WaveShaperNode.curve

The curve property of the WaveShaperNode interface is a Float32Array of numbers describing the distortion to apply.

The mid-element of the array is applied to any signal value of 0, the first one to signal values of -1, and the last to signal values of 1; values lower than -1 or greater than 1 are treated like -1 or 1 respectively.

If necessary, intermediate values of the distortion curve are linearly interpolated.

Syntax

var audioCtx = new AudioContext();
var distortion = audioCtx.createWaveShaper();
distortion.curve = myCurveDataArray; // myCurveDataArray is a Float32Array

Value

A Float32Array.

Example

The following example shows basic usage of an AudioContext to create a wave shaper node. For applied examples/information, check out our Voice-change-O-matic demo (see app.js for relevant code).

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var distortion = audioCtx.createWaveShaper();

  ...

function makeDistortionCurve(amount) {
  var k = typeof amount === 'number' ? amount : 50,
    n_samples = 44100,
    curve = new Float32Array(n_samples),
    deg = Math.PI / 180,
    i = 0,
    x;
  for ( ; i < n_samples; ++i ) {
    x = i * 2 / n_samples - 1;
    curve[i] = ( 3 + k ) * x * 20 * deg / ( Math.PI + k * Math.abs(x) );
  }
  return curve;
};

  ...

distortion.curve = makeDistortionCurve(400);
distortion.oversample = '4x';

Specifications

Specification	Status	Comment
Web Audio API The definition of 'curve' in that specification.	Working Draft

Browser compatibility

See also

• Using the Web Audio API