Anti-aliasing

In the previous sections, we worked on producing pixel-by-pixel lines where one pixel was chosen over another in order to create a continual line or circle. If you zoom in on these pixels, however, you will find that they are quite jagged in appearance, as illustrated by the zoomed-in section of a circle shown in Figure 3.10:

Figure 3.10: A zoomed-in section of the Bresenham circle pixels

This effect occurs because of the way that integer values are chosen to represent the drawing. However, when we looked at the actual equations for lines and circles in the The Naïve Way: Drawing a line with brute force and Drawing Circles the Bresenham way sections, it was clear they involved floating-point values and seemed to pass through more than one pixel. To improve the look of these kinds of drawings, a process called anti-aliasing is employed to blur the pixels that are neighbors of the line pixels to fade the edges of the line. Figure 3.11 shows...