Noise Drum Envelope
White Noise is a random audio signal with equal energy at every part of the frequency spectrum
*An Envelope is a series of fades, defined as time / value pairs.
*In this example, the p5.Env will be used to "play" the p5.Noise like a drum by controlling its output amplitude. A p5.Amplitude will get the level of all sound in the sketch, and we'll use this value to draw a green rectangle that shows the envelope in action.
To run this example locally, you will need the p5.sound library and a sound file.
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let noise, env, analyzer;
function setup() {
createCanvas(710, 200);
noise = new p5.Noise(); // other types include 'brown' and 'pink'
noise.start();
// multiply noise volume by 0
// (keep it quiet until we're ready to make noise!)
noise.amp(0);
env = new p5.Env();
// set attackTime, decayTime, sustainRatio, releaseTime
env.setADSR(0.001, 0.1, 0.2, 0.1);
// set attackLevel, releaseLevel
env.setRange(1, 0);
// p5.Amplitude will analyze all sound in the sketch
// unless the setInput() method is used to specify an input.
analyzer = new p5.Amplitude();
}
function draw() {
background(0);
// get volume reading from the p5.Amplitude analyzer
let level = analyzer.getLevel();
// use level to draw a green rectangle
let levelHeight = map(level, 0, 0.4, 0, height);
fill(100, 250, 100);
rect(0, height, width, -levelHeight);
}
function mousePressed() {
env.play(noise);
}
