<!-- AVATAR-FORGE · part 19 -->
ure.DEFAULT_ANISOTROPY = 1;

class Vector4 {

	constructor( x = 0, y = 0, z = 0, w = 1 ) {

		Vector4.prototype.isVector4 = true;

		this.x = x;
		this.y = y;
		this.z = z;
		this.w = w;

	}

	get width() {

		return this.z;

	}

	set width( value ) {

		this.z = value;

	}

	get height() {

		return this.w;

	}

	set height( value ) {

		this.w = value;

	}

	set( x, y, z, w ) {

		this.x = x;
		this.y = y;
		this.z = z;
		this.w = w;

		return this;

	}

	setScalar( scalar ) {

		this.x = scalar;
		this.y = scalar;
		this.z = scalar;
		this.w = scalar;

		return this;

	}

	setX( x ) {

		this.x = x;

		return this;

	}

	setY( y ) {

		this.y = y;

		return this;

	}

	setZ( z ) {

		this.z = z;

		return this;

	}

	setW( w ) {

		this.w = w;

		return this;

	}

	setComponent( index, value ) {

		switch ( index ) {

			case 0: this.x = value; break;
			case 1: this.y = value; break;
			case 2: this.z = value; break;
			case 3: this.w = value; break;
			default: throw new Error( 'index is out of range: ' + index );

		}

		return this;

	}

	getComponent( index ) {

		switch ( index ) {

			case 0: return this.x;
			case 1: return this.y;
			case 2: return this.z;
			case 3: return this.w;
			default: throw new Error( 'index is out of range: ' + index );

		}

	}

	clone() {

		return new this.constructor( this.x, this.y, this.z, this.w );

	}

	copy( v ) {

		this.x = v.x;
		this.y = v.y;
		this.z = v.z;
		this.w = ( v.w !== undefined ) ? v.w : 1;

		return this;

	}

	add( v ) {

		this.x += v.x;
		this.y += v.y;
		this.z += v.z;
		this.w += v.w;

		return this;

	}

	addScalar( s ) {

		this.x += s;
		this.y += s;
		this.z += s;
		this.w += s;

		return this;

	}

	addVectors( a, b ) {

		this.x = a.x + b.x;
		this.y = a.y + b.y;
		this.z = a.z + b.z;
		this.w = a.w + b.w;

		return this;

	}

	addScaledVector( v, s ) {

		this.x += v.x * s;
		this.y += v.y * s;
		this.z += v.z * s;
		this.w += v.w * s;

		return this;

	}

	sub( v ) {

		this.x -= v.x;
		this.y -= v.y;
		this.z -= v.z;
		this.w -= v.w;

		return this;

	}

	subScalar( s ) {

		this.x -= s;
		this.y -= s;
		this.z -= s;
		this.w -= s;

		return this;

	}

	subVectors( a, b ) {

		this.x = a.x - b.x;
		this.y = a.y - b.y;
		this.z = a.z - b.z;
		this.w = a.w - b.w;

		return this;

	}

	multiply( v ) {

		this.x *= v.x;
		this.y *= v.y;
		this.z *= v.z;
		this.w *= v.w;

		return this;

	}

	multiplyScalar( scalar ) {

		this.x *= scalar;
		this.y *= scalar;
		this.z *= scalar;
		this.w *= scalar;

		return this;

	}

	applyMatrix4( m ) {

		const x = this.x, y = this.y, z = this.z, w = this.w;
		const e = m.elements;

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

		return this;

	}

	divideScalar( scalar ) {

		return this.multiplyScalar( 1 / scalar );

	}

	setAxisAngleFromQuaternion( q ) {

		// http://www.euclideanspace.com/maths/geometry/rotations/conversions/quaternionToAngle/index.htm

		// q is assumed to be normalized

		this.w = 2 * Math.acos( q.w );

		const s = Math.sqrt( 1 - q.w * q.w );

		if ( s < 0.0001 ) {

			this.x = 1;
			this.y = 0;
			this.z = 0;

		} else {

			this.x = q.x / s;
			this.y = q.y / s;
			this.z = q.z / s;

		}

		return this;

	}

	setAxisAngleFromRotationMatrix( m ) {

		// http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToAngle/index.htm

		// assumes the upper 3x3 of m is a pure rotation matrix (i.e, unscaled)

		let angle, x, y, z; // variables for result
		const epsilon = 0.01,		// margin to allow for rounding errors
			epsilon2 = 0.1,		// margin to distinguish between 0 and 180 degrees

			te = m.elements,

			m11 = te[ 0 ], m12 = te[ 4 ], m13 = te[ 8 ],
			m21 = te[ 1 ], m22 = te[ 5 ], m23 = te[ 9 ],
			m31 = te[ 2 ], m32 = te[ 6 ], m33 = te[ 10 ];

		if ( ( Math.abs( m12 - m21 ) < epsilon ) &&
		     ( Math.abs( m13 - m31 ) < epsilon ) &&
		     ( Math.abs( m23 - m32 ) < epsilon ) ) {

			// singularity found
			// first check for identity matrix which must have +1 for all terms
			// in leading diagonal and zero in other terms

			if ( ( Math.abs( m12 + m21 ) < epsilon2 ) &&
			     ( Math.abs( m13 + m31 ) < epsilon2 ) &&
			     ( Math.abs( m23 + m32 ) < epsilon2 ) &&
			     ( Math.abs( m11 + m22 + m33 - 3 ) < epsilon2 ) ) {

				// this singularity is identity matrix so angle = 0

				this.set( 1, 0, 0, 0 );

				return this; // zero angle, arbitrary axis

			}

			// otherwise this singularity is angle = 180

			angle = Math.PI;

			const xx = ( m11 + 1 ) / 2;
			const yy = ( m22 + 1 ) / 2;
			const zz = ( m33 + 1 ) / 2;
			const xy = ( m12 + m21 ) / 4;
			const xz = ( m13 + m31 ) / 4;
			const yz = ( m23 + m32 ) / 4;

			if ( ( xx > yy ) && ( xx > zz ) ) {

				// m11 is the largest diagonal term

				if ( xx < epsilon