Формат 3DS: Первый шаг. (Комментарии к статье) (3 стр)

struct HierarchySubChunksForAllMaps 
{
  //Ýòî ïåðå÷èñëåíèå âêëþ÷àåò â ñåáÿ âñå ñïåöèàëèçàöèè èåðàðõèè êëàññîâ, 
  //äîëæíî õðàíèòñÿ îòñîðòèðîâàííûì è çàêàí÷èâàòüñÿ ÷èñëîì ýëåìåíòîâ ïåðå÷èñëåíèÿ enEndNumber
  enum enMemberList
  {
    eBlur_percent = 0xA353,        // Blur percent/
    eMapping_filename = 0xA300,      // Mapping filename/
    eMapping_parameters = 0xA351,    // Mapping parameters/
    eRGB_Luma_Alpha_tint_1 = 0xA360,  // RGB Luma/Alpha tint 1
    eRGB_Luma_Alpha_tint_2 = 0xA362,  // RGB Luma/Alpha tint 2
    eRGB_tint_B = 0xA368,        // RGB tint B/
    eRGB_tint_G = 0xA366,        // RGB tint G/
    eRGB_tint_R = 0xA364,        // RGB tint R/
    eRotation_angle = 0xA35C,      // Rotation angle/
    eU_offset = 0xA358,          // U offset/
    eU_scale = 0xA356,          // U scale/
    eV_offset = 0xA35A,          // V offset/
    eV_scale = 0xA354,          // V scale/
    enEndNumber = 12
  };

  class Parent 
  {
  public:
    Parent()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo()=0;
    static const enMemberList  id() { return enEndNumber; }
    virtual void operator>>(ofstream &outMotorFile) = 0;  
    virtual void operator<<(ifstream &inMotorFile) = 0;
  };
  
  template <enMemberList enAn> 
  class Chunk : virtual public Parent 
  {
    public:
    Chunk()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return enAn; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eBlur_percent> : virtual public Parent 
  {
  public:
    Chunk<eBlur_percent>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eBlur_percent; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eMapping_filename> : virtual public Parent 
  {
  public:
    Chunk<eMapping_filename>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eMapping_filename; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eMapping_parameters> : virtual public Parent 
  {
  public:
    Chunk<eMapping_parameters>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eMapping_parameters; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eRGB_Luma_Alpha_tint_1> : virtual public Parent 
  {
  public:
    Chunk<eRGB_Luma_Alpha_tint_1>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRGB_Luma_Alpha_tint_1; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eRGB_Luma_Alpha_tint_2> : virtual public Parent 
  {
  public:
    Chunk<eRGB_Luma_Alpha_tint_2>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRGB_Luma_Alpha_tint_2; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eRGB_tint_B> : virtual public Parent 
  {
  public:
    Chunk<eRGB_tint_B>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRGB_tint_B; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eRGB_tint_G> : virtual public Parent 
  {
  public:
    Chunk<eRGB_tint_G>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRGB_tint_G; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eRGB_tint_R> : virtual public Parent 
  {
  public:
    Chunk<eRGB_tint_R>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRGB_tint_R; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eRotation_angle> : virtual public Parent 
  {
  public:
    Chunk<eRotation_angle>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eRotation_angle; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  template <>
  class Chunk<eU_offset> : virtual public Parent 
  {
  public:
    Chunk<eU_offset>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eU_offset; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eU_scale> : virtual public Parent 
  {
  public:
    Chunk<eU_scale>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eU_scale; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eV_offset> : virtual public Parent 
  {
  public:
    Chunk<eV_offset>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eV_offset; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };  

  template <>
  class Chunk<eV_scale> : virtual public Parent 
  {
  public:
    Chunk<eV_scale>()
    {
      cout << "Constr " << id() << endl;
    };
    virtual void foo(){};
    static const enMemberList id() { return eV_scale; }
    virtual void operator>>(ofstream &outMotorFile) {};  
    virtual void operator<<(ifstream &inMotorFile) {};
  };

  //Âîçâðàùàåò óêàçàòåëü íà êëàññ èåðàðõèè êëàññîâ AnimalsHierarchy, 
  //íîìåð êîòîðîãî çàäàí â num
  static Parent * nameToThis(const int & num)
  {
    return Selector<HierarchySubChunksForAllMaps, Parent>::f<0>(num);
  }
 };

//Ñåëåêòîð òèïà. Èñïîëüçóåòñÿ ïîñëåäîâàòåëüíûé ïîèñê â ïåðå÷èñëåíèè Hierarchy::enMemberList.
//Âîçðàùàåò óêàçàòåëü íà êëàññ, èìÿ êîòîðîãî çàäàííî â ñòðîêå num.
//Ïðåèìóùåñòâî òàêîãî ñåëåêòîðà â ìåíüøåé çàãðóçêå ñòåêà ïðè áîëüøîì ðàçìåðå ïåðå÷èñëåíèÿ enMemberList.
template <typename Hierarchy,  //Hierarchy - ñòðóêòóðà â êîòîðîé óïàêîâàíà èåðàðõèÿ êëàññîâ
       typename Parent>  //Ïðåäîê âñåõ êëàññîâ Hierarchy       
struct Selector
{
  template <int n>      //èíäåêñ â ïåðå÷èñëåíèè Hierarchy::enMemberList
  static Parent * f(const int & num) 
  {      
    if (num == Hierarchy::enMemberList(n))
      return new Hierarchy::Chunk<Hierarchy::enMemberList(n)>;
    else 
      return f<n + 1>(num);
  }  
  template <>  static Parent * f<Hierarchy::enEndNumber>(const int & num) {return 0;}  
};