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Emulate volume envelope locking

This commit is contained in:
Lior Halphon 2021-02-22 13:48:56 +02:00
parent d50fdc52ea
commit 393269ae1f
2 changed files with 37 additions and 14 deletions
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48
Core/apu.c
View File

@ -333,7 +333,7 @@ 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];
gb->apu.square_channels[index].volume_countdown = nrx2 & 7;
if (gb->apu.is_square_envelope_locked[index]) return;
if (!(nrx2 & 7)) return;
if (gb->cgb_double_speed) {
if (index == GB_SQUARE_1) {
@ -344,15 +344,23 @@ static void tick_square_envelope(GB_gameboy_t *gb, enum GB_CHANNELS index)
}
}
if ((nrx2 & 8) && gb->apu.square_channels[index].current_volume < 0xF) {
gb->apu.square_channels[index].current_volume++;
if (nrx2 & 8) {
if (gb->apu.square_channels[index].current_volume < 0xF) {
gb->apu.square_channels[index].current_volume++;
}
else {
gb->apu.is_square_envelope_locked[index] = true;
}
}
else if (!(nrx2 & 8) && gb->apu.square_channels[index].current_volume > 0) {
gb->apu.square_channels[index].current_volume--;
else {
if (gb->apu.square_channels[index].current_volume > 0) {
gb->apu.square_channels[index].current_volume--;
}
else {
gb->apu.is_square_envelope_locked[index] = true;
}
}
if (gb->apu.is_active[index]) {
update_square_sample(gb, index);
}
@ -362,20 +370,30 @@ static void tick_noise_envelope(GB_gameboy_t *gb)
{
uint8_t nr42 = gb->io_registers[GB_IO_NR42];
if (gb->apu.is_noise_envelope_locked) return;
if (!(nr42 & 7)) return;
if (gb->cgb_double_speed) {
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++;
if (nr42 & 8) {
if (gb->apu.noise_channel.current_volume < 0xF) {
gb->apu.noise_channel.current_volume++;
}
else {
gb->apu.is_noise_envelope_locked = true;
}
}
else if (!(nr42 & 8) && gb->apu.noise_channel.current_volume > 0) {
gb->apu.noise_channel.current_volume--;
else {
if (gb->apu.noise_channel.current_volume > 0) {
gb->apu.noise_channel.current_volume--;
}
else {
gb->apu.is_noise_envelope_locked = true;
}
}
if (gb->apu.is_active[GB_NOISE]) {
update_sample(gb, GB_NOISE,
(gb->apu.noise_channel.lfsr & 1) ?
@ -975,6 +993,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
if (value & 0x80) {
/* Current sample index remains unchanged when restarting channels 1 or 2. It is only reset by
turning the APU off. */
gb->apu.is_square_envelope_locked[index] = false;
if (!gb->apu.is_active[index]) {
gb->apu.square_channels[index].sample_countdown = (gb->apu.square_channels[index].sample_length ^ 0x7FF) * 2 + 6 - gb->apu.lf_div;
if (gb->model <= GB_MODEL_CGB_C && gb->apu.lf_div) {
@ -983,7 +1002,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
}
else {
unsigned extra_delay = 0;
if (gb->model == GB_MODEL_CGB_E /* || gb->model == GB_MODEL_CGB_D */) {
if (gb->model == GB_MODEL_CGB_E /* || gb->model == GB_MODEL_CGB_D */) {
if ((!(value & 4) && ((gb->io_registers[reg] & 4) || old_sample_length == 0x3FF)) ||
(old_sample_length == 0x7FF && gb->apu.square_channels[index].sample_length != 0x7FF)) {
gb->apu.square_channels[index].current_sample_index++;
@ -1224,6 +1243,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
case GB_IO_NR44: {
if (value & 0x80) {
gb->apu.is_noise_envelope_locked = false;
if (!GB_is_cgb(gb) && (gb->apu.noise_channel.alignment & 3) != 0) {
gb->apu.channel_4_dmg_delayed_start = 6;
}

3
Core/apu.h
View File

@ -126,6 +126,9 @@ typedef struct
bool channel_4_countdown_reloaded;
uint8_t channel_4_dmg_delayed_start;
uint16_t channel1_completed_addend;
bool is_square_envelope_locked[2];
bool is_noise_envelope_locked;
} GB_apu_t;
typedef enum {