Input and games.

[Daniel Stone]

Hi,

On 29 April 2013 18:44, Bill Spitzak <spitzak at gmail.com> wrote:
> Has anybody thought about pens (ie wacom tablets)? These have 5 degrees of
> freedom (most cannot distinguish rotation about the long axis of the pen).
> There are also spaceballs with full 6 degrees of freedom.

As Todd said, these really need to be their own interface.  From a
purely abstract point of view, they kind of look the same, but if you
have one interface to represent everything, that interface ends up
looking a lot like XI2, which no-one uses because it's a monumental
pain in the behind.

The biggest blocker though, is that the compositor addresses gamepads
and tablets completely differently.  Tablets have particular focus,
and their co-ordinates need to be interpreted and scaled to
surface-local, whereas gamepads are going to have co-ordinates in a
totally different space, which is sometimes angular rather than
positional in a 2D space.

So, again, a tablet interface is a very useful thing to have - and
it's a discussion we absolutely need to have at some point - but it
has no bearing at all on this one.  A good starting point would be to
look at the X.Org Wacom driver and its capability set.

> Another idea was that buttons had the same api as analog controls, it's just
> that they only reported 0 or +1, never any fractions (and since it sounds
> like some controls have pressure-sensitive buttons this may make it easier
> to use the same code on different controls).

I think this falls into the same over-generalising trap, where you
look like a smart alec but don't produce anything near like a usable
API.

Cheers,
Daniel