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introduction of a zero lag mode when pilots are synched in time, eg using ntp.

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This commit is contained in:
jano 2020-01-14 11:10:28 +01:00
parent 1a7783c358
commit db295a9afc
2 changed files with 77 additions and 43 deletions
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112
src/AIModel/AIMultiplayer.cxx
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@ -50,6 +50,12 @@ FGAIMultiplayer::FGAIMultiplayer() :
lastUpdateTime = 0;
playerLag = 0.03;
compensateLag = 1;
realTime = false;
lastTime=0.0;
lagPpsAveraged = 1.0;
rawLag = 0.0;
rawLagMod = 0.0;
lagModAveraged = 0.0;
_searchOrder = PREFER_DATA;
}
@ -152,73 +158,96 @@ void FGAIMultiplayer::update(double dt)
// requested time to the most recent available packet. This is the
// target we want to reach in average.
double lag = it->second.lag;
rawLag = curentPkgTime - curtime;
realTime = false; //default behaviour
if (!mTimeOffsetSet) {
mTimeOffsetSet = true;
mTimeOffset = curentPkgTime - curtime - lag;
lastTime = curentPkgTime;
lagModAveraged = remainder((curentPkgTime - curtime), 3600.0);
props->setDoubleValue("lag/pps-averaged", lagPpsAveraged);
props->setDoubleValue("lag/lag-mod-averaged", lagModAveraged);
} else {
double offset = 0.0;
if ((curentPkgTime - lastTime) != 0) {
lagPpsAveraged = 0.99 * lagPpsAveraged + 0.01 * fabs( 1 / (lastTime - curentPkgTime));
lastTime = curentPkgTime;
rawLagMod = remainder(rawLag, 3600.0);
lagModAveraged = lagModAveraged *0.99 + 0.01 * rawLagMod;
props->setDoubleValue("lag/pps-averaged", lagPpsAveraged);
props->setDoubleValue("lag/lag-mod-averaged", lagModAveraged);
}
//spectator mode, more late to be in the interpolation zone
double offset = 0.0;
//spectator mode, more late to be in the interpolation zone
if (compensateLag == 3) { offset = curentPkgTime -curtime -lag + playerLag;
// old behaviour
// old behaviour
} else if (compensateLag == 1) { offset = curentPkgTime - curtime - lag;
// using the prediction mode to display the mpaircraft in the futur/past with given playerlag value
//currently compensatelag = 2
} else if (fabs(lagModAveraged) < 0.3) {
mTimeOffset = (round(rawLag/3600))*3600; //real time mode if close enough
realTime = true;
} else { offset = curentPkgTime - curtime + 0.48*lag + playerLag;
}
if ((!mAllowExtrapolation && offset + lag < mTimeOffset)
|| (offset - 10 > mTimeOffset)) {
mTimeOffset = offset;
SG_LOG(SG_AI, SG_DEBUG, "Resetting time offset adjust system to "
"avoid extrapolation: time offset = " << mTimeOffset);
} else {
// the error of the offset, respectively the negative error to avoid
// a minus later ...
double err = offset - mTimeOffset;
// limit errors leading to shorter lag values somehow, that is late
// arriving packets will pessimize the overall lag much more than
// early packets will shorten the overall lag
double sysSpeed;
//trying to slow the rudderlag phenomenon thus using more the prediction system
//if we are off by less than 1.5s, do a little correction, and bigger step above 1.5s
if (fabs(err) < 1.5) {
if (err < 0) {
sysSpeed = mLagAdjustSystemSpeed*err*0.01;
} else {
sysSpeed = SGMiscd::min(0.5*err*err, 0.05);
}
} else {
if (err < 0) {
if (!realTime) {
// Ok, we have some very late packets and nothing newer increase the
// lag by the given speedadjust
sysSpeed = mLagAdjustSystemSpeed*err;
} else {
// We have a too pessimistic display delay shorten that a small bit
sysSpeed = SGMiscd::min(0.1*err*err, 0.5);
}
}
if ((!mAllowExtrapolation && offset + lag < mTimeOffset)
|| (offset - 10 > mTimeOffset)) {
mTimeOffset = offset;
SG_LOG(SG_AI, SG_DEBUG, "Resetting time offset adjust system to "
"avoid extrapolation: time offset = " << mTimeOffset);
} else {
// the error of the offset, respectively the negative error to avoid
// a minus later ...
double err = offset - mTimeOffset;
// limit errors leading to shorter lag values somehow, that is late
// arriving packets will pessimize the overall lag much more than
// early packets will shorten the overall lag
double sysSpeed;
//trying to slow the rudderlag phenomenon thus using more the prediction system
//if we are off by less than 1.5s, do a little correction, and bigger step above 1.5s
if (fabs(err) < 1.5) {
if (err < 0) {
sysSpeed = mLagAdjustSystemSpeed*err*0.01;
} else {
sysSpeed = SGMiscd::min(0.5*err*err, 0.05);
}
} else {
if (err < 0) {
// Ok, we have some very late packets and nothing newer increase the
// lag by the given speedadjust
sysSpeed = mLagAdjustSystemSpeed*err;
} else {
// We have a too pessimistic display delay shorten that a small bit
sysSpeed = SGMiscd::min(0.1*err*err, 0.5);
}
}
// simple euler integration for that first order system including some
// overshooting guard to prevent to aggressive system speeds
// (stiff systems) to explode the systems state
double systemIncrement = dt*sysSpeed;
if (fabs(err) < fabs(systemIncrement))
systemIncrement = err;
mTimeOffset += systemIncrement;
double systemIncrement = dt*sysSpeed;
if (fabs(err) < fabs(systemIncrement))
systemIncrement = err;
mTimeOffset += systemIncrement;
SG_LOG(SG_AI, SG_DEBUG, "Offset adjust system: time offset = "
SG_LOG(SG_AI, SG_DEBUG, "Offset adjust system: time offset = "
<< mTimeOffset << ", expected longitudinal position error due to "
" current adjustment of the offset: "
<< fabs(norm(it->second.linearVel)*systemIncrement));
}
}
}
// Compute the time in the feeders time scale which fits the current time
// we need to
double tInterp = curtime + mTimeOffset;
@ -227,9 +256,10 @@ void FGAIMultiplayer::update(double dt)
SGQuatf ecOrient;
SGVec3f ecLinearVel;
if (tInterp <= curentPkgTime) {
if (tInterp < curentPkgTime) {
// Ok, we need a time prevous to the last available packet,
// that is good ...
// the case tInterp = curentPkgTime need to be in the interpolation, to avoid a bug zeroing the position
// Find the first packet before the target time
MotionInfo::iterator nextIt = mMotionInfo.upper_bound(tInterp);

8
src/AIModel/AIMultiplayer.hxx
View file

@ -86,11 +86,15 @@ private:
typedef std::map<unsigned, SGSharedPtr<SGPropertyNode> > PropertyMap;
PropertyMap mPropertyMap;
double mTimeOffset;
bool mTimeOffsetSet;
double playerLag;
bool realTime;
int compensateLag;
double playerLag;
double mTimeOffset;
double lastUpdateTime;
double lastTime;
double lagPpsAveraged;
double rawLag, rawLagMod, lagModAveraged;
/// Properties which are for now exposed for testing
bool mAllowExtrapolation;