I have done a patch to eliminate the jitter of 3D-objects near the viewpoint
(for example 3D cockpit objects).
The problem is the roundoff accuracy of the float values used in the
scenegraph together with the transforms of the eyepoint relative to the
scenery center.
The solution will be to move the scenery center near the view point.
This way floats relative accuracy is enough to show a stable picture.
To get that right I have introduced a transform node for the scenegraph which
is responsible for that shift and uses double values as long as possible.
The scenery subsystem now has a list of all those transforms required to place
objects in the world and will tell all those transforms that the scenery
center has changed when the set_scenery_center() of the scenery subsystem is
called.
The problem was not solvable by SGModelPlacement and SGLocation, since not all
objects, especially the scenery, are placed using these classes.
The first approach was to have the scenery center exactly at the eyepoint.
This works well for the cockpit.
But then the ground jitters a bit below the aircraft. With our default views
you can't see that, but that F-18 has a camera view below the left engine
intake with the nose gear and the ground in its field of view, here I could
see that.
Having the scenery center constant will still have this roundoff problems, but
like it is now too, the roundoff error here is exactly the same in each
frame, so you will not notice any jitter.
The real solution is now to keep the scenery center constant as long as it is
in a ball of 30m radius around the view point. If the scenery center is
outside this ball, just put it at the view point.
As a sideeffect of now beeing able to switch the scenery center in the whole
scenegraph with one function call, I was able to remove a one half of a
problem when switching views, where the scenery center was far off for one or
two frames past switching from one view to the next. Also included is a fix
to the other half of this problem, where the view position was not yet copied
into a view when it is switched (at least under glut). This was responsible
for the 'Error: ...' messages of the cloud subsystem when views were
switched.
FGAIMgr::GenerateSimpleAirportTraffic() tries to determine the airport's local
hour from the /sim/time/gmt-time string, which fails, because at this time the
property is still empty. That's why I don't get ATIS at LOWG (where it is *not*
midnight right now. :-) -> use sg's get_cur_time() instead
I just heard from John Wojnaroski that you and he are going to work on getting
a flightgear demo machine up for the linux expo thursday and Friday. John
indicated that he would very much like to get a CVS version with the new
traffic code up and running before the expo.
a single apt.dat.gz file which is in the native X-Plane format.
To do this I wrote a front end loader than builds the airport and runway
list. Some of the changes I needed to make had a cascading effect, so there
are minor naming changes scattered throughout the code.
I've finished the emigration of the radiostack, and I've also removed it
completely. It turned out that the comm radio is completely implemented in
the ATC subsystem. I've changed the affected ATC files to point
to /instrumentation/com, but I guess that the maintainer of the ATC code
should decide wether to make it configureable, and how.
I also had to change some files in Network and Main. The changes in network
should be obvious, but the changes in Main were a bit suspect. The files
included radiostack.hxx, but they weren't directly depending on
radiostack-hxx. They were depending on other files that were included by
radiostack.hxx. I got it to compile, but I'm not sure if I included the
correct directly depending file.
For the data directory I changed every occurrence of /radios/
with /instrumentation/ with this simple one-liner that I found on the net:
find -name '*.xml' -type f | xargs perl -pi -e
's/\/radios\//\/instrumentation\//g'
Instead of me sending all the files that got changed by this I suggest that
you execute the one-liner yourself. Of course I can not guarantee that this
will work perfectly, but I considered hand editing to be not an option (I'm
lazy). I don't want to test every aircraft to see if everything still works,
I think it's better to wait and see if anyone complaints about broken nav
radios/instruments.
configure and compile out-of-the-box on a MinGW target:
Use -lSDL instead of -lglut32 on windows builds when --enable-sdl
is set.
Link against alut.dll in addition to openal32.dll.
Replace BSD bcopy() with ANSI C memmove() in a few places. This is
simpler than trying to abstract it out as a platform dependency in a
header file; bcopy() has never been standard.
The ENABLE_THREADS handling has changed to be set to 0 when threads
are not in use. This breaks expressions like #ifdef ENABLE_THREADS.
Replace with a slightly more complicated expression. It might have
been better to fix the configure.ac script, but I didn't know how and
this whole setting is likely to go away soon anyway.
The MinGW C runtime actually does include snprintf, so only MSVC
builds (and not all WIN32 ones) need _snprintf in JSBSim/FGState.cpp
Building on a platform with no glut at all exposed some spots where
plib/pu.h was being included without a toolkit setting (it defaults to
glut). Include fg_os.hxx first.
And when still using glut, glut.h has a bizarre dependency on a
_WCHAR_T_DEFINED symbol. It it's not defined, it tries to redefine
(!!) wchar_t to disasterous effect.
