public decompose()

in packages/common/src/math/matrix.ts [554:603]
43 lines of code
13 McCabe index (conditional complexity)

	public decompose(scale?: Vector3, rotation?: Quaternion, translation?: Vector3): boolean {
		if (this._isIdentity) {
			if (translation) {
				translation.setAll(0);
			}
			if (scale) {
				scale.setAll(1);
			}
			if (rotation) {
				rotation.copyFromFloats(0, 0, 0, 1);
			}
			return true;
		}

		const m = this._m;
		if (translation) {
			translation.copyFromFloats(m[12], m[13], m[14]);
		}

		scale = scale || MathTmp.Vector3[0];
		scale.x = Math.sqrt(m[0] * m[0] + m[1] * m[1] + m[2] * m[2]);
		scale.y = Math.sqrt(m[4] * m[4] + m[5] * m[5] + m[6] * m[6]);
		scale.z = Math.sqrt(m[8] * m[8] + m[9] * m[9] + m[10] * m[10]);

		if (this.determinant() <= 0) {
			scale.y *= -1;
		}

		if (scale.x === 0 || scale.y === 0 || scale.z === 0) {
			if (rotation) {
				rotation.copyFromFloats(0.0, 0.0, 0.0, 1.0);
			}
			return false;
		}

		if (rotation) {
			const sx = 1 / scale.x, sy = 1 / scale.y, sz = 1 / scale.z;
			Matrix.FromValuesToRef(
				m[0] * sx, m[1] * sx, m[2] * sx, 0.0,
				m[4] * sy, m[5] * sy, m[6] * sy, 0.0,
				m[8] * sz, m[9] * sz, m[10] * sz, 0.0,
				0.0, 0.0, 0.0, 1.0,
				MathTmp.Matrix[0]
			);

			Quaternion.FromRotationMatrixToRef(MathTmp.Matrix[0], rotation);
		}

		return true;
	}