1 // TimeManager.cxx -- 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.
25 #include "TimeManager.hxx"
27 #include <simgear/timing/sg_time.hxx>
28 #include <simgear/structure/event_mgr.hxx>
29 #include <simgear/misc/sg_path.hxx>
30 #include <simgear/timing/lowleveltime.h>
31 #include <simgear/structure/commands.hxx>
32 #include <simgear/math/SGMath.hxx>
34 #include <Main/fg_props.hxx>
35 #include <Main/globals.hxx>
36 #include <Time/sunsolver.hxx>
40 static bool do_timeofday (const SGPropertyNode * arg)
42 const string &offset_type = arg->getStringValue("timeofday", "noon");
43 int offset = arg->getIntValue("offset", 0);
44 TimeManager* self = (TimeManager*) globals->get_subsystem("time");
45 if (offset_type == "real") {
46 // without this, setting 'real' time is a no-op, since the current
47 // wrap value (orig_warp) is retained in setTimeOffset. Ick.
48 fgSetInt("/sim/time/warp", 0);
51 self->setTimeOffset(offset_type, offset);
55 TimeManager::TimeManager() :
58 _sceneryLoaded("sim/sceneryloaded"),
59 _modelHz("sim/model-hz"),
60 _timeDelta("sim/time/delta-realtime-sec"),
61 _simTimeDelta("sim/time/delta-sec")
63 SGCommandMgr::instance()->addCommand("timeofday", do_timeofday);
66 void TimeManager::init()
69 // time manager has to be initialised early, so needs to be defensive
70 // about multiple initialisation
77 _adjustWarpOnUnfreeze = false;
79 _maxDtPerFrame = fgGetNode("/sim/max-simtime-per-frame", true);
80 _clockFreeze = fgGetNode("/sim/freeze/clock", true);
81 _timeOverride = fgGetNode("/sim/time/cur-time-override", true);
82 _warp = fgGetNode("/sim/time/warp", true);
83 _warp->addChangeListener(this);
85 _warpDelta = fgGetNode("/sim/time/warp-delta", true);
87 SGPath zone(globals->get_fg_root());
88 zone.append("Timezone");
90 _impl = new SGTime(globals->get_aircraft_position(), zone, _timeOverride->getLongValue());
92 _warpDelta->setIntValue(0);
94 globals->get_event_mgr()->addTask("updateLocalTime", this,
95 &TimeManager::updateLocalTime, 30*60 );
98 _impl->update(globals->get_aircraft_position(), _timeOverride->getLongValue(),
99 _warp->getIntValue());
100 globals->set_time_params(_impl);
102 // frame-rate / worst-case latency / update-rate counters
103 _frameRate = fgGetNode("/sim/frame-rate", true);
104 _frameLatency = fgGetNode("/sim/frame-latency-max-ms", true);
105 _frameRateWorst = fgGetNode("/sim/frame-rate-worst", true);
107 _frameLatencyMax = 0.0;
111 void TimeManager::postinit()
116 void TimeManager::reinit()
123 void TimeManager::shutdown()
125 _warp->removeChangeListener(this);
127 globals->set_time_params(NULL);
131 globals->get_event_mgr()->removeTask("updateLocalTime");
134 void TimeManager::valueChanged(SGPropertyNode* aProp)
136 if (aProp == _warp) {
137 if (_clockFreeze->getBoolValue()) {
138 // if the warp is changed manually while frozen, don't modify it when
139 // un-freezing - the user wants to unfreeze with exactly the warp
141 _adjustWarpOnUnfreeze = false;
144 _impl->update(globals->get_aircraft_position(),
145 _timeOverride->getLongValue(),
146 _warp->getIntValue());
150 void TimeManager::computeTimeDeltas(double& simDt, double& realDt)
152 // Update the elapsed time.
155 _firstUpdate = false;
156 _lastClockFreeze = _clockFreeze->getBoolValue();
159 bool wait_for_scenery = !_sceneryLoaded;
160 if (!wait_for_scenery) {
161 throttleUpdateRate();
165 // suppress framerate while initial scenery isn't loaded yet (splash screen still active)
170 SGTimeStamp currentStamp;
171 currentStamp.stamp();
172 double dt = (currentStamp - _lastStamp).toSecs();
173 if (dt > _frameLatencyMax)
174 _frameLatencyMax = dt;
176 // Limit the time we need to spend in simulation loops
177 // That means, if the /sim/max-simtime-per-frame value is strictly positive
178 // you can limit the maximum amount of time you will do simulations for
179 // one frame to display. The cpu time spent in simulations code is roughly
180 // at least O(real_delta_time_sec). If this is (due to running debug
181 // builds or valgrind or something different blowing up execution times)
182 // larger than the real time you will no longer get any response
183 // from flightgear. This limits that effect. Just set to property from
184 // your .fgfsrc or commandline ...
185 double dtMax = _maxDtPerFrame->getDoubleValue();
186 if (0 < dtMax && dtMax < dt) {
190 SGSubsystemGroup* fdmGroup =
191 globals->get_subsystem_mgr()->get_group(SGSubsystemMgr::FDM);
192 fdmGroup->set_fixed_update_time(1.0 / _modelHz);
194 // round the real time down to a multiple of 1/model-hz.
195 // this way all systems are updated the _same_ amount of dt.
