var Class = require('../utils/Class'); 
var Vector3 = require('./Vector3'); 
var Matrix3 = require('./Matrix3'); 
var EPSILON = 1e-06; 
var siNext = new Int8Array([1, 2, 0] ); 
var tmp = new Float32Array([0, 0, 0] ); 
var xUnitVec3 = new Vector3(1, 0, 0); 
var yUnitVec3 = new Vector3(0, 1, 0); 
var tmpvec = new Vector3(); 
var tmpMat3 = new Matrix3(); 
var Quaternion = new Class({ 
initialize: function Quaternion(x, y, z, w){ 
if (typeof x === 'object') { 
this.x = x.x || 0; 
this.y = x.y || 0; 
this.z = x.z || 0; 
this.w = x.w || 0; 
} 
 else { 
this.x = x || 0; 
this.y = y || 0; 
this.z = z || 0; 
this.w = w || 0; 
} 
} 
,
copy: function (src){ 
this.x = src.x; 
this.y = src.y; 
this.z = src.z; 
this.w = src.w; 
return this; 
} 
,
set: function (x, y, z, w){ 
if (typeof x === 'object') { 
this.x = x.x || 0; 
this.y = x.y || 0; 
this.z = x.z || 0; 
this.w = x.w || 0; 
} 
 else { 
this.x = x || 0; 
this.y = y || 0; 
this.z = z || 0; 
this.w = w || 0; 
} 
return this; 
} 
,
add: function (v){ 
this.x += v.x; 
this.y += v.y; 
this.z += v.z; 
this.w += v.w; 
return this; 
} 
,
subtract: function (v){ 
this.x -= v.x; 
this.y -= v.y; 
this.z -= v.z; 
this.w -= v.w; 
return this; 
} 
,
scale: function (scale){ 
this.x *= scale; 
this.y *= scale; 
this.z *= scale; 
this.w *= scale; 
return this; 
} 
,
length: function (){ 
var x = this.x; 
var y = this.y; 
var z = this.z; 
var w = this.w; 
return Math.sqrt(x * x + y * y + z * z + w * w); 
} 
,
lengthSq: function (){ 
var x = this.x; 
var y = this.y; 
var z = this.z; 
var w = this.w; 
return x * x + y * y + z * z + w * w; 
} 
,
normalize: function (){ 
var x = this.x; 
var y = this.y; 
var z = this.z; 
var w = this.w; 
var len = x * x + y * y + z * z + w * w; 
if (len > 0) { 
len = 1 / Math.sqrt(len); 
this.x = x * len; 
this.y = y * len; 
this.z = z * len; 
this.w = w * len; 
} 
return this; 
} 
,
dot: function (v){ 
return this.x * v.x + this.y * v.y + this.z * v.z + this.w * v.w; 
} 
,
lerp: function (v, t){ 
if (t === undefined) { 
t = 0; 
} 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
this.x = ax + t * (v.x - ax); 
this.y = ay + t * (v.y - ay); 
this.z = az + t * (v.z - az); 
this.w = aw + t * (v.w - aw); 
return this; 
} 
,
rotationTo: function (a, b){ 
var dot = a.x * b.x + a.y * b.y + a.z * b.z; 
if (dot < -0.999999) { 
if (tmpvec.copy(xUnitVec3).cross(a).length() < EPSILON) { 
tmpvec.copy(yUnitVec3).cross(a); 
} 
tmpvec.normalize(); 
return this.setAxisAngle(tmpvec, Math.PI); 
} 
 else if (dot > 0.999999) { 
this.x = 0; 
this.y = 0; 
this.z = 0; 
this.w = 1; 
return this; 
} 
 else { 
tmpvec.copy(a).cross(b); 
this.x = tmpvec.x; 
this.y = tmpvec.y; 
this.z = tmpvec.z; 
this.w = 1 + dot; 
return this.normalize(); 
} 
} 
,
setAxes: function (view, right, up){ 
var m = tmpMat3.val; 
m[0] = right.x; 
m[3] = right.y; 
m[6] = right.z; 
m[1] = up.x; 
m[4] = up.y; 
m[7] = up.z; 
m[2] = - view.x; 
m[5] = - view.y; 
m[8] = - view.z; 
return this.fromMat3(tmpMat3).normalize(); 
} 
,
identity: function (){ 
this.x = 0; 
this.y = 0; 
this.z = 0; 
this.w = 1; 
return this; 
} 
,
setAxisAngle: function (axis, rad){ 
rad = rad * 0.5; 
var s = Math.sin(rad); 
this.x = s * axis.x; 
this.y = s * axis.y; 
this.z = s * axis.z; 
this.w = Math.cos(rad); 
return this; 
} 
,
multiply: function (b){ 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
var bx = b.x; 
var by = b.y; 
var bz = b.z; 
var bw = b.w; 
