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->tie("tanker", SGRawValuePointer<bool>(&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");
105 props->untie("tanker");
109 void FGAIMultiplayer::update(double dt)
111 using namespace simgear;
116 FGAIBase::update(dt);
118 // Check if we already got data
119 if (mMotionInfo.empty())
122 // The current simulation time we need to update for,
123 // note that the simulation time is updated before calling all the
124 // update methods. Thus it contains the time intervals *end* time
125 double curtime = globals->get_sim_time_sec();
127 // Get the last available time
128 MotionInfo::reverse_iterator it = mMotionInfo.rbegin();
129 double curentPkgTime = it->second.time;
131 // Dynamically optimize the time offset between the feeder and the client
132 // Well, 'dynamically' means that the dynamic of that update must be very
133 // slow. You would otherwise notice huge jumps in the multiplayer models.
134 // The reason is that we want to avoid huge extrapolation times since
135 // extrapolation is highly error prone. For that we need something
136 // approaching the average latency of the packets. This first order lag
137 // component will provide this. We just take the error of the currently
138 // requested time to the most recent available packet. This is the
139 // target we want to reach in average.
140 double lag = it->second.lag;
141 if (!mTimeOffsetSet) {
142 mTimeOffsetSet = true;
143 mTimeOffset = curentPkgTime - curtime - lag;
145 double offset = curentPkgTime - curtime - lag;
146 if ((!mAllowExtrapolation && offset + lag < mTimeOffset)
147 || (offset - 10 > mTimeOffset)) {
148 mTimeOffset = offset;
149 SG_LOG(SG_GENERAL, SG_DEBUG, "Resetting time offset adjust system to "
150 "avoid extrapolation: time offset = " << mTimeOffset);
152 // the error of the offset, respectively the negative error to avoid
154 double err = offset - mTimeOffset;
155 // limit errors leading to shorter lag values somehow, that is late
156 // arriving packets will pessimize the overall lag much more than
157 // early packets will shorten the overall lag
160 // Ok, we have some very late packets and nothing newer increase the
161 // lag by the given speedadjust
162 sysSpeed = mLagAdjustSystemSpeed*err;
164 // We have a too pessimistic display delay shorten that a small bit
165 sysSpeed = SGMiscd::min(0.1*err*err, 0.5);
168 // simple euler integration for that first order system including some
169 // overshooting guard to prevent to aggressive system speeds
170 // (stiff systems) to explode the systems state
171 double systemIncrement = dt*sysSpeed;
172 if (fabs(err) < fabs(systemIncrement))
173 systemIncrement = err;
174 mTimeOffset += systemIncrement;
176 SG_LOG(SG_GENERAL, SG_DEBUG, "Offset adjust system: time offset = "
177 << mTimeOffset << ", expected longitudinal position error due to "
178 " current adjustment of the offset: "
179 << fabs(norm(it->second.linearVel)*systemIncrement));
184 // Compute the time in the feeders time scale which fits the current time
186 double tInterp = curtime + mTimeOffset;
191 if (tInterp <= curentPkgTime) {
192 // Ok, we need a time prevous to the last available packet,
195 // Find the first packet before the target time
196 MotionInfo::iterator nextIt = mMotionInfo.upper_bound(tInterp);
197 if (nextIt == mMotionInfo.begin()) {
198 SG_LOG(SG_GENERAL, SG_DEBUG, "Taking oldest packet!");
199 // We have no packet before the target time, just use the first one
200 MotionInfo::iterator firstIt = mMotionInfo.begin();
201 ecPos = firstIt->second.position;
202 ecOrient = firstIt->second.orientation;
203 speed = norm(firstIt->second.linearVel) * SG_METER_TO_NM * 3600.0;
205 std::vector<FGPropertyData*>::const_iterator firstPropIt;
206 std::vector<FGPropertyData*>::const_iterator firstPropItEnd;
207 firstPropIt = firstIt->second.properties.begin();
208 firstPropItEnd = firstIt->second.properties.end();
209 while (firstPropIt != firstPropItEnd) {
210 //cout << " Setting property..." << (*firstPropIt)->id;
