//Added the drum from "techno beat 1" by struss https://dittytoy.net/ditty/b3585fb3a3
// Another fork by paulofalcao
// https://dittytoy.net/ditty/568826700e
// Forked from "DT303" by srtuss
// https://dittytoy.net/ditty/0029103012
// TB303-like synth.
// 2022/12/4, srtuss
// patterns are encoded as 4 values per step: note,rest,slide,accent (rests are not implemented)
var pattern = [
c3,1,0,0,g5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,g5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,g5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,g5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,g5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,g5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,a5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,f5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,f5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,f5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,f5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,f5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,f5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,f5,1,0,0,c3,1,1,1,c5,1,0,0,
c3,1,0,0,c5,1,1,0,c3,1,0,0,c3,1,1,1,c3,1,0,0,g5,1,0,0,c3,1,1,1,c5,1,0,0,
];
const pblep = (t, dt) => {
if(t < dt) {
t /= dt;
return t + t - t * t - 1;
}
else if (t > 1 - dt) {
t = (t - 1) / dt;
return t * t + t + t + 1;
}
return 0;
}
input.gate=.58; // min=.1,max=1,step=.02
input.tune=-18; // min=-24,max=24,step=.01
input.waveform=0.43;
input.cutoff=0.40;
input.resonance=0.69;
input.envmod=0.01;
input.decay=0.05;
input.overdrive=0.45;
input.echo = .8; // value=.8
ditty.bpm = 138;
class SVFilter {
constructor() {
this.lastLp = 0;
this.lastHp = 0;
this.lastBp = 0;
this.kf = 0.1;
this.kq = .1;
}
process(input) {
var lp = this.lastLp + this.kf * this.lastBp;
var hp = input - lp - this.kq * this.lastBp;
var bp = this.lastBp + this.kf * hp;
this.lastLp = lp;
this.lastHp = hp;
this.lastBp = bp;
return lp;
}
}
class SVFilter2 {
constructor() {
this.f = [new SVFilter(), new SVFilter()];
this.lastLp = 0;
this.kf = 0.1;
this.kq = .3;
}
process(input) {
this.f[0].kf = this.kf;
this.f[0].kq = this.kq;
this.f[1].kf = this.kf;
this.f[1].kq = this.kq;
this.f[0].process(input);
this.f[1].process(this.f[0].lastLp);
this.lastLp = this.f[1].lastLp;
return this.lastLp;
}
}
class Convol {
constructor() {
this.kernel = [0.013475, 0.097598, 0.235621, 0.306612, 0.235621, 0.097598, 0.013475];
this.taps = new Float32Array(this.kernel.length);
}
process(v) {
var n = this.kernel.length;
var t = this.taps;
for(var i = n-1; i > 0; --i)
t[i] = t[i-1];
t[0] = v;
var o = 0;
for(var i = 0; i < n; ++i)
o += this.kernel[i] * t[i];
return o;
}
}
class TbVoice {
constructor(opt) {
this.ph = 0;
this.dtph = .001;
this.flt = new SVFilter2();
this.tclk = 0;
this.dtclk = ditty.bpm / 60 * 4 * ditty.dt;
this.clkidx = 0;
this.sqidx = 0;
this.globalidx = 0;
this.lastgate = 0;
this.venv = 0;
this.fenv = 0;
this.slide = 0;
this.note = 0;
this.notecap = 0;
this.att = 0;
this.accent = 0;
this.aenv = 0;
this.cut = 0;
this.us = new Convol();
this.ds = new Convol();
}
seqstep() {
var patdata = pattern;
var pl = patdata.length/4;
this.sqidx %= pl;
this.slide = patdata[this.sqidx*4+2];
this.xslide = patdata[((this.sqidx+pl-1)%pl)*4+2];
this.note = patdata[this.sqidx*4] + input.tune;
this.accent = patdata[this.sqidx*4+3];
this.cut = Math.sin(this.globalidx*0.05)*0.2 + Math.cos(this.sqidx*3.1415*0.125)*0.1 + input.cutoff;
this.sqidx++;
this.globalidx++;
this.sqidx %= pl;
}
process(note, env, tick, opt) {
while(this.tclk >= 1) {
this.tclk -= 1;
this.seqstep();
}
var gate = this.tclk < input.gate || this.slide;
this.tclk += this.dtclk;
