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CLK/Machines/Atari/2600/TIASound.cpp

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//
// Speaker.cpp
// Clock Signal
//
// Created by Thomas Harte on 03/12/2016.
// Copyright 2016 Thomas Harte. All rights reserved.
//
#include "TIASound.hpp"
using namespace Atari2600;
2022-07-16 18:41:04 +00:00
Atari2600::TIASound::TIASound(Concurrency::AsyncTaskQueue<false> &audio_queue) :
audio_queue_(audio_queue),
poly4_counter_{0x00f, 0x00f},
poly5_counter_{0x01f, 0x01f},
poly9_counter_{0x1ff, 0x1ff}
{}
void Atari2600::TIASound::set_volume(int channel, uint8_t volume) {
audio_queue_.enqueue([target = &volume_[channel], volume]() {
*target = volume & 0xf;
});
}
void Atari2600::TIASound::set_divider(int channel, uint8_t divider) {
audio_queue_.enqueue([this, channel, divider]() {
divider_[channel] = divider & 0x1f;
divider_counter_[channel] = 0;
});
}
void Atari2600::TIASound::set_control(int channel, uint8_t control) {
audio_queue_.enqueue([target = &control_[channel], control]() {
*target = control & 0xf;
});
}
#define advance_poly4(c) poly4_counter_[channel] = (poly4_counter_[channel] >> 1) | (((poly4_counter_[channel] << 3) ^ (poly4_counter_[channel] << 2))&0x008)
#define advance_poly5(c) poly5_counter_[channel] = (poly5_counter_[channel] >> 1) | (((poly5_counter_[channel] << 4) ^ (poly5_counter_[channel] << 2))&0x010)
#define advance_poly9(c) poly9_counter_[channel] = (poly9_counter_[channel] >> 1) | (((poly9_counter_[channel] << 4) ^ (poly9_counter_[channel] << 8))&0x100)
template <Outputs::Speaker::Action action>
void Atari2600::TIASound::apply_samples(std::size_t number_of_samples, Outputs::Speaker::MonoSample *target) {
for(unsigned int c = 0; c < number_of_samples; c++) {
Outputs::Speaker::MonoSample output = 0;
for(int channel = 0; channel < 2; channel++) {
divider_counter_[channel] ++;
int divider_value = divider_counter_[channel] / (38 / CPUTicksPerAudioTick);
int level = 0;
switch(control_[channel]) {
case 0x0: case 0xb: // constant 1
level = 1;
break;
case 0x4: case 0x5: // div2 tone
level = (divider_value / (divider_[channel]+1))&1;
break;
case 0xc: case 0xd: // div6 tone
level = (divider_value / ((divider_[channel]+1)*3))&1;
break;
case 0x6: case 0xa: // div31 tone
level = (divider_value / (divider_[channel]+1))%30 <= 18;
break;
case 0xe: // div93 tone
level = (divider_value / ((divider_[channel]+1)*3))%30 <= 18;
break;
case 0x1: // 4-bit poly
level = poly4_counter_[channel]&1;
if(divider_value == divider_[channel]+1) {
divider_counter_[channel] = 0;
advance_poly4(channel);
}
break;
case 0x2: // 4-bit poly div31
level = poly4_counter_[channel]&1;
if(divider_value%(30*(divider_[channel]+1)) == 18) {
advance_poly4(channel);
}
break;
case 0x3: // 5/4-bit poly
level = output_state_[channel];
if(divider_value == divider_[channel]+1) {
if(poly5_counter_[channel]&1) {
output_state_[channel] = poly4_counter_[channel]&1;
advance_poly4(channel);
}
advance_poly5(channel);
}
break;
case 0x7: case 0x9: // 5-bit poly
level = poly5_counter_[channel]&1;
if(divider_value == divider_[channel]+1) {
divider_counter_[channel] = 0;
advance_poly5(channel);
}
break;
case 0xf: // 5-bit poly div6
level = poly5_counter_[channel]&1;
if(divider_value == (divider_[channel]+1)*3) {
divider_counter_[channel] = 0;
advance_poly5(channel);
}
break;
case 0x8: // 9-bit poly
level = poly9_counter_[channel]&1;
if(divider_value == divider_[channel]+1) {
divider_counter_[channel] = 0;
advance_poly9(channel);
}
break;
}
output += (volume_[channel] * per_channel_volume_ * level) >> 4;
}
Outputs::Speaker::apply<action>(target[c], output);
}
}
template void Atari2600::TIASound::apply_samples<Outputs::Speaker::Action::Mix>(std::size_t, Outputs::Speaker::MonoSample *);
template void Atari2600::TIASound::apply_samples<Outputs::Speaker::Action::Store>(std::size_t, Outputs::Speaker::MonoSample *);
template void Atari2600::TIASound::apply_samples<Outputs::Speaker::Action::Ignore>(std::size_t, Outputs::Speaker::MonoSample *);
void Atari2600::TIASound::set_sample_volume_range(std::int16_t range) {
per_channel_volume_ = range / 2;
}