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More accurate div-event handling

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This commit is contained in:
Lior Halphon 2017-08-15 22:27:15 +03:00
parent 8d011ca4b9
commit 62878fdc7a
1 changed files with 7 additions and 8 deletions
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15
Core/apu.c
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@ -120,8 +120,7 @@ void GB_apu_div_event(GB_gameboy_t *gb)
if (!gb->apu.global_enable) return; if (!gb->apu.global_enable) return;
gb->apu.div_divider++; gb->apu.div_divider++;
/* gb->apu.div_divider is even; handle volume envelopes */ if ((gb->apu.div_divider & 7) == 0) {
if ((gb->apu.div_divider & 1) == 0) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) { for (unsigned i = GB_SQUARE_2 + 1; i--;) {
uint8_t nrx2 = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22]; uint8_t nrx2 = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22];
@ -135,7 +134,7 @@ void GB_apu_div_event(GB_gameboy_t *gb)
gb->apu.square_channels[i].current_volume--; gb->apu.square_channels[i].current_volume--;
} }
gb->apu.square_channels[i].volume_countdown = (nrx2 & 7) * 4; gb->apu.square_channels[i].volume_countdown = nrx2 & 7;
uint8_t duty = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR11 :GB_IO_NR21] >> 6; uint8_t duty = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR11 :GB_IO_NR21] >> 6;
update_sample(gb, i, update_sample(gb, i,
@ -158,7 +157,7 @@ void GB_apu_div_event(GB_gameboy_t *gb)
gb->apu.noise_channel.current_volume--; gb->apu.noise_channel.current_volume--;
} }
gb->apu.noise_channel.volume_countdown = (nr42 & 7) * 4; gb->apu.noise_channel.volume_countdown = nr42 & 7;
update_sample(gb, GB_NOISE, update_sample(gb, GB_NOISE,
(gb->apu.noise_channel.lfsr & 1) ? (gb->apu.noise_channel.lfsr & 1) ?
@ -167,8 +166,8 @@ void GB_apu_div_event(GB_gameboy_t *gb)
} }
} }
} }
/* gb->apu.div_divider is odd; handle length controls */
else { if ((gb->apu.div_divider & 1) == 1) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) { for (unsigned i = GB_SQUARE_2 + 1; i--;) {
if (gb->apu.square_channels[i].length_enabled) { if (gb->apu.square_channels[i].length_enabled) {
if (gb->apu.square_channels[i].pulse_length) { if (gb->apu.square_channels[i].pulse_length) {
@ -537,7 +536,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
} }
} }
gb->apu.square_channels[index].current_volume = gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] >> 4; gb->apu.square_channels[index].current_volume = gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] >> 4;
gb->apu.square_channels[index].volume_countdown = (gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] & 7) * 4; gb->apu.square_channels[index].volume_countdown = gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] & 7;
if ((gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] & 0xF8) != 0) { if ((gb->io_registers[index == GB_SQUARE_1 ? GB_IO_NR12 : GB_IO_NR22] & 0xF8) != 0) {
gb->apu.is_active[index] = true; gb->apu.is_active[index] = true;
@ -711,7 +710,7 @@ void GB_apu_write(GB_gameboy_t *gb, uint8_t reg, uint8_t value)
} }
gb->apu.noise_channel.current_volume = gb->io_registers[GB_IO_NR42] >> 4; gb->apu.noise_channel.current_volume = gb->io_registers[GB_IO_NR42] >> 4;
gb->apu.noise_channel.volume_countdown = (gb->io_registers[GB_IO_NR42] & 7) * 4; gb->apu.noise_channel.volume_countdown = gb->io_registers[GB_IO_NR42] & 7;
if ((gb->io_registers[GB_IO_NR42] & 0xF8) != 0) { if ((gb->io_registers[GB_IO_NR42] & 0xF8) != 0) {
gb->apu.is_active[GB_NOISE] = true; gb->apu.is_active[GB_NOISE] = true;