-int rectcollision(base_type* one, base_type* two);
-int rectcollision_offset(base_type* one, base_type* two, float off_x, float off_y);
-int collision_swept_object_map(base_type* old, base_type* current);
-int collision_object_map(base_type* object);
+enum CollisionType {
+ COLLISION_NORMAL,
+ COLLISION_BUMP,
+ COLLISION_SQUISH
+};
+
+bool rectcollision(const base_type& one, const base_type& two);
+bool rectcollision_offset(const base_type& one, const base_type& two, float off_x, float off_y);
+
+void collision_swept_object_map(base_type* old, base_type* current);
+bool collision_object_map(const base_type& object);
+
+/** Return a pointer to the tile at the given x/y coordinates */
+Tile* gettile(float x, float y);
+
+// Some little helper function to check for tile properties
+bool issolid(float x, float y);
+bool isbrick(float x, float y);
+bool isice(float x, float y);
+bool isspike(float x, float y);
+bool isfullbox(float x, float y);
+
+typedef void* (*tiletestfunction)(Tile* tile);
+/** invokes the function for each tile the baserectangle collides with. The
+ * function aborts and returns true as soon as the tiletestfunction returns
+ * != 0 then this value is returned. returns 0 if all tests failed.
+ */
+void* collision_func(const base_type& base, tiletestfunction* function);