<!-- SOLIDIVISM · part 122 -->
4 matrix of which the upper 3x3 of matrix is a pure rotation matrix (i.e. unscaled).
	 * @param {string} [order] - A string representing the order that the rotations are applied.
	 * @param {boolean} [update=true] - Whether the internal `onChange` callback should be executed or not.
	 * @return {Euler} A reference to this Euler instance.
	 */
	setFromRotationMatrix( m, order = this._order, update = true ) {

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

		switch ( order ) {

			case 'XYZ':

				this._y = Math.asin( clamp( m13, -1, 1 ) );

				if ( Math.abs( m13 ) < 0.9999999 ) {

					this._x = Math.atan2( - m23, m33 );
					this._z = Math.atan2( - m12, m11 );

				} else {

					this._x = Math.atan2( m32, m22 );
					this._z = 0;

				}

				break;

			case 'YXZ':

				this._x = Math.asin( - clamp( m23, -1, 1 ) );

				if ( Math.abs( m23 ) < 0.9999999 ) {

					this._y = Math.atan2( m13, m33 );
					this._z = Math.atan2( m21, m22 );

				} else {

					this._y = Math.atan2( - m31, m11 );
					this._z = 0;

				}

				break;

			case 'ZXY':

				this._x = Math.asin( clamp( m32, -1, 1 ) );

				if ( Math.abs( m32 ) < 0.9999999 ) {

					this._y = Math.atan2( - m31, m33 );
					this._z = Math.atan2( - m12, m22 );

				} else {

					this._y = 0;
					this._z = Math.atan2( m21, m11 );

				}

				break;

			case 'ZYX':

				this._y = Math.asin( - clamp( m31, -1, 1 ) );

				if ( Math.abs( m31 ) < 0.9999999 ) {

					this._x = Math.atan2( m32, m33 );
					this._z = Math.atan2( m21, m11 );

				} else {

					this._x = 0;
					this._z = Math.atan2( - m12, m22 );

				}

				break;

			case 'YZX':

				this._z = Math.asin( clamp( m21, -1, 1 ) );

				if ( Math.abs( m21 ) < 0.9999999 ) {

					this._x = Math.atan2( - m23, m22 );
					this._y = Math.atan2( - m31, m11 );

				} else {

					this._x = 0;
					this._y = Math.atan2( m13, m33 );

				}

				break;

			case 'XZY':

				this._z = Math.asin( - clamp( m12, -1, 1 ) );

				if ( Math.abs( m12 ) < 0.9999999 ) {

					this._x = Math.atan2( m32, m22 );
					this._y = Math.atan2( m13, m11 );

				} else {

					this._x = Math.atan2( - m23, m33 );
					this._y = 0;

				}

				break;

			default:

				warn( 'Euler: .setFromRotationMatrix() encountered an unknown order: ' + order );

		}

		this._order = order;

		if ( update === true ) this._onChangeCallback();

		return this;

	}

	/**
	 * Sets the angles of this Euler instance from a normalized quaternion.
	 *
	 * @param {Quaternion} q - A normalized Quaternion.
	 * @param {string} [order] - A string representing the order that the rotations are applied.
	 * @param {boolean} [update=true] - Whether the internal `onChange` callback should be executed or not.
	 * @return {Euler} A reference to this Euler instance.
	 */
	setFromQuaternion( q, order, update ) {

		_matrix$2.makeRotationFromQuaternion( q );

		return this.setFromRotationMatrix( _matrix$2, order, update );

	}

	/**
	 * Sets the angles of this Euler instance from the given vector.
	 *
	 * @param {Vector3} v - The vector.
	 * @param {string} [order] - A string representing the order that the rotations are applied.
	 * @return {Euler} A reference to this Euler instance.
	 */
	setFromVector3( v, order = this._order ) {

		return this.set( v.x, v.y, v.z, order );

	}

	/**
	 * Resets the euler angle with a new order by creating a quaternion from this
	 * euler angle and then setting this euler angle with the quaternion and the
	 * new order.
	 *
	 * Warning: This discards revolution information.
	 *
	 * @param {string} [newOrder] - A string representing the new order that the rotations are applied.
	 * @return {Euler} A reference to this Euler instance.
	 */
	reorder( newOrder ) {

		_quaternion$4.setFromEuler( this );

		return this.setFromQuaternion( _quaternion$4, newOrder );

	}

	/**
	 * Returns `true` if this Euler instance is equal with the given one.
	 *
	 * @param {Euler} euler - The Euler instance to test for equality.
	 * @return {boolean} Whether this Euler instance is equal with the given one.
	 */
	equals( euler ) {

		return ( euler._x === this._x ) && ( euler._y === this._y ) && ( euler._z === this._z ) && ( euler._order === this._order );

	}

	/**
	 * Sets this Euler instance's components to values from the given array. The first three
	 * entries of the array are assign to the x,y and z components. An optional fourth entry
	 * defines the Euler order.
	 *
	 * @param {Array<number,number,number,?string>} array - An array holding the Euler component values.
	 * @return {Euler} A reference to this Euler instance.
	 */
	fromArray( array ) {

		this._x = array[ 0 ];
		this._y = array[ 1 ];
		this._z = array[ 2 ];
		if ( array[ 3 ] !== undefined ) this._order = array[ 3 ];

		this._onChangeCallback();

		return this;

	}

	/**
	 * Writes the components of this Euler instan