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
35 void computeTimeDeltas(double& simDt, double& realDt);
38 virtual void reinit();
39 virtual void postinit();
40 virtual void shutdown();
42 void update(double dt);
44 // SGPropertyChangeListener overrides
45 virtual void valueChanged(SGPropertyNode *);
49 * Ensure a consistent update-rate using a combination of
50 * sleep()-ing and busy-waiting.
52 void throttleUpdateRate();
55 * Compute frame (update) rate and write it to a property
57 void computeFrameRate();
59 void updateLocalTime();
61 // set up a time offset (aka warp) if one is specified
62 void initTimeOffset();
66 SGTimeStamp _lastStamp;
69 SGPropertyNode_ptr _maxDtPerFrame;
70 SGPropertyNode_ptr _clockFreeze;
71 SGPropertyNode_ptr _timeOverride;
72 SGPropertyNode_ptr _warp;
73 SGPropertyNode_ptr _warpDelta;
75 bool _lastClockFreeze;
76 bool _adjustWarpOnUnfreeze;
78 SGPropertyNode_ptr _longitudeDeg;
79 SGPropertyNode_ptr _latitudeDeg;
81 // frame-rate / worst-case latency / update-rate counters
82 SGPropertyNode_ptr _frameRate;
83 SGPropertyNode_ptr _frameLatency;
84 time_t _lastFrameTime;
85 double _frameLatencyMax;
89 #endif // of FG_TIME_TIMEMANAGER_HXX