1 // TimeManager.hxx -- simulation-wide time management
3 // Written by James Turner, started July 2010.
5 // Copyright (C) 2010 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 #ifndef FG_TIME_TIMEMANAGER_HXX
22 #define FG_TIME_TIMEMANAGER_HXX
24 #include <simgear/structure/subsystem_mgr.hxx>
25 #include <simgear/props/props.hxx>
30 class TimeManager : public SGSubsystem, public SGPropertyChangeListener
34 virtual ~TimeManager();
36 void computeTimeDeltas(double& simDt, double& realDt);
39 virtual void reinit();
40 virtual void postinit();
41 virtual void shutdown();
43 virtual void unbind();
45 void update(double dt);
47 // SGPropertyChangeListener overrides
48 virtual void valueChanged(SGPropertyNode *);
50 void setTimeOffset(const std::string& offset_type, long int offset);
54 * Ensure a consistent update-rate using a combination of
55 * sleep()-ing and busy-waiting.
57 void throttleUpdateRate();
60 * Compute frame (update) rate and write it to a property
62 void computeFrameRate();
64 void updateLocalTime();
66 // set up a time offset (aka warp) if one is specified
67 void initTimeOffset();
71 SGTimeStamp _lastStamp;
74 SGPropertyNode_ptr _maxDtPerFrame;
75 SGPropertyNode_ptr _clockFreeze;
76 SGPropertyNode_ptr _timeOverride;
77 SGPropertyNode_ptr _warp;
78 SGPropertyNode_ptr _warpDelta;
80 bool _lastClockFreeze;
81 bool _adjustWarpOnUnfreeze;
83 // frame-rate / worst-case latency / update-rate counters
84 SGPropertyNode_ptr _frameRate;
85 SGPropertyNode_ptr _frameRateWorst;
86 SGPropertyNode_ptr _frameLatency;
87 time_t _lastFrameTime;
88 double _frameLatencyMax;
91 SGPropertyNode_ptr _sceneryLoaded;
92 SGPropertyNode_ptr _modelHz;
93 SGPropertyNode_ptr _timeDelta, _simTimeDelta;
96 #endif // of FG_TIME_TIMEMANAGER_HXX