When FG encounters an unknown property id in a MP packet, it discards
the remainder of the packet. This happens when adding new MP properties:
older clients will discard the property and anything that comes after.
This is normally not an issue because newer properties are placed at the
end of the packet.
However MP bool array properties (sim/generic/bool[*]) are transmitted
at the very end of a packet, meaning they get broken (for backward
compatibility) each time a property is added to the protocol.
Fix this by placing them earlier in the packet, with the same ordering
rules as other properties.
Commit 6aff646cf (Mach number added to mode-S XPDR properties, 2022-07-20)
added /instrumentation/transponder/mach-number as a new MP property.
It was inserted with other transponder properties, in the middle of
the list of MP properties. This breaks backward compatibility:
older FG client discard any property after this.
Move the new property to the end of the list, with the largest id.
This is by Lars Toenning <dev@ltoenning.de>, Roman Ludwicki <romek21@op.pl> and
SDeAstis <salvatore.deastis@gmail.com>, in 2021 Hackathon.
Also cope with removal of SGPropertyNode::getName() - use getNameString()
instead.
Also fixed uneven MP carrier motion.
If /ai/models/carrier[]/ai-latch is true (e.g. by MPCarrier.nas), we
set /position/* and /orientation/* in C++ every frame instead of in
nasal. For external multiplayer carriers the values are copied from
/ai/models/multiplayer[]/*, so the AI carrier follows the corresponding MP
carrier exactly. For this to be useful, multiplayer motion needs be smooth,
e.g. with /sim/time/simple-time/enabled=true.
scripts/python/recordreplay.py
Added --carrier test - checks that multiplayer carrier moves with even
speed.
src/AIModel/AIBase.hxx
Added speed_fps, to be kept up to date and tied to velocities/uBody-fps
when we are a carrier. Previously this was set from Nasal which doesn't
do what is required when all updates happen in C++.
src/AIModel/AICarrier.cxx
src/AIModel/AICarrier.hxx
If is-user-craft is true, we directly update /position/* every frame.
If ai-latch is true, we don't call TurnToLaunch(), TurnToRecover(),
ReturnToBox(), TurnToBase() etc, because our position and orientation is
determined only by multiplayer packets.
src/AIModel/AIMultiplayer.cxx
src/AIModel/AIMultiplayer.hxx
If an mp craft is a carrier, MP packets define velocities/speed-kts but
set ecLinearVel to all-zeros. So we now copy across to ensure that the
extrapolation algorithm has a velocity to work with. Previously the zero
velocity caused very uneven motion.
If ai-latch is true we set AI craft's position+velocities directly from
the equivalent (extrapolated or interpolated) MP position, every frame. We
also set AI craft's orientation. And we copy MP's uBody-fps to AI's
velocities/speed-kts which ensures that friction works between carrier deck
and aircraft undercarriage.
Added logging of raw speeds implied by multiplayer packets, activated by
/sim/log-multiplayer-callsign; used by scripts/python/recordreplay.py's
--carrier test.
src/AIModel/AIShip.cxx
Tie velocities/uBody-fps to new speed_fps member and set speed_fps in
update() along with members that are tied to properties.
Replaced code that calculated new position using heading and speed:
Previously the new position after dt was calculated using
ft_per_deg_lat, ft_per_deg_lon, speed_north_deg_sec and
speed_east_deg_sec. But this was moving slightly faster than the
specified speed.
This was leading to incremental errors when a different Flightgear
instance extrapolated the multiplayer position from the information in
multiplayer packets, because the specified velocity was too small, so
we jumped forwards when extrapolation moved to a new packet.
The fix is to use a Quaternion-based calculation to calculate movement
in the direction specified by (heading, pitch, roll), as done by other
code such as the view code.
src/Main/fg_init.cxx
Moved FGAIManager to just before FGMultiplayMgr so we send latest info in
mp packets.
src/MultiPlayer/multiplaymgr.cxx
Fixed minimum transmit rate calculation - if transmit rate is less than 1,
default to 1, not 10.
src/Network/props.cxx
Use more precision when sending double-precision values e.g. to telnet
client. Otherwise for example UTC times don't have sufficient resolution.
src/Viewer/viewmgr.cxx
Generate internal logs of multiplayer position and speed (after
interpolation/extrapolation) if /sim/log-multiplayer-callsign is set. Used
by scripts/python/recordreplay.py's --carrier test.
FGFlightRecorder::replay():
Fixed behaviour when going back in time while replaying - we were not
replaying initial property changes correctly because we deliberately
don't load signals data for some frames when we are only interested in
multiplayer or extra properties.
