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mirror of https://github.com/sehugg/8bitworkshop.git synced 2024-11-23 06:32:11 +00:00
8bitworkshop/src/audio.ts
2018-11-22 07:41:56 -05:00

405 lines
11 KiB
TypeScript

"use strict";
// from TSS
declare var MasterChannel, AudioLooper, PsgDeviceChannel;
export class MasterAudio {
master = new MasterChannel();
looper = new AudioLooper(512);
start() {
this.looper.setChannel(this.master);
this.looper.activate();
}
stop() {
this.looper.setChannel(null);
}
}
export class AY38910_Audio {
master : MasterAudio;
psg = new PsgDeviceChannel();
curreg = 0;
constructor(master : MasterAudio) {
this.master = master;
this.psg.setMode(PsgDeviceChannel.MODE_SIGNED);
this.psg.setDevice(PsgDeviceChannel.DEVICE_AY_3_8910);
master.master.addChannel(this.psg);
}
reset() {
for (var i=15; i>=0; i--) {
this.selectRegister(i);
this.setData(0);
}
}
selectRegister(val : number) {
this.curreg = val & 0xf;
}
setData(val : number) {
this.psg.writeRegisterAY(this.curreg, val & 0xff);
}
}
export class SN76489_Audio {
master : MasterAudio;
psg = new PsgDeviceChannel();
constructor(master : MasterAudio) {
this.master = master;
this.psg.setMode(PsgDeviceChannel.MODE_SIGNED);
this.psg.setDevice(PsgDeviceChannel.DEVICE_SN76489);
master.master.addChannel(this.psg);
}
reset() {
// TODO
}
setData(val : number) {
this.psg.writeRegisterSN(0, val & 0xff);
}
}
// https://en.wikipedia.org/wiki/POKEY
// https://user.xmission.com/~trevin/atari/pokey_regs.html
// http://krap.pl/mirrorz/atari/homepage.ntlworld.com/kryten_droid/Atari/800XL/atari_hw/pokey.htm
export var POKEYDeviceChannel = function() {
/* definitions for AUDCx (D201, D203, D205, D207) */
var NOTPOLY5 = 0x80 /* selects POLY5 or direct CLOCK */
var POLY4 = 0x40 /* selects POLY4 or POLY17 */
var PURE = 0x20 /* selects POLY4/17 or PURE tone */
var VOL_ONLY = 0x10 /* selects VOLUME OUTPUT ONLY */
var VOLUME_MASK = 0x0f /* volume mask */
/* definitions for AUDCTL (D208) */
var POLY9 = 0x80 /* selects POLY9 or POLY17 */
var CH1_179 = 0x40 /* selects 1.78979 MHz for Ch 1 */
var CH3_179 = 0x20 /* selects 1.78979 MHz for Ch 3 */
var CH1_CH2 = 0x10 /* clocks channel 1 w/channel 2 */
var CH3_CH4 = 0x08 /* clocks channel 3 w/channel 4 */
var CH1_FILTER = 0x04 /* selects channel 1 high pass filter */
var CH2_FILTER = 0x02 /* selects channel 2 high pass filter */
var CLOCK_15 = 0x01 /* selects 15.6999kHz or 63.9210kHz */
/* for accuracy, the 64kHz and 15kHz clocks are exact divisions of
the 1.79MHz clock */
var DIV_64 = 28 /* divisor for 1.79MHz clock to 64 kHz */
var DIV_15 = 114 /* divisor for 1.79MHz clock to 15 kHz */
/* the size (in entries) of the 4 polynomial tables */
var POLY4_SIZE = 0x000f
var POLY5_SIZE = 0x001f
var POLY9_SIZE = 0x01ff
var POLY17_SIZE = 0x0001ffff /* else use the full 17 bits */
/* channel/chip definitions */
var CHAN1 = 0
var CHAN2 = 1
var CHAN3 = 2
var CHAN4 = 3
var CHIP1 = 0
var CHIP2 = 4
var CHIP3 = 8
var CHIP4 = 12
var SAMPLE = 127
var FREQ_17_EXACT = 1789790.0 /* exact 1.79 MHz clock freq */
var FREQ_17_APPROX = 1787520.0 /* approximate 1.79 MHz clock freq */
// LFSR sequences
var bit1 = new Uint8Array( [ 0,1 ] );
var bit4 = new Uint8Array( [ 1,1,0,1,1,1,0,0,0,0,1,0,1,0,0 ] );
