Hey guys in my first english post I decided to share how I implemented collision. For those who don't know, I'm currently playing with the Slick2D framework for Java developing some kind of RPG/tower defense thing (Yeah, I know, not a really clear idea).

Tile based collision really isn't much of a secret and there are tons of articles and tutorials on that topic. But I wanted a bit more complex shapes than saying whether a square tile is blocked or not. My first approach (which you can see on the right side) simply calculated a rectangle or polygon for each tile and placed them on the map. The result worked but was quite slow since for each tile you have to do a complicated collision. (By the way, for collision between any kind of shapes I'm just using the built-in functions of Slick, which might not be very fast or well implemented, but they work for now.) Read more »