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drum-machine.html
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drum-machine.html
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<!--
Copyright 2010, Google Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>
</title>
<!-- Slider stuff -->
<script type="text/javascript" src="lib/events.js"></script>
<style type="text/css">
#slider { margin: 10px; }
</style>
<link rel="stylesheet" type="text/css" href = "style/simple.css" />
<!-- Our javascript code -->
<script type="text/javascript">
// Events
// init() once the page has finished loading.
window.onload = init;
var canvas;
var canvasContext;
var canvasWidth = 0;
var canvasHeight = 0;
var context;
var convolver;
var compressor;
var masterGainNode;
var sampleRate = 44100.0;
var nyquist = sampleRate * 0.5;
var startTime;
var lastDrawTime = -1;
var isLoaded = false;
var kits;
var kNumInstruments = 6;
var currentKit = 0;
var kickCutoff = 22050.0;
var snareCutoff = 22050.0;
var hihatCutoff = 22050.0;
var reverbMix = 0.25;
var kitCount = 0;
var kitElement = 0; // for list hilighting
var kitNames = [
"R8",
"CR78",
"KPR77",
"LINN",
"Kit3",
"Kit8",
"Techno",
"Stark",
"breakbeat8",
"breakbeat9",
"breakbeat13",
"acoustic-kit",
"4OP-FM"
];
var gridColor = "rgb(192,192,192)";
var playheadColor = "rgb(80, 100, 80)";
var noteColor = "rgb(200,60,20)";
function Kit(name) {
this.name = name;
this.pathName = function() {
var pathName = "sounds/drum-samples/" + this.name + "/";
return pathName;
};
var pathName = this.pathName();
var kickPath = pathName + "kick.wav";
var snarePath = pathName + "snare.wav";
var hihatPath = pathName + "hihat.wav";
var tom1Path = pathName + "tom1.wav";
var tom2Path = pathName + "tom2.wav";
var tom3Path = pathName + "tom3.wav";
this.kickBuffer = 0;
this.snareBuffer = 0;
this.hihatBuffer = 0;
this.instrumentCount = kNumInstruments;
this.instrumentLoadCount = 0;
this.loadSample(0, kickPath, false);
this.loadSample(1, snarePath, false);
this.loadSample(2, hihatPath, true); // we're panning only the hihat
this.loadSample(3, tom1Path, false);
this.loadSample(4, tom2Path, false);
this.loadSample(5, tom3Path, false);
}
Kit.prototype.loadSample = function(sampleID, url, mixToMono) {
// Load asynchronously
var request = new XMLHttpRequest();
request.open("GET", url, true);
request.responseType = "arraybuffer";
var kit = this;
request.onload = function() {
var buffer = context.createBuffer(request.response, mixToMono);
switch (sampleID) {
case 0: kit.kickBuffer = buffer; break;
case 1: kit.snareBuffer = buffer; break;
case 2: kit.hihatBuffer = buffer; break;
case 3: kit.tom1 = buffer; break;
case 4: kit.tom2 = buffer; break;
case 5: kit.tom3 = buffer; break;
}
kit.instrumentLoadCount++;
if (kit.instrumentLoadCount == kit.instrumentCount) finishLoading();
}
request.send();
}
function tempoHandler(event, ui) {
tempo = ui.value;
var info = document.getElementById("tempo-value");
info.innerHTML = "tempo = " + tempo + " BPM";
}
function cutoffKickHandler(event, ui) {
var value = ui.value;
var noctaves = Math.log(nyquist / 40.0) / Math.LN2;
var v2 = Math.pow(2.0, noctaves * (value - 1.0));
kickCutoff = v2*nyquist;
var info = document.getElementById("kick_cutoff-value");
info.innerHTML = "kick_cutoff = " + kickCutoff + " Hz";
}
function cutoffSnareHandler(event, ui) {
var value = ui.value;
var noctaves = Math.log(nyquist / 40.0) / Math.LN2;
