[very WIP]
You have installed a single camera somewhere in the interior of a room.
The room is described as a polygon with axis-aligned sides.
You wish to determine the area of the room that is visible from the camera,
modeled as a point that can see in all directions.
The complication is that the walls of the room are actually low-quality mirrors,
such that any part of the room from which light can reach the camera via at most one
reflection is visible from the camera (but not two or more reflections).

Author's note: The problem idea I originally wanted to propose was to compute the area
of the region in which you could install the camera such that it can see the entire
room. The case without reflections is well-known (it's called the "kernel" of a
polygon); however, the case with just one layer of reflections is really hairy
(it turns out it's not even polygonal).
