Notch filter support

.gitignore

@@ -3,4 +3,5 @@ logos
 *.sublime-project
 *.sublime-workspace
 *.pem
-npm-debug.log
+npm-debug.log
+.package-lock.json

.npmignore

@@ -2,4 +2,5 @@ node_modules
 logos
 *.sublime-project
 *.sublime-workspace
-site
+site
+.package-lock.json

README.md

@@ -55,6 +55,7 @@ Pizzicato aims to simplify the way you create and manipulate sounds via the Web
   - [Compressor](#compressor)
   - [Low-pass filter](#low-pass-filter)
   - [High-pass filter](#high-pass-filter)
+  - [Notch filter](#notch-filter)
   - [Stereo Panner](#stereo-panner)
   - [Convolver](#convolver)
   - [Reverb](#reverb)
@@ -853,6 +854,25 @@ sound.addEffect(highPassFilter);
 sound.play();
 ```
 
+<a name="notch-filter"/>
+
+### Notch filter ([example](https://alemangui.github.io/pizzicato/#notch-filter))
+Standard notch filter, also called a band-stop or band-rejection filter. It is the opposite of a bandpass filter: frequencies outside the give range of frequencies pass through; frequencies inside it are attenuated.
+
+* ```frequency``` _(min: 10, max: 22050, defaults to 350)_: The center of the range of frequencies.
+* ```peak``` _(min: 0.0001, max: 1000, defaults to 1)_: Controls the width of the frequency band. The greater peak value - the smaller frequency band.
+
+Example:
+```javascript
+var notchFilter = new Pizzicato.Effects.NotchFilter({
+    frequency: 1000,
+    peak: 3.0
+});
+
+sound.addEffect(notchFilter);
+sound.play();
+```
+
 <a name="stereo-panner"/>
 
 ### Stereo panner ([example](https://alemangui.github.io/pizzicato/#stereo-panner))

distr/Pizzicato.js

@@ -1317,6 +1317,16 @@
 		Filter.call(this, options, 'highpass');
 	};
 
+	/**
+	 * Frequencies outside the give range of 
+	 * frequencies pass through;
+	 * 
+	 * frequencies inside it are attenuated.
+	 */
+	Pizzicato.Effects.NotchFilter = function(options) {
+		Filter.call(this, options, 'notch');
+	};
+
 	/**
 	 * Filters used by Pizzicato stem from the biquad filter node. This 
 	 * function acts as a common constructor. The only thing that changes 
@@ -1328,7 +1338,8 @@
 
 		var defaults = {
 			frequency: 350,
-			peak: 1
+			peak: 1,
+			gain: 0,
 		};
 
 		this.inputNode = this.filterNode = Pz.context.createBiquadFilter();
@@ -1380,11 +1391,32 @@
 				if (Pizzicato.Util.isInRange(value, 0.0001, 1000))
 					this.filterNode.Q.value = value;
 			}
+		},
+
+		/**
+		 * The boost, in dB, to be applied;
+		 * if negative, it will be an attenuation.
+		 * MIN: -15.0
+		 * MAX: 15.0
+		 */
+		gain: {
+			enumerable: true,
+
+			get: function () {
+				return this.filterNode.gain.value;
+			},
+			set: function(value) {
+				// 15db used as common limit referenced from Ableton Live EQ8
+				if (Pizzicato.Util.isInRange(value, -15.0, 15.0))
+					this.filterNode.gain.value = value;
+			}
 		}
 	});
 
 	Pizzicato.Effects.LowPassFilter.prototype = filterPrototype;
 	Pizzicato.Effects.HighPassFilter.prototype = filterPrototype;
+	Pizzicato.Effects.NotchFilter.prototype = filterPrototype;
+
 	Pizzicato.Effects.Distortion = function(options) {
 
 		this.options = {};