Displaying things
Now that we have our home ship moving about, we should test to see if it works. To do that, we need to decide how we're going to display everything that's going on, including the ship, enemies, and bullets. There are two main options:
- Draw an object once before the screen is displayed, and once after. Using
Pt-Change(, this should work correctly, and it's a better option for games where only a limited portion of the screen (such as a small set of characters) need to be drawn every frame. But in a shoot-em-up, everything moves. - Clear and redraw the screen every frame. This is a better option in this case because everything's changing so quickly.
Our first display routine goes in the main program:
Notice that I've also commented the lines prgmASHMUPM and prgmASHMUPR, since we haven't actually made those programs yet.
Well, how does it look? Compile it and see for yourself.
It's a bit fast, but it works well enough for now. It will slow down after we add the enemies and bullets anyway, and that's what we're doing next.
