mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-10 23:05:01 +00:00
376 lines
12 KiB
C++
376 lines
12 KiB
C++
//
|
|
// Sound.cpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 04/11/2020.
|
|
// Copyright © 2020 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#include "Sound.hpp"
|
|
|
|
#include <cassert>
|
|
#include <cstdio>
|
|
#include <numeric>
|
|
|
|
// TODO: is it safe not to check for back-pressure in pending_stores_?
|
|
|
|
using namespace Apple::IIgs::Sound;
|
|
|
|
GLU::GLU(Concurrency::DeferringAsyncTaskQueue &audio_queue) : audio_queue_(audio_queue) {
|
|
// Reset all pending stores.
|
|
MemoryWrite disabled_write;
|
|
disabled_write.enabled = false;
|
|
for(int c = 0; c < StoreBufferSize; c++) {
|
|
pending_stores_[c].store(disabled_write);
|
|
}
|
|
}
|
|
|
|
void GLU::set_data(uint8_t data) {
|
|
if(local_.control & 0x40) {
|
|
// RAM access.
|
|
local_.ram_[address_] = data;
|
|
|
|
MemoryWrite write;
|
|
write.enabled = true;
|
|
write.address = address_;
|
|
write.value = data;
|
|
write.time = pending_store_write_time_;
|
|
pending_stores_[pending_store_write_].store(write, std::memory_order::memory_order_release);
|
|
|
|
pending_store_write_ = (pending_store_write_ + 1) % (StoreBufferSize - 1);
|
|
} else {
|
|
// Register access.
|
|
const auto address = address_; // To make sure I don't inadvertently 'capture' address_.
|
|
local_.set_register(address, data);
|
|
audio_queue_.defer([this, address, data] () {
|
|
remote_.set_register(address, data);
|
|
});
|
|
}
|
|
|
|
if(local_.control & 0x20) {
|
|
++address_;
|
|
}
|
|
}
|
|
|
|
void GLU::EnsoniqState::set_register(uint16_t address, uint8_t value) {
|
|
switch(address & 0xe0) {
|
|
case 0x00:
|
|
oscillators[address & 0x1f].velocity = uint16_t((oscillators[address & 0x1f].velocity & 0xff00) | (value << 0));
|
|
break;
|
|
case 0x20:
|
|
oscillators[address & 0x1f].velocity = uint16_t((oscillators[address & 0x1f].velocity & 0x00ff) | (value << 8));
|
|
break;
|
|
case 0x40:
|
|
oscillators[address & 0x1f].volume = value;
|
|
break;
|
|
case 0x60:
|
|
/* Does setting the last sample make any sense? */
|
|
break;
|
|
case 0x80:
|
|
oscillators[address & 0x1f].address = value;
|
|
break;
|
|
case 0xa0: {
|
|
oscillators[address & 0x1f].control = value;
|
|
|
|
// Halt + M0 => reset position.
|
|
if((oscillators[address & 0x1f].control & 0x3) == 3) {
|
|
oscillators[address & 0x1f].control |= 1;
|
|
}
|
|
} break;
|
|
case 0xc0:
|
|
oscillators[address & 0x1f].table_size = value;
|
|
|
|
// The most-significant bit that should be used is 16 + (value & 7).
|
|
oscillators[address & 0x1f].overflow_mask = ~(0xffffff >> (7 - (value & 7)));
|
|
break;
|
|
|
|
default:
|
|
switch(address & 0xff) {
|
|
case 0xe0:
|
|
/* Does setting the interrupt register really make any sense? */
|
|
break;
|
|
case 0xe1:
|
|
oscillator_count = 1 + ((value >> 1) & 31);
|
|
break;
|
|
case 0xe2:
|
|
/* Writing to the analogue to digital input definitely makes no sense. */
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
uint8_t GLU::get_data() {
|
|
const auto address = address_;
|
|
if(local_.control & 0x20) {
|
|
++address_;
|
|
}
|
|
|
|
switch(address & 0xe0) {
|
|
case 0x00: return local_.oscillators[address & 0x1f].velocity & 0xff;
|
|
case 0x20: return local_.oscillators[address & 0x1f].velocity >> 8;;
|
|
case 0x40: return local_.oscillators[address & 0x1f].volume;
|
|
case 0x60: return local_.oscillators[address & 0x1f].sample(local_.ram_); // i.e. look up what the sample was on demand.
