docs: public void setDirectionArrow(final Bitmap image){
  		this.DIRECTION_ARROW = image;
  		this.DIRECTION_ARROW_CENTER_X = this.DIRECTION_ARROW.getWidth() / 2 - 0.5f;
  		this.DIRECTION_ARROW_CENTER_Y = this.DIRECTION_ARROW.getHeight() / 2 - 0.5f;
  		this.DIRECTION_ARROW_HEIGHT = this.DIRECTION_ARROW.getHeight();
  		this.DIRECTION_ARROW_WIDTH = this.DIRECTION_ARROW.getWidth();
  	}