Research And Hardware Realization Of Line Raster And Anti-aliasing Algorithm

The Compass is one of the most important figures in cockpit display system, through which the pilot obtains airplane`s status. The dial on the compass has to rotate according to the changing status. In raster display system, this process is just to redraw lots of short lines which to form the dial. So how to quickly draw multiple short lines and alleviate distortion on the edge in limited times is one of the most important guidelines when designing the compass display system.The paper realizes line-raster module with anti-aliasing characteristic. The research contents and innovation are listd as follows:Had mapped arbitrary lines to referenced lines in specialized area. The hardware only has to realize raster function oriented to lines in the specialized area.Applied edge-judge function and area-traversal method as line-raster algorithm, which is to simplify the procedure of drawing multi-pixel wide lines and also to unify raster and anti-aliasing two processes.Combined lookup-table and linear interpolation two methods in realization of division module, which reduces computation error.The realization of line-raster module based on xc2vp30ff1152-6 FPGA platform, is programmed with VerilogHDL, synthesized by ISE, simulated in Modelsim. After synthesized and tested, the realization can work normally under 70MHZ, the system display rate exceeds 24frames/s, and the occupied resource is limited to 20%, which are consistent with system requirement.