fixed bug: ticks_since_last_event wasn't getting reset on button hold release

The visible symptom was: Ramp up for 1s or longer, release, wait more than 1s,
then hold again.  It should ramp up, but it would ramp down instead.  The
clause for resetting ramp_direction wasn't happening, because the EV_tick
counter started at a value higher than 1s where it would normally trigger.

The underlying cause was a bit complicated.  Recent changes in PCINT_inner()
were causing ticks_since_last_event to get set to 0 (at push_event()) and then
back to its previous value (at emit_current_event()).  The EV_tick counter would
then start at whatever the button release event used.

The fix involved removing the part of emit_current_event() where it would
set ticks_since_last_event to "arg".  That line was a very old bug which simply
hadn't caused any visible issues until recently.  Instead, it needs to set
ticks_since_last_event more carefully, at other locations.  Specifically, it
resets to 0 now in empty_event_sequence() and one more location in the deferred
WDT handler (when HOLD_TIMEOUT triggers).

Additionally, push_event() was only ever used from PCINT_inner()...  so I moved
the tick reset logic to PCINT_inner() instead.  This allows us to decrease size
by about 10 bytes, since PCINT_inner() no longer needs to copy the counter before
it gets reset.  However, it also means push_event() should never be called from
any other function.

1 files changed, 2 insertions, 2 deletions

diff --git a/spaghetti-monster/fsm-pcint.c b/spaghetti-monster/fsm-pcint.c
index eacc699..021a076 100644
--- a/spaghetti-monster/fsm-pcint.c
+++ b/spaghetti-monster/fsm-pcint.c
@@ -101,9 +101,9 @@ void PCINT_inner(uint8_t pressed) {
         emit_current_event(0);
     } else {  // user released button
         // how long was the button held?
-        uint16_t ticks_since_last = ticks_since_last_event;
         push_event(B_RELEASE);
-        emit_current_event(ticks_since_last);
+        emit_current_event(ticks_since_last_event);
     }
+    ticks_since_last_event = 0;
 }
 #endif