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WIP add GBA system

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This commit is contained in:
Natt Akuma 2024-01-10 11:17:36 +07:00
parent 892ee12d91
commit f3705fb435
22 changed files with 748 additions and 49 deletions
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46
src/engine/platform/sound/gb/apu.c
View file

@ -668,15 +668,17 @@ void GB_apu_run(GB_gameboy_t *gb)
if (gb->apu.is_active[GB_WAVE]) {
uint8_t cycles_left = cycles;
while (unlikely(cycles_left > gb->apu.wave_channel.sample_countdown)) {
uint8_t base = (!gb->apu.wave_channel.double_length && gb->apu.wave_channel.bank_select) ? 32 : 0;
cycles_left -= gb->apu.wave_channel.sample_countdown + 1;
gb->apu.wave_channel.sample_countdown = gb->apu.wave_channel.sample_length ^ 0x7FF;
gb->apu.wave_channel.current_sample_index++;
gb->apu.wave_channel.current_sample_index &= 0x1F;
gb->apu.wave_channel.current_sample_index &= gb->apu.wave_channel.double_length ? 0x3F : 0x1F;
gb->apu.wave_channel.current_sample =
gb->apu.wave_channel.wave_form[gb->apu.wave_channel.current_sample_index];
update_sample(gb, GB_WAVE,
gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift,
cycles - cycles_left);
gb->apu.wave_channel.wave_form[base + gb->apu.wave_channel.current_sample_index];
int8_t sample = gb->apu.wave_channel.force_3 ?
(gb->apu.wave_channel.current_sample * 3) >> 2 :
gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift;
update_sample(gb, GB_WAVE, sample, cycles - cycles_left);
gb->apu.wave_channel.wave_form_just_read = true;
}
if (cycles_left) {
@ -738,8 +740,10 @@ void GB_apu_init(GB_gameboy_t *gb)
memset(&gb->apu, 0, sizeof(gb->apu));
/* Restore the wave form */
for (unsigned reg = GB_IO_WAV_START; reg <= GB_IO_WAV_END; reg++) {
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2] = gb->io_registers[reg] >> 4;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2 + 1] = gb->io_registers[reg] & 0xF;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2] = gb->io_registers[reg] >> 4;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2 + 1] = gb->io_registers[reg] & 0xF;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2 + 32] = gb->io_registers[reg] >> 4;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2 + 33] = gb->io_registers[reg] & 0xF;
}
gb->apu.lf_div = 1;
/* APU glitch: When turning the APU on while DIV's bit 4 (or 5 in double speed mode) is on,
@ -1160,14 +1164,24 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
gb->apu.is_active[GB_WAVE] = false;
update_sample(gb, GB_WAVE, 0, 0);
}
if (gb->model==GB_MODEL_AGB_NATIVE) {
gb->apu.wave_channel.bank_select = value & 0x40;
gb->apu.wave_channel.double_length = value & 0x20;
}
break;
case GB_IO_NR31:
gb->apu.wave_channel.pulse_length = (0x100 - value);
break;
case GB_IO_NR32:
gb->apu.wave_channel.shift = (uint8_t[]){4, 0, 1, 2}[(value >> 5) & 3];
if (gb->model==GB_MODEL_AGB_NATIVE) {
gb->apu.wave_channel.force_3 = value & 0x80;
}
if (gb->apu.is_active[GB_WAVE]) {
update_sample(gb, GB_WAVE, gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift, 0);
int8_t sample = gb->apu.wave_channel.force_3 ?
(gb->apu.wave_channel.current_sample * 3) >> 2 :
gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift;
update_sample(gb, GB_WAVE, sample, 0);
}
break;
case GB_IO_NR33:
@ -1209,9 +1223,10 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
}
if (!gb->apu.is_active[GB_WAVE]) {
gb->apu.is_active[GB_WAVE] = true;
update_sample(gb, GB_WAVE,
gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift,
0);
int8_t sample = gb->apu.wave_channel.force_3 ?
(gb->apu.wave_channel.current_sample * 3) >> 2 :
gb->apu.wave_channel.current_sample >> gb->apu.wave_channel.shift;
update_sample(gb, GB_WAVE, sample, 0);
}
gb->apu.wave_channel.sample_countdown = (gb->apu.wave_channel.sample_length ^ 0x7FF) + 3;
gb->apu.wave_channel.current_sample_index = 0;
@ -1411,8 +1426,13 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
default:
if (reg >= GB_IO_WAV_START && reg <= GB_IO_WAV_END) {
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2] = value >> 4;
gb->apu.wave_channel.wave_form[(reg - GB_IO_WAV_START) * 2 + 1] = value & 0xF;
uint8_t base = 0;
if (gb->model == GB_MODEL_AGB_NATIVE &&
(!gb->apu.global_enable || !gb->apu.wave_channel.bank_select)) {
base = 32;
}
gb->apu.wave_channel.wave_form[base + (reg - GB_IO_WAV_START) * 2] = value >> 4;
gb->apu.wave_channel.wave_form[base + (reg - GB_IO_WAV_START) * 2 + 1] = value & 0xF;
}
}
gb->io_registers[reg] = value;

5
src/engine/platform/sound/gb/apu.h
View file

@ -93,12 +93,15 @@ typedef struct
uint8_t shift; // NR32
uint16_t sample_length; // NR33, NR34, in APU ticks
bool length_enabled; // NR34
bool double_length; // NR30
bool bank_select; // NR30
bool force_3; // NR32
uint16_t sample_countdown; // in APU ticks (Reloaded from sample_length, xorred $7FF)
uint8_t current_sample_index;
uint8_t current_sample; // Current sample before shifting.
int8_t wave_form[32];
int8_t wave_form[64];
bool wave_form_just_read;
} wave_channel;

1
src/engine/platform/sound/gb/gb.h
View file

@ -114,6 +114,7 @@ typedef enum {
// GB_MODEL_CGB_D = 0x204,
GB_MODEL_CGB_E = 0x205,
GB_MODEL_AGB = 0x206,
GB_MODEL_AGB_NATIVE = 0x226,
} GB_model_t;
enum {