Fix low FPS if a mouse, graphics tablet, or game controller is plugged in

[nmlgc]

On my system, TH09 is the only game affected by this, but there have been reports of TH11 causing the same issue on other systems. Therefore, this is not a DirectX 8 vs. DirectX 9 issue that could be solved with a converter DLL. It also happens in both DirectInput and WinMM modes.

[nmlgc]

Also triggered by USB microphones. The more devices are plugged in, the worse the FPS get.

[DankRank]

Also th10, th12. Maybe others.

[DankRank]

In my experience FPS can be improved by removing any HID device from the system. My old keyboard had many of those, but only one was used for the actual input (others were for macro keys). My UPS also shows up as a HID device.

Restarting the computer also seems to help.

Here are links to other people having the problem (posted these in the discord a long time ago)
https://www.shrinemaiden.org/forum/index.php?topic=8111.0
https://answers.microsoft.com/en-us/windows/forum/windows_7-gaming/touhou-games-running-at-about-25fps-instead-at/ea3d85d3-3344-e011-90b6-1cc1de79d2e2

[nmlgc]

Changing TH09's controller settings in custom.exe to keyboard rather than gamepad fixes the problem for me, even though I don't have any gamepad connected. Changing only one of the two players to keyboard still leaves a drop of about 10 FPS.

[nmlgc]

Started happening to me with TH06 now.