feat(sim): game state, state machine and audio cues

game/sim/stateMachine.py

@@ -0,0 +1,50 @@
+class State:
+    name = "state"
+
+    def onEnter(self, owner, world):
+        pass
+
+    def onExit(self, owner, world):
+        pass
+
+    def update(self, owner, world):
+        return None
+
+
+class StateMachine:
+    def __init__(self, owner):
+        self.owner = owner
+        self.states = {}
+        self.current = None
+        self.previous = None
+        self.timeInState = 0
+
+    def addState(self, state):
+        self.states[state.name] = state
+        return self
+
+    def setInitial(self, name, world=None):
+        self.current = self.states[name]
+        self.timeInState = 0
+        if world is not None:
+            self.current.onEnter(self.owner, world)
+        return self
+
+    def transition(self, name, world):
+        if name == self.current.name:
+            return
+        self.previous = self.current
+        self.current.onExit(self.owner, world)
+        self.current = self.states[name]
+        self.timeInState = 0
+        self.current.onEnter(self.owner, world)
+
+    def update(self, world):
+        self.timeInState += 1
+        nextState = self.current.update(self.owner, world)
+        if nextState is not None and nextState != self.current.name:
+            self.transition(nextState, world)
+
+    @property
+    def stateName(self):
+        return self.current.name if self.current else None