Removed incorrect code that tried to avoid replaying the same frame twice
in succession.
FGReplay::update(double dt):
Improved how we figure out which frames we need to replay just for multiplayer
or extra property changes.
FGReplay::makeTapePath():
New fn containing the code for converting tape name into path by prepending
tape dir and appending .fgtape as necessary. Called when loading tape at
startup or at runtime.
Cached some more property nodes in SGPropertyNode_ptr's.
Don't recordCHAT_MSG_ID messages; unfortunately it looks like most (all?)
chat message text is received as part of POS_DATA_ID messages tied to
sim/multiplay/chat, so this doesn't actually avoid recording chat messages.
Chase distances are supposed to be negative. Otherwise in external views
vertical mouse moves have reversed behaviour when changing view angle. E.g.
see:
https://sourceforge.net/p/flightgear/codetickets/2454
src/MultiPlayer/multiplaymgr.cxx
Fix +ve chase-distance-m for multiplayer aircraft.
src/Viewer/viewmgr.cxx
Fix +ve chase-distance-m for user aircraft.
This background recording keeps the user aircraft stationary while recording
all movements of multiplayer aircraft. Allows one to look at replay without,
for example, disturbing continuous record to file.
Fgtape:
If multipayer replay is active we write multiplayer packet information to
fgtape files. We also add /sim/replay/multiplayer to the properties written
to fgtape file so at load time we knows whether to expect multiplayer
packets.
New builds of fg can load and replay old recordings.
It is expected (but has not been tested) that old builds of fg will be able
to read new fgtape recordings where /sim/replay/multiplayer was unset or
false (currently the default).
Old builds of fg will not be able to load fgtape recordings that include
multiplayer data.
Avoid incorrect removal of multiplayer aircraft when replaying:
We now clear multiplayer motion history when we jump forwards or backwards
during replay. This ensures that multiplayer code doesn't remove
multiplayer aircraft because of inconsistent-looking time stamps.
We preserve some multiplay information when purging recorded information
to save space. This ensures that when replaying we get frequent enough
packets to avoid the multiplayer code thinking that multiplayer aircraft
have disappeared.
At the moment this only works for live replays - we don't (yet) write the
multiplayer information to fgtape files.
Enable with:
--prop:bool:/sim/replay/multiplayer=true
This works by copying all raw multiplayer packets into a buffer in
FGMultiplayMgr. Each time it is called, FGFlightRecorder::capture() moves all
the available packet from this buffer into its FGReplayData. Thus we store
roughly syncronised multiplayer packets along with the user aircraft's detailed
replay properties.
When replaying, FGFlightRecorder pushes packets into a buffer in
FGMultiplayMgr, which are used instead of live multiplayer packets. [Actually
when replaying FGMultiplayMgr still reads live packets in order to handle live
chat messages, and ignores chat messages from FGFlightRecorder.]
When loading -set.xml, we load into temporary 'set' node,
then copy across only set/sim/view[]/config/* values into
/ai/models/multiplayer[]/set/sim/view[]/config/.
This ensures that we have just the information required for multiplayer views,
and avoids problems where some properties in /ai/models/multiplayer[]/ were
being archived to autosave_*.xml and loaded in later flightgear sessions.
View 8 used to be new Tower View AGL view, but this interfered with hard-coded
aircraft view numbers. So fgdata now has removed Model View, meaning Tower
View AGL uses Model View's old number (7), which keeps sequential view numbers
unchanged.
src/MultiPlayer/multiplaymgr.cxx
src/MultiPlayer/multiplaymgr.hxx
removed starts_with() and ends_with() - already provided in simgear::.
removed output() fn for SGPropertyNode, as unused.
added makeStringPropertyNameSafe().
FGMultiplayMgr::addMultiplayer(): use std::find_if() to find model file.
added FGMultiplayMgr::subsystemName().
src/Viewer/view.cxx
src/Viewer/view.hxx
removed getDoubleValue() as not required.
moved agl code into new View::handleAGL() fn.
renamed View::Damping::setGet() => View::Damping::updateTarget().
Currently this works for all the default views except for Tower Look From (for
which it doesn't really make sense) and Fly-by View.
