(function() { var onDOMContentLoaded = function() { window.AudioContext = window.AudioContext || window.webkitAudioContext; try { // Create the instance of AudioContext var context = new AudioContext(); } catch (error) { window.alert(error.message + ' : Please use Chrome or Safari.'); return; } // Create the instance of OscillatorNode var oscillator = context.createOscillator(); // Parameter for the instance of OscillatorNode var type = oscillator.type; // for legacy browsers context.createGain = context.createGain || context.createGainNode; // Create the instance of GainNode (for Master Volume) var gain = context.createGain(); // Compressor // Create the instance of DynamicsCompressorNode var compressor = context.createDynamicsCompressor(); // Initialize parameters for Compressor compressor.threshold.value = document.getElementById('range-compressor-threshold').valueAsNumber; compressor.knee.value = document.getElementById('range-compressor-knee').valueAsNumber; compressor.ratio.value = document.getElementById('range-compressor-ratio').valueAsNumber; compressor.attack.value = document.getElementById('range-compressor-attack').valueAsNumber; compressor.release.value = document.getElementById('range-compressor-release').valueAsNumber; // Flag for starting or stopping sound var isStop = true; // Display "reduction" property in DynamicsCompressorNode var canvas = document.querySelector('canvas'); var canvasContext = canvas.getContext('2d'); var timerid = null; var draw = function(x, y) { if (isStop) { window.clearTimeout(timerid); timerid = null; return; } var TOTAL_TIME = 10000; // 10 sec var INTERVAL = 10; // 10 msec var MIN_DECIBEL = -100; // dB var MAX_DECIBEL = 0; // dB var RANGE = MAX_DECIBEL - MIN_DECIBEL; // dB var width = canvas.width; var height = canvas.height; var paddingTop = 20; var paddingBottom = 20; var paddingLeft = 30; var paddingRight = 30; var innerWidth = width - paddingLeft - paddingRight; var innerHeight = height - paddingTop - paddingBottom; var innerBottom = height - paddingBottom; var isDrawGrid = true; // Draw reduction (dB) canvasContext.beginPath(); if ((x === 0) || (x > (innerWidth + paddingLeft))) { // Clear previous data canvasContext.clearRect(0, 0, canvas.width, canvas.height); // Move start point if (x === 0) { canvasContext.moveTo(paddingLeft, paddingTop); } else { canvasContext.moveTo(paddingLeft, y); } // Update x x = paddingLeft; } else { // Move start point canvasContext.moveTo(x, y); // Update x x += INTERVAL * (innerWidth / TOTAL_TIME); isDrawGrid = false; } var y = paddingTop; // Compressor ON ? if (document.getElementById('toggle-effect').checked) { if (compressor.reduction.value === undefined) { y = Math.floor(-1 * ((compressor.reduction) / RANGE) * innerHeight) + paddingTop; } else { y = Math.floor(-1 * ((compressor.reduction.value) / RANGE) * innerHeight) + paddingTop; } } canvasContext.lineTo(x, y); canvasContext.strokeStyle = 'rgba(0, 0, 255, 1.0)'; canvasContext.lineWidth = 3; canvasContext.lineCap = 'round'; canvasContext.lineJoin = 'miter'; canvasContext.stroke(); if (isDrawGrid) { // Draw grid and text (X) every 1000 msec (1 sec) for (var i = 0; i <= TOTAL_TIME; i += INTERVAL) { if ((i % 1000) !