1 // FGAIMultiplayer - FGAIBase-derived class creates an AI multiplayer aircraft
3 // Based on FGAIAircraft
4 // Written by David Culp, started October 2003.
5 // Also by Gregor Richards, started December 2005.
7 // Copyright (C) 2003 David P. Culp - davidculp2@comcast.net
8 // Copyright (C) 2005 Gregor Richards
10 // This program is free software; you can redistribute it and/or
11 // modify it under the terms of the GNU General Public License as
12 // published by the Free Software Foundation; either version 2 of the
13 // License, or (at your option) any later version.
15 // This program is distributed in the hope that it will be useful, but
16 // WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 // General Public License for more details.
20 // You should have received a copy of the GNU General Public License
21 // along with this program; if not, write to the Free Software
22 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
30 #include "AIMultiplayer.hxx"
32 #include <simgear/scene/util/SGNodeMasks.hxx>
34 // #define SG_DEBUG SG_ALERT
36 FGAIMultiplayer::FGAIMultiplayer() : FGAIBase(otMultiplayer) {
39 mTimeOffsetSet = false;
40 mAllowExtrapolation = true;
41 mLagAdjustSystemSpeed = 10;
43 aip.getSceneGraph()->setNodeMask(~SG_NODEMASK_TERRAIN_BIT);
48 FGAIMultiplayer::~FGAIMultiplayer() {
51 bool FGAIMultiplayer::init(bool search_in_AI_path) {
52 props->setStringValue("sim/model/path", model_path.c_str());
53 //refuel_node = fgGetNode("systems/refuel/contact", true);
54 isTanker = false; // do this until this property is
55 // passed over the net
57 string str1 = _getCallsign();
58 string str2 = "MOBIL";
60 string::size_type loc1= str1.find( str2, 0 );
61 if ( (loc1 != string::npos && str2 != "") ){
62 // cout << " string found " << str2 << " in " << str1 << endl;
64 // cout << "isTanker " << isTanker << " " << mCallSign <<endl;
66 return FGAIBase::init(search_in_AI_path);
69 void FGAIMultiplayer::bind() {
72 props->tie("refuel/contact", SGRawValuePointer<bool>(&contact));
73 props->setBoolValue("tanker",isTanker);
75 props->tie("controls/invisible",
76 SGRawValuePointer<bool>(&invisible));
78 #define AIMPROProp(type, name) \
79 SGRawValueMethods<FGAIMultiplayer, type>(*this, &FGAIMultiplayer::get##name)
81 #define AIMPRWProp(type, name) \
82 SGRawValueMethods<FGAIMultiplayer, type>(*this, \
83 &FGAIMultiplayer::get##name, &FGAIMultiplayer::set##name)
85 //props->tie("callsign", AIMPROProp(const char *, CallSign));
87 props->tie("controls/allow-extrapolation",
88 AIMPRWProp(bool, AllowExtrapolation));
89 props->tie("controls/lag-adjust-system-speed",
90 AIMPRWProp(double, LagAdjustSystemSpeed));
97 void FGAIMultiplayer::unbind() {
100 //props->untie("callsign");
101 props->untie("controls/allow-extrapolation");
102 props->untie("controls/lag-adjust-system-speed");
103 props->untie("controls/invisible");
104 props->untie("refuel/contact");
107 void FGAIMultiplayer::update(double dt)
109 using namespace simgear;
114 FGAIBase::update(dt);
116 // Check if we already got data
117 if (mMotionInfo.empty())
120 // The current simulation time we need to update for,
121 // note that the simulation time is updated before calling all the
122 // update methods. Thus it contains the time intervals *end* time
123 double curtime = globals->get_sim_time_sec();
125 // Get the last available time
126 MotionInfo::reverse_iterator it = mMotionInfo.rbegin();
127 double curentPkgTime = it->second.time;
129 // Dynamically optimize the time offset between the feeder and the client
130 // Well, 'dynamically' means that the dynamic of that update must be very
131 // slow. You would otherwise notice huge jumps in the multiplayer models.
