code: public static int[] getTileScreenSize(double[] worldSize, double scale) {
  		int screenWidth = (int) Math.round(scale * worldSize[0]);
  		int screenHeight = (int) Math.round(scale * worldSize[1]);
  		return new int[] { screenWidth, screenHeight };
  	}
docs: Calculate the screen size of a tile. Normally the screen size is expressed in pixels and should therefore be
  integers, but for the sake of accuracy we try to keep a double value as long as possible.
  
  @param worldSize
  The width and height of a tile in the layer's world coordinate system.
  @param scale
  The current client side scale.
  @return Returns an array of double values where the first value is the tile screen width and the second value is
  the tile screen height.