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#ifndef TIMER_HH

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#define TIMER_HH

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#include <ClanLib/core.h>

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#include "Types.hh"

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/**

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 * Used to implement Physics ticks and Graphics frames. This will attempt to trigger sig_tick every <interval> ms,

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 * but if we miss some ticks or something else, then the tick_length passed to sig_tick will be longer than interval...

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 */

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class Timer : public CL_KeepAlive {

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    protected:

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        /**

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         * The target tick interval

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         */

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        TimeMS interval;

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        /**

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         * Number of ticks so far, updated by keep_alive

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         */

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        TickCount ticks;

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        /**

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         * Is the timer running?

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         */

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        bool enabled;

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        /**

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         * Single-shot mode?

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         */

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        bool single_shot;

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        /**

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         * Time of last tick, set to current time by start/fire_once/keep_alive

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         */

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        TimeMS last_tick;

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        /** The tick signal */

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        CL_Signal_v1<TimeMS> _sig_tick;

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    public:

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        /**

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         * Prepare a timer, sig_tick will be fired every interval ms after the timer is started.

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         *

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         * @param interval interval in milliseconds

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         */

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        Timer (TimeMS interval);

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        /*

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         * Returns the tick counter

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         */

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        TickCount get_ticks (void);

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        /**

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         * Start the timer in continuous-call mode, this should be called once keepalive starts getting called.

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         */

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        void start (void);

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        /**

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         * Tick the timer, but only once

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         */

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        void fire_once (void);

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    private:

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        /**

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         * If interval time has elapsed, fire sig_tick

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         */

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        void keep_alive (void);

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    public:

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        /**

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         * Triggered approximately every interval MS, but the given interval may also be longer if we've skipped ticks

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         */

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        CL_Signal_v1<TimeMS>& sig_tick (void) { return _sig_tick; }

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};

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#endif