-- Bezier.new(x1, y1, x2, y2)
-- @param numbers (x1, y1, x2, y2) The control points of your curve
-- @returns function(t [b, c, d])
--	@param number t the time elapsed [0, d]
--	@param number b beginning value being interpolated (default = 0)
--	@param number c change in value being interpolated (equivalent to: ending - beginning) (default = 1)
--	@param number d duration interpolation is occurring over (default = 1)