var v2 = Math.pow(2.0, noctaves * (value - 1.0));
snareCutoff = v2*nyquist;
var info = document.getElementById("snare_cutoff-value");
info.innerHTML = "snare_cutoff = " + snareCutoff + " Hz";
}
function cutoffHihatHandler(event, ui) {
var value = ui.value;
var noctaves = Math.log(nyquist / 40.0) / Math.LN2;
var v2 = Math.pow(2.0, noctaves * (value - 1.0));
hihatCutoff = v2*nyquist;
var info = document.getElementById("hihat_cutoff-value");
info.innerHTML = "hihat_cutoff = " + hihatCutoff + " Hz";
}
function reverbHandler(event, ui) {
var value = ui.value;
var info = document.getElementById("reverb-value");
info.innerHTML = "reverb = " + value;
reverbMix = value;
}
function makeKitsList() {
var s = "<h1>Kits</h1> <ul> ";
var numKits = kitNames.length;
for (var i = 0; i < numKits; i++) {
s += getKitString(i);
}
s += "</ul> ";
var kitElement = document.getElementById("kits");
kitElement.innerHTML = s;
}
function getKitString(index) {
var name = kitNames[index];
return "<li onmousedown=\"currentKit = kits[" + index + "]; highlightElement(this); \">"
+ name + "</li> ";
}
function highlightElement(object) {
if (kitElement) kitElement.style.backgroundColor = "white";
kitElement = object;
object.style.backgroundColor = "green";
}
var rhythm1 = [
1,
0,
0,
0,
0,
0,
0,
0,
1,
0,
1,
0,
0,
0,
0,
0
];
var rhythm2 = [
0,
0,
0,
0,
1,
0,
0,
0,
0,
0,
0,
0,
1,
0,
0,
0
];
var rhythm3 = [
0,
0,
1,
0,
0,
0,
1,
0,
0,
0,
1,
0,
0,
0,
1,
1
];
var rhythm4 = [
0,
0,
0,
0,
0,
0,
1,
0,
0,
0,
0,
0,
0,
0,
0,
0
];
var rhythm5 = [
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0
];
var rhythm6 = [
0,
0,
0,
0,
0,
0,
0,
1,
0,
1,
0,
0,
0,
0,
0,
0
];
var loopLength = 16;
var rhythmIndex = 0;
var loopNumber = 0;
var tempo = 115.0;
var noteTime = 0.0;
function advanceNote() {
// Advance time by a 16th note...
var secondsPerBeat = 60.0 / tempo;
noteTime += 0.25 * secondsPerBeat;
rhythmIndex++;
if (rhythmIndex == loopLength) {
rhythmIndex = 0;
loopNumber++
}
}
function playNote(buffer, pan, x, y, z, sendGain, mainGain, cutoff, resonance, noteTime) {
// Create the note
var voice = context.createBufferSource();
voice.buffer = buffer;
// Connect to filter
var hasBiquadFilter = context.createBiquadFilter;
var filter = hasBiquadFilter ? context.createBiquadFilter() : context.createLowPass2Filter();
if (hasBiquadFilter) {
filter.frequency.value = cutoff;
filter.Q.value = resonance; // this is actually resonance in dB
} else {
filter.cutoff.value = cutoff;
filter.resonance.value = resonance;
}
voice.connect(filter);
// Optionally, connect to a panner
var finalNode;
if (pan) {
var panner = context.createPanner();
panner.panningModel = AudioPannerNode.HRTF;
panner.setPosition(x, y, z);
filter.connect(panner);
finalNode = panner;
} else {
finalNode = filter;
}
// Connect to dry mix
var dryGainNode = context.createGainNode();
dryGainNode.gain.value = mainGain;
finalNode.connect(dryGainNode);
dryGainNode.connect(compressor);
// Connect to wet mix
var wetGainNode = context.createGainNode();
wetGainNode.gain.value = sendGain;
finalNode.connect(wetGainNode);
wetGainNode.connect(convolver);
voice.noteOn(noteTime);
}
function schedule() {
var currentTime = context.currentTime;
// The sequence starts at startTime, so normalize currentTime so that it's 0 at the start of the sequence.
currentTime -= startTime;
var resonance = 5.0;
while (noteTime < currentTime + 0.200) {
// Convert noteTime to context time.
