This was an optimization I was trying to implement. I was trying to create a Mario game, but when I was doing collision testing I was testing the collisions from the character against every single object in the game. This was very inefficient. I did some searching and found out that some Game Engines use a data structure called a Quadtree. I tried to create one and this is what I came up with. I never did end up implementing it in the actual game.
In order to run this clone this repository. Then make sure you have Java installed and JAVA_HOME set in your environment variables. Then run:
java TestQuadTree
You can move the character around with the arrow keys.