#ifndef __SIMSPHERE_H__
#define __SIMSPHERE_H__
/***************************************************************************
   File:        SimSphere.h                                                            
   Created:     01/22/02                                                            
   Author:      Maxim Garber                                                
                Computer Science Department                                 
                University of North Carolina - Chapel Hill                  
                garber@cs.unc.edu                                           
                                                                            
   DescriptioN: Projectile sphere which interacts with cloth simulation                                                           
                                                                            
----------------------------------------------------------------------------.
   Copyright 2002 Maxim Garber                                                                                   
                                                                            
                                                                            
*****************************************************************************/
#include "vec3fv.hpp"
#include "ProjectileLaunchParams.h"

class SimSphere
{
public:

   /*****************************************************************************
      Constructors & Destructor
   *****************************************************************************/
   SimSphere(char* fileName);
   ~SimSphere();

   /*****************************************************************************
      Launch
   *****************************************************************************/
   void  Launch(ProjectileLaunchParams params);
   
   /*****************************************************************************
      Accessors
   *****************************************************************************/
   const float* GetCenter()  const {return _center;                            }
   const float* GetForce()   const {return _force;                             }
   float GetRadius()         const {return _radius;                            }
   float GetDrawRadius()     const {return _drawRadius;                        }
   float GetInverseMass()    const {return _inverseMass;                       }
   bool  IsActive()          const {return _timeOnTheGround < _maxTimeOnGround;}

   /*****************************************************************************
      Collision Projection and External Forces
   *****************************************************************************/
   void  MoveCenter(float offset[3])           {Add3fv(_center, _center, offset);}
   void  SetCenter (float center[3])           {Copy3fv(_center, center);        }
   void  AddForce  (float  force[3])           {Add3fv(_force, _force, force);   }
   void  ClearForce()                          {Set3fv(_force, 0.0f, 0.0f, 0.0f);}
   unsigned char GetIsFree() const             {return _isFree;                  }
   void  SetIsFree(const unsigned char isFree) {_isFree = isFree;                }


   /*****************************************************************************
      Drawing
   *****************************************************************************/
   void Draw() const;

   /*****************************************************************************
      Simulation
   *****************************************************************************/
   void Update(const float timeStep);       // timeStep in seconds

private:
   // puck parameters
   float       _center[3];
   float       _prevCenter[3];
   float       _force[3];
   float       _drawRadius;
   float       _radius;
   float       _inverseMass;

   //rendering
   unsigned char _color[3];

   // fade out
   float _timeOnTheGround;
   float _maxTimeOnGround;

   // for simulation
   float               _timeStep;
   float               _gravity[3];
   float               _dampingFactor;
   unsigned int        _numIterations;
   unsigned char       _isFree;          // true if puck is free to move ** for replay **

   /*****************************************************************************
      Simulation Helper Functions
   *****************************************************************************/
   void _InitializeSimulation();
   void _AccumulateForces();
   void _Integrate();
   void _SatisfyConstraints();
};

/****************************************************************************
   Function   : SimSphereActive                                          
   Description: predicate function to test if the sphere is alive                                                          
****************************************************************************/
inline bool SimSphereActive(SimSphere* sphere)
{
  return sphere->IsActive();
}

#endif //__SIMSPHERE_H__