* in some cases more specific sg exception types were used in place
of the more generic one, e.g., sg_io_exception instead of sg_exception
when the context of the error was an IO error
* in some cases, the error message was made more specific
* minor style fix for exception rethrowing --- using throw; whenever
a re-throw is made; sometimes optimizing away the exception symbol name
in the catch handler at all
* more specific catch handlers added in some places -- e.g.,
an sg_io_exception caught ahead of sg_exception
Insert empty string as marker between FG_SCENERY path elements.
FG_SCENERY=A:B expands to [A/Terrain, A/Objects, "", B/Terrain, B/Objects, ""]
(assuming that both A/ and B/ have Terrain/ and Objects/ subdirs).
tileentry.cxx -- FGTileEntry::load():
Check all tile dirs in FG_SCENERY from left to right: add all objects
to the scenery until a terrain tile was found: In this case read the
rest of that group (i.e. the Objects/ twin dir) and then stop scanning.
Better structuring of log messages & fix warnings.
sea tile, and finally process the objects. This guarantees that all objects
are placed relative to a valid tile center, rather than to the origin (0/0/0).
This is important for objects in sea tiles, and allows to display objects
of *.stg files that came sooner in FG_SCENERY.
metar fetcher. Effectively this caused the metar thread and the main
thread to both attempt to fetch weather data. This could lead to long pauses
when the main thread decided to fetch the weather, and introduced a race
condition that could cause a segfault/crash.
Investigating this issue, I discovered that even longer ago, someone confused
#defines and #ifdef symbols with C/C++ variables. If I #define XYZ 0 it is
defined so #ifdef XYZ is true, not false like a variable. Our thread
detection made this mistake and there were follow up patches to work around
it.
So I fixed the configure script (ahhh, reading the autoconf manual is highly
recommended excercise for people editing the configure.ac file.) I also
discovered that we were hardwiring with_threads=yes with no way via configure
options to disable threads from the build so I fixed that.
Then I patched up the #ifdef's scattered through the code to match the
configure script changes, oh and by the way, I stumbled upon a past typo
that led to the race condition in the metar fetching thread and fixed that.
Take any arbitrary vector (not necessarily vertical) and intersect it with
the current set of loaded terrain tiles. Returns lon, lat, elev. This
could have a multitude of useful applications such as testing line of sight
between two objects, faking a terrain following lookahead radar system,
virtual georeferencing, etc.
I tried to make sure accessor functions which return by reference act
on const objects. also replaced some iterators with const_iterator
and a few return/pass by reference that were missed the first time
around.
* Use "const string&" rather than "string" in function calls when appropriate.
* Use "const Point3D&" instead of "Pint3D" in function calls when appropriate.
* Improved course calculation in calc_gc_course_dist()
* Safer thread handling code.
Vassilii Khachaturov:
Dont use "const Point3D&" for return types unless you're absolutely sure.
Erik Hofman:
* Use SGD_(2)PI(_[24]) as defined in simgear/constants.h rather than
calculating it by hand every time.
Using new gcc 4.0 I have some serios warnings about uninitialized
variables, that are used. I created a patch, but I have no idea if it
is possible to do it my way. Can you check this out please?
Erik: I've modified the patch slightly based on the contents of an older
version of hitlist.cxx. I think this is correct now.
I had a quick view over the ssgBase::ref() calls in flightgear.
I made them all symmetric and used ssgDeRefDelete to dereference them.
This has the basic advantage that ssgDeRefDelete additionaly deletes the
memory instead of just decrementing the reference cound without deletion ...
This includes an incorrect deref instead of a ssgDeRefDelete in the placement
transform registration I introduced earlier. I believe that this causes the
problems with long flights (unverified, but with a big propability).
I have done a valgrind run in flightgear. Just start it up and close it at the
fist change I had about half an hour later.
source-leak.diff:
Also two minor ones, but leaks ...
There was a patch from Manuel Masing a few months ago which cleaned up
SGLocation's way depending on input values. That means that with that patch
SGLocation does no longer have calls with unneeded input arguments.
I took his patch and integrated that into flightgear and made maximum use of
that changes.
Erik Hofman:
Remove some duplicate code that was moved to simgear/compiler.h
I have prepared a patch that:
- Introduces a FGTileMgr::scenery_available method which asks the tilemanager
if scenery for a given range around a lat/lon pair is already loaded and make
use of that method at some -9999 meter checks.
