Input and games.

[Bill Spitzak]

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.

One idea I remember from Irix was that all the analog controls were 
1-dimensional. A mouse was actually 2 analog controls. This avoids the 
need to define how many degrees of freedom a control has, instead it is 
just N different controls. Quaternions are a problem though because the 
4 numbers are not independent so there must be a way to get a set of 
changes together.

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).