var contextPlayTime = noteTime + startTime;
// Kick
if (rhythm1[rhythmIndex] == 1) {
playNote(currentKit.kickBuffer, false, 0,0,-2, 0.5 * reverbMix, 1.0, kickCutoff, resonance, contextPlayTime);
}
// Snare
if (rhythm2[rhythmIndex] == 1) {
playNote(currentKit.snareBuffer, false, 0,0,-2, reverbMix, 0.6, snareCutoff, resonance, contextPlayTime);
}
// Hihat
if (rhythm3[rhythmIndex] == 1) {
// Pan the hihat according to sequence position.
playNote(currentKit.hihatBuffer, true, 0.5*rhythmIndex - 4, 0, -1.0, reverbMix, 0.7, hihatCutoff, resonance, contextPlayTime);
}
// Toms
if (rhythm4[rhythmIndex] == 1) {
playNote(currentKit.tom1, false, 0,0,-2, reverbMix, 0.6, nyquist, resonance, contextPlayTime);
}
if (rhythm5[rhythmIndex] == 1) {
playNote(currentKit.tom2, false, 0,0,-2, reverbMix, 0.6, nyquist, resonance, contextPlayTime);
}
if (rhythm6[rhythmIndex] == 1) {
playNote(currentKit.tom3, false, 0,0,-2, reverbMix, 0.6, nyquist, resonance, contextPlayTime);
}
// Attempt to synchronize drawing time with sound
if (noteTime != lastDrawTime) {
lastDrawTime = noteTime;
drawPlayhead(rhythmIndex);
}
advanceNote();
}
setTimeout("schedule()", 0);
}
function drawDrumGrid() {
// draw center
var width = canvas.width;
var height = canvas.height;
// canvasContext.strokeStyle = "rgb(150, 255, 150)";
canvasContext.strokeStyle = gridColor;
canvasContext.lineWidth = 3;
var noteSize = width / 16.0;
var kInset = 2;
for (inst = 0; inst < kNumInstruments; ++inst) {
for (i = 0; i < 16; ++i) {
canvasContext.strokeRect(i * noteSize + kInset, kInset + inst*noteSize, noteSize - 2*kInset, noteSize - 2*kInset);
}
}
}
function loadImpulseResponse(url) {
// Load impulse response asynchronously
var request = new XMLHttpRequest();
request.open("GET", url, true);
request.responseType = "arraybuffer";
request.onload = function() {
try {
convolver.buffer = context.createBuffer(request.response, false);
} catch(e) {
alert('error decoding file data: ' + url);
}
}
request.send();
}
// Called when all audio assets are finished loading
function finishLoading() {
kitCount++;
if (kitCount < kitNames.length) return;
if (isLoaded) return;
// get rid of loading animation
var loading = document.getElementById("loading");
loading.innerHTML = "";
isLoaded = true;
// Setup initial drumkit
currentKit = kits[4];
makeKitsList();
addSlider("tempo");
addSlider("kick_cutoff");
addSlider("snare_cutoff");
addSlider("hihat_cutoff");
addSlider("reverb");
configureSlider("tempo", tempo, 50.0, 180.0, tempoHandler);
configureSlider("kick_cutoff", 0.99, 0.0, 1.0, cutoffKickHandler);
configureSlider("snare_cutoff", 0.99, 0.0, 1.0, cutoffSnareHandler);
configureSlider("hihat_cutoff", 0.99, 0.0, 1.0, cutoffHihatHandler);
configureSlider("reverb", reverbMix, 0.0, 1.0, reverbHandler);
startTime = context.currentTime + 0.160;
// Start playing
schedule();
}
function init() {
context = new AudioContext();
var audioBuffer = context.createBuffer(1, 1024, 44100.0);
// Create master gain control.
