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Improved emulation of envelope locking, fixes #522

This commit is contained in:
Lior Halphon 2023-01-10 01:19:07 +02:00
parent d90ecec085
commit aa8b7b0c03
2 changed files with 33 additions and 45 deletions
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73
Core/apu.c
View File

@ -331,6 +331,19 @@ static inline void update_wave_sample(GB_gameboy_t *gb, unsigned cycles)
}
}
static inline void set_envelope_clock(GB_envelope_clock_t *clock, bool value, bool direction, uint8_t volume)
{
if (clock->clock == value) return;
if (value) {
clock->clock = true;
clock->should_lock = (volume == 0xF && direction) || (volume == 0x0 && !direction);
}
else {
clock->clock = false;
clock->locked |= clock->should_lock;
}
}
static void _nrx2_glitch(uint8_t *volume, uint8_t value, uint8_t old_value, uint8_t *countdown, GB_envelope_clock_t *lock)
{
if (lock->clock) {
@ -371,22 +384,7 @@ static void _nrx2_glitch(uint8_t *volume, uint8_t value, uint8_t old_value, uint
*volume &= 0xF;
}
else if (!(value & 7) && lock->clock) {
// *lock->locked = false; // Excepted from the schematics, but doesn't actually happen on any model?
if (!should_invert) {
if (*volume == 0xF && (value & 8)) {
lock->locked = true;
}
else if (*volume == 0 && !(value & 8)) {
lock->locked = true;
}
}
else if (*volume == 1 && !(value & 8)) {
lock->locked = true;
}
else if (*volume == 0xE && (value & 8)) {
lock->locked = true;
}
lock->clock = false;
set_envelope_clock(lock, false, 0, 0);
}
}
@ -408,9 +406,10 @@ static void nrx2_glitch(GB_gameboy_t *gb, uint8_t *volume, uint8_t value, uint8_
static void tick_square_envelope(GB_gameboy_t *gb, GB_channel_t index)
{
set_envelope_clock(&gb->apu.square_channels[index].envelope_clock, false, 0, 0);
if (gb->apu.square_channels[index].envelope_clock.locked) return;
uint8_t nrx2 = gb->io_registers[index == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22];
if (gb->apu.square_channels[index].envelope_clock.locked) return;
if (!(nrx2 & 7)) return;
if (gb->cgb_double_speed) {
if (index == GB_SQUARE_1) {
@ -421,22 +420,14 @@ static void tick_square_envelope(GB_gameboy_t *gb, GB_channel_t index)
}
}
set_envelope_clock(&gb->apu.square_channels[index].envelope_clock, false, 0, 0);
if (nrx2 & 8) {
if (gb->apu.square_channels[index].current_volume < 0xF) {
gb->apu.square_channels[index].current_volume++;
}
else {
gb->apu.square_channels[index].envelope_clock.locked = true;
}
}
else {
if (gb->apu.square_channels[index].current_volume > 0) {
gb->apu.square_channels[index].current_volume--;
}
else {
gb->apu.square_channels[index].envelope_clock.locked = true;
}
}
if (gb->apu.is_active[index]) {
update_square_sample(gb, index);
@ -445,9 +436,10 @@ static void tick_square_envelope(GB_gameboy_t *gb, GB_channel_t index)
static void tick_noise_envelope(GB_gameboy_t *gb)
{
uint8_t nr42 = gb->io_registers[GB_IO_NR42];
set_envelope_clock(&gb->apu.noise_channel.envelope_clock, false, 0, 0);
if (gb->apu.noise_channel.envelope_clock.locked) return;
uint8_t nr42 = gb->io_registers[GB_IO_NR42];
if (!(nr42 & 7)) return;
if (gb->cgb_double_speed) {
@ -455,21 +447,11 @@ static void tick_noise_envelope(GB_gameboy_t *gb)
}
if (nr42 & 8) {
if (gb->apu.noise_channel.current_volume < 0xF) {
gb->apu.noise_channel.current_volume++;
}
else {
gb->apu.noise_channel.envelope_clock.locked = true;
}
}
else {
if (gb->apu.noise_channel.current_volume > 0) {
gb->apu.noise_channel.current_volume--;
}
else {
gb->apu.noise_channel.envelope_clock.locked = true;
}
}
if (gb->apu.is_active[GB_NOISE]) {
update_sample(gb, GB_NOISE,
@ -534,13 +516,11 @@ void GB_apu_div_event(GB_gameboy_t *gb)
unrolled for (unsigned i = GB_SQUARE_2 + 1; i--;) {
if (gb->apu.square_channels[i].envelope_clock.clock) {
tick_square_envelope(gb, i);
gb->apu.square_channels[i].envelope_clock.clock = false;
}
}
if (gb->apu.noise_channel.envelope_clock.clock) {
tick_noise_envelope(gb);
gb->apu.noise_channel.envelope_clock.clock = false;
}
if ((gb->apu.div_divider & 1) == 1) {
@ -598,12 +578,19 @@ void GB_apu_div_secondary_event(GB_gameboy_t *gb)
unrolled for (unsigned i = GB_SQUARE_2 + 1; i--;) {
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) {
gb->apu.square_channels[i].envelope_clock.clock = (gb->apu.square_channels[i].volume_countdown = nrx2 & 7);
set_envelope_clock(&gb->apu.square_channels[i].envelope_clock,
(gb->apu.square_channels[i].volume_countdown = nrx2 & 7),
nrx2 & 8,
gb->apu.square_channels[i].current_volume);
}
}
if (gb->apu.is_active[GB_NOISE] && gb->apu.noise_channel.volume_countdown == 0) {
gb->apu.noise_channel.envelope_clock.clock = (gb->apu.noise_channel.volume_countdown = gb->io_registers[GB_IO_NR42] & 7);
set_envelope_clock(&gb->apu.noise_channel.envelope_clock,
(gb->apu.noise_channel.volume_countdown = gb->io_registers[GB_IO_NR42] & 7),
gb->io_registers[GB_IO_NR42] & 8,
gb->apu.noise_channel.current_volume);
}
}

5
Core/apu.h
View File

@ -48,9 +48,10 @@ typedef enum {
typedef struct
{
bool locked:1;
bool locked:1; // Represents FYNO's output on channel 4
bool clock:1; // Represents FOSY on channel 4
unsigned padding:6;
bool should_lock:1; // Represents FYNO's input on channel 4
unsigned padding:5;
} GB_envelope_clock_t;
typedef void (*GB_sample_callback_t)(GB_gameboy_t *gb, GB_sample_t *sample);