|
|
case 0x80: return local_.oscillators[address & 0x1f].address;
|
|
case 0xa0: return local_.oscillators[address & 0x1f].control;
|
|
case 0xc0: return local_.oscillators[address & 0x1f].table_size;
|
|
|
|
default:
|
|
switch(address & 0xff) {
|
|
case 0xe0: {
|
|
// Find the first enabled oscillator that is signalling an interrupt and has interrupts enabled.
|
|
for(int c = 0; c < local_.oscillator_count; c++) {
|
|
if(local_.oscillators[c].interrupt_request && (local_.oscillators[c].control & 0x08)) {
|
|
local_.oscillators[c].interrupt_request = false;
|
|
return uint8_t(0x41 | (c << 1));
|
|
}
|
|
}
|
|
|
|
// No interrupt found.
|
|
return 0xc1;
|
|
} break;
|
|
case 0xe1: return uint8_t((local_.oscillator_count - 1) << 1); // TODO: should other bits be 0 or 1?
|
|
case 0xe2: return 128; // Input audio. Unimplemented!
|
|
}
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool GLU::get_interrupt_line() {
|
|
// Return @c true if any oscillator currently has its interrupt request
|
|
// set, and has interrupts enabled.
|
|
for(int c = 0; c < local_.oscillator_count; c++) {
|
|
if(local_.oscillators[c].interrupt_request && (local_.oscillators[c].control & 0x08)) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// MARK: - Time entry points.
|
|
|
|
void GLU::run_for(Cycles cycles) {
|
|
// Update local state, without generating audio.
|
|
skip_audio(local_, cycles.as<size_t>());
|
|
|
|
// Update the timestamp for memory writes;
|
|
pending_store_write_time_ += cycles.as<uint32_t>();
|
|
}
|
|
|
|
void GLU::get_samples(std::size_t number_of_samples, std::int16_t *target) {
|
|
// Update remote state, generating audio.
|
|
generate_audio(number_of_samples, target);
|
|
}
|
|
|
|
void GLU::skip_samples(const std::size_t number_of_samples) {
|
|
// Update remote state, without generating audio.
|
|
skip_audio(remote_, number_of_samples);
|
|
|
|
// Apply any pending stores.
|
|
std::atomic_thread_fence(std::memory_order::memory_order_acquire);
|
|
const uint32_t final_time = pending_store_read_time_ + uint32_t(number_of_samples);
|
|
while(true) {
|
|
auto next_store = pending_stores_[pending_store_read_].load(std::memory_order::memory_order_acquire);
|
|
if(!next_store.enabled) break;
|
|
if(next_store.time >= final_time) break;
|
|
remote_.ram_[next_store.address] = next_store.value;
|
|
next_store.enabled = false;
|
|
pending_stores_[pending_store_read_].store(next_store, std::memory_order::memory_order_relaxed);
|
|
|
|
pending_store_read_ = (pending_store_read_ + 1) & (StoreBufferSize - 1);
|
|
}
|
|
}
|
|
|
|
void GLU::set_sample_volume_range(std::int16_t range) {
|
|
output_range_ = range;
|
|
}
|
|
|
|
// MARK: - Interface boilerplate.
|
|
|
|
void GLU::set_control(uint8_t control) {
|
|
local_.control = control;
|
|
audio_queue_.defer([this, control] () {
|
|
remote_.control = control;
|
|
});
|
|
}
|
|
|
|
uint8_t GLU::get_control() {
|
|
return local_.control;
|
|
}
|
|
|
|
void GLU::set_address_low(uint8_t low) {
|
|
address_ = uint16_t((address_ & 0xff00) | low);
|
|
}
|
|
|
|
uint8_t GLU::get_address_low() {
|
|
return address_ & 0xff;
|
|
}
|
|
|
|
void GLU::set_address_high(uint8_t high) {
|
|
address_ = uint16_t((high << 8) | (address_ & 0x00ff));
|
|
}
|
|
|
|
uint8_t GLU::get_address_high() {
|
|
return address_ >> 8;
|
|
}
|
|
|
|
// MARK: - Update logic.
