All right, you’ve built a solid design and have the start of what could become a pretty cool game. Again, the concept of the game is that a player will control one sprite and try to avoid hitting the chasing sprites as they fly across the screen, while also trying to catch the evading sprites. Now you need to add some scoring and some game logic and do some other fine-tuning to get your game to where you want it.
The first thing you’ll do in this chapter is add some scoring to your game. The first step when you’re writing a game and you start to look at scoring is to decide what events will trigger a change in score. Sometimes scores will change when a weapon of some kind hits the player. At other times, you’ll change the score when the player hits something herself. Still other times, you’ll want to change the score when the user accomplishes something (e.g., answers a question, solves a puzzle, etc.).
In this game, you’re going to change the score when an enemy sprite leaves the screen without having run into the player (meaning that the player successfully avoided that sprite).
It would make sense, given that scoring mechanism, for you to add a score value to each individual sprite. Some sprites might be worth more than others, based on their speed or some other factor that you determine.
In addition to deciding how to calculate the score, you need to be able to draw the score on the screen. We’ll tackle that side of the scoring problem first, and ...