Most of the drawing routines we’ve looked at so far have been relatively simple. They have resulted in a static rasterized image that is then composited to the screen.
In this chapter we will look at extending this to produce richer visual effects.
An animation is nothing more than a sequence of still images. Anything that allows you to produce still images can be used for animation, as long as you can do it fast enough. The human brain will create the illusion of movement when shown two similar images in quick succession. If you draw an image by a small distance from where it was last drawn, the viewer will perceive it as having moved.
The key here is the speed at which you update. Twenty-four ...