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#ifndef TIMER_H
#define TIMER_H

// Copyright ***********************************************************
//
//      The information in this file is copyright 1991 by David Orme.
//
//            Anyone may use this information for any purpose as long as he takes
//            responsability for any and all libility incurred from its use
//            or misuse and acknowledges its use in the user documentation.  This
//            information is provided AS IS with no warrenty of any kind, either
//            expressed or implied.
//
// End *****************************************************************


// Contents **********************************************************
//
//            Timer class definition
//
// Description
//
//            The timer class implements a simple DOS timer ISR and allows
//            timing tasks to be accomplished while other processing
//            occurs.  Note that all instances of this class reference the
//            _same_ timer ISR in memory.
//
// End ***************************************************************


// Interface dependencies ---------------------------------------------

// -- NONE --


// Implementation dependencies ----------------------------------------

// -- NONE --



// Global variables ---------------------------------------------------

const int TIMER = 0x1c;  // DOS timer int vector


class Timer {
private:
        static volatile unsigned long ticker;
        static void interrupt (far *oldtimer)(...);
        static void interrupt far NewTimer(...);

public:
        Timer();
        ~Timer();
        void Set(float seconds=0)       { ticker=seconds*182/10+1; }
        int TimeOut()               { return !ticker; }
};

// Description ---------------------------------------------------------
//
//            Defines the Timer class;  The constructor sets up NewTimer
//            as an ISR on the DOS timer interrupt and sets the ticker
//            to 0.  The timer may be set to time any task in the background
//            while other processing occurs and requires a minimal amount
//            of CPU time.
//
// SetTimer(unsigned seconds=0)
//
//            Set the timer to return to 0 in as many secs as you like.
//
// int TimeOut()
//
//            Returns true (!0) when the time set by SetTimer has elapsed.
//
// End -----------------------------------------------------------------




#endif