Re: [9front] nusb/kb mouse handling

[umbraticus@prosimetrum.com]

Thanks to sigrid, who committed the part of the patch that fixes my
trackball.  We decided to leave the button mapping for the time being.

Currently, if a USB mouse has more than three buttons, b4 acts as
another b2 and anything above that is ignored.  I had suggested
instead just sending through b4 and higher as is.  This results in b4
and b5 acting as alternatives for the scroll wheel; perhaps a nice
side effect for some mice:

	b |= s->b & ~6 | (s->b & 2) << 1 | (s->b & 4) >> 1;

Or perhaps extra buttons should be exposed in case anyone wants to
make use of them but not overlap with scroll wheel:

	b |= s->b & 1 | (s->b & 2) << 1 | (s->b & 4) >> 1 | (s->b & ~7) << 2;

The current behaviour was introduced with revison 3acb9fdd26cc
nusb/kb: map button 4 to middle button 2 (for logitech 5 button mouse)
so I assume someone wanted it.  What about b5 though?  Perhaps this
should be mapped to b3 for some kind of consistency?

 			/* map to mouse buttons */
 			b |= s->b & 1;
 			if(s->b & (4|8))
 				b |= 2;
-			if(s->b & 2)
+			if(s->b & (2|16))
 				b |= 4;

What do others think should happen to buttons >3?

umbraticus