/
jsfx.js
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jsfx.js
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var jsfx = {};
(function () {
this.Parameters = []; // will be constructed in the end
this.Generators = {
square : audio.generators.square,
saw : audio.generators.saw,
sine : audio.generators.sine,
noise : audio.generators.noise,
synth : audio.generators.synth
};
this.getGeneratorNames = function(){
var names = [];
for(e in this.Generators)
names.push(e);
return names;
}
var nameToParam = function(name){
return name.replace(/ /g, "");
}
this.getParameters = function () {
var params = [];
var grp = 0;
// add param
var ap = function (name, min, max, def, step) {
if (step === undefined)
step = (max - min) / 1000;
var param = { name: name, id: nameToParam(name),
min: min, max: max, step:step, def: def,
type: "range", group: grp};
params.push(param);
};
// add option
var ao = function(name, options, def){
var param = {name: name, id: nameToParam(name),
options: options, def: def,
type: "option", group: grp };
params.push(param);
}
var gens = this.getGeneratorNames();
ao("Generator", gens, gens[0]);
ap("Super Sampling Quality", 0, 16, 0, 1);
ap("Master Volume", 0, 1, 0.4);
grp++;
ap("Attack Time", 0, 1, 0.1); // seconds
ap("Sustain Time", 0, 2, 0.3); // seconds
ap("Sustain Punch", 0, 3, 2);
ap("Decay Time", 0, 2, 1); // seconds
grp++;
ap("Min Frequency", 20, 2400, 0, 1);
ap("Start Frequency", 20, 2400, 440, 1);
ap("Max Frequency", 20, 2400, 2000, 1);
ap("Slide", -1, 1, 0);
ap("Delta Slide", -1, 1, 0);
grp++;
ap("Vibrato Depth", 0, 1, 0);
ap("Vibrato Frequency", 0.01, 48, 8);
ap("Vibrato Depth Slide", -0.3, 1, 0);
ap("Vibrato Frequency Slide", -1, 1, 0);
grp++;
ap("Change Amount", -1, 1, 0);
ap("Change Speed", 0, 1, 0.1);
grp++;
ap("Square Duty", 0, 0.5, 0);
ap("Square Duty Sweep", -1, 1, 0);
grp++;
ap("Repeat Speed", 0, 0.8, 0);
grp++;
ap("Phaser Offset", -1, 1, 0);
ap("Phaser Sweep", -1, 1, 0);
grp++;
ap("LP Filter Cutoff", 0, 1, 1);
ap("LP Filter Cutoff Sweep", -1, 1, 0);
ap("LP Filter Resonance", 0, 1, 0);
ap("HP Filter Cutoff", 0, 1, 0);
ap("HP Filter Cutoff Sweep", -1, 1, 0);
return params;
};
/**
* Input params object has the same parameters as described above
* except all the spaces have been removed
*
* This returns an array of float values of the generated audio.
*
* To make it into a wave use:
* data = jsfx.generate(params)
* audio.make(data)
*/
this.generate = function(params){
// useful consts/functions
var TAU = 2 * Math.PI,
sin = Math.sin,
cos = Math.cos,
pow = Math.pow,
abs = Math.abs;
var SampleRate = audio.SampleRate;
// super sampling
var super_sampling_quality = params.SuperSamplingQuality | 0;
if(super_sampling_quality < 1) super_sampling_quality = 1;
SampleRate = SampleRate * super_sampling_quality;
// enveloping initialization
var _ss = 1.0 + params.SustainPunch;
var envelopes = [ {from: 0.0, to: 1.0, time: params.AttackTime},
{from: _ss, to: 1.0, time: params.SustainTime},
{from: 1.0, to: 0.0, time: params.DecayTime}];
var envelopes_len = envelopes.length;
// envelope sample calculation
for(var i = 0; i < envelopes_len; i++){
envelopes[i].samples = 1 + ((envelopes[i].time * SampleRate) | 0);
}
// envelope loop variables
var envelope = undefined;
var envelope_cur = 0.0;
var envelope_idx = -1;
var envelope_increment = 0.0;
var envelope_last = -1;
// count total samples
var totalSamples = 0;
for(var i = 0; i < envelopes_len; i++){
totalSamples += envelopes[i].samples;
}
// fix totalSample limit
if( totalSamples < SampleRate / 2){
totalSamples = SampleRate / 2;
}
