Sams Teach Yourself Windows® Phone 7 Game Programming in 24 Hours

Hour 10. When Objects Collide

What You’ll Learn in This Hour:

• Boundary collision detection

• Radial collision detection

• Assessing the damage

Thus far, we have learned a lot about drawing things on the small but high-resolution screen of WP7 devices. Drawing is only the first step in making a game. There must be some way for objects to interact, to affect each other during gameplay. This interaction usually involves bumping into each other, which might be a rocket hitting an alien ship, a soldier jumping on top of a crate, a plumber bonking evil turtles, a blue hedgehog grabbing coins, a yellow mouth eating dots. The list goes on and on. In every case, there is a situation in which one sprite “touches” another, triggering some event. Detecting ...