The research and implementation of line anti-aliasing algorithm based on coordinate system rotation

This paper presents an algorithm of line antialiasing based on coordinate system rotation. The line direction for drawing is changed to horizontal or vertical one in new coordinate system. A pixel is divided into 16 grids. The weight of the grid point is the number of the grids which the point is in. The ratio of area is concluded by judging the position relationship of pixel grids and expanded rectangle. The single precision floating-point number is fully adopted in this algorithm comparing with traditional algorithm. The complexity of calculations is decreased in generation of expanded rectangle and area ratio of pixel. The shifter and adder is introduced which avoiding a lot of multiplications.