three.js/src/math/Matrix4.js

/**
 * @author mrdoob / http://mrdoob.com/
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author philogb / http://blog.thejit.org/
 * @author jordi_ros / http://plattsoft.com
 * @author D1plo1d / http://github.com/D1plo1d
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author timknip / http://www.floorplanner.com/
 * @author bhouston / http://exocortex.com
 */


THREE.Matrix4 = function ( n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44 ) {

	this.elements = new Float32Array( 16 );

	this.set(

		( n11 !== undefined ) ? n11 : 1, n12 || 0, n13 || 0, n14 || 0,
		n21 || 0, ( n22 !== undefined ) ? n22 : 1, n23 || 0, n24 || 0,
		n31 || 0, n32 || 0, ( n33 !== undefined ) ? n33 : 1, n34 || 0,
		n41 || 0, n42 || 0, n43 || 0, ( n44 !== undefined ) ? n44 : 1

	);

};

THREE.Matrix4.prototype = {

	constructor: THREE.Matrix4,

	set: function ( n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44 ) {

		var te = this.elements;

		te[0] = n11; te[4] = n12; te[8] = n13; te[12] = n14;
		te[1] = n21; te[5] = n22; te[9] = n23; te[13] = n24;
		te[2] = n31; te[6] = n32; te[10] = n33; te[14] = n34;
		te[3] = n41; te[7] = n42; te[11] = n43; te[15] = n44;

		return this;

	},

	identity: function () {

		this.set(

			1, 0, 0, 0,
			0, 1, 0, 0,
			0, 0, 1, 0,
			0, 0, 0, 1

		);

		return this;

	},

	copy: function ( m ) {

		var me = m.elements;

		this.set(

			me[0], me[4], me[8], me[12],
			me[1], me[5], me[9], me[13],
			me[2], me[6], me[10], me[14],
			me[3], me[7], me[11], me[15]

		);

		return this;

	},

	setRotationFromEuler: function ( v, order ) {

		var te = this.elements;

		var x = v.x, y = v.y, z = v.z;
		var a = Math.cos( x ), b = Math.sin( x );
		var c = Math.cos( y ), d = Math.sin( y );
		var e = Math.cos( z ), f = Math.sin( z );

		if ( order === undefined || order === 'XYZ' ) {

			var ae = a * e, af = a * f, be = b * e, bf = b * f;

			te[0] = c * e;
			te[4] = - c * f;
			te[8] = d;

			te[1] = af + be * d;
			te[5] = ae - bf * d;
			te[9] = - b * c;

			te[2] = bf - ae * d;
			te[6] = be + af * d;
			te[10] = a * c;

		} else if ( order === 'YXZ' ) {

			var ce = c * e, cf = c * f, de = d * e, df = d * f;

			te[0] = ce + df * b;
			te[4] = de * b - cf;
			te[8] = a * d;

			te[1] = a * f;
			te[5] = a * e;
			te[9] = - b;

			te[2] = cf * b - de;
			te[6] = df + ce * b;
			te[10] = a * c;

		} else if ( order === 'ZXY' ) {

			var ce = c * e, cf = c * f, de = d * e, df = d * f;

			te[0] = ce - df * b;
			te[4] = - a * f;
			te[8] = de + cf * b;

			te[1] = cf + de * b;
			te[5] = a * e;
			te[9] = df - ce * b;

			te[2] = - a * d;
			te[6] = b;
			te[10] = a * c;

		} else if ( order === 'ZYX' ) {

			var ae = a * e, af = a * f, be = b * e, bf = b * f;

			te[0] = c * e;
			te[4] = be * d - af;
			te[8] = ae * d + bf;

			te[1] = c * f;
			te[5] = bf * d + ae;
			te[9] = af * d - be;

			te[2] = - d;
			te[6] = b * c;
			te[10] = a * c;

		} else if ( order === 'YZX' ) {

			var ac = a * c, ad = a * d, bc = b * c, bd = b * d;

			te[0] = c * e;
			te[4] = bd - ac * f;
			te[8] = bc * f + ad;

			te[1] = f;
			te[5] = a * e;
			te[9] = - b * e;

			te[2] = - d * e;
			te[6] = ad * f + bc;
			te[10] = ac - bd * f;

