audiolib.js: simple automation and effects

osclfodel.js

/* First, we need a Sink */
var dev = Sink();

/* So, here we'll create an oscillator and an LFO to control the oscillator FM. */
var osc = audioLib.Oscillator(dev.sampleRate, 440);
var lfo = audioLib.Oscillator(dev.sampleRate, 0.1);

/*
 Then we'll put a delay effect after the oscillator.
 Note that we have to use createBufferBased() to make a multi-channel effect.
 Arguments are sampleRate, delayTime, feedback.
*/
var del = audioLib.Delay.createBufferBased(dev.channelCount, dev.sampleRate, 1777, 0.4);

/*
 Set up the automation.
 First we tell what we want to automate, then what to automate it with, then how much and finally, what operation we'd like to use to automate.
*/
osc.addAutomation('fm', lfo, 1.0, 'assignment');

/* Now let's make it a little less loud */
osc.mix = 0.2;

/* Setup a callback to fill the audio buffers */
dev.on('audioprocess', function (buffer, channelCount) {
    /* First off, we need to prepare the data for automation. This needs to be a buffer of the length of a single channel. */
    lfo.generateBuffer(buffer.length / channelCount);

    /* Now, let's run the effects on the buffer */
    osc.append(buffer, channelCount);
    del.append(buffer, channelCount);
});