this.x = ax * bw + aw * bx + ay * bz - az * by; 
this.y = ay * bw + aw * by + az * bx - ax * bz; 
this.z = az * bw + aw * bz + ax * by - ay * bx; 
this.w = aw * bw - ax * bx - ay * by - az * bz; 
return this; 
} 
,
slerp: function (b, t){ 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
var bx = b.x; 
var by = b.y; 
var bz = b.z; 
var bw = b.w; 
var cosom = ax * bx + ay * by + az * bz + aw * bw; 
if (cosom < 0) { 
cosom = - cosom; 
bx = - bx; 
by = - by; 
bz = - bz; 
bw = - bw; 
} 
var scale0 = 1 - t; 
var scale1 = t; 
if ((1 - cosom) > EPSILON) { 
var omega = Math.acos(cosom); 
var sinom = Math.sin(omega); 
scale0 = Math.sin((1 - t) * omega) / sinom; 
scale1 = Math.sin(t * omega) / sinom; 
} 
this.x = scale0 * ax + scale1 * bx; 
this.y = scale0 * ay + scale1 * by; 
this.z = scale0 * az + scale1 * bz; 
this.w = scale0 * aw + scale1 * bw; 
return this; 
} 
,
invert: function (){ 
var a0 = this.x; 
var a1 = this.y; 
var a2 = this.z; 
var a3 = this.w; 
var dot = a0 * a0 + a1 * a1 + a2 * a2 + a3 * a3; 
var invDot = (dot)? 1 / dot: 0; 
this.x = - a0 * invDot; 
this.y = - a1 * invDot; 
this.z = - a2 * invDot; 
this.w = a3 * invDot; 
return this; 
} 
,
conjugate: function (){ 
this.x = - this.x; 
this.y = - this.y; 
this.z = - this.z; 
return this; 
} 
,
rotateX: function (rad){ 
rad *= 0.5; 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
var bx = Math.sin(rad); 
var bw = Math.cos(rad); 
this.x = ax * bw + aw * bx; 
this.y = ay * bw + az * bx; 
this.z = az * bw - ay * bx; 
this.w = aw * bw - ax * bx; 
return this; 
} 
,
rotateY: function (rad){ 
rad *= 0.5; 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
var by = Math.sin(rad); 
var bw = Math.cos(rad); 
this.x = ax * bw - az * by; 
this.y = ay * bw + aw * by; 
this.z = az * bw + ax * by; 
this.w = aw * bw - ay * by; 
return this; 
} 
,
rotateZ: function (rad){ 
rad *= 0.5; 
var ax = this.x; 
var ay = this.y; 
var az = this.z; 
var aw = this.w; 
var bz = Math.sin(rad); 
var bw = Math.cos(rad); 
this.x = ax * bw + ay * bz; 
this.y = ay * bw - ax * bz; 
this.z = az * bw + aw * bz; 
this.w = aw * bw - az * bz; 
return this; 
} 
,
calculateW: function (){ 
var x = this.x; 
var y = this.y; 
var z = this.z; 
this.w = - Math.sqrt(Math.abs(1 - x * x - y * y - z * z)); 
return this; 
} 
,
fromMat3: function (mat){ 
var m = mat.val; 
var fTrace = m[0] + m[4] + m[8]; 
var fRoot; 
if (fTrace > 0) { 
fRoot = Math.sqrt(fTrace + 1); 
this.w = 0.5 * fRoot; 
fRoot = 0.5 / fRoot; 
this.x = (m[7] - m[5]) * fRoot; 
this.y = (m[2] - m[6]) * fRoot; 
this.z = (m[3] - m[1]) * fRoot; 
} 
 else { 
var i = 0; 
if (m[4] > m[0]) { 
i = 1; 
} 
if (m[8] > m[i * 3 + i]) { 
i = 2; 
} 
var j = siNext[i]; 
var k = siNext[j]; 
fRoot = Math.sqrt(m[i * 3 + i] - m[j * 3 + j] - m[k * 3 + k] + 1); 
tmp[i] = 0.5 * fRoot; 
fRoot = 0.5 / fRoot; 
tmp[j] = (m[j * 3 + i] + m[i * 3 + j]) * fRoot; 
tmp[k] = (m[k * 3 + i] + m[i * 3 + k]) * fRoot; 
this.x = tmp[0]; 
this.y = tmp[1]; 
this.z = tmp[2]; 
this.w = (m[k * 3 + j] - m[j * 3 + k]) * fRoot; 
} 
return this; 
} 
}
); 
Quaternion.prototype.idt = Quaternion.prototype.identity; 
Quaternion.prototype.sub = Quaternion.prototype.subtract; 
Quaternion.prototype.mul = Quaternion.prototype.multiply; 
Quaternion.prototype.len = _AN_Read_length('length', Quaternion.prototype); 
Quaternion.prototype.lenSq = Quaternion.prototype.lengthSq; 
Quaternion.prototype.reset = Quaternion.prototype.idt; 
module.exports = Quaternion;