|
|
|
|
Cycles GLU::get_next_sequence_point() const {
|
|
uint32_t result = std::numeric_limits<decltype(result)>::max();
|
|
|
|
for(int c = 0; c < local_.oscillator_count; c++) {
|
|
// Don't do anything for halted oscillators, or for oscillators that can't hit stops.
|
|
if((local_.oscillators[c].control&3) != 2) {
|
|
continue;
|
|
}
|
|
|
|
// Determine how many cycles until a stop is hit and update the pending result
|
|
// if this is the new soonest-to-expire oscillator.
|
|
const auto first_overflow_value = (local_.oscillators[c].overflow_mask - 1) << 1;
|
|
const auto time_until_stop = (first_overflow_value - local_.oscillators[c].position + local_.oscillators[c].velocity - 1) / local_.oscillators[c].velocity;
|
|
result = std::min(result, time_until_stop);
|
|
}
|
|
return Cycles(result);
|
|
}
|
|
|
|
void GLU::skip_audio(EnsoniqState &state, size_t number_of_samples) {
|
|
// Just advance all oscillator pointers and check for interrupts.
|
|
// If a read occurs to the current-output level, generate it then.
|
|
for(int c = 0; c < state.oscillator_count; c++) {
|
|
// Don't do anything for halted oscillators.
|
|
if(state.oscillators[c].control&1) continue;
|
|
|
|
// Update phase.
|
|
state.oscillators[c].position += state.oscillators[c].velocity * number_of_samples;
|
|
|
|
// Check for stops, and any interrupts that therefore flow.
|
|
if((state.oscillators[c].control & 2) && (state.oscillators[c].position & state.oscillators[c].overflow_mask)) {
|
|
// Apply halt, set interrupt request flag.
|
|
state.oscillators[c].position = 0;
|
|
state.oscillators[c].control |= 1;
|
|
state.oscillators[c].interrupt_request = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
void GLU::generate_audio(size_t number_of_samples, std::int16_t *target) {
|
|
auto next_store = pending_stores_[pending_store_read_].load(std::memory_order::memory_order_acquire);
|
|
uint8_t next_amplitude = 255;
|
|
for(size_t sample = 0; sample < number_of_samples; sample++) {
|
|
|
|
// TODO: there's a bit of a hack here where it is assumed that the input clock has been
|
|
// divided in advance. Real hardware divides by 8, I think?
|
|
|
|
// Seed output as 0.
|
|
int output = 0;
|
|
|
|
// Apply phase updates to all enabled oscillators.
|
|
for(int c = 0; c < remote_.oscillator_count; c++) {
|
|
// Don't do anything for halted oscillators.
|
|
if(remote_.oscillators[c].control&1) continue;
|
|
|
|
remote_.oscillators[c].position += remote_.oscillators[c].velocity;
|
|
|
|
// Test for a new halting event.
|
|
switch(remote_.oscillators[c].control & 6) {
|
|
case 0: // Free-run mode; don't truncate the position at all, in case the
|
|
// accumulator bits in use changes.
|
|
output += remote_.oscillators[c].output(remote_.ram_);
|
|
break;
|
|
|
|
case 2: // One-shot mode; check for end of run. Otherwise update sample.
|
|
if(remote_.oscillators[c].position & remote_.oscillators[c].overflow_mask) {
|
|
remote_.oscillators[c].position = 0;
|
|
remote_.oscillators[c].control |= 1;
|
|
}
|
|
break;
|
|
|
|
case 4: // Sync/AM mode.
|
|
if(c&1) {
|
|
// Oscillator is odd-numbered; it will amplitude-modulate the next voice.
