Sams Teach Yourself Android Game Programming in 24 Hours

Hour 21. Collision Detection

What You’ll Learn in This Hour

• Collision detection techniques

• Bounding rectangles (box collision)

• Bounding circles (radial collision)

• Testing collision detection

Collision detection makes a game look and feel realistic by allowing objects to hit each other and react to those collision events. This hour explores the two most common and efficient techniques for detecting collisions between game objects, with a theoretical discussion of the algorithms and an applied example.

Collision Detection Techniques

The two collision techniques we will study get their names from the techniques they employ: bounding rectangles and bounding circles. We’ll study each in detail and then create an example to test collisions. ...