class Wall {
    PVector start, end;

    Wall(PVector s, PVector e) {
        start = s.copy();
        end = e.copy();
    }

    void show() {
        stroke(255);
        fill(255);
        line(start.x, start.y, end.x, end.y);
        stroke(0,0,255);
        fill(0,0,255);
        ellipse(start.x, start.y, PROJECTILE_RADIUS*2, PROJECTILE_RADIUS*2);
        ellipse(end.x, end.y, PROJECTILE_RADIUS*2, PROJECTILE_RADIUS*2);
    }
}