211 PropertyMap::iterator pIt = mPropertyMap.find((*firstPropIt)->id);
212 if (pIt != mPropertyMap.end())
214 //cout << "Found " << pIt->second->getPath() << ":";
215 switch ((*firstPropIt)->type) {
219 pIt->second->setIntValue((*firstPropIt)->int_value);
220 //cout << "Int: " << (*firstPropIt)->int_value << "\n";
224 pIt->second->setFloatValue((*firstPropIt)->float_value);
225 //cout << "Flo: " << (*firstPropIt)->float_value << "\n";
228 case props::UNSPECIFIED:
229 pIt->second->setStringValue((*firstPropIt)->string_value);
230 //cout << "Str: " << (*firstPropIt)->string_value << "\n";
233 // FIXME - currently defaults to float values
234 pIt->second->setFloatValue((*firstPropIt)->float_value);
235 //cout << "Unknown: " << (*firstPropIt)->float_value << "\n";
241 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*firstPropIt)->id << "\n");
247 // Ok, we have really found something where our target time is in between
248 // do interpolation here
249 MotionInfo::iterator prevIt = nextIt;
252 // Interpolation coefficient is between 0 and 1
253 double intervalStart = prevIt->second.time;
254 double intervalEnd = nextIt->second.time;
255 double intervalLen = intervalEnd - intervalStart;
256 double tau = (tInterp - intervalStart)/intervalLen;
258 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer vehicle interpolation: ["
259 << intervalStart << ", " << intervalEnd << "], intervalLen = "
260 << intervalLen << ", interpolation parameter = " << tau);
262 // Here we do just linear interpolation on the position
263 ecPos = ((1-tau)*prevIt->second.position + tau*nextIt->second.position);
264 ecOrient = interpolate((float)tau, prevIt->second.orientation,
265 nextIt->second.orientation);
266 speed = norm((1-tau)*prevIt->second.linearVel
267 + tau*nextIt->second.linearVel) * SG_METER_TO_NM * 3600.0;
269 if (prevIt->second.properties.size()
270 == nextIt->second.properties.size()) {
271 std::vector<FGPropertyData*>::const_iterator prevPropIt;
272 std::vector<FGPropertyData*>::const_iterator prevPropItEnd;
273 std::vector<FGPropertyData*>::const_iterator nextPropIt;
274 std::vector<FGPropertyData*>::const_iterator nextPropItEnd;
275 prevPropIt = prevIt->second.properties.begin();
276 prevPropItEnd = prevIt->second.properties.end();
277 nextPropIt = nextIt->second.properties.begin();
278 nextPropItEnd = nextIt->second.properties.end();
279 while (prevPropIt != prevPropItEnd) {
280 PropertyMap::iterator pIt = mPropertyMap.find((*prevPropIt)->id);
281 //cout << " Setting property..." << (*prevPropIt)->id;
283 if (pIt != mPropertyMap.end())
285 //cout << "Found " << pIt->second->getPath() << ":";
289 switch ((*prevPropIt)->type) {
293 ival = (int) (0.5+(1-tau)*((double) (*prevPropIt)->int_value) +
294 tau*((double) (*nextPropIt)->int_value));
295 pIt->second->setIntValue(ival);
296 //cout << "Int: " << ival << "\n";
300 val = (1-tau)*(*prevPropIt)->float_value +
301 tau*(*nextPropIt)->float_value;
302 //cout << "Flo: " << val << "\n";
303 pIt->second->setFloatValue(val);
306 case props::UNSPECIFIED:
307 //cout << "Str: " << (*nextPropIt)->string_value << "\n";
308 pIt->second->setStringValue((*nextPropIt)->string_value);
311 // FIXME - currently defaults to float values
312 val = (1-tau)*(*prevPropIt)->float_value +
313 tau*(*nextPropIt)->float_value;
314 //cout << "Unk: " << val << "\n";
315 pIt->second->setFloatValue(val);
321 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*prevPropIt)->id << "\n");
329 // Now throw away too old data
330 if (prevIt != mMotionInfo.begin())
334 MotionInfo::iterator delIt;
335 delIt = mMotionInfo.begin();
337 while (delIt != prevIt)
339 std::vector<FGPropertyData*>::const_iterator propIt;
340 std::vector<FGPropertyData*>::const_iterator propItEnd;
341 propIt = delIt->second.properties.begin();
342 propItEnd = delIt->second.properties.end();
344 //cout << "Deleting data\n";
346 while (propIt != propItEnd)
355 mMotionInfo.erase(mMotionInfo.begin(), prevIt);
359 // Ok, we need to predict the future, so, take the best data we can have
360 // and do some eom computation to guess that for now.
