BBGamelib.CGAffineTransform.Invert C# (CSharp) Method

		public static CGAffineTransform Invert(CGAffineTransform xform){
			CGAffineTransform result;
			float determinant;
			
			determinant=xform.a*xform.d-xform.c*xform.b;
			if(FloatUtils.EQ(determinant, 0)){
				return xform;
			}
			
			result.a=xform.d/determinant;
			result.b=-xform.b/determinant;
			result.c=-xform.c/determinant;
			result.d=xform.a/determinant;
			result.tx=(-xform.d*xform.tx+xform.c*xform.ty)/determinant;
			result.ty=(xform.b*xform.tx-xform.a*xform.ty)/determinant;
			
			return result;
		}
		public static CGAffineTransform Concat(CGAffineTransform xform,CGAffineTransform append){

        public CGAffineTransform parentToNodeTransform()
        {
            if (_isInverseDirty)
            {
                _inverse        = CGAffineTransform.Invert(nodeToParentTransform());
                _isInverseDirty = false;
            }

            return(_inverse);
        }