We now search for and load a -set.xml that matches the model .xml,
when new multiplayer aircraft is set up. This allows us to find view
offsets etc, e.g. allowing cockpit and helicopter views to work with
multiplayer aircraft. Properties from the -set.xml are placed into
/ai/models/multiplayer[]/set, so for example viewing offsets are in
/ai/models/multiplayer[]/set/sim/view[]/config/target-{x,y,z}-offset-m. We also
copy the aircraft's chase-distance into the view config params, similar to how
fgdata:defaults.xml does for the user's aircraft. And we also fill in views'
missing offsets from the Helicopter View config; e.g. this enables the new
Tower View AGL to show aircraft correctly centred, despite aircraft currently
not having this view defined in their -set.xml. [We don't currently attempt to
cache or reuse -set.xml data.]
Have ensured that view position responds to mouse movement in the same way for
viewing the user's aircraft as for multiplayer aircraft (previously, Model View
reversed the affect of vertical mouse movements).
Added new Tower AGL view. Behaves similarly to Tower view, but automatically
scales and pans vertically in order to always show the vertical range
extending from just above the aircraft down to the ground immediately below
the aircraft. We use aircrafts chase-distance as an indication of size. We
damp the ground level value to reduce the viewing jumping around too much
e.g. if the aircraft flies over buildings. The amount of damping is set by
fgdata:defaults.xml's lookat-agl-damping value.
Fixed problem where Tower View eye position moves slightly as target
aircraft heading changes. This was caused by us unnecessarily applying the
aircraft-centre correction to the eye position.
src/FDM/flight.cxx: also make /orientation/true-heading-deg. This allows
local orientation to be used like multiplayer orientation, which only
has /ai/models/multiplayer[]/orientation/true-heading-deg. [A better fix
might be to replace all occurrencies of /orientation/true-heading-deg with
/orientation/heading-deg, but this would be a rather large commit.]
Details:
src/Viewer/view.*: removed View::updateData() as is no longer required.
src/MultiPlayer/multiplaymgr.cxx: use helicopter view target offsets as
defaults. E.g. in tower view agl, aircraft won't currently be defining these
offsets. More generally, this allows aircraft to define target offsets only in
helicoter view.
src/FDM/flight.cxx
FGMultiplayMgr::FillMsgHdr(): Added tie of /orientation/true-heading-deg to
get_Psi_deg, so it duplictes the existing /orientation/heading-deg.
src/MultiPlayer/multiplaymgr.cxx
src/MultiPlayer/multiplaymgr.hxx
FGMultiplayMgr::addMultiplayer(): look for and load -set.xml that matches
the model. Patch various view-related things up in similar way to what we
do for the user's aircraft, so that multiplayer views work.
Made FGMultiplayMgr::getMultiplayer() public, so it can be used by
src/Viewer/view.cxx.
src/Viewer/view.cxx
src/Viewer/view.hxx
View::View(): Added lookat_agl, lookat_agl_damping params for new Tower
View AGL. Preserve user's field-of-view in separate variable so that Tower
View AGL can modify the actual field of view independently.
Added view_index param so that we can find multiplayer view[]/config/
properties.
getViewOffsets(): new fn that finds view offsets for user aircraft or
multiplayer aircraft.
View::recalcLookFrom() View::recalcLookAt: Lots of changes to allow things
to work with multiplayer aircraft. View::recalcLookAt() can now do Tower
View AGL.
View::Damping: support for damping, used by Tower View AGL. Might be good
to use this for other damping.
View::updateData(): removed, as calculations are now all done inside
View::recalc*().
put properties {x,y,z}-offset-m into new View::_adjust_offset_m member
instead of _offset_m. This avoids confusion between a view's offsets and
the offsets added in by the user via the 'Adjust View Position' dialogue.
src/Viewer/viewmgr.cxx
FGViewMgr::init(): pass view number to
flightgear::View::createFromProperties().
This is a clean up commit prior to the subsystem API standardisation to simplify
the diffs. It includes all SGSubsystem and SGSubsystemGroup derived classes.
PTT now uses an int channel number (0 means not pressed, 1 = comm radio 1 (index [0]),etc...)
/comm-radio-selected is the default comm channel to use. This should usually be the same as will be set by PTT into /controls/radios/comm-ptt
However PTT will switch the FG comm inbound and outbound frequency to whichever radio was PTT'd.
New properties also set in multi-player to indicate the transmission frequency and normalised power (currently just set to 1.0)
13001(int) : sim/multiplay/comm-transmit-frequency-hz
13002(short-norm) : sim/multiplay/comm-transmit-power-norm
Aircraft can now set a /sim/model/fallback-model-index property that is transmitted over the MP network.
Receiving clients use this as an index into AI/Aircraft/fallback_models.xml to determine a model to use if the model path (/sim/model/path) cannot be found under Aircraft or AI/Aircraft. This allows aircraft developers to identify a suitable fallback model to be used for those who do not have their aircraft installed.