var outSamples = (totalSamples / super_sampling_quality)|0;
// out data samples
var out = new Array(outSamples);
var sample = 0;
var sample_accumulator = 0;
// main generator
var generator = jsfx.Generators[params.Generator];
if (generator === undefined)
generator = this.Generators.square;
var generator_A = 0;
var generator_B = 0;
// square generator
generator_A = params.SquareDuty;
square_slide = params.SquareDutySweep / SampleRate;
// phase calculation
var phase = 0;
var phase_speed = params.StartFrequency * TAU / SampleRate;
// phase slide calculation
var phase_slide = 1.0 + pow(params.Slide, 3.0) * 64.0 / SampleRate;
var phase_delta_slide = pow(params.DeltaSlide, 3.0) / (SampleRate * 1000);
if (super_sampling_quality !== undefined)
phase_delta_slide /= super_sampling_quality; // correction
// frequency limiter
if(params.MinFrequency > params.StartFrequency)
params.MinFrequency = params.StartFrequency;
if(params.MaxFrequency < params.StartFrequency)
params.MaxFrequency = params.StartFrequency;
var phase_min_speed = params.MinFrequency * TAU / SampleRate;
var phase_max_speed = params.MaxFrequency * TAU / SampleRate;
// frequency vibrato
var vibrato_phase = 0;
var vibrato_phase_speed = params.VibratoFrequency * TAU / SampleRate;
var vibrato_amplitude = params.VibratoDepth;
// frequency vibrato slide
var vibrato_phase_slide = 1.0 + pow(params.VibratoFrequencySlide, 3.0) * 3.0 / SampleRate;
var vibrato_amplitude_slide = params.VibratoDepthSlide / SampleRate;
// arpeggiator
var arpeggiator_time = 0;
var arpeggiator_limit = params.ChangeSpeed * SampleRate;
var arpeggiator_mod = pow(params.ChangeAmount, 2);
if (params.ChangeAmount > 0)
arpeggiator_mod = 1 + arpeggiator_mod * 10;
else
arpeggiator_mod = 1 - arpeggiator_mod * 0.9;
// phaser
var phaser_max = 1024;
var phaser_mask = 1023;
var phaser_buffer = new Array(phaser_max);
for(var _i = 0; _i < phaser_max; _i++)
phaser_buffer[_i] = 0;
var phaser_pos = 0;
var phaser_offset = pow(params.PhaserOffset, 2.0) * (phaser_max - 4);
var phaser_offset_slide = pow(params.PhaserSweep, 3.0) * 4000 / SampleRate;
var phaser_enabled = (abs(phaser_offset_slide) > 0.00001) ||
(abs(phaser_offset) > 0.00001);
// lowpass filter
var filters_enabled = (params.HPFilterCutoff > 0.001) || (params.LPFilterCutoff < 0.999);
var lowpass_pos = 0;
var lowpass_pos_slide = 0;
var lowpass_cutoff = pow(params.LPFilterCutoff, 3.0) / 10;
var lowpass_cutoff_slide = 1.0 + params.HPFilterCutoffSweep / 10000;
var lowpass_damping = 5.0 / (1.0 + pow(params.LPFilterResonance, 2) * 20 ) *
(0.01 + params.LPFilterCutoff);
if ( lowpass_damping > 0.8)
lowpass_damping = 0.8;
lowpass_damping = 1.0 - lowpass_damping;
var lowpass_enabled = params.LPFilterCutoff < 0.999;
// highpass filter
var highpass_accumulator = 0;
var highpass_cutoff = pow(params.HPFilterCutoff, 2.0) / 10;
var highpass_cutoff_slide = 1.0 + params.HPFilterCutoffSweep / 10000;
// repeat
var repeat_time = 0;
var repeat_limit = totalSamples;
if (params.RepeatSpeed > 0){
repeat_limit = pow(1 - params.RepeatSpeed, 2.0) * SampleRate + 32;
}
// master volume controller
var master_volume = params.MasterVolume;
var k = 0;
for(var i = 0; i < totalSamples; i++){
// main generator
sample = generator(phase, generator_A, generator_B);
// square generator
generator_A += square_slide;
if(generator_A < 0.0){
generator_A = 0.0;
} else if (generator_A > 0.5){
generator_A = 0.5;
}
if( repeat_time > repeat_limit ){
// phase reset
phase = 0;
phase_speed = params.StartFrequency * TAU / SampleRate;
// phase slide reset
phase_slide = 1.0 + pow(params.Slide, 3.0) * 3.0 / SampleRate;