if(gate) {
if(!this.lastgate) {
this.fenv = 1;
this.att = 0;
this.aenv = this.accent;
}
this.venv = 1;
this.att = Math.min(this.att+ditty.dt/.0005, 1);
}
this.lastgate = gate;
if(this.xslide) {
this.notecap += (this.note - this.notecap) * .0005;
}
else {
this.notecap = this.note;
}
this.dtph = midi_to_hz(this.notecap) * ditty.dt;
this.venv *= .995;
this.fenv *= Math.exp(-(1-input.decay) * .004);
var blep0 = pblep(this.ph, this.dtph);
var saw = this.ph * 2 - 1 - blep0;
var pw = Math.max(.5, input.waveform)*.95;
var square = (this.ph > pw ? 1 : -1) + pblep((this.ph-pw+1)%1, this.dtph) - blep0;
var v = lerp(saw, square, clamp01(input.waveform * 2));
this.flt.kq = 1 - input.resonance * .9 - this.aenv * .1;
this.flt.kf = 2 ** Math.min(0, this.cut * 7 - 7 + this.fenv * input.envmod * 5 + this.aenv * .4);
this.flt.process(v);
v = this.flt.process(v);
this.ph += this.dtph;
while(this.ph >= 1) {
this.ph -= 1;
}
v = v * this.venv * this.att * (this.aenv + 1);
this.aenv *= .9995;
v *= .5;
if(input.overdrive > 0) {
var e = [0, 0, 0, 0];
e[0] = this.us.process(v*4);
e[1] = this.us.process(0);
e[2] = this.us.process(0);
e[3] = this.us.process(0);
for(var i = 0; i < 4; ++i) {
e[i] = clamp(e[i] * (1+input.overdrive*8), -1, 1);
}
this.ds.process(e[0]);
this.ds.process(e[1]);
this.ds.process(e[2]);
v = this.ds.process(e[3]);
}
return v;
}
}
class Delayline {
constructor(n) {
this.n = ~~n;
this.p = 0;
this.lastOutput = 0;
this.data = new Float32Array(n);
}
clock(input) {
this.lastOutput = this.data[this.p];
this.data[this.p] = input;
if(++this.p >= this.n) {
this.p = 0;
}
}
tap(offset) {
var x = this.p - offset - 1;
x %= this.n;
if(x < 0) {
x += this.n;
}
return this.data[x];
}
}
const stereoEcho = filter.def(class {
constructor(options) {
this.lastOutput = [0, 0];
var time = 60 / ditty.bpm;
//time *= 3 / 4;
time /= 2;
var n = Math.floor(time / ditty.dt);
this.delay = [new Delayline(n), new Delayline(n)];
this.dside = new Delayline(500);
this.kfbl = .4;
this.kfbr = .7;
}
process(inv, options) {
this.dside.clock(inv[0]);
var new0 = (this.dside.lastOutput + this.delay[1].lastOutput) * this.kfbl;
var new1 = (inv[1] + this.delay[0].lastOutput) * this.kfbr;
this.lastOutput[0] = inv[0] + this.delay[0].lastOutput * input.echo;
this.lastOutput[1] = inv[1] + this.delay[1].lastOutput * input.echo;
this.delay[0].clock(new0);
this.delay[1].clock(new1);
return this.lastOutput;
}
});
const tbvoice = synth.def(TbVoice);
loop( () => {
tbvoice.play(c0, {duration:600, release:.1, amp: .25});
sleep(600);
}, { name: 'acid' }).connect(stereoEcho.create());
// Drum from "techno beat 1" by struss https://dittytoy.net/ditty/b3585fb3a3
// WIP
// Basic elements of a beat/bassline as commonly found in (modern) techno.
function processSVF(s, input, a1, a2, a3, k) {
var v1, v2, v3;
v3 = input - s.ic2eq;
v1 = a1 * s.ic1eq + a2 * v3;
v2 = s.ic2eq + a2 * s.ic1eq + a3 * v3;
s.ic1eq = 2 * v1 - s.ic1eq;
s.ic2eq = 2 * v2 - s.ic2eq;
s.lp = v2;
s.bp = v1;
s.hp = input - k * v1 - v2;
s.ap = s.lp + s.hp - k * s.bp;
}
// State Variable Filter based on an article by cytomic Sound Music Software
// https://cytomic.com/files/dsp/SvfLinearTrapOptimised2.pdf
class SVF {
constructor(opt)
{
this.stages = [];
this.mode = opt ? opt.mode || 'lp' : 'lp';
this.fc = 0;
this.q = 1;
this.num = opt ? opt.num || 1 : 1;
// g parameter determines cutoff
// k parameter = 1/Q
for(var i = 0; i < this.num; ++i) {
this.stages.push({lp:0, bp:0, hp:0, ap:0, ic1eq:0, ic2eq:0});
}
this.q = opt && isFinite(opt.q) ? opt.q : 1;
this.fc = opt && isFinite(opt.fc) ? opt.fc : .25;
}
process(input)
{
if(this.fc != this._fc) {
this._fc = this.fc;
this._q = this.q;
var fc = this.fc * .5;
