polywad.js

import {
	logMessage,
	context,
	constructFilter,
	constructReverb,
	constructPanning,
	constructDelay,
	constructCompressor,
	setUpPanningOnPlay,
	setUpDelayOnPlay,
	setUpTunaOnPlay,
	plugEmIn,
	setUpReverbOnPlay,
	createFilters,
} from './common';
import {
	pitches,
	pitchesArray,
} from './pitches';
import _ from 'lodash';


let buflen = 2048;
let buf = new Uint8Array( buflen );
let MINVAL = 134;  // 128 == zero.  MINVAL is the "minimum detected signal" level.

let noteFromPitch = function( frequency ) {
	let noteNum = 12 * (Math.log( frequency / 440 )/Math.log(2) );
	return Math.round( noteNum ) + 69;
};

let frequencyFromNoteNumber = function( note ) {
	return 440 * Math.pow(2,(note-69)/12);
};

let centsOffFromPitch = function( frequency, note ) {
	return Math.floor( 1200 * Math.log( frequency / frequencyFromNoteNumber( note ))/Math.log(2) );
};


let autoCorrelate = function( buf, sampleRate ) {
	let MIN_SAMPLES = 4;    // corresponds to an 11kHz signal
	let MAX_SAMPLES = 1000; // corresponds to a 44Hz signal
	let SIZE = 1000;
	let best_offset = -1;
	let best_correlation = 0;
	let rms = 0;
	let foundGoodCorrelation = false;

	if (buf.length < (SIZE + MAX_SAMPLES - MIN_SAMPLES))
		return -1;  // Not enough data

	for ( let i = 0; i < SIZE; i++ ) {
		let val = ( buf[i] - 128 ) / 128;
		rms += val * val;
	}
	rms = Math.sqrt(rms/SIZE);
	if (rms<0.01) {
		return -1;
	}

	let lastCorrelation=1;
	for (let offset = MIN_SAMPLES; offset <= MAX_SAMPLES; offset++) {
		let correlation = 0;

		for (let i=0; i<SIZE; i++) {
			correlation += Math.abs(((buf[i] - 128)/128)-((buf[i+offset] - 128)/128));
		}
		correlation = 1 - (correlation/SIZE);
		if ((correlation>0.9) && (correlation > lastCorrelation))
			foundGoodCorrelation = true;
		else if (foundGoodCorrelation) {
			// short-circuit - we found a good correlation, then a bad one, so we'd just be seeing copies from here.
			return sampleRate/best_offset;
		}
		lastCorrelation = correlation;
		if (correlation > best_correlation) {
			best_correlation = correlation;
			best_offset = offset;
		}
	}
	if (best_correlation > 0.01) {
		// logMessage("f = " + sampleRate/best_offset + "Hz (rms: " + rms + " confidence: " + best_correlation + ")")
		return sampleRate/best_offset;
	}
	return -1;
	//  var best_frequency = sampleRate/best_offset;
};

let volumeAudioProcess = function( event ) {
	let buf = event.inputBuffer.getChannelData(0);
	let bufLength = buf.length;
	let sum = 0;
	let x;
    
	// Do a root-mean-square on the samples: sum up the squares...
	for (let i=0; i<bufLength; i++) {
		x = buf[i];
		if (Math.abs(x)>=this.clipLevel) {
			this.clipping = true;
			this.lastClip = window.performance.now();
		}
		sum += x * x;
	}
    
	// ... then take the square root of the sum.
	let rms =  Math.sqrt(sum / bufLength);
    
	// Now smooth this out with the averaging factor applied
	// to the previous sample - take the max here because we
	// want "fast attack, slow release."
	this.volume = Math.max(rms, this.volume*this.averaging);
};


function createAudioMeter(audioContext,clipLevel,averaging,clipLag) {
	let processor = audioContext.createScriptProcessor(512);
	processor.onaudioprocess = volumeAudioProcess;
	processor.clipping = false;
	processor.lastClip = 0;
	processor.volume = 0;
	processor.clipLevel = clipLevel || 0.98;
	processor.averaging = averaging || 0.95;
	processor.clipLag = clipLag || 750;
    
