Writing urandom to the framebuffer is a joy in and of itself. You actually reminded me to have users add themselves to the video and input group (which does require root privileges usually), but this way they can then run the library without sudo.
IDK about the video group, but being a member of the input group is a bit of a security concern, since it allows the user to monitor all keyboard input system-wide and even inject their own input events. No big deal if you're playing with a raspberry pi, but not something you'd want to do on your workstation.