var bit5 = new Uint8Array( [ 0,0,1,1,0,0,0,1,1,1,1,0,0,1,0,1,0,1,1,0,1,1,1,0,1,0,0,0,0,0,1 ] );
var bit17 = new Uint8Array(1<<17);
var bit17_5 = new Uint8Array(1<<17);
var bit5_4 = new Uint8Array(1<<17);
for (var i=0; i<bit17.length; i++) {
bit17[i] = Math.random() > 0.5 ? 1 : 0;
bit17_5[i] = bit17[i] & bit5[i % bit5.length];
bit5_4[i] = bit5[i % bit5.length] & bit4[i % bit4.length];
}
var wavetones = [
bit17_5, bit5, bit5_4, bit5,
bit17, bit1, bit4, bit1
];
// registers
var regs = new Uint8Array(16);
var counters = new Float32Array(4);
var deltas = new Float32Array(4);
var volume = new Float32Array(4);
var audc = new Uint8Array(4);
var waveforms = [bit1, bit1, bit1, bit1];
var buffer;
var sampleRate;
var clock, baseDelta;
var dirty = true;
//
this.setBufferLength = function (length) {
buffer = new Int32Array(length);
};
this.getBuffer = function () {
return buffer;
};
this.setSampleRate = function (rate) {
sampleRate = rate;
baseDelta = FREQ_17_EXACT / rate / 1.2; // TODO?
};
function updateValues(addr) {
var ctrl = regs[8];
var base = (ctrl & CLOCK_15) ? DIV_15 : DIV_64;
var div;
var i = addr & 4;
var j = i>>1;
var k = i>>2;
if (ctrl & (CH1_CH2>>k)) {
if (ctrl & (CH1_179>>k))
div = regs[i+2] * 256 + regs[i+0] + 7;
else
div = (regs[i+2] * 256 + regs[i+0] + 1) * base;
deltas[j+1] = baseDelta / div;
deltas[j+0] = 0;
} else {
if (ctrl & (CH1_179>>k)) {
div = regs[i+0] + 4;
} else {
div = (regs[i+0] + 1) * base;
}
deltas[j+0] = baseDelta / div;
div = (regs[i+2] + 1) * base;
deltas[j+1] = baseDelta / div;
}
//console.log(addr, ctrl.toString(16), div, deltas[j+0], deltas[j+1]);
}
this.setRegister = function(addr, value) {
addr &= 0xf;
value &= 0xff;
if (regs[addr] != value) {
regs[addr] = value;
switch (addr) {
case 0:
case 2:
case 4:
case 6: // AUDF
case 8: // ctrl
dirty = true;
break;
case 1:
case 3:
case 5:
case 7: // AUDC
volume[addr>>1] = value & 0xf;
waveforms[addr>>1] = wavetones[value>>5];
break;
}
}
}
this.generate = function (length) {
if (dirty) {
updateValues(0);
updateValues(4);
dirty = false;
}
for (var s=0; s<length; s+=2) {
var sample = 0;
for (var i=0; i<4; i++) {
var d = deltas[i];
var v = volume[i];
if (d > 0 && d < 1 && v > 0) {
var wav = waveforms[i];
var cnt = counters[i] += d;
if (cnt > wav.length) {
cnt = counters[i] = cnt - Math.floor(cnt / wav.length) * wav.length;
}
var on = wav[Math.floor(cnt)];
if (on) {
sample += v;
}
}
}
sample *= 128;
buffer[s] = sample;
buffer[s+1] = sample;
}
}
}
////// Worker sound
export var WorkerSoundChannel = function(worker) {
var sampleRate;
var output;
var pending = [];
var pendingLength = 0;
worker.onmessage = function(e) {
if (e && e.data && e.data.samples && output) {
pending.push(e.data.samples);
pendingLength += e.data.samples.length;
}
};
this.setBufferLength = function (length) {
output = new Int16Array(length);
//worker.postMessage({bufferLength:length,numChannels:2});
pendingLength = 0;
};
this.getBuffer = function () {
return output;
};
this.setSampleRate = function (rate) {
sampleRate = rate;
worker.postMessage({sampleRate:rate});
};
this.generate = function (length) {
if (pendingLength < length*3) {
//console.log(length, pendingLength);
output.fill(0);
return; // TODO: send sync msg?
