text: //
  // Copyright (c) 2008-2017 the Urho3D project.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  //
  
  #pragma once
  
  #include "../Scene/Component.h"
  
  namespace Urho3D
  {
  
  /// Bitmask for using the scene update event.
  static const unsigned char USE_UPDATE = 0x1;
  /// Bitmask for using the scene post-update event.
  static const unsigned char USE_POSTUPDATE = 0x2;
  /// Bitmask for using the physics update event.
  static const unsigned char USE_FIXEDUPDATE = 0x4;
  /// Bitmask for using the physics post-update event.
  static const unsigned char USE_FIXEDPOSTUPDATE = 0x8;
  
  /// Helper base class for user-defined game logic components that hooks up to update events and forwards them to virtual functions similar to ScriptInstance class.
  class URHO3D_API LogicComponent : public Component
  {
      URHO3D_OBJECT(LogicComponent, Component);
  
      /// Construct.
      LogicComponent(Context* context);
      /// Destruct.
      virtual ~LogicComponent() override;
  
      /// Handle enabled/disabled state change. Changes update event subscription.
      virtual void OnSetEnabled() override;
  
      /// Called when the component is added to a scene node. Other components may not yet exist.
      virtual void Start() { }
  
      /// Called before the first update. At this point all other components of the node should exist. Will also be called if update events are not wanted; in that case the event is immediately unsubscribed afterward.
      virtual void DelayedStart() { }
  
      /// Called when the component is detached from a scene node, usually on destruction. Note that you will no longer have access to the node and scene at that point.
      virtual void Stop() { }
  
      /// Called on scene update, variable timestep.
      virtual void Update(float timeStep);
      /// Called on scene post-update, variable timestep.
      virtual void PostUpdate(float timeStep);
      /// Called on physics update, fixed timestep.
      virtual void FixedUpdate(float timeStep);
      /// Called on physics post-update, fixed timestep.
      virtual void FixedPostUpdate(float timeStep);
  
      /// Set what update events should be subscribed to. Use this for optimization: by default all are in use. Note that this is not an attribute and is not saved or network-serialized, therefore it should always be called eg. in the subclass constructor.
      void SetUpdateEventMask(unsigned char mask);
  
      /// Return what update events are subscribed to.
      unsigned char GetUpdateEventMask() const { return updateEventMask_; }
  
      /// Return whether the DelayedStart() function has been called.
      bool IsDelayedStartCalled() const { return delayedStartCalled_; }
  
  protected:
      /// Handle scene node being assigned at creation.
      virtual void OnNodeSet(Node* node) override;
      /// Handle scene being assigned.
      virtual void OnSceneSet(Scene* scene) override;
  
  private:
      /// Subscribe/unsubscribe to update events based on current enabled state and update event mask.
      void UpdateEventSubscription();
      /// Handle scene update event.
      void HandleSceneUpdate(StringHash eventType, VariantMap& eventData);
      /// Handle scene post-update event.
      void HandleScenePostUpdate(StringHash eventType, VariantMap& eventData);
  #if defined(URHO3D_PHYSICS) || defined(URHO3D_URHO2D)
      /// Handle physics pre-step event.
      void HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData);
      /// Handle physics post-step event.
      void HandlePhysicsPostStep(StringHash eventType, VariantMap& eventData);
  #endif
      /// Requested event subscription mask.
      unsigned char updateEventMask_;
      /// Current event subscription mask.
      unsigned char currentEventMask_;
      /// Flag for delayed start.
      bool delayedStartCalled_;
  };
  
  }
  