	// this will have no effect, since we don't copy the input to the output,
	// but works around a current Chrome bug.
	processor.connect(audioContext.destination);
    
	processor.checkClipping = function(){
		if (!this.clipping){
			return false;
		}
		if ((this.lastClip + this.clipLag) < window.performance.now()){
			this.clipping = false;
		}
		return this.clipping;
	};
    
	processor.shutdown = function(){
		this.disconnect();
		this.onaudioprocess = null;
	};
    
	return processor;
}


let constructRecorder = function(thatWad,arg){
	thatWad.recorder = {};
	thatWad.recorder.mediaStreamDestination = context.createMediaStreamDestination();
	thatWad.output.connect(thatWad.recorder.mediaStreamDestination);
	thatWad.recorder.mediaRecorder = new MediaRecorder(thatWad.recorder.mediaStreamDestination.stream, arg.recorder.options || {
		//audioBitsPerSecond : 128000,
		mimeType : 'audio/webm'
	});
	thatWad.recorder.chunks = [];
	thatWad.recorder.mediaRecorder.ondataavailable = function(evt) {
		// push each chunk (blobs) in an array
		thatWad.recorder.chunks.push(evt.data);
	};

	thatWad.recorder.mediaRecorder.onstop = arg.recorder.onstop || function(evt) {
		// Make blob out of our chunks, and open it.
		let blob = new Blob(this.recorder.chunks, { 'type' : 'audio/webm;codecs=opus' });
		window.open(URL.createObjectURL(blob));
	};
	thatWad.recorder.mediaRecorder.onstop = thatWad.recorder.mediaRecorder.onstop.bind(thatWad);

	// add some aliases to make the API a bit simpler
	for ( let method of ['start', 'stop', 'pause', 'resume' , 'requestData'] ) {
		thatWad.recorder[method] = thatWad.recorder.mediaRecorder[method].bind(thatWad.recorder.mediaRecorder);
	}
};

class Polywad {
	constructor(arg){

		if ( !arg ) { arg = {}; }
		this.isSetUp  = false;
		this.playable = 1;

		if ( arg.reverb ) {
			this.reverb = constructReverb(this, arg); // We need to make sure we have downloaded the impulse response before continuing with the setup.
		}
		else {
			this.setUp(arg);
		}
	}
	setUp(arg){ // Anything that needs to happen before reverb is set up can go here.
		this.wads              = [];
		this.input             = context.createAnalyser();
		this.input.fftSize     = 2048;
		this.nodes             = [this.input];
		this.destination       = arg.destination || context.destination; // the last node the sound is routed to
		this.volume            = arg.volume || 1;
		this.volume            = _.get(arg, 'volume', 1)
		this.gain              = context.createGain();
		this.gain.gain.value   = this.volume;
		this.output            = context.createAnalyser();
		this.tuna              = arg.tuna || null;
		this.audioMeter        = null;
		this.recorder          = null;

		if ( arg.audioMeter ) {
			this.audioMeter = createAudioMeter(context, arg.audioMeter.clipLevel, arg.audioMeter.averaging, arg.audioMeter.clipLag);
			this.output.connect(this.audioMeter);
		}


		constructFilter(this, arg);
		if ( this.filter ) { createFilters(this, arg); }

		if ( this.reverb ) { setUpReverbOnPlay(this, arg); }

		this.constructExternalFx(arg, context);

		this.panning = constructPanning(arg);
		setUpPanningOnPlay(this, arg);
		if ( arg.compressor ) { constructCompressor(this, arg); }
		if ( arg.recorder ) { constructRecorder(this, arg); }