132 // The reason is that we want to avoid huge extrapolation times since
133 // extrapolation is highly error prone. For that we need something
134 // approaching the average latency of the packets. This first order lag
135 // component will provide this. We just take the error of the currently
136 // requested time to the most recent available packet. This is the
137 // target we want to reach in average.
138 double lag = it->second.lag;
139 if (!mTimeOffsetSet) {
140 mTimeOffsetSet = true;
141 mTimeOffset = curentPkgTime - curtime - lag;
143 double offset = curentPkgTime - curtime - lag;
144 if ((!mAllowExtrapolation && offset + lag < mTimeOffset)
145 || (offset - 10 > mTimeOffset)) {
146 mTimeOffset = offset;
147 SG_LOG(SG_GENERAL, SG_DEBUG, "Resetting time offset adjust system to "
148 "avoid extrapolation: time offset = " << mTimeOffset);
150 // the error of the offset, respectively the negative error to avoid
152 double err = offset - mTimeOffset;
153 // limit errors leading to shorter lag values somehow, that is late
154 // arriving packets will pessimize the overall lag much more than
155 // early packets will shorten the overall lag
158 // Ok, we have some very late packets and nothing newer increase the
159 // lag by the given speedadjust
160 sysSpeed = mLagAdjustSystemSpeed*err;
162 // We have a too pessimistic display delay shorten that a small bit
163 sysSpeed = SGMiscd::min(0.1*err*err, 0.5);
166 // simple euler integration for that first order system including some
167 // overshooting guard to prevent to aggressive system speeds
168 // (stiff systems) to explode the systems state
169 double systemIncrement = dt*sysSpeed;
170 if (fabs(err) < fabs(systemIncrement))
171 systemIncrement = err;
172 mTimeOffset += systemIncrement;
174 SG_LOG(SG_GENERAL, SG_DEBUG, "Offset adjust system: time offset = "
175 << mTimeOffset << ", expected longitudinal position error due to "
176 " current adjustment of the offset: "
177 << fabs(norm(it->second.linearVel)*systemIncrement));
182 // Compute the time in the feeders time scale which fits the current time
184 double tInterp = curtime + mTimeOffset;
189 if (tInterp <= curentPkgTime) {
190 // Ok, we need a time prevous to the last available packet,
193 // Find the first packet before the target time
194 MotionInfo::iterator nextIt = mMotionInfo.upper_bound(tInterp);
195 if (nextIt == mMotionInfo.begin()) {
196 SG_LOG(SG_GENERAL, SG_DEBUG, "Taking oldest packet!");
197 // We have no packet before the target time, just use the first one
198 MotionInfo::iterator firstIt = mMotionInfo.begin();
199 ecPos = firstIt->second.position;
200 ecOrient = firstIt->second.orientation;
201 speed = norm(firstIt->second.linearVel) * SG_METER_TO_NM * 3600.0;
203 std::vector<FGPropertyData*>::const_iterator firstPropIt;
204 std::vector<FGPropertyData*>::const_iterator firstPropItEnd;
205 firstPropIt = firstIt->second.properties.begin();
206 firstPropItEnd = firstIt->second.properties.end();
207 while (firstPropIt != firstPropItEnd) {
208 //cout << " Setting property..." << (*firstPropIt)->id;
209 PropertyMap::iterator pIt = mPropertyMap.find((*firstPropIt)->id);
210 if (pIt != mPropertyMap.end())
212 //cout << "Found " << pIt->second->getPath() << ":";
213 switch ((*firstPropIt)->type) {
217 pIt->second->setIntValue((*firstPropIt)->int_value);
218 //cout << "Int: " << (*firstPropIt)->int_value << "\n";
222 pIt->second->setFloatValue((*firstPropIt)->float_value);
223 //cout << "Flo: " << (*firstPropIt)->float_value << "\n";
226 case props::UNSPECIFIED:
227 pIt->second->setStringValue((*firstPropIt)->string_value);
