Ray Casting a transparent PNG in Java with LWJGL

Question

Im making a game and id like to implement raycasting for the hero's laser (and other stuff in the future), i have my sprites in a sprite sheet which i bind in the beggining and access when i draw since each element knows how to draw itself, but the spritesheet is a PNG, and thus some elements posess transparency, which works ok in openGL. i know each element's position, size etc but if some sprites have transparency, the position and size arent enough for the ray cast to be perfect since it would only hit the "bounding box". So is there a way to throw a ray using Bresenham algorithm (i believe it is the lightest way, correct me if im wrong) and make it pixel perfect in openGL, so that i can acquire the collision point of the ray with the actual non-transparent zone of the first sprite it appears in the way?

Answer 1

There is no easy way to do this. You would have to create a custom collision checker for your raycast to see if it would pass through or if it would collide with part of the sprite.

However it might be a better idea to use a smaller bounding box, or a circle to represent it, or both. These are much easier and faster to calculate then checking every pixel within the texture.