1 files changed, 137 insertions, 0 deletions
diff --git a/spaghetti-monster/fsm-events.c b/spaghetti-monster/fsm-events.c
new file mode 100644
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--- /dev/null
+++ b/spaghetti-monster/fsm-events.c
@@ -0,0 +1,137 @@
+/*
+ * fsm-events.c: Event-handling functions for SpaghettiMonster.
+ *
+ * Copyright (C) 2017 Selene ToyKeeper
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef FSM_EVENTS_C
+#define FSM_EVENTS_C
+
+// TODO: maybe compare events by number instead of pointer?
+//       (number = index in event types array)
+//       (comparison would use full event content, but send off index to callbacks)
+//       (saves space by using uint8_t instead of a pointer)
+//       (also eliminates the need to duplicate single-entry events like for voltage or timer tick)
+
+// return 1 if (a == b), 0 otherwise
+uint8_t compare_event_sequences(uint8_t *a, const uint8_t *b) {
+    for(uint8_t i=0; (i<EV_MAX_LEN) && (a[i] == pgm_read_byte(b+i)); i++) {
+        // end of zero-terminated sequence
+        if (a[i] == 0) return 1;
+    }
+    // if we ever fall out, that means something was different
+    // (or the sequence is too long)
+    return 0;
+}
+
+void empty_event_sequence() {
+    for(uint8_t i=0; i<EV_MAX_LEN; i++) current_event[i] = 0;
+}
+
+uint8_t push_event(uint8_t ev_type) {
+    ticks_since_last_event = 0;  // something happened
+    uint8_t i;
+    uint8_t prev_event = 0;  // never push the same event twice in a row
+    for(i=0; current_event[i] && (i<EV_MAX_LEN); i++)
+        prev_event = current_event[i];
+    if ((i < EV_MAX_LEN)  &&  (prev_event != ev_type)) {
+        current_event[i] = ev_type;
+        return 1;  // event pushed
+    } else {
+        // TODO: ... something?
+    }
+    return 0;  // no event pushed
+}
+
+// find and return last action in the current event sequence
+/*
+uint8_t last_event(uint8_t offset) {
+    uint8_t i;
+    for(i=0; current_event[i] && (i<EV_MAX_LEN); i++);
+    if (i == EV_MAX_LEN) return current_event[EV_MAX_LEN-offset];
+    else if (i >= offset) return current_event[i-offset];
+    return 0;
+}
+*/
+
+inline uint8_t last_event_num() {
+    uint8_t i;
+    for(i=0; current_event[i] && (i<EV_MAX_LEN); i++);
+    return i;
+}
+
+
+void append_emission(EventPtr event, uint16_t arg) {
+    uint8_t i;
+    // find last entry
+    for(i=0;
+        (i<EMISSION_QUEUE_LEN) && (emissions[i].event != NULL);
+        i++) { }
+    // add new entry
+    if (i < EMISSION_QUEUE_LEN) {
+        emissions[i].event = event;
+        emissions[i].arg = arg;
+    } else {
+        // TODO: if queue full, what should we do?
+    }
+}
+
+void delete_first_emission() {
+    uint8_t i;
+    for(i=0; i<EMISSION_QUEUE_LEN-1; i++) {
+        emissions[i].event = emissions[i+1].event;
+        emissions[i].arg = emissions[i+1].arg;
+    }
+    emissions[i].event = NULL;
+    emissions[i].arg = 0;
+}
+
+// Call stacked callbacks for the given event until one handles it.
+uint8_t emit_now(EventPtr event, uint16_t arg) {
+    for(int8_t i=state_stack_len-1; i>=0; i--) {
+        uint8_t err = state_stack[i](event, arg);
+        if (! err) return 0;
+    }
+    return 1;  // event not handled
+}
+
+void emit(EventPtr event, uint16_t arg) {
+    // add this event to the queue for later,
+    // so we won't use too much time during an interrupt
+    append_emission(event, arg);
+}
+
+// Search the pre-defined event list for one matching what the user just did,
+// and emit it if one was found.
+void emit_current_event(uint16_t arg) {
+    //uint8_t err = 1;
+    for (uint8_t i=0; i<(sizeof(event_sequences)/sizeof(EventPtr)); i++) {
+        if (events_match(current_event, event_sequences[i])) {
+            //DEBUG_FLASH;
+            //err = emit(event_sequences[i], arg);
+            //return err;
+            emit(event_sequences[i], arg);
+            return;
+        }
+    }
+    //return err;
+}
+
+// TODO? add events to a queue when inside an interrupt
+//       instead of calling the event functions directly?
+//       (then empty the queue in main loop?)
+
+#endif