- Introduces a FGScenery::get_elevation_m method which queries the altitude at
a given position. In constrast to the groundcache functions this is the best
choice if you ask for one *single* altitude value. Make use of that thing in
AI/ATC classes and for the current views ground level. At the current views
part the groundcache is reused if possible.
- The computation of the 'current groundlevel' is no longer done on the
tilemanagers update since the required functions are now better seperated.
Alltogether it eliminates somehow redundant terrain level computations which
are now superseeded by that more finegrained functions and the existence of
the groundcache. Additionally it introduces an api to commonly required
functions which was very complex to do prevously.
I did some profiling of the code and found a few interessant things. Some corrections are obvious like the one in the multiplayer code, the fps is no more divided by 2 or 3 when another plane is on screen.
Other things like collision detection and computation of agl can not really be optimized. I changed a few things in hitlist.cxx but this only give a very low increase of fps. The groundcache eats a lot of cpu but I think that the real way to do it is to use a real collision system like OPCODE or something like that.
And I added an option to disable the recording of replay data. It takes more cpu than we can think.
Changes
=======
- panel.cxx :
moved the computation of the instruments diffuse color outside the texturelayer code
since this is constant during a frame, this is a big speedup for 2D panels ;
- hitlist.cxx :
changed the computation of the intersection between ray and triangle, optimized
the sphere culling by using a normalized direction vector. This can give a
35% speedup on the computation of elevation in some situations ;
- renderer.cxx, acmodel.cxx :
call ssgDrawAndCull with plane scene graph in external or internal view,
calling ssgDrawAndCull with the root scene graph was drawing other players plane
a second time in multiplayer mode ;
- mplayer.cxx :
removed the calls to ssgFlatten and ssgStripify because it was degenerating models,
causing a massive drop in frame rate ;
- replay.cxx :
added an option to disable the recording of the flight
- fgclouds.cxx :
changed the path of cloudlayer properties to match preferences.xml ;
set the altitude of clouds from scenarios to a more correct value if metar is not enabled ;
Changes
=======
New volumetric shadows for FlightGear.
There is now two new checkboxes in the rendering dialog to enable/disable shadows
for the user aircraft and for static scenery objects (ie those defined in the .stg files).
AI and random objects are not handled for the moment.
known bugs
==========
- ghost objects
this is basically the past patch I sent to the list and which should now
really (...!?!?) fix the no ground below aircraft problem.
Reasons:
I understood my remaining thinko I introduced with the prevous patch, and the
same thinko I made in my test cases.
The feedback from the list told me that it should help.
2.
I made YASim query the the ground cache at the wrong place. This one fixed
this, one can now land the bo105 on top of the oracle buildings :)
3.
Is a followup of the scenery center update code: Register the scenery center
transform at the time it is put into the scene graph not at creation time.
4.
I held that part back from the past hitlist patch, because I hoped that it
will be sufficient (and the last one was in fact the biggest part) without.
As some test cases from Melchior showed me, it is not. We have additionally
to the wrong computed transform from the prevous patch some roundoff
problems. This patch adds some small tolerance to for the point in triangle
test.
... may be one even needs to increase the eps value further if starting at
some tile boundaries still fails.
5.
That is a big chunk.
Tested now for two days while hunting the second patch :) .
That is a partial rewrite of the groundcache to use its own datastructures for
that flat scenegraph in the cache. The basic advantage is, what Erik
suggested, to precompute some often used values of these triangles. Also
allmost all computations are now in double precision which should decrease
(hopefully fix), together with a similar tolerance for some point in triangle
tests, the problems with 'no ground below aircraft'.
I am playing with octrees for the groundcache, that will finally solve the
performance problem when high triangular count models end up in the
groundcache. This patch is also some prework for those octrees ...
It happens regularly during normal operation (ufo!) and only informs about
unfortunate, but known and deliberate behavior. The user can't do anything
about it, anyway. And finally: flooding the console with this message does
only *add* to fgfs' sluggish performance and makes every other message
go unnoticed.
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.
ssgSetNearFar(). This by default creates a symmetric view frustum which is
typically what an application wants.
However, to get control of the view frustum in order to build support for
asymmetric view frustums, we need to wrap these calls with a bit of our own
logic.