		} else if ( order === 'XZY' ) {

			var ac = a * c, ad = a * d, bc = b * c, bd = b * d;

			te[0] = c * e;
			te[4] = - f;
			te[8] = d * e;

			te[1] = ac * f + bd;
			te[5] = a * e;
			te[9] = ad * f - bc;

			te[2] = bc * f - ad;
			te[6] = b * e;
			te[10] = bd * f + ac;

		}

		return this;

	},

	setRotationFromQuaternion: function ( q ) {

		var te = this.elements;

		var x = q.x, y = q.y, z = q.z, w = q.w;
		var x2 = x + x, y2 = y + y, z2 = z + z;
		var xx = x * x2, xy = x * y2, xz = x * z2;
		var yy = y * y2, yz = y * z2, zz = z * z2;
		var wx = w * x2, wy = w * y2, wz = w * z2;

		te[0] = 1 - ( yy + zz );
		te[4] = xy - wz;
		te[8] = xz + wy;

		te[1] = xy + wz;
		te[5] = 1 - ( xx + zz );
		te[9] = yz - wx;

		te[2] = xz - wy;
		te[6] = yz + wx;
		te[10] = 1 - ( xx + yy );

		return this;

	},

	lookAt: function ( eye, target, up ) {

		var te = this.elements;

		var x = THREE.Matrix4.__v1;
		var y = THREE.Matrix4.__v2;
		var z = THREE.Matrix4.__v3;

		z.subVectors( eye, target ).normalize();

		if ( z.length() === 0 ) {

			z.z = 1;

		}

		x.crossVectors( up, z ).normalize();

		if ( x.length() === 0 ) {

			z.x += 0.0001;
			x.crossVectors( up, z ).normalize();

		}

		y.crossVectors( z, x );


		te[0] = x.x; te[4] = y.x; te[8] = z.x;
		te[1] = x.y; te[5] = y.y; te[9] = z.y;
		te[2] = x.z; te[6] = y.z; te[10] = z.z;

		return this;

	},

	multiply: function ( m, n ) {

		if ( n !== undefined ) {

			console.warn( 'DEPRECATED: Matrix4\'s .multiply() now only accepts one argument. Use .multiplyMatrices( a, b ) instead.' );
			return this.multiplyMatrices( m, n );

		}

		return this.multiplyMatrices( this, m );

	},

	multiplyMatrices: function ( a, b ) {

		var ae = a.elements;
		var be = b.elements;
		var te = this.elements;

		var a11 = ae[0], a12 = ae[4], a13 = ae[8], a14 = ae[12];
		var a21 = ae[1], a22 = ae[5], a23 = ae[9], a24 = ae[13];
		var a31 = ae[2], a32 = ae[6], a33 = ae[10], a34 = ae[14];
		var a41 = ae[3], a42 = ae[7], a43 = ae[11], a44 = ae[15];

		var b11 = be[0], b12 = be[4], b13 = be[8], b14 = be[12];
		var b21 = be[1], b22 = be[5], b23 = be[9], b24 = be[13];
		var b31 = be[2], b32 = be[6], b33 = be[10], b34 = be[14];
		var b41 = be[3], b42 = be[7], b43 = be[11], b44 = be[15];

		te[0] = a11 * b11 + a12 * b21 + a13 * b31 + a14 * b41;
		te[4] = a11 * b12 + a12 * b22 + a13 * b32 + a14 * b42;
		te[8] = a11 * b13 + a12 * b23 + a13 * b33 + a14 * b43;
		te[12] = a11 * b14 + a12 * b24 + a13 * b34 + a14 * b44;

		te[1] = a21 * b11 + a22 * b21 + a23 * b31 + a24 * b41;
		te[5] = a21 * b12 + a22 * b22 + a23 * b32 + a24 * b42;
		te[9] = a21 * b13 + a22 * b23 + a23 * b33 + a24 * b43;
		te[13] = a21 * b14 + a22 * b24 + a23 * b34 + a24 * b44;