228 //cout << "Str: " << (*firstPropIt)->string_value << "\n";
231 // FIXME - currently defaults to float values
232 pIt->second->setFloatValue((*firstPropIt)->float_value);
233 //cout << "Unknown: " << (*firstPropIt)->float_value << "\n";
239 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*firstPropIt)->id << "\n");
245 // Ok, we have really found something where our target time is in between
246 // do interpolation here
247 MotionInfo::iterator prevIt = nextIt;
250 // Interpolation coefficient is between 0 and 1
251 double intervalStart = prevIt->second.time;
252 double intervalEnd = nextIt->second.time;
253 double intervalLen = intervalEnd - intervalStart;
254 double tau = (tInterp - intervalStart)/intervalLen;
256 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer vehicle interpolation: ["
257 << intervalStart << ", " << intervalEnd << "], intervalLen = "
258 << intervalLen << ", interpolation parameter = " << tau);
260 // Here we do just linear interpolation on the position
261 ecPos = ((1-tau)*prevIt->second.position + tau*nextIt->second.position);
262 ecOrient = interpolate((float)tau, prevIt->second.orientation,
263 nextIt->second.orientation);
264 speed = norm((1-tau)*prevIt->second.linearVel
265 + tau*nextIt->second.linearVel) * SG_METER_TO_NM * 3600.0;
267 if (prevIt->second.properties.size()
268 == nextIt->second.properties.size()) {
269 std::vector<FGPropertyData*>::const_iterator prevPropIt;
270 std::vector<FGPropertyData*>::const_iterator prevPropItEnd;
271 std::vector<FGPropertyData*>::const_iterator nextPropIt;
272 std::vector<FGPropertyData*>::const_iterator nextPropItEnd;
273 prevPropIt = prevIt->second.properties.begin();
274 prevPropItEnd = prevIt->second.properties.end();
275 nextPropIt = nextIt->second.properties.begin();
276 nextPropItEnd = nextIt->second.properties.end();
277 while (prevPropIt != prevPropItEnd) {
278 PropertyMap::iterator pIt = mPropertyMap.find((*prevPropIt)->id);
279 //cout << " Setting property..." << (*prevPropIt)->id;
281 if (pIt != mPropertyMap.end())
283 //cout << "Found " << pIt->second->getPath() << ":";
287 switch ((*prevPropIt)->type) {
291 ival = (int) (0.5+(1-tau)*((double) (*prevPropIt)->int_value) +
292 tau*((double) (*nextPropIt)->int_value));
293 pIt->second->setIntValue(ival);
294 //cout << "Int: " << ival << "\n";
298 val = (1-tau)*(*prevPropIt)->float_value +
299 tau*(*nextPropIt)->float_value;
300 //cout << "Flo: " << val << "\n";
301 pIt->second->setFloatValue(val);
304 case props::UNSPECIFIED:
305 //cout << "Str: " << (*nextPropIt)->string_value << "\n";
306 pIt->second->setStringValue((*nextPropIt)->string_value);
309 // FIXME - currently defaults to float values
310 val = (1-tau)*(*prevPropIt)->float_value +
311 tau*(*nextPropIt)->float_value;
312 //cout << "Unk: " << val << "\n";
313 pIt->second->setFloatValue(val);
319 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*prevPropIt)->id << "\n");
327 // Now throw away too old data
328 if (prevIt != mMotionInfo.begin())
332 MotionInfo::iterator delIt;
333 delIt = mMotionInfo.begin();
335 while (delIt != prevIt)
337 std::vector<FGPropertyData*>::const_iterator propIt;
338 std::vector<FGPropertyData*>::const_iterator propItEnd;
339 propIt = delIt->second.properties.begin();
340 propItEnd = delIt->second.properties.end();
342 //cout << "Deleting data\n";
344 while (propIt != propItEnd)
353 mMotionInfo.erase(mMotionInfo.begin(), prevIt);
357 // Ok, we need to predict the future, so, take the best data we can have
358 // and do some eom computation to guess that for now.
