The animation demo for this section is one in which a background, a clear night’s sky, is invaded by a flying saucer that bounces about, probably looking for someone to abduct. The program is actually quite simple—in fact, much simpler than the Win32 version, which involved using a series of BitBlt() and masking operations to achieve transparency.
The Win32 Version of the application is still around and compiled under VCL.NET. You’ll find it under the CD directory:
First, let’s look at the class that contains the sprite, the flying saucer. This is shown in Listing 7.22.
1: type 2: 3: TSpriteDirection = (sdLeft, sdRight, sdUp, sdDown); 4: TSpriteDirections ...