		te[2] = a31 * b11 + a32 * b21 + a33 * b31 + a34 * b41;
		te[6] = a31 * b12 + a32 * b22 + a33 * b32 + a34 * b42;
		te[10] = a31 * b13 + a32 * b23 + a33 * b33 + a34 * b43;
		te[14] = a31 * b14 + a32 * b24 + a33 * b34 + a34 * b44;

		te[3] = a41 * b11 + a42 * b21 + a43 * b31 + a44 * b41;
		te[7] = a41 * b12 + a42 * b22 + a43 * b32 + a44 * b42;
		te[11] = a41 * b13 + a42 * b23 + a43 * b33 + a44 * b43;
		te[15] = a41 * b14 + a42 * b24 + a43 * b34 + a44 * b44;

		return this;

	},

	multiplyToArray: function ( a, b, r ) {

		var te = this.elements;

		this.multiplyMatrices( a, b );

		r[ 0 ] = te[0]; r[ 1 ] = te[1]; r[ 2 ] = te[2]; r[ 3 ] = te[3];
		r[ 4 ] = te[4]; r[ 5 ] = te[5]; r[ 6 ] = te[6]; r[ 7 ] = te[7];
		r[ 8 ]  = te[8]; r[ 9 ]  = te[9]; r[ 10 ] = te[10]; r[ 11 ] = te[11];
		r[ 12 ] = te[12]; r[ 13 ] = te[13]; r[ 14 ] = te[14]; r[ 15 ] = te[15];

		return this;

	},

	multiplyScalar: function ( s ) {

		var te = this.elements;

		te[0] *= s; te[4] *= s; te[8] *= s; te[12] *= s;
		te[1] *= s; te[5] *= s; te[9] *= s; te[13] *= s;
		te[2] *= s; te[6] *= s; te[10] *= s; te[14] *= s;
		te[3] *= s; te[7] *= s; te[11] *= s; te[15] *= s;

		return this;

	},

	multiplyVector3Array: function ( a ) {

		var tmp = THREE.Matrix4.__v1;

		for ( var i = 0, il = a.length; i < il; i += 3 ) {

			tmp.x = a[ i ];
			tmp.y = a[ i + 1 ];
			tmp.z = a[ i + 2 ];

			this.multiplyVector3( tmp );

			a[ i ]     = tmp.x;
			a[ i + 1 ] = tmp.y;
			a[ i + 2 ] = tmp.z;

		}

		return a;

	},

	rotateAxis: function ( v ) {

		var te = this.elements;
		var vx = v.x, vy = v.y, vz = v.z;

		v.x = vx * te[0] + vy * te[4] + vz * te[8];
		v.y = vx * te[1] + vy * te[5] + vz * te[9];
		v.z = vx * te[2] + vy * te[6] + vz * te[10];

		v.normalize();

		return v;

	},

	crossVector: function ( a ) {

		var te = this.elements;
		var v = new THREE.Vector4();

		v.x = te[0] * a.x + te[4] * a.y + te[8] * a.z + te[12] * a.w;
		v.y = te[1] * a.x + te[5] * a.y + te[9] * a.z + te[13] * a.w;
		v.z = te[2] * a.x + te[6] * a.y + te[10] * a.z + te[14] * a.w;

		v.w = ( a.w ) ? te[3] * a.x + te[7] * a.y + te[11] * a.z + te[15] * a.w : 1;

		return v;

	},

	determinant: function () {

		var te = this.elements;

		var n11 = te[0], n12 = te[4], n13 = te[8], n14 = te[12];
		var n21 = te[1], n22 = te[5], n23 = te[9], n24 = te[13];
		var n31 = te[2], n32 = te[6], n33 = te[10], n34 = te[14];
		var n41 = te[3], n42 = te[7], n43 = te[11], n44 = te[15];

