What I want is basically: A way to blur every object/sprite on the scene, but have a "blur-free" circular zone, that can move. And everything that's behind that circular zone won't have the blur effect applied to it.
In a 2D mobile game, how would I do that, especially in a way that's not too heavy, performance-wise(if possible).
And if it's not possible to do that in a way that won't completely destroy my performance, I also have those sprites already "pre-blurred" so maybe there's a way to have both blurred and "unblurred" objects at the same position, and only draw the right parts of them as they go through the scene and reach the blur-free zone. If there's a way to do that, that'd also help immensely.
Thanks for your time.