== 0) { continue; } var gx = Math.floor(i * (innerWidth / TOTAL_TIME)) + paddingLeft; var text = i + ' msec'; // Draw grid (X) canvasContext.fillStyle = 'rgba(255, 0, 0, 1.0)'; canvasContext.fillRect(gx, paddingTop, 1, innerHeight); // Draw text (X) canvasContext.fillStyle = 'rgba(255, 255, 255, 1.0)'; canvasContext.font = '12px "Times New Roman"'; canvasContext.textAlign = 'center'; canvasContext.fillText(text, gx, (height - 3)); } // Draw grid and text (Y) for (var i = MIN_DECIBEL; i <= MAX_DECIBEL; i += 10) { var gy = Math.floor(-1 * ((i - MAX_DECIBEL) / RANGE) * innerHeight) + paddingTop; // Draw grid (Y) canvasContext.fillStyle = 'rgba(255, 0, 0, 1.0)'; canvasContext.fillRect(paddingLeft, gy, innerWidth, 1); // Draw text (Y) canvasContext.fillStyle = 'rgba(255, 255, 255, 1.0)'; canvasContext.font = '12px "Times New Roman"'; canvasContext.textAlign = 'left'; canvasContext.fillText((i + ' dB'), 3, gy); } } timerid = window.setTimeout(function() { draw(x, y); }, INTERVAL); }; /* * Event Listener */ // Start or Stop sound var PIANO_88S = [ 'A-4', 'A-4h', 'B-4', 'C-3', 'C-3h', 'D-3', 'D-3h', 'E-3', 'F-3', 'F-3h', 'G-3', 'G-3h', 'A-3', 'A-3h', 'B-3', 'C-2', 'C-2h', 'D-2', 'D-2h', 'E-2', 'F-2', 'F-2h', 'G-2', 'G-2h', 'A-2', 'A-2h', 'B-2', 'C-1', 'C-1h', 'D-1', 'D-1h', 'E-1', 'F-1', 'F-1h', 'G-1', 'G-1h', 'A-1', 'A-1h', 'B-1', 'C', 'Ch', 'D', 'Dh', 'E', 'F', 'Fh', 'G', 'Gh', 'A', 'Ah', 'B', 'C1', 'C1h', 'D1', 'D1h', 'E1', 'F1', 'F1h', 'G1', 'G1h', 'A1', 'A1h', 'B1', 'C2', 'C2h', 'D2', 'D2h', 'E2', 'F2', 'F2h', 'G2', 'G2h', 'A2', 'A2h', 'B2', 'C3', 'C3h', 'D3', 'D3h', 'E3', 'F3', 'F3h', 'G3', 'G3h', 'A3', 'A3h', 'B3', 'C4' ]; var pianoKeys = Array.prototype.slice.call(document.querySelectorAll('#piano ul li'), 0); var convertIndex = function(index) { // // The 12 equal temparement // // Min -> A 27.5Hz, Max -> C 4186 Hz // // Example : // A * 1.059463 -> A# (half up) // var FREQUENCY_RATIO = Math.pow(2, (1 / 12)); // about 1.059463; var MIN_A = 27.5; return (MIN_A * Math.pow(FREQUENCY_RATIO, index)); }; pianoKeys.forEach(function(element, index, array) { // Start sound element.addEventListener(EventWrapper.START, function(event) { if (!isStop) { oscillator.stop(0); } var pianoIndex = PIANO_88S.indexOf(this.id); var frequency = convertIndex(pianoIndex); // Create the instance of OscillatorNode oscillator = context.createOscillator(); // for legacy browsers oscillator.start = oscillator.start || oscillator.noteOn; oscillator.stop = oscillator.stop || oscillator.noteOff; // GainNode (Master Volume) -> AudioDestinationNode (Output) gain.connect(context.destination); // Clear connection oscillator.disconnect(0); compressor.disconnect(0); if (document.getElementById('toggle-effect').checked) { // Compressor ON // Connect nodes for effect (Compressor) sound // OscillatorNode (Input) -> DynamicsCompressorNode (Compressor) -> GainNode (Master Volume) (-> AudioDestinationNode (Output)) oscillator.connect(compressor); compressor.connect(gain); } else { // Compressor OFF // OscillatorNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output)) oscillator.connect(gain); } // Set parameters oscillator.type = type; oscillator.frequency.value = frequency; // Start sound oscillator.start(0); isStop = false; // Stop previous drawing if (timerid !== null) { window.clearTimeout(timerid); timerid = null; } // Start drawing "reduction" draw(0, 0); this.classList.remove('key-off'); this.classList.add('key-on'); }, false); // Stop sound element.addEventListener(EventWrapper.END, function() { if (isStop) { return; } // Stop sound oscillator.stop(0); isStop = true; this.classList.remove('key-on'); this.classList.add('key-off'); }, false); }); // Control Master Volume document.getElementById('range-volume').addEventListener('input', function() { var min = gain.gain.minValue || 0; var max = gain.gain.maxValue || 1; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { gain.gain.value = this.valueAsNumber; document.getElementById('output-volume').textContent = this.value; } }, false); // Select type document.getElementById('form-wave-type').addEventListener('change', function() { for (var i = 0, len = this.elements['radio-wave-type'].length; i < len; i++) { if (this.elements['radio-wave-type'][i].checked) { oscillator.type = type = (typeof oscillator.type === 'string') ? this.elements['radio-wave-type'][i].value : i; break; } } }, false); // Toggle Effect document.getElementById('toggle-effect').addEventListener(EventWrapper.CLICK, function() { // Clear connection oscillator.disconnect(0); compressor.disconnect(0); if (this.checked) { // Compressor ON // Connect nodes for effect (Compressor) sound // OscillatorNode (Input) -> DynamicsCompressorNode (Compressor) -> GainNode (Master Volume) (-> AudioDestinationNode (Output)) oscillator.connect(compressor); compressor.connect(gain); } else { // Compressor OFF // OscillatorNode (Input) -> GainNode (Master Volume) (-> AudioDestinationNode (Output)) oscillator.connect(gain); } }, false); // Control threshold document.getElementById('range-compressor-threshold').addEventListener('input', function() { var min = compressor.threshold.minValue || -100; var max = compressor.threshold.maxValue || 0; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { compressor.threshold.value = this.valueAsNumber; document.getElementById('output-compressor-threshold').textContent = this.value; } }, false); // Control knee document.getElementById('range-compressor-knee').addEventListener('input', function() { var min = compressor.knee.minValue || 0; var max = compressor.knee.maxValue || 40; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { compressor.knee.value = this.valueAsNumber; document.getElementById('output-compressor-knee').textContent = this.value; } }, false); // Control ratio document.getElementById('range-compressor-ratio').addEventListener('input', function() { var min = compressor.ratio.minValue || 1; var max = compressor.ratio.maxValue || 20; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { compressor.ratio.value = this.valueAsNumber; document.getElementById('output-compressor-ratio').textContent = this.value; } }, false); // Control attack document.getElementById('range-compressor-attack').addEventListener('input', function() { var min = compressor.attack.minValue || 0; var max = compressor.attack.maxValue || 1; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { compressor.attack.value = this.valueAsNumber; document.getElementById('output-compressor-attack').textContent = this.value; } }, false); // Control release document.getElementById('range-compressor-release').addEventListener('input', function() { var min = compressor.release.minValue || 0.01; var max = compressor.release.maxValue || 1; if ((this.valueAsNumber >= min) && (this.valueAsNumber <= max)) { compressor.release.value = this.valueAsNumber; document.getElementById('output-compressor-release').textContent = this.value; } }, false); }; if ((document.readyState === 'interactive') || (document.readyState === 'complete')) { onDOMContentLoaded(); } else { document.addEventListener('DOMContentLoaded', onDOMContentLoaded, true); } })();
function EventWrapper(){ } (function(){ var click = ''; var start = ''; var move = ''; var end = ''; // Touch Panel ? if (/iPhone|iPad|iPod|Android/.test(navigator.userAgent)) { click = 'click'; start = 'touchstart'; move = 'touchmove'; end = 'touchend'; } else { click = 'click'; start = 'mousedown'; move = 'mousemove'; end = 'mouseup'; } EventWrapper.CLICK = click; EventWrapper.START = start; EventWrapper.MOVE = move; EventWrapper.END = end; })();