		//TODO: make this more efficient
		//( based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm )

		return (
			n41 * (
				+n14 * n23 * n32
				-n13 * n24 * n32
				-n14 * n22 * n33
				+n12 * n24 * n33
				+n13 * n22 * n34
				-n12 * n23 * n34
			) +
			n42 * (
				+n11 * n23 * n34
				-n11 * n24 * n33
				+n14 * n21 * n33
				-n13 * n21 * n34
				+n13 * n24 * n31
				-n14 * n23 * n31
			) +
			n43 * (
				+n11 * n24 * n32
				-n11 * n22 * n34
				-n14 * n21 * n32
				+n12 * n21 * n34
				+n14 * n22 * n31
				-n12 * n24 * n31
			) +
			n44 * (
				-n13 * n22 * n31
				-n11 * n23 * n32
				+n11 * n22 * n33
				+n13 * n21 * n32
				-n12 * n21 * n33
				+n12 * n23 * n31
			)

		);

	},

	transpose: function () {

		var te = this.elements;
		var tmp;

		tmp = te[1]; te[1] = te[4]; te[4] = tmp;
		tmp = te[2]; te[2] = te[8]; te[8] = tmp;
		tmp = te[6]; te[6] = te[9]; te[9] = tmp;

		tmp = te[3]; te[3] = te[12]; te[12] = tmp;
		tmp = te[7]; te[7] = te[13]; te[13] = tmp;
		tmp = te[11]; te[11] = te[14]; te[14] = tmp;

		return this;

	},

	flattenToArray: function ( flat ) {

		var te = this.elements;
		flat[ 0 ] = te[0]; flat[ 1 ] = te[1]; flat[ 2 ] = te[2]; flat[ 3 ] = te[3];
		flat[ 4 ] = te[4]; flat[ 5 ] = te[5]; flat[ 6 ] = te[6]; flat[ 7 ] = te[7];
		flat[ 8 ] = te[8]; flat[ 9 ] = te[9]; flat[ 10 ] = te[10]; flat[ 11 ] = te[11];
		flat[ 12 ] = te[12]; flat[ 13 ] = te[13]; flat[ 14 ] = te[14]; flat[ 15 ] = te[15];

		return flat;

	},

	flattenToArrayOffset: function( flat, offset ) {

		var te = this.elements;
		flat[ offset ] = te[0];
		flat[ offset + 1 ] = te[1];
		flat[ offset + 2 ] = te[2];
		flat[ offset + 3 ] = te[3];

		flat[ offset + 4 ] = te[4];
		flat[ offset + 5 ] = te[5];
		flat[ offset + 6 ] = te[6];
		flat[ offset + 7 ] = te[7];

		flat[ offset + 8 ]  = te[8];
		flat[ offset + 9 ]  = te[9];
		flat[ offset + 10 ] = te[10];
		flat[ offset + 11 ] = te[11];

		flat[ offset + 12 ] = te[12];
		flat[ offset + 13 ] = te[13];
		flat[ offset + 14 ] = te[14];
		flat[ offset + 15 ] = te[15];

		return flat;

	},

	getPosition: function () {

		var te = this.elements;
		return THREE.Matrix4.__v1.set( te[12], te[13], te[14] );

	},

	setPosition: function ( v ) {

		var te = this.elements;

		te[12] = v.x;
		te[13] = v.y;
		te[14] = v.z;

		return this;

	},

	getColumnX: function () {

		var te = this.elements;
		return THREE.Matrix4.__v1.set( te[0], te[1], te[2] );

	},

	getColumnY: function () {

		var te = this.elements;
		return THREE.Matrix4.__v1.set( te[4], te[5], te[6] );

	},

	getColumnZ: function() {

		var te = this.elements;
		return THREE.Matrix4.__v1.set( te[8], te[9], te[10] );

	},

	getInverse: function ( m, throwOnInvertible ) {

		// based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm
		var te = this.elements;
		var me = m.elements;

		var n11 = me[0], n12 = me[4], n13 = me[8], n14 = me[12];
		var n21 = me[1], n22 = me[5], n23 = me[9], n24 = me[13];
		var n31 = me[2], n32 = me[6], n33 = me[10], n34 = me[14];
		var n41 = me[3], n42 = me[7], n43 = me[11], n44 = me[15];

