wram analysis

snes/wram/event.c

@@ -0,0 +1,106 @@
+#include <stdlib.h>
+
+#include "data.h";
+#include "event.h";
+
+event *events;
+
+void initEvents(void)
+{
+    events = NULL;
+}
+
+event *createEvent(char (*callback) (word counter))
+{
+    event *myEvent;
+
+    myEvent = (event *) malloc(sizeof(event));
+
+    myEvent->VBlankCount = 0;
+    myEvent->callback = callback;
+    myEvent->nextEvent = NULL;
+    myEvent->previousEvent = NULL;
+
+
+    return myEvent;
+}
+
+event *addEvent(char (*callback) (word counter), int noDuplicateCallback)
+{
+
+    event *lastEvent;
+    event *myEvent;
+
+    if (events == NULL) {
+        events = createEvent(callback);
+        return events;
+    } else {
+        lastEvent = events;
+        // TODO optimise this with noduplicate
+        while (lastEvent->nextEvent != NULL) {
+            if (noDuplicateCallback == 1 && lastEvent->callback == *callback) {
+                return NULL;
+            }
+            lastEvent = lastEvent->nextEvent;
+        }
+        if (noDuplicateCallback == 1 && lastEvent->callback == *callback) {
+            return NULL;
+        }
+        myEvent = createEvent(callback);
+        myEvent->previousEvent = lastEvent;
+        lastEvent->nextEvent = myEvent;
+        return myEvent;
+    }
+
+
+}
+
+void removeEvent(event * eventElement)
+{
+
+    byte alone = 0;
+    event *next, *previous;
+
+    next = eventElement->nextEvent;
+    previous = eventElement->previousEvent;
+
+    if (eventElement->nextEvent != NULL && eventElement->previousEvent != NULL) {
+        alone++;
+        next->previousEvent = previous;
+        previous->nextEvent = next;
+
+    } else if (eventElement->nextEvent != NULL) {
+        alone++;
+        next->previousEvent = NULL;
+        events = next;
+
+    } else if (eventElement->previousEvent != NULL) {
+        alone++;
+        previous->nextEvent = NULL;
+    }
+
+    free(eventElement);
+
+    if (alone == 0) {
+        events = NULL;
+    }
+}
+
+void processEvents(void)
+{
+
+    event *currentEvent;
+    char returnValue;
+
+    currentEvent = events;
+    while (currentEvent != NULL) {
+        returnValue = currentEvent->callback(currentEvent->VBlankCount);
+        if (returnValue == EVENT_CONTINUE) {
+            currentEvent->VBlankCount++;
+        } else {
+            removeEvent(currentEvent);
+        }
+        currentEvent = currentEvent->nextEvent;
+    }
+
+}