359 FGExternalMotionData motionInfo = it->second;
361 // The time to predict, limit to 5 seconds
362 double t = tInterp - motionInfo.time;
363 t = SGMisc<double>::min(t, 5);
365 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer vehicle extrapolation: "
366 "extrapolation time = " << t);
368 // Do a few explicit euler steps with the constant acceleration's
369 // This must be sufficient ...
370 ecPos = motionInfo.position;
371 ecOrient = motionInfo.orientation;
372 SGVec3f linearVel = motionInfo.linearVel;
373 SGVec3f angularVel = motionInfo.angularVel;
379 SGVec3d ecVel = toVec3d(ecOrient.backTransform(linearVel));
381 ecOrient += h*ecOrient.derivative(angularVel);
383 linearVel += h*(cross(linearVel, angularVel) + motionInfo.linearAccel);
384 angularVel += h*motionInfo.angularAccel;
389 std::vector<FGPropertyData*>::const_iterator firstPropIt;
390 std::vector<FGPropertyData*>::const_iterator firstPropItEnd;
391 speed = norm(linearVel) * SG_METER_TO_NM * 3600.0;
392 firstPropIt = it->second.properties.begin();
393 firstPropItEnd = it->second.properties.end();
394 while (firstPropIt != firstPropItEnd) {
395 PropertyMap::iterator pIt = mPropertyMap.find((*firstPropIt)->id);
396 //cout << " Setting property..." << (*firstPropIt)->id;
398 if (pIt != mPropertyMap.end())
400 switch ((*firstPropIt)->type) {
404 pIt->second->setIntValue((*firstPropIt)->int_value);
405 //cout << "Int: " << (*firstPropIt)->int_value << "\n";
409 pIt->second->setFloatValue((*firstPropIt)->float_value);
410 //cout << "Flo: " << (*firstPropIt)->float_value << "\n";
413 case props::UNSPECIFIED:
414 pIt->second->setStringValue((*firstPropIt)->string_value);
415 //cout << "Str: " << (*firstPropIt)->string_value << "\n";
418 // FIXME - currently defaults to float values
419 pIt->second->setFloatValue((*firstPropIt)->float_value);
420 //cout << "Unk: " << (*firstPropIt)->float_value << "\n";
426 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*firstPropIt)->id << "\n");
433 // extract the position
434 pos = SGGeod::fromCart(ecPos);
435 altitude_ft = pos.getElevationFt();
437 // The quaternion rotating from the earth centered frame to the
438 // horizontal local frame
439 SGQuatf qEc2Hl = SGQuatf::fromLonLatRad((float)pos.getLongitudeRad(),
440 (float)pos.getLatitudeRad());
441 // The orientation wrt the horizontal local frame
442 SGQuatf hlOr = conj(qEc2Hl)*ecOrient;
443 float hDeg, pDeg, rDeg;
444 hlOr.getEulerDeg(hDeg, pDeg, rDeg);
449 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer position and orientation: "
450 << ecPos << ", " << hlOr);
452 //###########################//
453 // do calculations for radar //
454 //###########################//
455 double range_ft2 = UpdateRadar(manager);
457 //************************************//
459 //************************************//
463 if ( (range_ft2 < 250.0 * 250.0) &&
466 // refuel_node->setBoolValue(true);
469 // refuel_node->setBoolValue(false);
480 FGAIMultiplayer::addMotionInfo(const FGExternalMotionData& motionInfo,
483 mLastTimestamp = stamp;
485 if (!mMotionInfo.empty()) {
486 double diff = motionInfo.time - mMotionInfo.rbegin()->first;
488 // packet is very old -- MP has probably reset (incl. his timebase)
492 // drop packets arriving out of order
496 mMotionInfo[motionInfo.time] = motionInfo;
500 FGAIMultiplayer::setDoubleProperty(const std::string& prop, double val)
502 SGPropertyNode* pNode = props->getChild(prop.c_str(), true);
503 pNode->setDoubleValue(val);