crossfade v1.0.0

crossfade

Simple cross fader between two AudioNodes for WebAudio.

Usage

• Example usage

npm install crossfader

var crossfader = require('crossfader');
var c = crossfader(context, node1, node2);
c.connect(context.destination);

document.getElementById('slider').addEventListener('input', function(){
	c.fade.value = parseFloat(this.value);
});

API

Constructor

eg : var c = crossfader(context, node1, node2);

• context: AudioContext - The AudioContext within which the AudioNodes have been created.
• node1 : AudioNode - Any AudioNode within the AudioContext. Will be assigned to the negative value of the fade property.
• node2 : AudioNode - Any AudioNode within the AudioContext. Will be assigned to the negative value of the fade property.

Methods

• connect : Connect the crossfade Node to other AudioNodes. eg :

  	```
  	c.connect(context.destination);
  	```
  	- arguments :
  		- `destination` : _AudioNode_ - The AudioNode to connect the output of the crossfader to.

• disconnect : Disconnect the crossfade Node from other AudioNodes. eg :

  	```
  	c.disconnect();
  	```
  	- supports the same arguments as [disconnect method on AudioNodes](http://webaudio.github.io/web-audio-api/#widl-AudioNode-disconnect-void)

Properties

• fade: AudioParam - A value in the range -1,1 that defines how much to cross fade between node1 and node2.

  	eg:
  	```
  	c.fade.value = 0.5; //Cross fade position with equal volume from both AudioNodes
  	c.fade.linearRampToValueAtTime(1, context.currentTime + 5); // Automation
  	```
  
  	`fade` property is an [AudioParam](http://webaudio.github.io/web-audio-api/#idl-def-AudioParam) and supports all [AudioParam automation methods](http://webaudio.github.io/web-audio-api/#widl-AudioParam-exponentialRampToValueAtTime-void-float-value-double-endTime).
  
  	- A `fade` value of -1 implies 100% volume on node1, and 0% volume on node2, while a `fade` value of 1 implies 0% volume on node1, and 100% volume on node2.
  
  	- The mapping between the value of fade and the volume follows the [equal power curve](http://www.soundonsound.com/sos/feb07/articles/ptworkshop_0207.htm).

Credits

Thanks to tambien for the his idea of using a generator + shaper to create a-rate, first class, custom AudioParams (like fade in this case).

License

MIT

See License file