inside BJoystick.
* Add joystick_module_info flag to communicate support for variably sized reads.
* The variably sized data structure is set up to describe either the actual
amount of data, when variably sized reads are supported by the driver, or it
is set up so that it exactly matches the data layout of the extended_joystick
structure. This allows us to support both as input data, while only needing to
care about a single format inside BJoystick. Convenience pointers allow the
data to be retrieved without additional overhead or extra logic.
* Add some sanity checks and ensure some boundaries when dealing reading data
from the variably sized structure (as there might not be any buttons, hats,
axis at all now).
* Ensure that the extended_joystick structure doesn't change in size due to
padding by making it _PACKED (it wasn't padded though).
This is still supposed to work exactly as before. However, it opens up the
possibility to actually support arbitrary controllers with arbitrary axis, hat
and button counts. It therefore allows to actually deliver what the BJoystick
API was designed to handle all along.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@41885 a95241bf-73f2-0310-859d-f6bbb57e9c96
ab1763688f