This set of changes wraps all calls to ssgSetFOV() and ssgSetNearFar() with
FGRenderer methods.
I also standardized how the FGRenderer class is handled in globals.[ch]xx.
This led to some cascading changes in a variety of source files.
As I was working my way through the changes, I fixed a few warnings along
the way.
The attached patch allows to put comments in *.stg files[1]. Lines with
# in the first column (and only there!) are skipped. This has no effect
on overall performance, but has two advantages:
A) possibility to temporarily comment out objects during scenery design,
(or to put other remarks there);
B) possibility to put marks like "# BEGIN" and "# END" there that allow
automated merging of local landmarks etc.
--
[1] actually, comments are possible now, too. But they aren't explicitly
handled and fgfs tries to parse words in "comments" piece by piece. Ugly!
[2] Idea by Chris METZLER, that I make already use of. I have a local
scenery dir for some tiles with extra objects, such as VOR/DME for
all of Austria. These are surrounded by "# BEGIN LOCAL" and "# END LOCAL",
and today I was able to merge the new 0.9.7 scenery with my locally
changed files. :-)
I have now split out the ground cache functions into src/FDM/groundcache.[ch]xx
Attached are the two files and the patch to integrate that cache into
FGInterface.
The code is nowhere used at the moment, the fdm's need to be updated to use
that ground cache. The JSBSim-dropin.tar.gz from Martins ftp server does this
for example.
The carrier's scenegraph is not yet processed to be visible for ground
intersection testing. So the only benefit up to now is that the api is set
up. Using this I can put the changes to make JSBSim work with that into
JSBSim's cvs. Also I aim to provide Andy a patch to make use of that with
YASim.
This is a patch to make display list usage optional. They are on by default.
Use --prop:/sim/rendering/use-display-list=false to use immediate mode.
There is also a change in exception handling in main.cxx and bootstrap.cxx
Split up main.cxx into a program manegement part (which remains in
main.cxx) and a render part (the new renderer.?xx files). Also turn
the renderer into a small class of it's own. At this time not really
exctining because most of the stuff is still global, but it allows us
to slowly migrate some of the global definitions into the new class.
The FGRenderer class is now managed by globals, so to get the renderer
just call gloabals->get_renderer()
At some pijt it might be a good idea to also turn the remaining code in
main into a class of it's own. With a bit of luck we end up with a more
robust, and better maintainable code.
paging system much more robust when position change is very rapid and sporadic.
Recall that we must load 3d models in the main render thread because model
loading can trigger opengl calls (i.e. with texture loading) and all opengl
calls *must* happen in the main render thread.
To accomplish this we load the base tile in the pager thread and build a work
queue of external models that need to be loaded. We never allow a tile to be
paged out of the tile cache until all it's pending model loads are complete.
However, when changing position very rapidly, we can quickly create a huge
backlog of pending model loads because we are changing positions faster than we
can load the associated models for the existing tiles. The end result is
that tiles that are long out of range can't be removed because there is still
a huge backlog of pending model load requests and memory blows up.
This change being committed allows the tile paging system to remove tiles
if they are out of range, even when there are pending models to load. The
model loading code in the render thread can now check to see if the tile
exists and discard any model load request for tiles that no longer exist.
This situation should never occur in normal operation, but could occur in
"contrived" situations where an external script was rapidly changing
the simulator position to then be able to query FG terrain height, and doing
this for a large number of points that are distributed across a large area.
Wouldn't it be better to prepare the whole list of paths (or two
separate ones for Terrain/Objects if necessary) in FGGlobals::set_fg_scenery,
and to pass the vector<string>s to FGTileEntry::load? It doesn't seem to make
a lot of sense to split the path up, modify it, mount it together to one string
again, and then let FGTileEntry::load split it up again.
Here we go:
Main/globals.cxx
================
As fg_scenery is now a string_list, we don't need initialization. Furthermore,
this list is cleared with every set_fg_scenery() call.
ctor: create default dir from fg_root if necessary. Otherwise check all paths
of --fg-scenery/FG_SCENERY: If the path doesn't exist, ignore it. If it contains
a dir Terrain and/or Objects, then only add that to the list. If it contains
neither, then use the path as is.
Scenery/tileentry.cxx
=====================
Trivial: don't split a "base path", but use the given path_list as is.
