rotaryio: shared_module_softencoder_state_update: no need for BAD state

All we do on a BAD state transition is avoid counting up or down,
but the same is accomplished by using the "0" table value instead.

Author: jepler

shared-module/rotaryio/IncrementalEncoder.c

@@ -35,21 +35,20 @@ void shared_module_softencoder_state_init(rotaryio_incrementalencoder_obj_t *sel
 }
 
 void shared_module_softencoder_state_update(rotaryio_incrementalencoder_obj_t *self, uint8_t new_state) {
-    #define BAD 7
     static const int8_t transitions[16] = {
         0,    // 00 -> 00 no movement
         -1,   // 00 -> 01 3/4 ccw (11 detent) or 1/4 ccw (00 at detent)
         +1,   // 00 -> 10 3/4 cw or 1/4 cw
-        BAD,  // 00 -> 11 non-Gray-code transition
+        0,     // 00 -> 11 non-Gray-code transition
         +1,   // 01 -> 00 2/4 or 4/4 cw
         0,    // 01 -> 01 no movement
-        BAD,  // 01 -> 10 non-Gray-code transition
+        0,    // 01 -> 10 non-Gray-code transition
         -1,   // 01 -> 11 4/4 or 2/4 ccw
         -1,   // 10 -> 00 2/4 or 4/4 ccw
-        BAD,  // 10 -> 01 non-Gray-code transition
+        0,    // 10 -> 01 non-Gray-code transition
         0,    // 10 -> 10 no movement
         +1,   // 10 -> 11 4/4 or 2/4 cw
-        BAD,  // 11 -> 00 non-Gray-code transition
+        0,    // 11 -> 00 non-Gray-code transition
         +1,   // 11 -> 01 1/4 or 3/4 cw
         -1,   // 11 -> 10 1/4 or 3/4 ccw
         0,    // 11 -> 11 no movement
@@ -60,10 +59,6 @@ void shared_module_softencoder_state_update(rotaryio_incrementalencoder_obj_t *s
     self->state = new_state;
 
     int8_t quarter_incr = transitions[idx];
-    if (quarter_incr == BAD) {
-        // Missed a transition. We don't know which way we're going, so do nothing.
-        return;
-    }
 
     self->quarter_count += quarter_incr;