1) ?
0); gb->apu.noise_channel.current_volume : 0,
} 0);
} }
} }
} }
@ -931,10 +930,6 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
case GB_IO_NR12: case GB_IO_NR12:
case GB_IO_NR22: { case GB_IO_NR22: {
unsigned index = reg == GB_IO_NR22? GB_SQUARE_2: GB_SQUARE_1; unsigned index = reg == GB_IO_NR22? GB_SQUARE_2: GB_SQUARE_1;
if (((value & 0x7) == 0) && ((gb->io_registers[reg] & 0x7) != 0)) {
/* Envelope disabled */
gb->apu.square_channels[index].volume_countdown = 0;
}
if ((value & 0xF8) == 0) { if ((value & 0xF8) == 0) {
/* This disables the DAC */ /* This disables the DAC */
gb->io_registers[reg] = value; gb->io_registers[reg] = value;
@ -1179,10 +1174,6 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
} }
case GB_IO_NR42: { case GB_IO_NR42: {
if (((value & 0x7) == 0) && ((gb->io_registers[reg] & 0x7) != 0)) {
/* Envelope disabled */
gb->apu.noise_channel.volume_countdown = 0;
}
if ((value & 0xF8) == 0) { if ((value & 0xF8) == 0) {
/* This disables the DAC */ /* This disables the DAC */
gb->io_registers[reg] = value; gb->io_registers[reg] = value;