}
protected void makeWorld() {
world = new GridLimitedOptionsWorld(20, 20, cellwidth, cellheight);
Body wall = new Phys2DBody( new StaticBox(4*cellwidth, cellheight), 10, true );
wall.setLocation(2*cellwidth, 10*cellheight+0.5*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(4*cellwidth, cellheight), 10, true );
wall.setLocation(7*cellwidth, 10*cellheight+0.5*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(cellwidth, 2*cellheight), 10, true );
wall.setLocation(9*cellwidth+0.5*cellwidth, cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(cellwidth, 12*cellheight), 10, true );
wall.setLocation(9*cellwidth+0.5*cellwidth, 9*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(cellwidth, 4*cellheight), 10, true );
wall.setLocation(9*cellwidth+0.5*cellwidth, 18*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(6*cellwidth, cellheight), 10, true );
wall.setLocation(13*cellwidth, 8*cellheight+0.5*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
wall = new Phys2DBody( new StaticBox(3*cellwidth, cellheight), 10, true );
wall.setLocation(18.5*cellwidth, 8*cellheight+0.5*cellheight);
wall.setType(Body.OBSTACLE);
world.addFixedBody(wall);
rf = new GridRewardFunction();