masterGainNode = context.createGainNode();
masterGainNode.gain.value = 0.7;
masterGainNode.connect(context.destination);
// Create compressor to sweeten overall mix
if (context.createDynamicsCompressor) {
compressor = context.createDynamicsCompressor();
compressor.connect(masterGainNode);
} else {
compressor = masterGainNode;
}
// Create convolver for reverb
convolver = context.createConvolver();
convolver.connect(compressor);
loadImpulseResponse('impulse-responses/house-impulses/living-kitchen-leveled.wav');
// loadImpulseResponse('test.html');
// Initialize drum kits
var numKits = kitNames.length;
kits = new Array(numKits);
for (var i = 0; i < numKits; i++) {
kits[i] = new Kit(kitNames[i]);
}
initCanvas();
}
function initCanvas() {
canvas = document.getElementById('canvasID');
canvasContext = canvas.getContext('2d');
canvas.addEventListener("mousedown", handleMouseDown, true);
canvas.addEventListener("mousemove", handleMouseMove, true);
canvas.addEventListener("mouseup", handleMouseUp, true);
canvasWidth = parseFloat(window.getComputedStyle(canvas, null).width);
canvasHeight = parseFloat(window.getComputedStyle(canvas, null).height);
drawDrumGrid();
for (i = 0; i < 16; ++i) {
drawNote(rhythm1[i], i, 0);
drawNote(rhythm2[i], i, 1);
drawNote(rhythm3[i], i, 2);
drawNote(rhythm4[i], i, 3);
drawNote(rhythm5[i], i, 4);
drawNote(rhythm6[i], i, 5);
}
}
var gIsMouseDown = false;
var gLastX = 0;
var gLastY = 0;
function handleMouseDown(event) {
gIsMouseDown = true;
var posx = event.clientX;
var posy = event.clientY;
var eventInfo = {event: event, element:canvas};
var c = getRelativeCoordinates(eventInfo);
var x = c.x;
var y = c.y;
var noteSize = canvasWidth / 16.0;
var kInset = 2;
var gridIndex = Math.floor(x / noteSize);
var instrumentIndex = Math.floor(y / noteSize);
var notes = rhythm1;
switch (instrumentIndex) {
case 0: notes = rhythm1; break;
case 1: notes = rhythm2; break;
case 2: notes = rhythm3; break;
case 3: notes = rhythm4; break;
case 4: notes = rhythm5; break;
case 5: notes = rhythm6; break;
}
notes[gridIndex] = 1 - notes[gridIndex];
var gridX = gridIndex * noteSize;
drawNote(notes[gridIndex], gridIndex, instrumentIndex);
}
function drawNote(draw, xindex, yindex) {
var noteSize = canvasWidth / 16.0;
var gridX = xindex * noteSize;
var gridY = yindex * noteSize
var radius = 10;
if (draw == 1) {
canvasContext.fillStyle = noteColor;
radius = 10;
} else {
canvasContext.fillStyle = "rgb(255,255,255)";
radius = 12;
}
canvasContext.beginPath();
canvasContext.arc(gridX + 0.5*noteSize, gridY + 0.5*noteSize, radius, 0, Math.PI*2, true);
canvasContext.fill();
}
function drawPlayhead(xindex) {
var noteSize = canvasWidth / 16.0;
var yindex = 0;
var kInset = 2;
var lastIndex = (xindex - 1 + 16) % 16;
for (i = 0; i < kNumInstruments; ++i) {
// erase old playhead
canvasContext.strokeStyle = gridColor;
canvasContext.lineWidth = 3;
canvasContext.strokeRect(lastIndex * noteSize + kInset, i * noteSize + kInset, noteSize - 2*kInset, noteSize - 2*kInset);
// draw new playhead
canvasContext.strokeStyle = playheadColor;
canvasContext.lineWidth = 2;
canvasContext.strokeRect(xindex * noteSize + kInset, i * noteSize + kInset, noteSize - 2*kInset, noteSize - 2*kInset);
}
}
function handleMouseUp(event) {
gIsMouseDown = false;
}
function handleMouseMove(event) {
if (gIsMouseDown) {
}
}
</script>
</head>
<body>
<div id="info">
</div>
<canvas id="canvasID" width="600" height="226" style="border: 2px inset blue;">
</canvas>
<br><br>
<!-- Sliders and other controls will be added here -->
<div id="controls"> </div>
<div id="info"> </div>
<div id="kits">
</div>
<!-- Initial loading animation -->
<div id="loading">
<img src="images/loading.gif" width="200" height="200">
</div>
</body>
</html>