361 FGExternalMotionData motionInfo = it->second;
363 // The time to predict, limit to 5 seconds
364 double t = tInterp - motionInfo.time;
365 t = SGMisc<double>::min(t, 5);
367 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer vehicle extrapolation: "
368 "extrapolation time = " << t);
370 // Do a few explicit euler steps with the constant acceleration's
371 // This must be sufficient ...
372 ecPos = motionInfo.position;
373 ecOrient = motionInfo.orientation;
374 SGVec3f linearVel = motionInfo.linearVel;
375 SGVec3f angularVel = motionInfo.angularVel;
381 SGVec3d ecVel = toVec3d(ecOrient.backTransform(linearVel));
383 ecOrient += h*ecOrient.derivative(angularVel);
385 linearVel += h*(cross(linearVel, angularVel) + motionInfo.linearAccel);
386 angularVel += h*motionInfo.angularAccel;
391 std::vector<FGPropertyData*>::const_iterator firstPropIt;
392 std::vector<FGPropertyData*>::const_iterator firstPropItEnd;
393 speed = norm(linearVel) * SG_METER_TO_NM * 3600.0;
394 firstPropIt = it->second.properties.begin();
395 firstPropItEnd = it->second.properties.end();
396 while (firstPropIt != firstPropItEnd) {
397 PropertyMap::iterator pIt = mPropertyMap.find((*firstPropIt)->id);
398 //cout << " Setting property..." << (*firstPropIt)->id;
400 if (pIt != mPropertyMap.end())
402 switch ((*firstPropIt)->type) {
406 pIt->second->setIntValue((*firstPropIt)->int_value);
407 //cout << "Int: " << (*firstPropIt)->int_value << "\n";
411 pIt->second->setFloatValue((*firstPropIt)->float_value);
412 //cout << "Flo: " << (*firstPropIt)->float_value << "\n";
415 case props::UNSPECIFIED:
416 pIt->second->setStringValue((*firstPropIt)->string_value);
417 //cout << "Str: " << (*firstPropIt)->string_value << "\n";
420 // FIXME - currently defaults to float values
421 pIt->second->setFloatValue((*firstPropIt)->float_value);
422 //cout << "Unk: " << (*firstPropIt)->float_value << "\n";
428 SG_LOG(SG_GENERAL, SG_DEBUG, "Unable to find property: " << (*firstPropIt)->id << "\n");
435 // extract the position
436 pos = SGGeod::fromCart(ecPos);
437 altitude_ft = pos.getElevationFt();
439 // The quaternion rotating from the earth centered frame to the
440 // horizontal local frame
441 SGQuatf qEc2Hl = SGQuatf::fromLonLatRad((float)pos.getLongitudeRad(),
442 (float)pos.getLatitudeRad());
443 // The orientation wrt the horizontal local frame
444 SGQuatf hlOr = conj(qEc2Hl)*ecOrient;
445 float hDeg, pDeg, rDeg;
446 hlOr.getEulerDeg(hDeg, pDeg, rDeg);
451 SG_LOG(SG_GENERAL, SG_DEBUG, "Multiplayer position and orientation: "
452 << ecPos << ", " << hlOr);
454 //###########################//
455 // do calculations for radar //
456 //###########################//
457 double range_ft2 = UpdateRadar(manager);
459 //************************************//
461 //************************************//
465 //cout << "IS tanker ";
466 if ( (range_ft2 < 250.0 * 250.0) &&
469 // refuel_node->setBoolValue(true);
470 //cout << "in contact" << endl;
473 // refuel_node->setBoolValue(false);
474 //cout << "not in contact" << endl;
478 //cout << "NOT tanker " << endl;
486 FGAIMultiplayer::addMotionInfo(const FGExternalMotionData& motionInfo,
489 mLastTimestamp = stamp;
491 if (!mMotionInfo.empty()) {
492 double diff = motionInfo.time - mMotionInfo.rbegin()->first;
494 // packet is very old -- MP has probably reset (incl. his timebase)
498 // drop packets arriving out of order
502 mMotionInfo[motionInfo.time] = motionInfo;
506 FGAIMultiplayer::setDoubleProperty(const std::string& prop, double val)
508 SGPropertyNode* pNode = props->getChild(prop.c_str(), true);
509 pNode->setDoubleValue(val);