-/*] Copyright (c) 2009-2010, Charles McGarvey [**************************
+/*] Copyright (c) 2009-2011, Charles McGarvey [*****************************
**] All rights reserved.
*
-* vi:ts=4 sw=4 tw=75
-*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
-**************************************************************************/
+*****************************************************************************/
#ifndef _MOOF_TIMER_HH_
#define _MOOF_TIMER_HH_
-/**
- * \file timer.hh
- * Functions for measuring time in a friendly unit.
- */
-
#include <boost/bind.hpp>
#include <boost/function.hpp>
#include <boost/noncopyable.hpp>
#include <moof/math.hh>
+/**
+ * \file timer.hh
+ * Functions for measuring time in a friendly unit.
+ */
+
namespace moof {
+// forward declarations
+class runloop;
+
+/**
+ * A timer source is an object that keeps track of increasing time in units
+ * of seconds. A timer source does not necessarily have to increment at
+ * the same rate or in the same way as the real time. The time source must
+ * begin at zero and always remain the same or increase each time the time
+ * is queried.
+ */
+class timer_source
+{
+public:
+
+ /**
+ * Deconstruct a timer source.
+ */
+ virtual ~timer_source() {}
+
+ /**
+ * Get the number seconds since the timer source was created or reset.
+ */
+ virtual scalar ticks() const = 0;
+
+ /**
+ * Reset the timer such that the current time will become zero.
+ */
+ virtual void reset() = 0;
+
+ /**
+ * Scale the time. After calling this, the timer source should either
+ * increment faster or slower, depending on the scale factor.
+ */
+ virtual void scale(scalar factor) = 0;
+};
+
+
/**
* A class to represent a timer for scheduled events. The timer events
* will be executed on or sometime after their schedculed time. The
*/
enum mode
{
- invalid = -1, /// Timer is not scheduled.
- relative = 0, /// Timer is scheduled by a relative time.
- absolute = 1, /// Timer is scheduled by an absolute time.
- repeat = 2 /// Timer is scheduled by a periodic time.
+ invalid = 0, /// Timer is not scheduled.
+ relative = 1, /// Timer is scheduled by a relative time.
+ absolute = 2, /// Timer is scheduled by an absolute time.
+ repeat = 3 /// Timer is scheduled by a periodic time.
};
/**
* Function protocol for a timer event handler. A function matching
* this protocol will be called when the timer expires. The function
* takes two parameters: the timer object that just expired, and the
- * absolute time.
+ * absolute time of the time source which caused the timer to expire.
*/
typedef boost::function<void(timer&,scalar)> function;
-
/**
* Construct an invalid (uninitialized) timer.
*/
timer() :
mode_(invalid),
- absolute_(SCALAR(0.0)) {}
+ absolute_(SCALAR(0.0)),
+ runloop_(0) {}
/**
* Construct a scheduled timer.
* again at that many seconds from the expiration time. A repeating
* timer can be invalidated manually using invalidate().
*/
- timer(const function& function, scalar seconds, mode mode = relative)
+ timer(const function& function,
+ scalar seconds,
+ mode mode = relative,
+ timer_source& source = default_source()) :
+ runloop_(0)
{
- init(function, seconds, mode);
+ init(function, seconds, mode, source);
}
/**
* Deconstruct a timer. This will automagically invalidate the timer,
* so it will not expire or fire an event.
*/
- ~timer()
- {
- invalidate();
- }
-
+ ~timer();
/**
* Initialize a timer with a scheduled time. If the timer is already
*/
void init(const function& function,
scalar seconds,
- mode mode = relative);
-
-
- /**
- * Get whether or not the timer is valid. If a timer is valid, it is
- * still scheduled to expired. You can get the time remaining from
- * seconds_remaining().
- */
- bool is_valid() const;
+ enum mode mode = relative,
+ timer_source& source = default_source());
/**
* Manually invalidated the timer, removing any schedule such that the
*/
void invalidate();
+ enum mode mode() const
+ {
+ return mode_;
+ }
/**
* Manually fire the timer event. Usually, the timer event will be
* prematurely. If the timer is scheduled, it will be invalidated. If
* the timer is already invalid (but is initialized with an event
* handler), the event will be fired and the timer will remain invalid.
+ * \param t The absolute time passed to the timer event function.
*/
- void fire();
+ void fire(scalar t);
+ void fire()
+ {
+ fire(source_->ticks());
+ }
+ /**
+ * Fire the timer event if it is expired.
+ * \param t The absolute time used as a reference to determine if the
+ * timer is expired; defaults to the current time.
+ * \return The absolute time of the next expiration (if repeating), or
+ * 0.0 otherwise.
+ */
+ bool fire_if_expired(scalar t)
+ {
+ if (is_expired(t))
+ {
+ fire(t);
+ return true;
+ }
+ return false;
+ }
+ bool fire_if_expired()
+ {
+ return fire_if_expired(source_->ticks());
+ }
+
+ /**
+ * Get the absolute time of the next expiration of this timer.
