private void addPoint ( Point point , Collidable collidable ) { final Integer group = collidable . getGroup ( ) ; if ( ! collidables . containsKey ( group ) ) { collidables . put ( group , new HashMap < Point , Set < Collidable > > ( ) ) ; } final Map < Point , Set < Collidable > > elements = collidables . get ( group ) ; if ( ! elements . containsKey ( point ) ) { elements . put ( point , new HashSet < Collidable > ( ) ) ; } elements . get ( point ) . add ( collidable ) ; }
Add point . Create empty list of not existing .