set radius of a circle using toxi.math.BezierInterpolation and mouse.x

RadiusTween.js

define(function (require) {
	'use strict';
	var _ = require('underscore');
	var PIXI = require('pixi');
	var PMath = require('utils/PMath');
	var toxi = require('toxi');
	var TColor = toxi.color.TColor;
	var BezierInterpolation = toxi.math.BezierInterpolation;

	var TweenBall = function() {};

	TweenBall.prototype = {
		init: function() {

			this.graphics = new PIXI.Graphics();
			this.colour = TColor.newHex('155e73');
			this.gameStage.addChild(this.graphics);

			this.tween = new BezierInterpolation(3,-3);
			
			this.mouseData = {x:0, y:0};

			this.graphics.alpha = 0.01;
			this.graphics.setInteractive(true);
			this.graphics.mousemove = _.bind(function(mouseData) {
				
				this.mouseData = mouseData.getLocalPosition(this.gameStage);

			}, this);

		},

		drawCircle: function(x, y, size) {

			this.graphics.beginFill(this.colour.toInt());
			this.graphics.lineStyle(2, this.colour.toInt());
			this.graphics.drawCircle(x, y, size);
			this.graphics.endFill();

		},

		update: function() {

			//this.graphics.clear();
			
			var normX = this.mouseData.x/this.gameWidth;
			if(normX !== this.lastNormX) {	
				var r = this.tween.interpolate(0, 150, normX);
				this.drawCircle(this.gameWidth/2, this.gameHeight/2, r);
				this.lastNormX = normX;
			}

		}
	};

	return TweenBall; 
});