Add distortion unit test

lib/p5.sound.js

@@ -9152,6 +9152,7 @@ distortion = function () {
      *  @type {Object}  AudioNode
      */
     this.waveShaperNode = this.ac.createWaveShaper();
+    this.amount = amount;
     this.waveShaperNode.curve = makeDistortionCurve(amount);
     this.waveShaperNode.oversample = oversample;
     this.input.connect(this.waveShaperNode);
@@ -9173,12 +9174,19 @@ distortion = function () {
    */
   p5.Distortion.prototype.set = function (amount, oversample) {
     if (amount) {
+      this.amount = amount;
       this.waveShaperNode.curve = makeDistortionCurve(amount);
     }
     if (oversample) {
       this.waveShaperNode.oversample = oversample;
     }
   };
+  p5.Distortion.prototype.getAmount = function () {
+    return this.amount;
+  };
+  p5.Distortion.prototype.getOversample = function () {
+    return this.waveShaperNode.oversample;
+  };
   /**
    *  Send output to a p5.sound or web audio object
    *
@@ -9200,8 +9208,7 @@ distortion = function () {
   p5.Distortion.prototype.dispose = function () {
     var index = p5sound.soundArray.indexOf(this);
     p5sound.soundArray.splice(index, 1);
-    this.waveShaperNode.curve = null;
-    this.waveShaperNode.oversample = null;
+    this.waveShaperNode = null;
     if (typeof this.output !== 'undefined') {
       this.output.disconnect();
       this.output = null;

src/distortion.js

@@ -3,7 +3,6 @@ define(function (require) {
 
   var p5sound = require('master');
 
-
   /*
    * Adapted from [Kevin Ennis on StackOverflow](http://stackoverflow.com/questions/22312841/waveshaper-node-in-webaudio-how-to-emulate-distortion)
    */
@@ -58,6 +57,7 @@ define(function (require) {
      */
      this.waveShaperNode = this.ac.createWaveShaper();
 
+     this.amount = amount;
      this.waveShaperNode.curve = makeDistortionCurve(amount);
      this.waveShaperNode.oversample = oversample;
 
@@ -84,13 +84,22 @@ define(function (require) {
    */
   p5.Distortion.prototype.set = function(amount, oversample) {
     if (amount) {
+      this.amount = amount;
       this.waveShaperNode.curve = makeDistortionCurve(amount);
     }
     if (oversample) {
       this.waveShaperNode.oversample = oversample;
     }
   }
 
+  p5.Distortion.prototype.getAmount = function() {
+    return this.amount;
+  }
+
+  p5.Distortion.prototype.getOversample = function() {
+    return this.waveShaperNode.oversample;
+  }
+
   /**
    *  Send output to a p5.sound or web audio object
    *
@@ -115,8 +124,7 @@ define(function (require) {
     var index = p5sound.soundArray.indexOf(this);
     p5sound.soundArray.splice(index, 1);
 
-    this.waveShaperNode.curve = null;
-    this.waveShaperNode.oversample = null;
+    this.waveShaperNode = null;
 
     if (typeof this.output !== 'undefined') {
       this.output.disconnect();

test/test.js

@@ -6,7 +6,7 @@ require.config({
 	}
 });
 
-var allTests = ['tests/p5.SoundFile', 'tests/p5.Amplitude', 'tests/p5.Oscillator', 'test/p5.Distortion'];
+var allTests = ['tests/p5.SoundFile', 'tests/p5.Amplitude', 'tests/p5.Oscillator', 'tests/p5.Distortion'];
 
 p5.prototype.masterVolume(0);
 

test/tests/p5.Distortion.js

@@ -0,0 +1,24 @@
+define(['chai'],
+  function(chai) {
+
+    var expect = chai.expect;
+
+    describe('p5.Distortion', function() {
+      this.timeout(1000);
+
+      var dist = new p5.Distortion();
+
+      it('can be created and disposed', function() {
+        var d = new p5.Distortion();
+        d.dispose();
+      });
+
+      it('can set the amount and oversample', function() {
+        var initialAmt = dist.getAmount();
+        var initialOS = dist.getOversample();
+        dist.set(1000, '4x');
+        expect(dist.getAmount()).not.equal(initialAmt);
+        expect(dist.getOversample()).not.equal(initialOS);
+      });
+    });
+});