		te[0] = n23*n34*n42 - n24*n33*n42 + n24*n32*n43 - n22*n34*n43 - n23*n32*n44 + n22*n33*n44;
		te[4] = n14*n33*n42 - n13*n34*n42 - n14*n32*n43 + n12*n34*n43 + n13*n32*n44 - n12*n33*n44;
		te[8] = n13*n24*n42 - n14*n23*n42 + n14*n22*n43 - n12*n24*n43 - n13*n22*n44 + n12*n23*n44;
		te[12] = n14*n23*n32 - n13*n24*n32 - n14*n22*n33 + n12*n24*n33 + n13*n22*n34 - n12*n23*n34;
		te[1] = n24*n33*n41 - n23*n34*n41 - n24*n31*n43 + n21*n34*n43 + n23*n31*n44 - n21*n33*n44;
		te[5] = n13*n34*n41 - n14*n33*n41 + n14*n31*n43 - n11*n34*n43 - n13*n31*n44 + n11*n33*n44;
		te[9] = n14*n23*n41 - n13*n24*n41 - n14*n21*n43 + n11*n24*n43 + n13*n21*n44 - n11*n23*n44;
		te[13] = n13*n24*n31 - n14*n23*n31 + n14*n21*n33 - n11*n24*n33 - n13*n21*n34 + n11*n23*n34;
		te[2] = n22*n34*n41 - n24*n32*n41 + n24*n31*n42 - n21*n34*n42 - n22*n31*n44 + n21*n32*n44;
		te[6] = n14*n32*n41 - n12*n34*n41 - n14*n31*n42 + n11*n34*n42 + n12*n31*n44 - n11*n32*n44;
		te[10] = n12*n24*n41 - n14*n22*n41 + n14*n21*n42 - n11*n24*n42 - n12*n21*n44 + n11*n22*n44;
		te[14] = n14*n22*n31 - n12*n24*n31 - n14*n21*n32 + n11*n24*n32 + n12*n21*n34 - n11*n22*n34;
		te[3] = n23*n32*n41 - n22*n33*n41 - n23*n31*n42 + n21*n33*n42 + n22*n31*n43 - n21*n32*n43;
		te[7] = n12*n33*n41 - n13*n32*n41 + n13*n31*n42 - n11*n33*n42 - n12*n31*n43 + n11*n32*n43;
		te[11] = n13*n22*n41 - n12*n23*n41 - n13*n21*n42 + n11*n23*n42 + n12*n21*n43 - n11*n22*n43;
		te[15] = n12*n23*n31 - n13*n22*n31 + n13*n21*n32 - n11*n23*n32 - n12*n21*n33 + n11*n22*n33;

		var det = me[ 0 ] * te[ 0 ] + me[ 1 ] * te[ 4 ] + me[ 2 ] * te[ 8 ] + me[ 3 ] * te[ 12 ];

		if ( det == 0 ) {

			var msg = "Matrix4.getInverse(): can't invert matrix, determinant is 0";

			if ( throwOnInvertible || false ) {

				throw new Error( msg ); 

			} else {

				console.warn( msg );

			}

			this.identity();

			return this;
		}

		this.multiplyScalar( 1 / det );

		return this;

	},

	compose: function ( translation, rotation, scale ) {

		var te = this.elements;
		var mRotation = THREE.Matrix4.__m1;
		var mScale = THREE.Matrix4.__m2;

		mRotation.identity();
		mRotation.setRotationFromQuaternion( rotation );

		mScale.makeScale( scale );

		this.multiplyMatrices( mRotation, mScale );

		te[12] = translation.x;
		te[13] = translation.y;
		te[14] = translation.z;

		return this;

	},

	decompose: function ( translation, rotation, scale ) {

		var te = this.elements;

		// grab the axis vectors
		var x = THREE.Matrix4.__v1;
		var y = THREE.Matrix4.__v2;
		var z = THREE.Matrix4.__v3;

		x.set( te[0], te[1], te[2] );
		y.set( te[4], te[5], te[6] );
		z.set( te[8], te[9], te[10] );

		translation = ( translation instanceof THREE.Vector3 ) ? translation : new THREE.Vector3();
		rotation = ( rotation instanceof THREE.Quaternion ) ? rotation : new THREE.Quaternion();
		scale = ( scale instanceof THREE.Vector3 ) ? scale : new THREE.Vector3();

		scale.x = x.length();
		scale.y = y.length();
		scale.z = z.length();

		translation.x = te[12];
		translation.y = te[13];
		translation.z = te[14];

