stateMachine增加传递上下文，允许在stateHandle时使用this指向Func<T>

src/Engine/StateMahines/StateMachine.ts

@@ -1,3 +1,4 @@
+import Func from '../ECS/Function';
 import StateHandler from './StateHandler';
 
 class StateMachine<T> {
@@ -36,25 +37,53 @@ class StateMachine<T> {
     this.currentState = null;
   }
 
-  public addState(label: T, handler: StateHandler<T>): void;
+  /**
+   * 
+   * @param label 状态机标识
+   * @param handler 状态机句柄
+   * @param context 上下文
+   */
+  public addState(label: T, handler: StateHandler<T>, context?: Func<T>): void;
+  /**
+   * 
+   * @param label 状态机标识
+   * @param onStart 进入状态机
+   * @param onUpdate 状态机执行中
+   * @param onStop 离开状态机
+   * @param context 上下文
+   */
   public addState(
     label: T,
     onStart: Function | null,
     onUpdate: Function | null,
     onStop: Function | null,
+    context?: Func<T>, // 上下文
   ): void;
   public addState(
     label: T,
     query: Function | StateHandler<T> | null,
-    onUpdate?: Function | null,
+    onUpdate?: Function | Func<T> | null,
     onStop?: Function | null,
+    context?: Func<T>,
   ): void {
     let newState;
+    if (onUpdate instanceof Func<T>) context = onUpdate;
     if (query instanceof Function || query === null) {
-      newState = new State<T>(label, query, onUpdate!, onStop!);
+      if (onUpdate instanceof Func<T>) throw new Error('参数传递错误');
+      newState = new State<T>(
+        label,
+        query?.bind(context || this),
+        onUpdate?.bind(context || this),
+        onStop?.bind(context || this),
+      );
     } else {
       const { stateIn, stateRunning, stateExit } = query;
-      newState = new State<T>(label, stateIn, stateRunning, stateExit);
+      newState = new State<T>(
+        label,
+        stateIn?.bind(context || this),
+        stateRunning?.bind(context || this),
+        stateExit?.bind(context || this),
+      );
     }
     this.stateMap.set(label, newState);
     if (this.currentState == null) {