Listing 1: Partial listing of delta.h
struct deltacontrol{ int current; int delta; int len; int togo; }; class DeltaControl { public: DeltaControl(); virtual void SetFrom(int Major, int Minor); virtual void SetTo(int Major, int Minor); virtual BOOL Next(); int GetMajor() {return m_Major.current;}; int GetMinor() {return m_Minor.current;}; virtual int GetLength() {return m_Minor.len + m_Major.len;}; protected: virtual void OnMajorChange(int Current) {}; virtual void OnMinorChange(int Current) {}; deltacontrl m_Major; deltacontrl m_Minor; int m_ErrorTerm; virtual void SetTo(int In, deltacontrol *Out); BOOL m_MinorLast; }; End of Listing