		constructDelay(this, arg);
		setUpDelayOnPlay(this, arg);
		setUpTunaOnPlay(this, arg);
		this.nodes.push(this.gain);
		this.nodes.push(this.output);
		plugEmIn(this, arg);
		this.isSetUp = true;
		if ( arg.callback ) { arg.callback(this); }
	}

	updatePitch() {
		this.input.getByteTimeDomainData( buf );
		let ac = autoCorrelate( buf, context.sampleRate );

		if ( ac !== -1 && ac !== 11025 && ac !== 12000 ) {
			let pitch = ac;
			this.pitch = Math.floor( pitch ) ;
			let note = noteFromPitch( pitch );
			this.noteName = pitchesArray[note - 12];
			// Detune doesn't seem to work.
			// var detune = centsOffFromPitch( pitch, note );
			// if (detune == 0 ) {
			//     this.detuneEstimate = 0;
			// } else {

			//     this.detuneEstimate = detune
			// }
		}
		let that = this;
		that.rafID = window.requestAnimationFrame( function(){ that.updatePitch(); } );
	}

	stopUpdatingPitch(){
		cancelAnimationFrame(this.rafID);
	}

	/**
	 * @param {number} volume 
	 */
	setVolume(volume){
		if ( this.isSetUp ) {
			this.gain.gain.value = volume;
		}
		else {
			logMessage('This PolyWad is not set up yet.');
		}
		return this;
	}

	/**
	 * @param {string|number} pitch 
	 */
	setPitch(pitch){
		this.wads.forEach(function(wad){
				
			if ( pitch in pitches ) {
				if ( wad.soundSource ) {
					wad.soundSource.frequency.value = pitches[pitch];
				}
				wad.pitch = pitches[pitch];
			}
			else {
				if ( wad.soundSource ) {
					wad.soundSource.frequency.value = pitch;
				}
				wad.pitch = pitch;
			}
			return this;
		});
	}
	
 
	/**
	 * @param {number|array} panning 
	 * @param {number} [timeConstant] 
	 */
	setPanning(panning, timeConstant){
		Wad.prototype.setPanning.call(this, panning, timeConstant);
	}

	/**
	 * @param {PlayArgs} [arg]
	 */
	play(arg){
		if ( this.isSetUp ) {
			if ( this.playable < 1 ) {
				this.playOnLoad    = true;
				this.playOnLoadArg = arg;
			}
			else {
				if ( arg && arg.volume ) {
					this.gain.gain.value = arg.volume; // if two notes are played with volume set as a play arg, does the second one overwrite the first? maybe input should be an array of gain nodes, like regular wads.
					arg.volume = undefined; // if volume is set, it should change the gain on the polywad's gain node, NOT the gain nodes for individual wads inside the polywad.
				}
				for ( var i = 0; i < this.wads.length; i++ ) {
					this.wads[i].play(arg);
				}
			}
		}
		else {
			logMessage('This PolyWad is not set up yet.');
		}
		return this;
	}

	stop(arg){
		if ( this.isSetUp ) {
			for ( let i = 0; i < this.wads.length; i++ ) {
				this.wads[i].stop(arg);
			}
		}
	}

	add(wad){
		if ( this.isSetUp ) {
			if ( wad instanceof Polywad ) {
				wad.output.disconnect(wad.destination);
				wad.output.connect(this.input);
			}
			wad.destination = this.input;
			this.wads.push(wad);
		}
		else {
			logMessage('This PolyWad is not set up yet.');
		}
		return this;
	}
	remove(wad){
		if ( this.isSetUp ) {
			for ( let i = 0; i < this.wads.length; i++ ) {
				if ( this.wads[i] === wad ) {
					if ( wad instanceof Polywad ) {
						wad.output.disconnect(wad.destination);
						wad.output.connect(context.destination);
					}
					this.wads[i].destination = context.destination;
					this.wads.splice(i,1);
				}
			}
		}
		return this;
	}

	constructExternalFx(arg, context){ }
}


export default Polywad;