Method invert

src/math/Matrix3.js:293–325

* Inverts this matrix, using the [analytic method](https://en.wikipedia.org/wiki/Invertible_matrix#Analytic_solution). * You can not invert with a determinant of zero. If you attempt this, the method produces * a zero matrix instead. * * @return {Matrix3} A reference to this matrix.

()

	 * @return {Matrix3} A reference to this matrix.
	 */
	invert() {

		const te = this.elements,

			n11 = te[ 0 ], n21 = te[ 1 ], n31 = te[ 2 ],
			n12 = te[ 3 ], n22 = te[ 4 ], n32 = te[ 5 ],
			n13 = te[ 6 ], n23 = te[ 7 ], n33 = te[ 8 ],

			t11 = n33 * n22 - n32 * n23,
			t12 = n32 * n13 - n33 * n12,
			t13 = n23 * n12 - n22 * n13,

			det = n11 * t11 + n21 * t12 + n31 * t13;

		if ( det === 0 ) return this.set( 0, 0, 0, 0, 0, 0, 0, 0, 0 );

		const detInv = 1 / det;

		te[ 0 ] = t11 * detInv;
		te[ 1 ] = ( n31 * n23 - n33 * n21 ) * detInv;
		te[ 2 ] = ( n32 * n21 - n31 * n22 ) * detInv;

		te[ 3 ] = t12 * detInv;
		te[ 4 ] = ( n33 * n11 - n31 * n13 ) * detInv;
		te[ 5 ] = ( n31 * n12 - n32 * n11 ) * detInv;

		te[ 6 ] = t13 * detInv;
		te[ 7 ] = ( n21 * n13 - n23 * n11 ) * detInv;
		te[ 8 ] = ( n22 * n11 - n21 * n12 ) * detInv;

		return this;

	}

	/**
	 * Transposes this matrix in place.