//=============================================================================
  // PSystem.h by Frank Luna (C) 2004 All Rights Reserved.
  //=============================================================================
  
  ifndef PSYSTEM_H
  define PSYSTEM_H
  
  include <d3dUtil.h>
  include <Vertex.h>
  include <vector>
  
  //===============================================================
  class PSystem
  {
  public:
          PSystem(
                  const std::string& fxName, 
                  const std::string& techName, 
                  const std::string& texName, 
                  const D3DXVECTOR3& accel, 
                  const AABB& box,
                  int maxNumParticles,
                  float timePerParticle);
  
          virtual ~PSystem();
  
          // Access Methods
          float getTime();
          void  setTime(float t);
          const AABB& getAABB()const;
  
          void setWorldMtx(const D3DXMATRIX& world);
          void addParticle();
  
          virtual void onLostDevice();
          virtual void onResetDevice();
  
          virtual void initParticle(Particle& out) = 0;
          virtual void update(float dt);
          virtual void draw();
  
  protected:
          // In practice, some sort of ID3DXEffect and IDirect3DTexture9 manager should
          // be used so that you do not duplicate effects/textures by having several
          // instances of a particle system.
          ID3DXEffect* mFX;
          D3DXHANDLE mhTech;
          D3DXHANDLE mhWVP;
          D3DXHANDLE mhEyePosL;
          D3DXHANDLE mhTex;
          D3DXHANDLE mhTime;
          D3DXHANDLE mhAccel;
          D3DXHANDLE mhViewportHeight;
  
          IDirect3DTexture9* mTex;
          IDirect3DVertexBuffer9* mVB;
          D3DXMATRIX mWorld;
          D3DXMATRIX mInvWorld;
          float mTime;
          D3DXVECTOR3 mAccel;
          AABB mBox;
          int mMaxNumParticles;
          float mTimePerParticle;
  
          std::vector<Particle> mParticles;
          std::vector<Particle*> mAliveParticles;
          std::vector<Particle*> mDeadParticles; 
  };
  
  endif // P_SYSTEM