Complications with Cross-Platform Input Handling
It was bound to happen eventually, but the input handling module is the first part of the project to display different behavior across platforms. winit provides a fairly solid basis for input handling, but Windows and Linux differ in terms of what sort of event is delivered to the program.
Initially, I used
WindowEvents for everything. This works perfectly well for
keystrokes and mouse clicks, but mouse movement may still have acceleration
applied, which is undesirable for camera control.
winit also offers
DeviceEvents for this purpose. I tried just handling mouse movement with raw
input, keeping all other inputs in
WindowEvents, but it seems that handling
DeviceEvents on Linux causes the
WindowEvents to be eaten.
The next obvious solution is to simply handle everything with
but this presents additional problems. First, Windows doesn't seem to even
deliver keyboard input as a
DeviceEvent -- keyboard input still needs to be
polled as a
WindowEvent. It also means that window focus has to be handled
DeviceEvents are delivered regardless of whether the window
is focused or not.
To add to the complexity of this problem, apparently not all window managers
are well-behaved when it comes to determining focus. I run i3wm on my
Linux install, and it doesn't deliver
WindowEvent::Focused events when
toggling focus or switching workspaces. This will have to remain an unsolved
problem for the time being.