Doing multiple rectangles rotated around a common point would not be ideal however, would definitely be the easiest way to get a circular (relatively) boundary to check against a rectangles boundary. you could perhaps figure out a clever way to use pixel checking for collision in comparison for colors. This also inst a great way to do it, but you would need to put your frame to a sf::Image and use getPixel(x, y); and use some fancy equations to create coordinates to check for a circular boundary. The downfall is that you would have to check collision with color.