code: boolean intersect(float x, float y, float radius) {
  		return (x1 < (x + radius) && x2 > (x - radius) &&
  				y1 < (y + radius) && y2 > (y - radius));
  	}
docs: Utility method to check if light is on the screen
  @param x      - light center x-coord
  @param y      - light center y-coord
  @param radius - maximal light distance
  
  @return true if camera screen intersects or contains provided
  light, represented by circle/box area