text: //
  // Copyright (c) 2008-2015 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"
  
  #include <Box2D/Box2D.h>
  
  namespace Urho3D
  {
  
  class RigidBody2D;
  class PhysicsWorld2D;
  
  /// 2D physics constraint component.
  class URHO3D_API Constraint2D : public Component
  {
      URHO3D_OBJECT(Constraint2D, Component);
  
  public:
      /// Construct.
      Constraint2D(Context* context);
      /// Destruct.
      virtual ~Constraint2D();
      /// Register object factory.
      static void RegisterObject(Context* context);
  
      /// Handle enabled/disabled state change.
      virtual void OnSetEnabled();
      /// Create Joint.
      void CreateJoint();
      /// Release Joint.
      void ReleaseJoint();
  
      /// Set other rigid body.
      void SetOtherBody(RigidBody2D* body);
      /// Set collide connected.
      void SetCollideConnected(bool collideConnected);
      /// Set attached constriant (for gear).
      void SetAttachedConstraint(Constraint2D* constraint);
  
      /// Return owner body.
      RigidBody2D* GetOwnerBody() const { return ownerBody_; }
  
      /// Return other body.
      RigidBody2D* GetOtherBody() const { return otherBody_; }
  
      /// Return collide connected.
      bool GetCollideConnected() const { return collideConnected_; }
  
      /// Return attached constraint (for gear).
      Constraint2D* GetAttachedConstraint() const { return attachedConstraint_; }
  
      /// Return Box2D joint.
      b2Joint* GetJoint() const { return joint_; }
  
  protected:
      /// Handle node being assigned.
      virtual void OnNodeSet(Node* node);
      /// Handle scene being assigned.
      virtual void OnSceneSet(Scene* scene);
      /// Return joint def.
      virtual b2JointDef* GetJointDef() { return 0; };
      /// Recreate joint.
      void RecreateJoint();
      /// Initialize joint def.
      void InitializeJointDef(b2JointDef* jointDef);
  
      /// Physics world.
      WeakPtr<PhysicsWorld2D> physicsWorld_;
      /// Box2D joint.
      b2Joint* joint_;
      /// Owner body.
      WeakPtr<RigidBody2D> ownerBody_;
      /// Other body.
      WeakPtr<RigidBody2D> otherBody_;
      /// Collide connected.
      bool collideConnected_;
      /// Attached constraint.
      WeakPtr<Constraint2D> attachedConstraint_;
  };
  
  }
  