		// scale the rotation part

		var matrix = THREE.Matrix4.__m1;

		matrix.copy( this );

		matrix.elements[0] /= scale.x;
		matrix.elements[1] /= scale.x;
		matrix.elements[2] /= scale.x;

		matrix.elements[4] /= scale.y;
		matrix.elements[5] /= scale.y;
		matrix.elements[6] /= scale.y;

		matrix.elements[8] /= scale.z;
		matrix.elements[9] /= scale.z;
		matrix.elements[10] /= scale.z;

		rotation.setFromRotationMatrix( matrix );

		return [ translation, rotation, scale ];

	},

	extractPosition: function ( m ) {

		var te = this.elements;
		var me = m.elements;

		te[12] = me[12];
		te[13] = me[13];
		te[14] = me[14];

		return this;

	},

	extractRotation: function ( m ) {

		var te = this.elements;
		var me = m.elements;

		var vector = THREE.Matrix4.__v1;

		var scaleX = 1 / vector.set( me[0], me[1], me[2] ).length();
		var scaleY = 1 / vector.set( me[4], me[5], me[6] ).length();
		var scaleZ = 1 / vector.set( me[8], me[9], me[10] ).length();

		te[0] = me[0] * scaleX;
		te[1] = me[1] * scaleX;
		te[2] = me[2] * scaleX;

		te[4] = me[4] * scaleY;
		te[5] = me[5] * scaleY;
		te[6] = me[6] * scaleY;

		te[8] = me[8] * scaleZ;
		te[9] = me[9] * scaleZ;
		te[10] = me[10] * scaleZ;

		return this;

	},

	//

	translate: function ( v ) {

		var te = this.elements;
		var x = v.x, y = v.y, z = v.z;

		te[12] = te[0] * x + te[4] * y + te[8] * z + te[12];
		te[13] = te[1] * x + te[5] * y + te[9] * z + te[13];
		te[14] = te[2] * x + te[6] * y + te[10] * z + te[14];
		te[15] = te[3] * x + te[7] * y + te[11] * z + te[15];

		return this;

	},

	rotateX: function ( angle ) {

		var te = this.elements;
		var m12 = te[4];
		var m22 = te[5];
		var m32 = te[6];
		var m42 = te[7];
		var m13 = te[8];
		var m23 = te[9];
		var m33 = te[10];
		var m43 = te[11];
		var c = Math.cos( angle );
		var s = Math.sin( angle );

		te[4] = c * m12 + s * m13;
		te[5] = c * m22 + s * m23;
		te[6] = c * m32 + s * m33;
		te[7] = c * m42 + s * m43;

		te[8] = c * m13 - s * m12;
		te[9] = c * m23 - s * m22;
		te[10] = c * m33 - s * m32;
		te[11] = c * m43 - s * m42;

		return this;

	},

	rotateY: function ( angle ) {

		var te = this.elements;
		var m11 = te[0];
		var m21 = te[1];
		var m31 = te[2];
		var m41 = te[3];
		var m13 = te[8];
		var m23 = te[9];
		var m33 = te[10];
		var m43 = te[11];
		var c = Math.cos( angle );
		var s = Math.sin( angle );

		te[0] = c * m11 - s * m13;
		te[1] = c * m21 - s * m23;
		te[2] = c * m31 - s * m33;
		te[3] = c * m41 - s * m43;

		te[8] = c * m13 + s * m11;
		te[9] = c * m23 + s * m21;
		te[10] = c * m33 + s * m31;
		te[11] = c * m43 + s * m41;

		return this;

	},

	rotateZ: function ( angle ) {

		var te = this.elements;
		var m11 = te[0];
		var m21 = te[1];
		var m31 = te[2];
		var m41 = te[3];
		var m12 = te[4];
		var m22 = te[5];
		var m32 = te[6];
		var m42 = te[7];
		var c = Math.cos( angle );
		var s = Math.sin( angle );

		te[0] = c * m11 + s * m12;
		te[1] = c * m21 + s * m22;
		te[2] = c * m31 + s * m32;
		te[3] = c * m41 + s * m42;

		te[4] = c * m12 - s * m11;
		te[5] = c * m22 - s * m21;
		te[6] = c * m32 - s * m31;
		te[7] = c * m42 - s * m41;

		return this;