(I considered a variable name "path_list" better suited than "search".)
Scenery/FGTileLoader.cxx
========================
No more fiddling with sub-paths. This has to be delivered by get_fg_scenery
already.
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.
The message 'Alert: catching up on tile delete queue'
comes from the fact that 48 tiles are scheduled and
added to the cache at startup before the plane location
is initialized. My proposed patch is to initialize
SGLocation with an invalid position and detect this
fact before scheduling tiles. I prefer to do that
rather than testing for lon and lat being 0,0 because
it is a valid position and someone could want to fly
near Accra.
account for variation in lighting alignment, but it's more useful than the
previous attempt which was based on a misunderstanding of how environment
mapping worked.
places now use sgCartToGeod() instead of rolling their own
approximation. And YASim is now using exactly the same 3D coordinate
system as the rest of FlightGear is.
are cosmetic, but we now have a combination of code that seems to work
very robustly. I was able to land the yf23 at about 130 kts on the lower
level of the bay bridge and then taxi the entire length.
traingle strips right ... it was mixing up the vertex ordering slightly.
Oh what the heck, it was really screwing up tristrips. Everything else looks
correct though. :-) Hurray for the red book.
1. Do not stop scanning STG files after OBJECT_BASE is found.
2. Load OBJECT_BASE only once.
3. Load OBJECT only when no OBJECT_BASE has been found or when
OBJECT_BASE was found in the same file (probably should be only the
latter, if we constrain OBJECT_BASE always to come first).
4. Always load OBJECT_STATIC and OBJECT_SHARED.
from the rest of the runway lighting. VASI/PAPI lights are generally
always on. Also, the red/white VASI coloring has never worked right.
This is also a step towards fixing that problem.
This patch is there to correct a problem that prevent to load static objects when specifying a relative fg-root or a different, relative, fg-scenery. It appears that there is a mix between fg-root, fg-scenery and PLIB's model-dir.
It has been reported on the list that users are not able to see the buildings, especially those running the win32 builds because they run 'runfgfs.bat' that set FG_ROOT=./DATA.
I decided not to use model-dir because it just add confusion and to build a valid path earlier.
search when loading scenery tiles. (I am not set on using ";" as the
delimiter because it is a command separator in unix, but ":" is a critical
part of the windows file naming scheme (c:\foo\bar) so that is even worse.)
Example:
--fg-scenery=/stage/fgfs04/curt/Scenery-0.9.1/Scenery;/stage/helio1/curt/Scenery
-0.7.9
the ascii scenery file format has actually worked in quite some time, and the
ADA runway light code has been supersceded by a slightly different mechanism.
scene management code and organizing it within simgear. My strategy is
to identify the code I want to move, and break it's direct flightgear
dependencies. Then it will be free to move over into the simgear package.
- Moved some property specific code into simgear/props/
- Split out the condition code from fgfs/src/Main/fg_props and put it
in it's own source file in simgear/props/
- Created a scene subdirectory for scenery, model, and material property
related code.
- Moved location.[ch]xx into simgear/scene/model/
- The location and condition code had dependencies on flightgear's global
state (all the globals-> stuff, the flightgear property tree, etc.) SimGear
code can't depend on it so that data has to be passed as parameters to the
functions/methods/constructors.
- This need to pass data as function parameters had a dramatic cascading
effect throughout the FlightGear code.
maintianed or upgraded in a *long* time so it didn't support many new
features like the runway lighting. If anyone was using it for anything,
it should not be a huge amount of work to switch to the binary format.
SimGear includes a reader and writer for the binary format.
That's a little too small to resolve differences at 16bpp. Try the
patch below. It decreases the lifting substantially. You will see
a slight increase in z-buffer flickering but it isn't bad. Note
that we removed the "distance" component the other day, the purpose
of it was to lift the lights higher when viewed at shallow viewing
angles. The distance component is critical for the street lights that
can be very long distances away.
But with the distances we're working with here it really doesn't
do all that much. The factor used in this patch is about as shallow
a lift as can be used when looking straight down at the airport. At
24bpp there's no effect from incorporating a distance component.
The choice is to reintroduce a distance component...one that works (and
only for 16bpp), or alter the factor used in the patch below to strike an
acceptable balance between different viewing angles when in 16bpp mode.
