'use strict'; // constructor function WaveFormer(audioContext, freqStart, freqEnd, volStart, volEnd, semitones, anchorOutputTo, octaveCrosser) { this.STATUS_DESTROYED = "This WaveFormer is destroyed!"; this.destroyed = false; this.semitones = semitones; // how many steps (more steps -> slower) this.freqStart = freqStart; this.freqEnd = freqEnd; this.anchor = anchorOutputTo; this.volume = volStart; this.mv = 1; this.oscillator = audioContext.createOscillator(freqStart); this.oscillator.type = waveType; this.oscillator.frequency.value = freqStart; this.gainNode = audioContext.createGain(); this.gainNode.gain.value=0; this.oscillator.connect(this.gainNode); this.gainNode.connect(anchorOutputTo); this.octaveCrosser = octaveCrosser; if(this.octaveCrosser) this.frequencyMidpoint = (this.freqStart + this.freqEnd) / 2; /* Reberb would be nice...feedback is not: this.delay=audioContext.createDelay(); this.delay.delayTime.value=0.5; this.feedback=audioContext.createGain(); this.feedback.gain.value=0.0000000000000000001; this.delay.connect(this.feedback); this.feedback.connect(this.delay); this.oscillator.connect(this.delay); this.delay.connect(anchorOutputTo);*/ this.freqStep = (freqEnd - freqStart) / semitones; this.volStep = (volEnd - volStart) / semitones; this.freqLimitReached = freqStart < freqEnd ? function() { return this.oscillator.frequency.value >= this.freqEnd; } : function() { return this.oscillator.frequency.value <= this.freqEnd; } } WaveFormer.prototype.setMasterVolume = function setMasterVolume(mv) { this.mv = mv; } WaveFormer.prototype.next = function next() { if(this.octaveCrosser && this.oscillator.frequency.value > this.frequencyMidpoint) this.oscillator.frequency.value += this.freqStep *2; else this.oscillator.frequency.value += this.freqStep; this.volume += this.volStep; if (this.volume < 0) this.volume = 0; this.gainNode.gain.value = this.volume * this.mv; return ! this.freqLimitReached(); } WaveFormer.prototype.destroy = function destroy() { if(this.destroyed) return this.STATUS_DESTROYED; this.gainNode.gain.value=0; this.oscillator.stop(); this.gainNode.disconnect(); this.oscillator.disconnect(); this.gainNode = null; this.oscillator = null; this.destroyed = true; } // var speedOfSound = 340.29; // meters per second // notes var c4,c5,c6,c7; /* a notes are better. Filling in a's for c's, below. c4 = 65.4063913251495; c4 = 130.812782650299; //shh c4 = 261.625565300599; c5 = 523.251130601197; c6 = 1046.50226120239; 2093.00452240479;*/ c4=110; c5=220; c6=440; c7=880; var c4pt5 = (c5+c4)/2; var c6pt5 = (c6+c5)/2; function MasterControl(canvas) { this.STATUS_DESTROYED = "MasterControl is destroyed!"; this.canvas = document.querySelector(canvas); this.canvasCtx = this.canvas.getContext("2d"); this.masterVolume = document.querySelector("#volumeControl").value/100; this.actx = new window.AudioContext(); this.waveforms = []; this.analysers = []; this.dataArrays = []; this.addAnalyser(); //oscillator1.noteOn(0) } // TODO: Abstractions MasterControl.prototype.addAnalyser = function addAnalyser() { if(this.destroyed) return this.STATUS_DESTROYED; var analyser = this.actx.createAnalyser(); analyser.fftSize = Math.pow(2, initialFFTPower); var dataArray = new Uint8Array(analyser.fftSize); analyser.connect(this.actx.destination); this.analysers.push(analyser); this.dataArrays.push(dataArray); } MasterControl.prototype.newWaveFormerAt = function newWaveFormerAt(index) { var wf; switch(index) { case 0: wf = new WaveFormer(this.actx, c4, c5, 0, 1, semitones, this.analysers[0], false); break; case 1: wf = new WaveFormer(this.actx, c5, c6, 1, 0, semitones, this.analysers[0], false); break; case 2: wf = new WaveFormer(this.actx, c4pt5, c6pt5, 0, 0.5, semitones, this.analysers[0], true); break; default: return null; break; } wf.setMasterVolume(this.masterVolume); while(this.waveforms.length < index) this.waveforms.push(null); if(this.waveforms[index] != null) this.waveforms[index].destroy(); this.waveforms[index] = wf; this.waveforms[index].oscillator.start(); return true; } MasterControl.prototype.draw = function draw(timestamp) { if(this.destroyed) return this.STATUS_DESTROYED; // TODO: hardcoded at 0 var data = this.dataArrays[0]; this.analysers[0].getByteTimeDomainData(data); this.canvasCtx.fillStyle = 'rgb(200, 200, 200)'; this.canvasCtx.fillRect(0, 0, this.canvas.width, this.canvas.height); this.canvasCtx.lineWidth = 2; this.canvasCtx.strokeStyle = 'rgb(0, 0, 0)'; this.canvasCtx.beginPath(); var bufferLength = data.length; var sliceWidth = this.canvas.width * 1.0 / bufferLength; var x = 0; this.canvasCtx.moveTo(x, y); for(var i=0; i"); this.newWaveFormerAt(i); } } MasterControl.prototype.destroy = function destroy() { if(this.destroyed) return this.STATUS_DESTROYED; // cancelAnimationFrame(this.draw); for(var i = 0; i nextT) { document.querySelector("#fps").innerHTML = frames; frames = 0; nextT = t + 1000; } else { frames += 1; } mc.next(); vol1el.innerHTML = "Volume 1: "+parseInt(mc.waveforms[0].volume * 100)+"%"; vol2el.innerHTML = "Volume 2: "+parseInt(mc.waveforms[1].volume * 100)+"%"; freq1el.innerHTML = "Frequency 1: "+parseInt(mc.waveforms[0].oscillator.frequency.value) + " Hz"; freq2el.innerHTML = "Frequency 2: "+parseInt(mc.waveforms[1].oscillator.frequency.value) + " Hz"; freq3el.innerHTML = "Frequency 3: "+parseInt(mc.waveforms[2].oscillator.frequency.value) + " Hz"; mc.draw(); // Prevent RAF from passing 'Window' as 'this' ... probably a bind() solution; I didn't look at it requestAnimationFrame(draw); } window.onbeforeunload = function() { // shut down the animation system // works when SoloLearn tabs are switched cancelAnimationFrame(draw); mc.destroy(); }

Dark Knight/Batpod (Shepard Tone Illusion) [Audio] (bug check)