}
for (var i=0; i<output.length;) {
if (pending.length == 0) break; // TODO?
var buf = pending.shift();
pendingLength -= buf.length;
var l = output.length-i;
if (buf.length < l) {
output.set(buf, i);
} else {
output.set(buf.slice(0, l), i);
pending.unshift(buf.slice(l));
pendingLength += buf.length-l;
}
i += buf.length;
}
}
}
// SampleAudio
export var SampleAudio = function(clockfreq) {
var self = this;
var sfrac, sinc, accum;
var buffer, bufpos, bufferlist;
var idrain, ifill;
var nbuffers = 4;
function mix(ape) {
var buflen=ape.outputBuffer.length;
var lbuf = ape.outputBuffer.getChannelData(0);
var m = this.module;
if (!m) m = ape.srcElement.module;
if (!m) return;
if (m.callback) {
m.callback(lbuf);
return;
} else {
var buf = bufferlist[idrain];
for (var i=0; i<lbuf.length; i++) {
lbuf[i] = buf[i];
//lbuf[i] = (i&128) ? 1.0 : 0.33;
}
idrain = (idrain + 1) % bufferlist.length;
}
}
function createContext() {
var AudioContext = window['AudioContext'] || window['webkitAudioContext'] || window['mozAudioContext'];
if (! AudioContext) {
console.log("no web audio context");
return;
}
self.context = new AudioContext();
self.sr=self.context.sampleRate;
self.bufferlen=2048;
// Amiga 500 fixed filter at 6kHz. WebAudio lowpass is 12dB/oct, whereas
// older Amigas had a 6dB/oct filter at 4900Hz.
self.filterNode=self.context.createBiquadFilter();
self.filterNode.frequency.value=6000;
// mixer
if ( typeof self.context.createScriptProcessor === 'function') {
self.mixerNode=self.context.createScriptProcessor(self.bufferlen, 1, 1);
} else {
self.mixerNode=self.context.createJavaScriptNode(self.bufferlen, 1, 1);
}
self.mixerNode.module=self;
self.mixerNode.onaudioprocess=mix;
// compressor for a bit of volume boost, helps with multich tunes
self.compressorNode=self.context.createDynamicsCompressor();
// patch up some cables :)
self.mixerNode.connect(self.filterNode);
self.filterNode.connect(self.compressorNode);
self.compressorNode.connect(self.context.destination);
}
this.start = function() {
if (!this.context) createContext();
sinc = this.sr * 1.0 / clockfreq;
sfrac = 0;
accum = 0;
bufpos = 0;
bufferlist = [];
idrain = 1;
ifill = 0;
for (var i=0; i<nbuffers; i++) {
var arrbuf = new ArrayBuffer(self.bufferlen*4);
bufferlist[i] = new Float32Array(arrbuf);
}
buffer = bufferlist[0];
}
this.stop = function() {
if (this.context) {
this.context.close();
this.context = null;
}
}
this.addSingleSample = function(value) {
if (!buffer) return;
buffer[bufpos++] = value;
if (bufpos >= buffer.length) {
bufpos = 0;
bufferlist[ifill] = buffer;
var inext = (ifill + 1) % bufferlist.length;
if (inext == idrain) {
ifill = Math.floor(idrain + nbuffers/2) % bufferlist.length;
//console.log('audio skipped', idrain, ifill);
} else {
ifill = inext;
}
buffer = bufferlist[ifill];
}
}
this.feedSample = function(value, count) {
while (count-- > 0) {
accum += value;
sfrac += sinc;
while (sfrac >= 1) {
sfrac -= 1;
value *= sfrac;
this.addSingleSample(accum - value);
accum = value;
}
}
}
}