	},

	rotateByAxis: function ( axis, angle ) {

		var te = this.elements;

		// optimize by checking axis

		if ( axis.x === 1 && axis.y === 0 && axis.z === 0 ) {

			return this.rotateX( angle );

		} else if ( axis.x === 0 && axis.y === 1 && axis.z === 0 ) {

			return this.rotateY( angle );

		} else if ( axis.x === 0 && axis.y === 0 && axis.z === 1 ) {

			return this.rotateZ( angle );

		}

		var x = axis.x, y = axis.y, z = axis.z;
		var n = Math.sqrt(x * x + y * y + z * z);

		x /= n;
		y /= n;
		z /= n;

		var xx = x * x, yy = y * y, zz = z * z;
		var c = Math.cos( angle );
		var s = Math.sin( angle );
		var oneMinusCosine = 1 - c;
		var xy = x * y * oneMinusCosine;
		var xz = x * z * oneMinusCosine;
		var yz = y * z * oneMinusCosine;
		var xs = x * s;
		var ys = y * s;
		var zs = z * s;

		var r11 = xx + (1 - xx) * c;
		var r21 = xy + zs;
		var r31 = xz - ys;
		var r12 = xy - zs;
		var r22 = yy + (1 - yy) * c;
		var r32 = yz + xs;
		var r13 = xz + ys;
		var r23 = yz - xs;
		var r33 = zz + (1 - zz) * c;

		var m11 = te[0], m21 = te[1], m31 = te[2], m41 = te[3];
		var m12 = te[4], m22 = te[5], m32 = te[6], m42 = te[7];
		var m13 = te[8], m23 = te[9], m33 = te[10], m43 = te[11];
		var m14 = te[12], m24 = te[13], m34 = te[14], m44 = te[15];

		te[0] = r11 * m11 + r21 * m12 + r31 * m13;
		te[1] = r11 * m21 + r21 * m22 + r31 * m23;
		te[2] = r11 * m31 + r21 * m32 + r31 * m33;
		te[3] = r11 * m41 + r21 * m42 + r31 * m43;

		te[4] = r12 * m11 + r22 * m12 + r32 * m13;
		te[5] = r12 * m21 + r22 * m22 + r32 * m23;
		te[6] = r12 * m31 + r22 * m32 + r32 * m33;
		te[7] = r12 * m41 + r22 * m42 + r32 * m43;

		te[8] = r13 * m11 + r23 * m12 + r33 * m13;
		te[9] = r13 * m21 + r23 * m22 + r33 * m23;
		te[10] = r13 * m31 + r23 * m32 + r33 * m33;
		te[11] = r13 * m41 + r23 * m42 + r33 * m43;

		return this;

	},

	scale: function ( v ) {

		var te = this.elements;
		var x = v.x, y = v.y, z = v.z;

		te[0] *= x; te[4] *= y; te[8] *= z;
		te[1] *= x; te[5] *= y; te[9] *= z;
		te[2] *= x; te[6] *= y; te[10] *= z;
		te[3] *= x; te[7] *= y; te[11] *= z;

		return this;

	},

	getMaxScaleOnAxis: function () {

		var te = this.elements;

		var scaleXSq = te[0] * te[0] + te[1] * te[1] + te[2] * te[2];
		var scaleYSq = te[4] * te[4] + te[5] * te[5] + te[6] * te[6];
		var scaleZSq = te[8] * te[8] + te[9] * te[9] + te[10] * te[10];

		return Math.sqrt( Math.max( scaleXSq, Math.max( scaleYSq, scaleZSq ) ) );

	},

	//

	makeTranslation: function ( offset ) {

		this.set(

			1, 0, 0, offset.x,
			0, 1, 0, offset.y,
			0, 0, 1, offset.z,
			0, 0, 0, 1

		);

		return this;

