package Collision
import Entity

public constant globalWorld = new CollisionWorld(playableMapRect)

public tuple rectangle(vec2 min, vec2 max)

public function rectangle.intersect(rectangle other) returns boolean
	return not (other.min.x > this.max.x or other.max.x < this.min.x or other.max.y > this.min.y or other.min.y < this.max.y)

public function rectangle.contains(vec2 point) returns boolean
	return point.x > this.min.x and point.x < this.max.x and point.y > this.min.y and point.y < this.max.y


public interface CollisionShape
	abstract function intersect(Entity e1, Entity e2) returns boolean

public abstract class CollisionListener
	abstract function onHit(Entity other)

public class SphereShape implements CollisionShape

	override function intersect(Entity e1, Entity e2) returns boolean
		return (e1.getPos() + vec3(0, 0, e1.radius / 2) ).distanceToSq(e2.getPos() + vec3(0, 0, e1.radius / 2)) <= e1.radius2 + e2.radius2

public constant SHAPE_SPHERE = new SphereShape()

public function registerCollider(Entity e, CollisionShape shape, CollisionListener listener)
	shapes[e castTo int] = shape
	listeners[e castTo int] = listener
	globalWorld.colliders.add(e)

public function registerCollidable(Entity e, CollisionListener listener)
	listeners[e castTo int] = listener
	globalWorld.collidables.add(e)

public function removeCollidable(Entity e)
	if listeners[e castTo int] != null
		destroy listeners[e castTo int]
		listeners[e castTo int] = null
	globalWorld.collidables.remove(e)

public function removeCollider(Entity e)
	if listeners[e castTo int] != null
		destroy listeners[e castTo int]
		listeners[e castTo int] = null
	globalWorld.colliders.remove(e)

CollisionShape array shapes
CollisionListener array listeners
public class CollisionWorld
	rectangle worldBounds
	let colliders = new LinkedList<Entity>()
	let collidables = new LinkedList<Entity>()

	construct(rect re)
		worldBounds = rectangle(vec2(re.getMinX(), re.getMinY()), vec2(re.getMaxX(), re.getMaxY()))

	function update(real _delta)
		for collider in colliders
			for collidable in collidables
				if collider != null and not collider.done and collidable != null and not collidable.done and collider != collidable and shapes[collider castTo int].intersect(collider, collidable)
					listeners[collider castTo int].onHit(collidable)
					listeners[collidable castTo int].onHit(collider)