197 int multiLoop = long(floor(dt * _modelHz));
198 multiLoop = SGMisc<long>::max(0, multiLoop);
199 _dtRemainder = dt - double(multiLoop)/double(_modelHz);
200 dt = double(multiLoop)/double(_modelHz);
203 if (_clockFreeze->getBoolValue() || wait_for_scenery) {
209 _lastStamp = currentStamp;
210 globals->inc_sim_time_sec(simDt);
212 // These are useful, especially for Nasal scripts.
214 _simTimeDelta = simDt;
217 void TimeManager::update(double dt)
219 bool freeze = _clockFreeze->getBoolValue();
220 time_t now = time(NULL);
223 // clock freeze requested
224 if (_timeOverride->getLongValue() == 0) {
225 _timeOverride->setLongValue(now);
226 _adjustWarpOnUnfreeze = true;
229 // no clock freeze requested
230 if (_lastClockFreeze) {
231 if (_adjustWarpOnUnfreeze) {
232 // clock just unfroze, let's set warp as the difference
233 // between frozen time and current time so we don't get a
234 // time jump (and corresponding sky object and lighting
236 int adjust = _timeOverride->getLongValue() - now;
237 SG_LOG(SG_GENERAL, SG_INFO, "adjusting on un-freeze:" << adjust);
238 _warp->setIntValue(_warp->getIntValue() + adjust);
240 _timeOverride->setLongValue(0);
243 int warpDelta = _warpDelta->getIntValue();
244 if (warpDelta != 0) {
245 _warp->setIntValue(_warp->getIntValue() + warpDelta);
249 _lastClockFreeze = freeze;
250 _impl->update(globals->get_aircraft_position(),
251 _timeOverride->getLongValue(),
252 _warp->getIntValue());
257 void TimeManager::computeFrameRate()
259 // Calculate frame rate average
260 if ((_impl->get_cur_time() != _lastFrameTime)) {
261 _frameRate->setIntValue(_frameCount);
262 _frameLatency->setDoubleValue(_frameLatencyMax*1000);
263 if (_frameLatencyMax>0)
264 _frameRateWorst->setIntValue(1/_frameLatencyMax);
266 _frameLatencyMax = 0.0;
269 _lastFrameTime = _impl->get_cur_time();
273 void TimeManager::throttleUpdateRate()
275 // common case, no throttle requested
276 double throttle_hz = fgGetDouble("/sim/frame-rate-throttle-hz", 0.0);
277 if (throttle_hz <= 0)
280 // sleep for exactly 1/hz seconds relative to the past valid timestamp
281 SGTimeStamp::sleepUntil(_lastStamp + SGTimeStamp::fromSec(1/throttle_hz));
284 // periodic time updater wrapper
285 void TimeManager::updateLocalTime()
287 SGPath zone(globals->get_fg_root());
288 zone.append("Timezone");
289 _impl->updateLocal(globals->get_aircraft_position(), zone.str());
292 void TimeManager::initTimeOffset()
295 long int offset = fgGetLong("/sim/startup/time-offset");
296 string offset_type = fgGetString("/sim/startup/time-offset-type");
297 setTimeOffset(offset_type, offset);
300 void TimeManager::setTimeOffset(const std::string& offset_type, long int offset)
302 // Handle potential user specified time offsets
303 int orig_warp = _warp->getIntValue();
304 time_t cur_time = _impl->get_cur_time();
305 time_t currGMT = sgTimeGetGMT( gmtime(&cur_time) );
306 time_t systemLocalTime = sgTimeGetGMT( localtime(&cur_time) );
307 time_t aircraftLocalTime =
308 sgTimeGetGMT( fgLocaltime(&cur_time, _impl->get_zonename() ) );
310 // Okay, we now have several possible scenarios
311 SGGeod loc = globals->get_aircraft_position();
314 if ( offset_type == "real" ) {
316 } else if ( offset_type == "dawn" ) {
317 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 90.0, true );
318 } else if ( offset_type == "morning" ) {
319 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 75.0, true );
320 } else if ( offset_type == "noon" ) {
321 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 0.0, true );
322 } else if ( offset_type == "afternoon" ) {
323 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 75.0, false );
324 } else if ( offset_type == "dusk" ) {
325 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 90.0, false );
326 } else if ( offset_type == "evening" ) {
327 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 100.0, false );
328 } else if ( offset_type == "midnight" ) {
329 warp = fgTimeSecondsUntilSunAngle( cur_time, loc, 180.0, false );
330 } else if ( offset_type == "system-offset" ) {
333 } else if ( offset_type == "gmt-offset" ) {
334 warp = offset - (currGMT - systemLocalTime);
336 } else if ( offset_type == "latitude-offset" ) {
337 warp = offset - (aircraftLocalTime - systemLocalTime);
339 } else if ( offset_type == "system" ) {
340 warp = offset - (systemLocalTime - currGMT) - cur_time;
341 } else if ( offset_type == "gmt" ) {
342 warp = offset - cur_time;
343 } else if ( offset_type == "latitude" ) {
344 warp = offset - (aircraftLocalTime - currGMT)- cur_time;
346 SG_LOG( SG_GENERAL, SG_ALERT,
347 "TimeManager::setTimeOffset: unsupported offset: " << offset_type );
351 _warp->setIntValue( orig_warp + warp );
353 SG_LOG( SG_GENERAL, SG_INFO, "After TimeManager::setTimeOffset(): warp = "
354 << _warp->getIntValue() );