var Class = require('../utils/Class'); 
var Vector2 = new Class({ 
initialize: function Vector2(x, y){ 
this.x = 0; 
this.y = 0; 
if (typeof x === 'object') { 
this.x = x.x || 0; 
this.y = x.y || 0; 
} 
 else { 
if (y === undefined) { 
y = x; 
} 
this.x = x || 0; 
this.y = y || 0; 
} 
} 
,
clone: function (){ 
return new Vector2(this.x, this.y); 
} 
,
copy: function (src){ 
this.x = src.x || 0; 
this.y = src.y || 0; 
return this; 
} 
,
setFromObject: function (obj){ 
this.x = obj.x || 0; 
this.y = obj.y || 0; 
return this; 
} 
,
set: function (x, y){ 
if (y === undefined) { 
y = x; 
} 
this.x = x; 
this.y = y; 
return this; 
} 
,
setTo: function (x, y){ 
return this.set(x, y); 
} 
,
setToPolar: function (azimuth, radius){ 
if (radius == null ) { 
radius = 1; 
} 
this.x = Math.cos(azimuth) * radius; 
this.y = Math.sin(azimuth) * radius; 
return this; 
} 
,
equals: function (v){ 
return ((this.x === v.x) && (this.y === v.y)); 
} 
,
angle: function (){ 
var angle = Math.atan2(this.y, this.x); 
if (angle < 0) { 
angle += 2 * Math.PI; 
} 
return angle; 
} 
,
add: function (src){ 
this.x += src.x; 
this.y += src.y; 
return this; 
} 
,
subtract: function (src){ 
this.x -= src.x; 
this.y -= src.y; 
return this; 
} 
,
multiply: function (src){ 
this.x *= src.x; 
this.y *= src.y; 
return this; 
} 
,
scale: function (value){ 
if (isFinite(value)) { 
this.x *= value; 
this.y *= value; 
} 
 else { 
this.x = 0; 
this.y = 0; 
} 
return this; 
} 
,
divide: function (src){ 
this.x /= src.x; 
this.y /= src.y; 
return this; 
} 
,
negate: function (){ 
this.x = - this.x; 
this.y = - this.y; 
return this; 
} 
,
distance: function (src){ 
var dx = src.x - this.x; 
var dy = src.y - this.y; 
return Math.sqrt(dx * dx + dy * dy); 
} 
,
distanceSq: function (src){ 
var dx = src.x - this.x; 
var dy = src.y - this.y; 
return dx * dx + dy * dy; 
} 
,
length: function (){ 
var x = this.x; 
var y = this.y; 
return Math.sqrt(x * x + y * y); 
} 
,
lengthSq: function (){ 
var x = this.x; 
var y = this.y; 
return x * x + y * y; 
} 
,
normalize: function (){ 
var x = this.x; 
var y = this.y; 
var len = x * x + y * y; 
if (len > 0) { 
len = 1 / Math.sqrt(len); 
this.x = x * len; 
this.y = y * len; 
} 
return this; 
} 
,
normalizeRightHand: function (){ 
var x = this.x; 
this.x = this.y * -1; 
this.y = x; 
return this; 
} 
,
dot: function (src){ 
return this.x * src.x + this.y * src.y; 
} 
,
cross: function (src){ 
return this.x * src.y - this.y * src.x; 
} 
,
lerp: function (src, t){ 
if (t === undefined) { 
t = 0; 
} 
var ax = this.x; 
var ay = this.y; 
this.x = ax + t * (src.x - ax); 
this.y = ay + t * (src.y - ay); 
return this; 
} 
,
transformMat3: function (mat){ 
var x = this.x; 
var y = this.y; 
var m = mat.val; 
this.x = m[0] * x + m[3] * y + m[6]; 
this.y = m[1] * x + m[4] * y + m[7]; 
return this; 
} 
,
transformMat4: function (mat){ 
var x = this.x; 
var y = this.y; 
var m = mat.val; 
this.x = m[0] * x + m[4] * y + m[12]; 
this.y = m[1] * x + m[5] * y + m[13]; 
return this; 
} 
,
reset: function (){ 
this.x = 0; 
this.y = 0; 
return this; 
} 
}
); 
Vector2.ZERO = new Vector2(); 
module.exports = Vector2;