Method isIdentity

packages/melonjs/src/math/matrix3d.ts:778–800

* Check if the matrix is an identity matrix. * @returns true if the matrix is an identity matrix

()

	 * @returns true if the matrix is an identity matrix
	 */
	isIdentity() {
		const a = this.val;

		// check translation first (most commonly non-zero), then diagonal, then rest
		return (
			a[12] === 0 &&
			a[13] === 0 &&
			a[0] === 1 &&
			a[5] === 1 &&
			a[10] === 1 &&
			a[15] === 1 &&
			a[1] === 0 &&
			a[2] === 0 &&
			a[3] === 0 &&
			a[4] === 0 &&
			a[6] === 0 &&
			a[7] === 0 &&
			a[8] === 0 &&
			a[9] === 0 &&
			a[11] === 0 &&
			a[14] === 0
		);
	}

	/**
	 * return true if the two matrices are identical