+ * \return Seconds.
+ */
+ scalar expiration() const
+ {
+ return absolute_;
+ }
/**
* Get the number of seconds remaining before the timer is scheduled to
* expired. If the timer is invalid, the retured value will be
* negative.
+ * \param t The absolute time used as a reference to determine the
+ * amount of time left; defaults to the current time.
* \return Seconds.
*/
- scalar seconds_remaining() const;
-
- scalar next_expiration() const;
+ scalar remaining(scalar t) const
+ {
+ return expiration() - t;
+ }
+ scalar remaining() const
+ {
+ return remaining(source_->ticks());
+ }
/**
* Get whether or not the timer is expired. A timer on a repeating
* expiration time in the future. If the timer is expired but not
* invalid, the timer event has not yet fired; the timer will be
* invalidated when it does fire.
+ * \param t The absolute time used as a reference to determine if the
+ * timer is expired; defaults to the current time.
* \return True if the timer is expired, false otherwise.
*/
- bool is_expired() const;
-
- /**
- * Get whether or not the timer is on a repeating schedule.
- * \return True if the timer is repeating, false otherwise.
- */
- bool is_repeating() const;
+ bool is_expired(scalar t) const
+ {
+ return remaining(t) < SCALAR(0.0);
+ }
+ bool is_expired() const
+ {
+ return is_expired(source_->ticks());
+ }
+ static timer_source& default_source();
/**
- * Get the number of seconds since a fixed, arbitrary point in the
- * past.
+ * Get the number of real seconds since the default timer was first
+ * created or last reset.
* \return Seconds.
*/
static scalar ticks();
-
/**
* Put the thread to sleep for a certain period of time. If absolute
- * is true, then it will sleep until seconds after the fixed time in
- * the past. If absolute is false, it will sleep for seconds starting
- * now. Unlike system sleep functions, this one automatically resumes
- * sleep if sleep was interrupted by a signal. Therefore, calling this
- * function is guaranteed to sleep for the requested amount of time
- * (and maybe longer).
+ * is true, then it will sleep until the default timer reaches the
+ * specified number of seconds. If the mode is relative, the thread
+ * will sleep for that many seconds. Unlike system sleep functions,
+ * this one automatically resumes sleep if sleep was interrupted by a
+ * signal. Therefore, calling this function is guaranteed to sleep for
+ * at least the requested amount of time.
* \param seconds Number of seconds.
* \param mode The timer mode.
*/
- static void sleep(scalar seconds, mode mode = relative);
+ static void sleep(scalar seconds, enum mode mode = relative);
+private:
- /**
- * Get the absolute time when the next timer is scheduled to expire.
- * \return Absolute time, in seconds.
- */
- static scalar next_event()
+ void added_to_runloop(runloop& runloop);
+ void detach_from_runloop();
+
+ function function_;
+ enum mode mode_;
+ scalar absolute_;
+ scalar interval_;
+ timer_source* source_;
+ runloop* runloop_;
+};
+
+
+class game_time : public timer_source
+{
+public:
+
+ game_time(scalar timestep = SCALAR(1.0)) :
+ scale_(timestep),
+ scalefactor_(SCALAR(1.0))
{
- return next_event_;
+ reset(timestep);
}
+ scalar ticks() const
+ {
+ return reference_ + scalar(ticks_) * scale_;
+ }
- /**
- * Fire any timers which are not yet invalidated but have an expiration
- * time in the past.
- */
- static void fire_expired_timers()
+ void reset()
+ {
+ reference_ = SCALAR(0.0);
+ ticks_ = 0;
+ }
+ void reset(scalar timestep)
{
- fire_expired_timers(ticks());
+ reset();
+ timestep_ = timestep;
+ scale_ = timestep_ * scalefactor_;
}
- /**
- * Fire any timers which are not yet invalidated but have an expiration
- * time before a given absolute time.
- */
- static void fire_expired_timers(scalar t);
+ void scale(scalar factor)
+ {
+ reference_ = ticks();
+ ticks_ = 0;
+ scale_ = timestep_ * factor;
+ scalefactor_ = factor;
+ }
+ scalar step(unsigned step = 1)
+ {
+ ticks_ += step;
+ return scale_;
+ }
private:
- static unsigned new_identifier();
- static scalar find_next_event();
-
- function function_;
- mode mode_;
- scalar absolute_;
- scalar interval_;
- unsigned id_;
-
- static scalar next_event_;
- static hash<unsigned,timer*,hash_function> timers_;
+ scalar reference_;
+ unsigned ticks_;
+ scalar timestep_;
+ scalar scale_;
+ scalar scalefactor_;
};
projects / chaz / yoink / blobdiff