phase_delta_slide = pow(params.DeltaSlide, 3.0) / (SampleRate * 1000);
if (super_sampling_quality !== undefined)
phase_delta_slide /= super_sampling_quality; // correction
// arpeggiator reset
arpeggiator_time = 0;
arpeggiator_limit = params.ChangeSpeed * SampleRate;
arpeggiator_mod = 1 + (params.ChangeAmount | 0) / 12.0;
// repeat reset
repeat_time = 0;
}
repeat_time += 1;
// phase calculation
phase += phase_speed;
// phase slide calculation
phase_slide += phase_delta_slide;
phase_speed *= phase_slide;
// arpeggiator
if ( arpeggiator_time > arpeggiator_limit ){
phase_speed *= arpeggiator_mod;
arpeggiator_limit = totalSamples;
}
arpeggiator_time += 1;
// frequency limiter
if (phase_speed > phase_max_speed){
phase_speed = phase_max_speed;
} else if(phase_speed < phase_min_speed){
phase_speed = phase_min_speed;
}
// frequency vibrato
vibrato_phase += vibrato_phase_speed;
var _vibrato_phase_mod = phase_speed * sin(vibrato_phase) * vibrato_amplitude;
phase += _vibrato_phase_mod;
// frequency vibrato slide
vibrato_phase_speed *= vibrato_phase_slide;
if(vibrato_amplitude_slide){
vibrato_amplitude += vibrato_amplitude_slide;
if(vibrato_amplitude < 0){
vibrato_amplitude = 0;
vibrato_amplitude_slide = 0;
} else if (vibrato_amplitude > 1){
vibrato_amplitude = 1;
vibrato_amplitude_slide = 0;
}
}
// filters
if( filters_enabled ){
if( abs(highpass_cutoff) > 0.001){
highpass_cutoff *= highpass_cutoff_slide;
if(highpass_cutoff < 0.00001){
highpass_cutoff = 0.00001;
} else if(highpass_cutoff > 0.1){
highpass_cutoff = 0.1;
}
}
var _lowpass_pos_old = lowpass_pos;
lowpass_cutoff *= lowpass_cutoff_slide;
if(lowpass_cutoff < 0.0){
lowpass_cutoff = 0.0;
} else if ( lowpass_cutoff > 0.1 ){
lowpass_cutoff = 0.1;
}
if(lowpass_enabled){
lowpass_pos_slide += (sample - lowpass_pos) * lowpass_cutoff;
lowpass_pos_slide *= lowpass_damping;
} else {
lowpass_pos = sample;
lowpass_pos_slide = 0;
}
lowpass_pos += lowpass_pos_slide;
highpass_accumulator += lowpass_pos - _lowpass_pos_old;
highpass_accumulator *= 1.0 - highpass_cutoff;
sample = highpass_accumulator;
}
// phaser
if (phaser_enabled) {
phaser_offset += phaser_offset_slide;
if( phaser_offset < 0){
phaser_offset = -phaser_offset;
phaser_offset_slide = -phaser_offset_slide;
}
if( phaser_offset > phaser_mask){
phaser_offset = phaser_mask;
phaser_offset_slide = 0;
}
phaser_buffer[phaser_pos] = sample;
// phaser sample modification
var _p = (phaser_pos - (phaser_offset|0) + phaser_max) & phaser_mask;
sample += phaser_buffer[_p];
phaser_pos = (phaser_pos + 1) & phaser_mask;
}
// envelope processing
if( i > envelope_last ){
envelope_idx += 1;
if(envelope_idx < envelopes_len) // fault protection
envelope = envelopes[envelope_idx];
else // the trailing envelope is silence
envelope = {from: 0, to: 0, samples: totalSamples};
envelope_cur = envelope.from;
envelope_increment = (envelope.to - envelope.from) / (envelope.samples + 1);
envelope_last += envelope.samples;
}
sample *= envelope_cur;
envelope_cur += envelope_increment;
// master volume controller
sample *= master_volume;
// prepare for next sample
if(super_sampling_quality > 1){
sample_accumulator += sample;
if( (i + 1) % super_sampling_quality === 0){
out[k] = sample_accumulator / super_sampling_quality;
k += 1;
sample_accumulator = 0;
}
} else {
out[i] = sample;
}
}
// return out;
// add padding 10ms
var len = (SampleRate / 100)|0;
padding = new Array(len);
for(var i = 0; i < len; i++)
padding[i] = 0;
return padding.concat(out).concat(padding);
}
this.Parameters = this.getParameters();
}).apply(jsfx);