/**
  * Check how much overlap there is on the right side of the rectangle.
  *
  * @param other rectangle of other object.
  * @return amount of overlap.
  */
 public final float overlapRight(GameObject other) {
   float overlap = 0;
   if (collidesWith(other) && getRight() <= other.getRight()) {
     overlap = getRight() - other.getLeft();
   }
   return overlap;
 }