Vasarely Dots

Saw a neat Victor Vasarely piece, Cassiopée, built on rotated snipped circles and had to make a version. You can try random arrangements or input functions.[br][br]If the functions are integer valued on integers, you'll get quarter turns, or you can output non-integers for more turns. The function on x & y is computed for position i,j in the array.

Information: Vasarely Dots