	},

	makeRotationX: function ( theta ) {

		var c = Math.cos( theta ), s = Math.sin( theta );

		this.set(

			1, 0,  0, 0,
			0, c, -s, 0,
			0, s,  c, 0,
			0, 0,  0, 1

		);

		return this;

	},

	makeRotationY: function ( theta ) {

		var c = Math.cos( theta ), s = Math.sin( theta );

		this.set(

			 c, 0, s, 0,
			 0, 1, 0, 0,
			-s, 0, c, 0,
			 0, 0, 0, 1

		);

		return this;

	},

	makeRotationZ: function ( theta ) {

		var c = Math.cos( theta ), s = Math.sin( theta );

		this.set(

			c, -s, 0, 0,
			s,  c, 0, 0,
			0,  0, 1, 0,
			0,  0, 0, 1

		);

		return this;

	},

	makeRotationAxis: function ( axis, angle ) {

		// Based on http://www.gamedev.net/reference/articles/article1199.asp

		var c = Math.cos( angle );
		var s = Math.sin( angle );
		var t = 1 - c;
		var x = axis.x, y = axis.y, z = axis.z;
		var tx = t * x, ty = t * y;

		this.set(

			tx * x + c, tx * y - s * z, tx * z + s * y, 0,
			tx * y + s * z, ty * y + c, ty * z - s * x, 0,
			tx * z - s * y, ty * z + s * x, t * z * z + c, 0,
			0, 0, 0, 1

		);

		 return this;

	},

	makeScale: function ( factor ) {

		this.set(

			factor.x, 0, 0, 0,
			0, factor.y, 0, 0,
			0, 0, factor.z, 0,
			0, 0, 0, 1

		);

		return this;

	},

	makeFrustum: function ( left, right, bottom, top, near, far ) {

		var te = this.elements;
		var x = 2 * near / ( right - left );
		var y = 2 * near / ( top - bottom );

		var a = ( right + left ) / ( right - left );
		var b = ( top + bottom ) / ( top - bottom );
		var c = - ( far + near ) / ( far - near );
		var d = - 2 * far * near / ( far - near );

		te[0] = x;	te[4] = 0;	te[8] = a;	te[12] = 0;
		te[1] = 0;	te[5] = y;	te[9] = b;	te[13] = 0;
		te[2] = 0;	te[6] = 0;	te[10] = c;	te[14] = d;
		te[3] = 0;	te[7] = 0;	te[11] = - 1;	te[15] = 0;

		return this;

	},

	makePerspective: function ( fov, aspect, near, far ) {

		var ymax = near * Math.tan( THREE.Math.degToRad( fov * 0.5 ) );
		var ymin = - ymax;
		var xmin = ymin * aspect;
		var xmax = ymax * aspect;

		return this.makeFrustum( xmin, xmax, ymin, ymax, near, far );

	},

	makeOrthographic: function ( left, right, top, bottom, near, far ) {

		var te = this.elements;
		var w = right - left;
		var h = top - bottom;
		var p = far - near;

		var x = ( right + left ) / w;
		var y = ( top + bottom ) / h;
		var z = ( far + near ) / p;

		te[0] = 2 / w;	te[4] = 0;	te[8] = 0;	te[12] = -x;
		te[1] = 0;	te[5] = 2 / h;	te[9] = 0;	te[13] = -y;
		te[2] = 0;	te[6] = 0;	te[10] = -2/p;	te[14] = -z;
		te[3] = 0;	te[7] = 0;	te[11] = 0;	te[15] = 1;

		return this;

	},

	clone: function () {

		var te = this.elements;

		return new THREE.Matrix4(

			te[0], te[4], te[8], te[12],
			te[1], te[5], te[9], te[13],
			te[2], te[6], te[10], te[14],
			te[3], te[7], te[11], te[15]

		);

	}

};

THREE.Matrix4.__v1 = new THREE.Vector3();
THREE.Matrix4.__v2 = new THREE.Vector3();
THREE.Matrix4.__v3 = new THREE.Vector3();

THREE.Matrix4.__m1 = new THREE.Matrix4();
THREE.Matrix4.__m2 = new THREE.Matrix4();