Method and apparatus for fast flicker-free displaying overlapped sparse graphs with optional shape

A method for converting graphic elements containing sparse graphs into graphic layers is described, comprising the steps of: correspondingly mapping respective sparse graphs to respective sparse graphic layers, and projecting sequentially from top to bottom the regular graphs between the sparse graphs into a projection plane to form a regular graphic composition layer. Also described is a method for fast flicker-free displaying overlapped sparse graphs with optional shape, comprising: converting graphic element containing sparse graphs to be displayed into graphic layers; deciding whether to plot or erase the sparse graph to be displayed, and, when the sparse graph is decided to be erased, setting various points on the corresponding sparse graph to be transparent; and completing the plotting of points of the sparse graph point by point based on the shape of the sparse graph to be displayed. Apparatuses corresponding to the above methods are also described.