>During debugging, I discovered that we're actually getting events showing
>*future* tap positions! Since I don't think we've invented a time machine
>(reminiscent of Jame's Hogan's "Thrice Upon a Time") I'm assuming that the
>pen-up/down structures are corrupted *after* they're already enqueued.
After an "arguetecting" session, we decided it looks like pen-up and pen-down
events are handled somewhat differently...
It looks like the pen coordinates of pen-down events are remembered "properly" -
as you'd expect; the event with its associated pen coordinates.
But it looks like only the *last* pen UP coordinate is remembered, although it
seems to remember that a pen up occured.
so a sequence like:
d 26, 6 'z' u 26, 6
d 25, 25 'f' u 26, 22
d 42, 6 'v' u 42, 6
d 43, 20 'i' u 43, 20
d 57, 7 'c' u 57, 7
d 59, 20 't' u 59, 20
d 69, 8 'h' u 71, 21* 'H'
d 71, 21 'a' u 84, 20* 'A'
d 80, 8 'w' u 99, 14* 'W'
d 84, 20 'l' u 99, 14* 'L'
d 97, 3 'k' u 99, 14* 'K'
d 99, 14 'y' u 99, 14
happens something like this...
up until the pen-down for the H is fine...
then (chronologically) we have:
event 1: pen-down at 69,8 (for the H)
event 2: pen-up - remember that a penUp occured,
and remember the "last pen-up position" as 69,8
At this point, Fitaly calls EvtGetEvent and gets event 1; penDown with the
proper coordinates
event 3: pen-down at 71,21 (for the A)
event 4: pen-up - remember that this penUp occured,
and update the "last pen-up position" as 71,21
At this point, Fitaly calls EvtGetEvent and gets event 2; penUp, but with the
now-wrong (for that penUp event) coordinates of 71,21
pen-down at 80,8 (for the W)
pen-up - remember that this penUp occured, and update the "last pen-up position"
as 80, 8
event 5: pen-down at 84, 20 (for the L)
event 6: pen-up - remember that this penUp occured,
and update the "last pen-up position" as 84, 20
Fitaly gets event 3; penDown with the proper coordinates
Fitaly gets event 4; penUp, but with the now-wrong (for that penUp event)
coordinates of 84, 20
event 7: pen-down at 97,3 (for the K)
event 8: pen-up - remember that this penUp occured,
and update the "last pen-up position" as 97,3
Fitaly gets event 5; penDown with the proper coordinates
event 9: pen-down at 99,14 (for the Y)
event 10:
pen-up - remember that this penUp occured,
and update the "last pen-up position" as 99,14
Fitaly gets event 6; penUp, but with the now-wrong (for that penUp event)
coordinates of 99, 14
Fitaly gets event 7; penDown with the proper coordinates
Fitaly gets event 8; penUp, but with the now-wrong (for that penUp event)
coordinates of 99, 14
Fitaly gets event 9; penDown with the proper coordinates
Fitaly gets event 9; penUp with the proper coordinates (because there were no
more penUp events to corrupt the "last pen-up position"
Naturally, I'm showing Fitaly processing the events "just so" the errors make
sense; there can be some jitter in the above sequence and failures still occur
properly - I don't have any way to track the processing and pen activity quite
that closely... (darn! I wish I could trap the pen enqueuing! :)
Is this what's happening under the covers? Is it really not tracking each penUp
position individually?
- Al -
--
-- Alan Weiner -- [EMAIL PROTECTED] -- http://www.ajw.com
