text: //
  // Copyright (c) 2008-2014 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.
  //
  
  #include "Precompiled.h"
  #include "Log.h"
  #include "LogicComponent.h"
  #include "PhysicsEvents.h"
  #include "PhysicsWorld.h"
  #include "Scene.h"
  #include "SceneEvents.h"
  
  namespace Urho3D
  {
  
  LogicComponent::LogicComponent(Context* context) :
      Component(context),
      updateEventMask_(USE_UPDATE | USE_POSTUPDATE | USE_FIXEDUPDATE | USE_FIXEDPOSTUPDATE),
      currentEventMask_(0),
      delayedStartCalled_(false)
  {
  }
  
  LogicComponent::~LogicComponent()
  {
  }
  
  void LogicComponent::OnSetEnabled()
  {
      UpdateEventSubscription();
  }
  
  void LogicComponent::SetUpdateEventMask(unsigned char mask)
  {
      if (updateEventMask_ != mask)
      {
          updateEventMask_ = mask;
          UpdateEventSubscription();
      }
  }
  
  void LogicComponent::OnNodeSet(Node* node)
  {
      if (node)
      {
          // We have been attached to a node. Set initial update event subscription state
          UpdateEventSubscription();
          // Then execute the user-defined start function
          Start();
      }
      else
      {
          // We are being detached from a node: execute user-defined stop function and prepare for destruction
          Stop();
      }
  }
  
  void LogicComponent::UpdateEventSubscription()
  {
      // If scene node is not assigned yet, no need to update subscription
      if (!node_)
          return;
      
      Scene* scene = GetScene();
      if (!scene)
      {
          LOGWARNING("Node is detached from scene, can not subscribe to update events");
          return;
      }
      
      bool enabled = IsEnabledEffective();
      
      bool needUpdate = enabled && ((updateEventMask_ & USE_UPDATE) || !delayedStartCalled_);
      if (needUpdate && !(currentEventMask_ & USE_UPDATE))
      {
          SubscribeToEvent(scene, E_SCENEUPDATE, HANDLER(LogicComponent, HandleSceneUpdate));
          currentEventMask_ |= USE_UPDATE;
      }
      else if (!needUpdate && (currentEventMask_ & USE_UPDATE))
      {
          UnsubscribeFromEvent(scene, E_SCENEUPDATE);
          currentEventMask_ &= ~USE_UPDATE;
      }
      
      bool needPostUpdate = enabled && (updateEventMask_ & USE_POSTUPDATE);
      if (needPostUpdate && !(currentEventMask_ & USE_POSTUPDATE))
      {
          SubscribeToEvent(scene, E_SCENEPOSTUPDATE, HANDLER(LogicComponent, HandleScenePostUpdate));
          currentEventMask_ |= USE_POSTUPDATE;
      }
      else if (!needUpdate && (currentEventMask_ & USE_POSTUPDATE))
      {
          UnsubscribeFromEvent(scene, E_SCENEPOSTUPDATE);
          currentEventMask_ &= ~USE_POSTUPDATE;
      }
      
      PhysicsWorld* world = scene->GetComponent<PhysicsWorld>();
      if (!world)
          return;
  
      bool needFixedUpdate = enabled && (updateEventMask_ & USE_FIXEDUPDATE);
      if (needFixedUpdate && !(currentEventMask_ & USE_FIXEDUPDATE))
      {
          SubscribeToEvent(world, E_PHYSICSPRESTEP, HANDLER(LogicComponent, HandlePhysicsPreStep));
          currentEventMask_ |= USE_FIXEDUPDATE;
      }
      else if (!needFixedUpdate && (currentEventMask_ & USE_FIXEDUPDATE))
      {
          UnsubscribeFromEvent(world, E_PHYSICSPRESTEP);
          currentEventMask_ &= ~USE_FIXEDUPDATE;
      }
      
      bool needFixedPostUpdate = enabled && (updateEventMask_ & USE_FIXEDPOSTUPDATE);
      if (needFixedPostUpdate && !(currentEventMask_ & USE_FIXEDPOSTUPDATE))
      {
          SubscribeToEvent(world, E_PHYSICSPOSTSTEP, HANDLER(LogicComponent, HandlePhysicsPostStep));
          currentEventMask_ |= USE_FIXEDPOSTUPDATE;
      }
      else if (!needFixedPostUpdate && (currentEventMask_ & USE_FIXEDPOSTUPDATE))
      {
          UnsubscribeFromEvent(world, E_PHYSICSPOSTSTEP);
          currentEventMask_ &= ~USE_FIXEDPOSTUPDATE;
      }
  }
  
  void LogicComponent::HandleSceneUpdate(StringHash eventType, VariantMap& eventData)
  {
      using namespace SceneUpdate;
      
      // Execute user-defined delayed start function before first update
      if (!delayedStartCalled_)
      {
          DelayedStart();
          delayedStartCalled_ = true;
          
          // If did not need actual update events, unsubscribe now
          if (!(updateEventMask_ & USE_UPDATE))
          {
              UnsubscribeFromEvent(GetScene(), E_SCENEUPDATE);
              currentEventMask_ &= ~USE_UPDATE;
              return;
          }
      }
      
      // Then execute user-defined update function
      Update(eventData[P_TIMESTEP].GetFloat());
  }
  
  void LogicComponent::HandleScenePostUpdate(StringHash eventType, VariantMap& eventData)
  {
      using namespace ScenePostUpdate;
      
      // Execute user-defined post-update function
      PostUpdate(eventData[P_TIMESTEP].GetFloat());
  }
  
  void LogicComponent::HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData)
  {
      using namespace PhysicsPreStep;
      
      // Execute user-defined fixed update function
      FixedUpdate(eventData[P_TIMESTEP].GetFloat());
  }
  
  void LogicComponent::HandlePhysicsPostStep(StringHash eventType, VariantMap& eventData)
  {
      using namespace PhysicsPostStep;
      
      // Execute user-defined fixed post-update function
      FixedUpdate(eventData[P_TIMESTEP].GetFloat());
  }
  
  }
  