Area Filling Algorithms

Before we go ahead with area filling algorithms, a word about pixel addressing and object geometry. You know that line segments are discretized into finite number of pixels and each pixel has its height and width depending upon the aspect ratio of the display unit.Therefore, if you plot a single pixel it will occupy some area on display unit.  This contributes to the object geometry resulting in aberrations from the actual size.  For example, if you have to plot a line segment starting from (10,10) to (15,10), then length of the segment is 5 whereas, in plotting this line segment, six pixel areas will be contributing to this segment, resulting in increased length of line segment by one unit.