|
|
next_amplitude = remote_.oscillators[c].sample(remote_.ram_);
|
|
continue;
|
|
} else {
|
|
// Oscillator is even-numbered; it will 'sync' to the even voice, i.e. any
|
|
// time it wraps around, it will reset the next oscillator.
|
|
if(remote_.oscillators[c].position & remote_.oscillators[c].overflow_mask) {
|
|
remote_.oscillators[c].position &= remote_.oscillators[c].overflow_mask;
|
|
remote_.oscillators[c+1].position = 0;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case 6: // Swap mode; possibly trigger partner, and update sample.
|
|
// Per tech note #11: "Whenever a swap occurs from a higher-numbered
|
|
// oscillator to a lower-numbered one, the output signal from the corresponding
|
|
// generator temporarily falls to the zero-crossing level (silence)"
|
|
if(remote_.oscillators[c].position & remote_.oscillators[c].overflow_mask) {
|
|
remote_.oscillators[c].control |= 1;
|
|
remote_.oscillators[c].position = 0;
|
|
remote_.oscillators[c^1].control &= ~1;
|
|
}
|
|
break;
|
|
}
|
|
|
|
// Don't add output for newly-halted oscillators.
|
|
if(remote_.oscillators[c].control&1) continue;
|
|
|
|
// Append new output.
|
|
output += (remote_.oscillators[c].output(remote_.ram_) * next_amplitude) / 255;
|
|
next_amplitude = 255;
|
|
}
|
|
|
|
// Maximum total output was 32 channels times a 16-bit range. Map that down.
|
|
// TODO: dynamic total volume?
|
|
target[sample] = (output * output_range_) >> 20;
|
|
|
|
// Apply any RAM writes that interleave here.
|
|
++pending_store_read_time_;
|
|
if(!next_store.enabled) continue;
|
|
if(next_store.time != pending_store_read_time_) continue;
|
|
remote_.ram_[next_store.address] = next_store.value;
|
|
next_store.enabled = false;
|
|
pending_stores_[pending_store_read_].store(next_store, std::memory_order::memory_order_relaxed);
|
|
pending_store_read_ = (pending_store_read_ + 1) & (StoreBufferSize - 1);
|
|
}
|
|
}
|
|
|
|
uint8_t GLU::EnsoniqState::Oscillator::sample(uint8_t *ram) {
|
|
// Determines how many you'd have to shift a 16-bit pointer to the right for,
|
|
// in order to hit only the position-supplied bits.
|
|
const int pointer_shift = 8 - ((table_size >> 3) & 7);
|
|
|
|
// Table size mask should be 0x8000 for the largest table size, and 0xff00 for
|
|
// the smallest.
|
|
const uint16_t table_size_mask = 0xffff >> pointer_shift;
|
|
|
|
// The pointer should use (at most) 15 bits; starting with bit 1 for resolution 0
|
|
// and starting at bit 8 for resolution 7.
|
|
const uint16_t table_pointer = uint16_t(position >> ((table_size&7) + pointer_shift));
|
|
|
|
// The full pointer is composed of the bits of the programmed address not touched by
|
|
// the table pointer, plus the table pointer.
|
|
const uint16_t sample_address = ((address << 8) & ~table_size_mask) | (table_pointer & table_size_mask);
|
|
|
|
// Ignored here: bit 6 should select between RAM banks. But for now this is IIgs-centric,
|
|
// and that has only one bank of RAM.
|
|
return ram[sample_address];
|
|
}
|
|
|
|
int16_t GLU::EnsoniqState::Oscillator::output(uint8_t *ram) {
|
|
const auto level = sample(ram);
|
|
|
|
// "An oscillator will halt when a zero is encountered in its waveform table."
|
|
// TODO: only if in free-run mode, I think? Or?
|
|
if(!level) {
|
|
control |= 1;
|
|
return 0;
|
|
}
|
|
|
|
// Samples are unsigned 8-bit; do the proper work to make volume work correctly.
|
|
return int8_t(level ^ 128) * volume;
|
|
}
|