code: def point(self, pos):
          
          return ((1 - pos) ** 3 * self.start) + \
                 (3 * (1 - pos) ** 2 * pos * self.control1) + \
                 (3 * (1 - pos) * pos ** 2 * self.control2) + \
                 (pos ** 3 * self.end)
docs: Calculate the x,y position at a certain position of the path