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Fixing a bug where where zero-shift sweep wouldn't tick

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This commit is contained in:
Lior Halphon 2021-01-02 14:56:45 +02:00
parent 5c854dbdca
commit b54a72d9b9
2 changed files with 5 additions and 4 deletions
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7
Core/apu.c
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@ -394,7 +394,7 @@ static void trigger_sweep_calculation(GB_gameboy_t *gb)
/* Recalculation and overflow check only occurs after a delay */
gb->apu.square_sweep_calculate_countdown = (gb->io_registers[GB_IO_NR10] & 0x7) * 2 + 5 - gb->apu.lf_div;
gb->apu.unshifted_sweep = !(gb->io_registers[GB_IO_NR10] & 0x7);
gb->apu.square_sweep_countdown = ((gb->io_registers[GB_IO_NR10] >> 4) & 7) ^ 7;
}
}
@ -524,7 +524,7 @@ void GB_apu_run(GB_gameboy_t *gb)
gb->apu.noise_channel.alignment += cycles;
if (gb->apu.square_sweep_calculate_countdown &&
((gb->io_registers[GB_IO_NR10] & 7) ||
(((gb->io_registers[GB_IO_NR10] & 7) || gb->apu.unshifted_sweep) ||
gb->apu.square_sweep_calculate_countdown <= (gb->model > GB_MODEL_CGB_C? 3 : 1))) { // Calculation is paused if the lower bits
if (gb->apu.square_sweep_calculate_countdown > cycles) {
gb->apu.square_sweep_calculate_countdown -= cycles;
@ -875,6 +875,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
if (gb->io_registers[GB_IO_NR10] & 7) {
/* APU bug: if shift is nonzero, overflow check also occurs on trigger */
gb->apu.square_sweep_calculate_countdown = (gb->io_registers[GB_IO_NR10] & 0x7) * 2 + 5 - gb->apu.lf_div;
gb->apu.unshifted_sweep = false;
if (gb->model > GB_MODEL_CGB_C) {
gb->apu.square_sweep_calculate_countdown += 2;
}
@ -884,7 +885,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
else {
gb->apu.sweep_length_addend = 0;
}
gb->apu.channel_1_restart_hold = 4 - gb->apu.lf_div;
gb->apu.channel_1_restart_hold = 2 - gb->apu.lf_div + GB_is_cgb(gb) * 2;
gb->apu.square_sweep_countdown = ((gb->io_registers[GB_IO_NR10] >> 4) & 7) ^ 7;
}
}

2
Core/apu.h
View File

@ -66,7 +66,7 @@ typedef struct
uint8_t square_sweep_calculate_countdown; // In 2 MHz
uint16_t sweep_length_addend;
uint16_t shadow_sweep_sample_length;
GB_PADDING(bool, sweep_enabled);
bool unshifted_sweep;
GB_PADDING(bool, sweep_decreasing);
struct {