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The volume envelopes and length controls are handled in different phases of the div-divider

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This commit is contained in:
Lior Halphon 2017-08-12 20:17:20 +03:00
parent 4b8be255ce
commit 688991f57f
1 changed files with 34 additions and 29 deletions
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63
Core/apu.c
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@ -97,17 +97,9 @@ void GB_apu_div_event(GB_gameboy_t *gb)
if (!gb->apu.global_enable) return;
gb->apu.div_divider++;
if ((gb->apu.div_divider & 1) == 1) {
/* gb->apu.div_divider is even; handle volume envelopes */
if ((gb->apu.div_divider & 1) == 0) {
for (unsigned i = GB_SQUARE_2 + 1; i--;) {
if (gb->apu.square_channels[i].length_enabled) {
if (gb->apu.square_channels[i].pulse_length) {
if (!--gb->apu.square_channels[i].pulse_length) {
gb->apu.is_active[i] = false;
update_sample(gb, i, 0, 0);
}
}
}
uint8_t nrx2 = gb->io_registers[i == GB_SQUARE_1? GB_IO_NR12 : GB_IO_NR22];
if (gb->apu.square_channels[i].volume_countdown) {
@ -131,25 +123,6 @@ void GB_apu_div_event(GB_gameboy_t *gb)
}
}
if (gb->apu.wave_channel.length_enabled) {
if (gb->apu.wave_channel.pulse_length) {
if (!--gb->apu.wave_channel.pulse_length) {
gb->apu.is_active[GB_WAVE] = false;
gb->apu.wave_channel.current_sample = 0;
update_sample(gb, GB_WAVE, 0, 0);
}
}
}
if (gb->apu.noise_channel.length_enabled) {
if (gb->apu.noise_channel.pulse_length) {
if (!--gb->apu.noise_channel.pulse_length) {
gb->apu.is_active[GB_NOISE] = false;
update_sample(gb, GB_NOISE, 0, 0);
}
}
}
uint8_t nr42 = gb->io_registers[GB_IO_NR42];
if (gb->apu.noise_channel.volume_countdown) {
@ -171,6 +144,38 @@ void GB_apu_div_event(GB_gameboy_t *gb)
}
}
}
/* gb->apu.div_divider is odd; handle length controls */
else {
for (unsigned i = GB_SQUARE_2 + 1; i--;) {
if (gb->apu.square_channels[i].length_enabled) {
if (gb->apu.square_channels[i].pulse_length) {
if (!--gb->apu.square_channels[i].pulse_length) {
gb->apu.is_active[i] = false;
update_sample(gb, i, 0, 0);
}
}
}
}
if (gb->apu.wave_channel.length_enabled) {
if (gb->apu.wave_channel.pulse_length) {
if (!--gb->apu.wave_channel.pulse_length) {
gb->apu.is_active[GB_WAVE] = false;
gb->apu.wave_channel.current_sample = 0;
update_sample(gb, GB_WAVE, 0, 0);
}
}
}
if (gb->apu.noise_channel.length_enabled) {
if (gb->apu.noise_channel.pulse_length) {
if (!--gb->apu.noise_channel.pulse_length) {
gb->apu.is_active[GB_NOISE] = false;
update_sample(gb, GB_NOISE, 0, 0);
}
}
}
}
if ((gb->apu.div_divider & 3) == 3) {
if (gb->apu.square_sweep_countdown) {