Tile-Based Collision

Abstract

There are two main ways that you can check for collisions in games. The first is to compare the x and y pixel positions of sprites on the screen. If their shapes are overlapping, you have a collision. This is a collision detection strategy called narrow-phase collision. If you’ve used a game engine with collision functions that might have names like hitTestRectangle or hitTestCircle to check whether shapes are overlapping, it’s likely that these are narrow-phase collision functions. They use vector math (linear algebra) to figure out if the shapes of the sprites are overlapping. Because of that you can achieve very precise pixel-level collision accuracy, which is very important for physics-based action games.