Merge branch 'experiments/fsm'

index.html

@@ -33,6 +33,7 @@
 	<script src="js/BikerEnemy.js"></script>
 	<script src="js/EnemyAlienGuard.js"></script>
 	<script src="js/PlayerColliderManager.js"></script>
+	<script src="js/FSM.js"></script>
 	<script src="js/Player.js"></script>
 	<script src="js/EnemyMech.js"></script>
 	<script src="js/Camera.js"></script>

js/FSM.js

@@ -0,0 +1,43 @@
+function FSM(initial) {
+	const NOSTATE = 'none';
+	let currentState = NOSTATE;
+	const states = {};
+	const transitions = [];
+
+	this.addState = function(name, enterFunc, updateFunc, exitFunc) {
+		states[name] = {
+			enter: enterFunc,
+			update: updateFunc,
+			exit: exitFunc,
+		};
+	};
+
+	this.addTransition = function(statesFrom, stateTo, conditionFunc) {
+		transitions.push({
+			from: statesFrom,
+			to: stateTo,
+			cond: conditionFunc,
+		});
+	};
+
+	this.update = function(deltaTime) {
+		if (currentState == NOSTATE) {
+			currentState = initial;
+			states[currentState].enter(deltaTime);
+		}
+		states[currentState].update(deltaTime);
+		for (let transition of transitions) {
+			for (let fromState of transition.from) {
+				if (fromState == currentState && transition.cond()) {
+					if (DEBUG) {
+						console.log('FSM: switch from', fromState, 'to', transition.to);
+					}
+					states[currentState].exit(deltaTime);
+					currentState = transition.to;
+					states[currentState].enter(deltaTime);
+					return;
+				}
+			}
+		}
+	};
+}

js/Input.js

@@ -207,4 +207,40 @@ function mouseInside(x, y, width, height) {
 
 function pointInside(pointX, pointY, x, y, width, height) {
 	return pointX > x && pointX < x + width && pointY > y && pointY < y + height;
-}
+}
+
+function getKeyChecker(keys) {
+	const keyChecker = function() {
+		for (let i=0; i<heldButtons.length; i++) {
+			for (let j=0; j<keys.length; j++) {
+				if (heldButtons[i] == keys[j]) {
+					return true;
+				}
+			}
+		}
+		return false;
+	};
+	return keyChecker;
+}
+
+function getExclusiveKeyChecker(keys) {
+	const keysSet = new Set(keys)
+	const exclusiveKeyChecker = function() {
+		if (heldButtons.length != 1) {
+			return false;
+		}
+		const heldSet = new Set(heldButtons);
+		for (let key of keysSet) {
+			heldSet.delete(key);
+			if (heldSet.size == 0) {
+				break;
+			}
+		}
+		return heldSet.size == 0;
+	};
+	return exclusiveKeyChecker;
+}
+
+function checkForPressedKeys(keys) {
+	return getKeyChecker(keys)();
+}