if (fc >= 0 && fc < .5) {
this.g = Math.tan(Math.PI * fc);
this.k = 1 / this.q;
this.a1 = 1 / (1 + this.g * (this.g + this.k));
this.a2 = this.g * this.a1;
this.a3 = this.g * this.a2;
}
}
if(this.q != this._q) {
this._q = this.q;
this.k = 1 / this.q;
this.a1 = 1 / (1 + this.g * (this.g + this.k));
this.a2 = this.g * this.a1;
this.a3 = this.g * this.a2;
}
for(var i = 0; i < this.num; ++i) {
processSVF(this.stages[i], input, this.a1, this.a2, this.a3, this.k);
processSVF(this.stages[i], input, this.a1, this.a2, this.a3, this.k);
input = this.stages[i][this.mode];
}
return input;
}
}
input.compressorThreshold = -15; // min=-30, max=0, step=0.1
input.compressorGain = 4; // min=1, max=4, step=0.1
input.compressorEn = 1; // min=0, max=1, step=1 (off, on)
const dB2gain = v => 10 ** (v / 20);
const gain2dB = v => Math.log10(v) * 20;
const compressor = filter.def(class Compressor {
constructor(opt) {
this.gain = 1;
this.threshold = -40; // PARAM min:-30 max:-1
this.ratio = .9; // PARAM
this.peak = 0.01;
this.active = 1; // PARAM
}
process(inv, opt) {
this.threshold = input.compressorThreshold;
this.gain = input.compressorGain;
this.active = input.compressorEn;
var inputLevel = Math.max(Math.abs(inv[0]), Math.abs(inv[1]));
if(inputLevel > this.peak)
this.peak = inputLevel;
else
this.peak *= .9999;
inputLevel = gain2dB(this.peak);
var compression = Math.max(0, inputLevel - this.threshold);
var dgain = compression ? dB2gain(-compression * this.ratio) : 1;
dgain *= this.gain;
if(this.active > .5)
return [inv[0] * dgain, inv[1] * dgain];
else
return inv;
}
}).createShared();
//input.ws0 = 0.5;
input.kickWs1 = 0.58;
input.kickWsAsym = 0.52;
//const wf1 = x => x > input.ws0 ? (x > input.ws1 ? input.ws0+input.ws1 - x : input.ws0) : x;
const wf1 = (x, a) => x > a ? a-(x-a) : x;
const wf0 = (x, a) => x > 0 ? wf1(x,a) : -wf1(-x,a)
const bd = synth.def(class {
constructor(opt) {
this.t = 0;
this.p = 0;
this.svf = new SVF({num:2});
this.svfw = new SVF({num:1, fc:.03, q: 2, mode:'bp'});
}
process(note, env, tick, opt) {
var v = Math.sin(this.p * Math.PI * 2);
this.p += lerp(200, midi_to_hz(note), clamp01(this.t * 20)) * ditty.dt;
this.t += ditty.dt;
var nse = (Math.random() - .5) * 2;
this.svf.fc = lerp(350, 200, clamp01(this.t * 10)) * ditty.dt;
v += this.svf.process(nse);
v += this.svfw.process(Math.random()) * Math.exp(this.t * -20) * .2;
v += (Math.random()) * Math.exp(this.t * -80) * .1;
return wf0((v+input.kickWsAsym-.5) * env.value, input.kickWs1);
return v*env.value;
}
}, {duration: .02, release: .6, attack: .0001});
const triangle = x => 1-Math.abs(1-x%2);
const signed = (x, l) => x > 0 ? l(x) : -l(-x);
const nonlin = x => Math.min(x - (clamp(x, .4, .6)-.4)*2, .6);
ditty.bpm = 138;
const distructor = filter.def(class {
constructor(opt) {
this.stages = [];
for(var i = 0; i < 1; ++i) {
this.stages.push({flt: new SVF({num: 2, mode: 'bp', fc: .008, q:2}), flt2:new SVF({num: 2, mode: 'bp', fc: .02, q:2})});
}
}
process(inn, opt) {
var stage = this.stages[0];
var v = signed((inn[0]*input.ws0+input.ws1)*10, x=>nonlin(x)**.5);
v = v+stage.flt.process(v)*.4+stage.flt2.process(v)*.8;
v = signed((v*input.ws0+input.ws1), x=>nonlin(x)**.5);
return [v, v];
}
});
const post = filter.def(class {
constructor(opt) {
this.flt = [new SVF({mode:'hp', num:2}), new SVF({mode:'hp', num:2})];
}
process(inn, opt) {
var x = ditty.tick%64;
this.flt[0].fc = this.flt[1].fc = .0005;
inn[0] = this.flt[0].process(inn[0]);
inn[1] = this.flt[1].process(inn[1]);
return inn;
}
});
loop( () => {
var r = .6;// [.3, .6].choose();
for(var i = 0; i < 16; ++i) {
bd.play(g1, {release:r, amp: .4});
sleep(1.0);
}
}, { name: 'bd' }).connect(post.create()).connect(compressor);
