OpenSpace/include/openspace/util/timemanager.h

/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2018                                                               *
 *                                                                                       *
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 * or substantial portions of the Software.                                              *
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#ifndef __OPENSPACE_CORE___TIMEMANAGER___H__
#define __OPENSPACE_CORE___TIMEMANAGER___H__

#include <openspace/util/syncdata.h>
#include <openspace/util/time.h>
#include <openspace/util/timeline.h>
#include <functional>
#include <utility>
#include <vector>

#include <deque>
#include <functional>
#include <openspace/util/timeline.h>
#include <openspace/util/time.h>
#include <openspace/util/syncdata.h>
#include <openspace/properties/propertyowner.h>
#include <openspace/properties/scalar/floatproperty.h>

namespace openspace {

struct TimeKeyframeData {
    Time time;
    double delta;
    bool pause = false;
    bool jump = false;
};

class TimeManager : public properties::PropertyOwner {
public:
    TimeManager();

    using CallbackHandle = int;
    using TimeChangeCallback = std::function<void()>;

    const Time& time() const;
    const Time& integrateFromTime() const;
    const Timeline<TimeKeyframeData>& timeline();

    std::vector<Syncable*> getSyncables();
    void preSynchronization(double dt);

    TimeKeyframeData interpolate(double applicationTime);

    void setTimeNextFrame(Time t);
    void setDeltaTime(double deltaTime);
    void setPause(bool pause);

    /**
     * Returns the delta time, unaffected by pause
     */
    double targetDeltaTime() const;

    /*
     * Returns the current delta time, as affected by pause
     */
    double deltaTime() const;
    bool isPaused() const;

    float defaultTimeInterpolationDuration() const;
    float defaultDeltaTimeInterpolationDuration() const;
    float defaultPauseInterpolationDuration() const;
    float defaultUnpauseInterpolationDuration() const;

    void interpolateTime(double targetTime, double durationSeconds);
    void interpolateDeltaTime(double targetDeltaTime, double durationSeconds);
    void interpolatePause(bool pause, double durationSeconds);

    void addKeyframe(double timestamp, TimeKeyframeData kf);
    void removeKeyframesBefore(double timestamp, bool inclusive = false);
    void removeKeyframesAfter(double timestamp, bool inclusive = false);

    size_t nKeyframes() const;
    void clearKeyframes();

    CallbackHandle addTimeChangeCallback(TimeChangeCallback cb);
    CallbackHandle addDeltaTimeChangeCallback(TimeChangeCallback cb);
    CallbackHandle addTimeJumpCallback(TimeChangeCallback cb);
    CallbackHandle addTimelineChangeCallback(TimeChangeCallback cb);

    void removeTimeChangeCallback(CallbackHandle handle);
    void removeDeltaTimeChangeCallback(CallbackHandle handle);
    void removeTimeJumpCallback(CallbackHandle handle);
    void removeTimelineChangeCallback(CallbackHandle handle);
private:
    void progressTime(double dt);
    void applyKeyframeData(const TimeKeyframeData& keyframe);
    TimeKeyframeData interpolate(const Keyframe<TimeKeyframeData>& past,
        const Keyframe<TimeKeyframeData>& future, double time);

    Timeline<TimeKeyframeData> _timeline;
    SyncData<Time> _currentTime;
    SyncData<Time> _integrateFromTime;

    bool _timePaused = false;
    double _targetDeltaTime = 1.0;
    double _deltaTime = 0.0;
    double _lastTime = 0;
    double _lastDeltaTime = 0;

    properties::FloatProperty _defaultTimeInterpolationDuration;
    properties::FloatProperty _defaultDeltaTimeInterpolationDuration;
    properties::FloatProperty _defaultPauseInterpolationDuration;
    properties::FloatProperty _defaultUnpauseInterpolationDuration;

    bool _shouldSetTime = false;
    Time _timeNextFrame;

    bool _timelineChanged;

    double _latestConsumedTimestamp = -std::numeric_limits<double>::max();
    int _nextCallbackHandle = 0;

    std::vector<std::pair<CallbackHandle, TimeChangeCallback>> _timeChangeCallbacks;
    std::vector<std::pair<CallbackHandle, TimeChangeCallback>> _deltaTimeChangeCallbacks;
    std::vector<std::pair<CallbackHandle, TimeChangeCallback>> _timeJumpCallbacks;
    std::vector<std::pair<CallbackHandle, TimeChangeCallback>> _timelineChangeCallbacks;
};

} // namespace openspace

#endif // __OPENSPACE_CORE___TIMEMANAGER___H__