366 8. Human Interface Devices (HID)
player or camera code itself. That way, if the camera decides to ignore
the deflection of the right thumb stick, for example, other game engine
systems still have the freedom to read the state of that stick for other
purposes.8.6 Human Interface Devices in Practice
Correct and smooth handling of human interface devices is an important part
of any good game. Conceptually speaking, HIDs may seem quite straightfor-
ward. However, there can be quite a few “gotchas” to deal with, including
variations between diff erent physical input devices, proper implementation
of low-pass fi ltering, bug-free handling of control scheme mappings, achiev-
ing just the right “feel” in your joypad rumble, limitations imposed by console
manufacturers via their technical requirements checklists (TRCs), and the list
goes on. A game team should expect to devote a non-trivial amount of time
and engineering bandwidth to a careful and complete implementation of the
human interface device system. This is extremely important because the HID
system forms the underpinnings of your game’s most precious resource—its
player mechanics.