The biggest and coolest patch adds mouse sensitivity to the 3D
cockpits, so we can finally work the radios. This ended up requiring
significant modifications outside of the 3D cockpit code. Stuff folks
will want to look at:
+ The list of all "3D" cockpits is stored statically in the
panelnode.cxx file. This is clumsy, and won't migrate well to a
multiple-aircraft feature. Really, there should be a per-model list
of 3D panels, but I couldn't find a clean place to put this. The
only handle you get back after parsing a model is a generic ssg
node, to which I obviously can't add panel-specific methods.
+ The aircraft model is parsed *very* early in the initialization
order. Earlier, in fact, than the static list of allowable command
bindings is built in fgInitCommands(). This is bad, as it means
that mouse bindings on the instruments can't work yet. I moved the
call to fgInitCommands, but someone should look carefully to see
that I picked the right place. There's a lot of initialization
code, and I got a little lost in there... :)
+ I added yet another "update" hook to the fgRenderFrame routine to
hook the updates for the 3D panels. This is only required for
"mouse press delay", and it's a fairly clumsy mechanism based on
frame rate instead of real time. There appears to be delay handling
already in place in the Input stuff, and there's a discussion going
on about different mouse behavior right now. Maybe this is a good
time to unify these two (now three) approaches?
parts of the tree left over at the end which the failsafe was catching, but
this could impose a huge framerate hit if the missed portion of the tree
was large enough (and it very often was.)
a tile boundary. (Potentially imposes a slight performance penalty, but
getting the correct answer needs to be higher priority than getting the
wrong answer really quickly.)
are now working. A runway light is defined by a point and a direction. The
point and direction are combined with the local up vector to create a small
triangle orthogonal to the direction. The two ficticous corners of the
triangle are given an alpha value of zero, the orignal corner is given an
alpha of one. The triangle is drawn in glPolygonMode(GL_FRONT, GL_POINT)
mode which means only the corner points are drawn, and since two have alpha=0
only the original point is drawn. This is a long way to go to draw a point,
but it ensures that the point is only visible within 90 degrees of the light
direction, behind the light it is not visible. This is still a long way
to get to drawing a point, but we use an environement map, with the direction
vector as the normal to mimic a light that is brightest when viewed head
on and dimmest when viewed perpendicularly or disappears when viewed from
behind.
- warning, there is a bug in how the current runway light direction vector
is calculated which will adversely effect runway lighting. The airports
should be regenerated in order to fix this problem.
fgLoad3DModel() throws an exception if it fails to load the requested model.
This causes FGTileMgr::update(...) to exit. So I've added a try/catch block
to catch the exception and display an error message instead.
- Removed some old cruft.
- Removed some support for older versions of automake which technically was
correct, but caused the newer automakes to squawk warnings during an
initial sanity check (which isn't done very intelligently.)
NOTE: this fix is technically not correct for older version of automake.
These older version use the variable "INCLUDES" internally and could have
them already set to an important value. That is why we were appending
our values to them. However, newer versions of automake don't set this
value themselves so it is an error to append to a non-existant variable.
We seem to "get away" with overwriting the value on older versions of
automake, but if you have problems, consider upgrading to at least
automake-1.5.
* Finally I think I have the partial ssg tree deletion routine working correctly
after I managed to break it (and other confusion in the code cause it to
never be called so I didn't notice the problem.)
* Converted several SG_INFO statements to SG_DEBUG to clean up some
extraneous console output.
* This *should* conclude my investigation into a massive memory leak. :-)
Animations are now contained within the scene graph itself and are
updated whenever the graph is traversed -- that saves time by not
updating animations not currently in sight, and it allows animations
to be used for static objects and random objects as well.
Added new FGModelLoader and FGTextureLoader classes. These are intern
tables for models, to guarantee (mostly) that no model is loaded more
than once. FGTextureLoader is not yet used anywhere, but
FGModelLoader is now in place everywhere that ssgLoad* used to be
used (thus adding the ability to use animations).
In the future, FGModelLoader will add some interesting functionality,
including the ability to reload 3D models on the fly.
the tile cache it's ssg elements are disconnected from the main ssg scene
graph, and then the tile is thrown on the end of a delete queue. The
tilemgr->update() routine runs every frame. It looks at this queue and if
it is non-empty, it incrementally frees the compents of the first tile
on the queue. When the tile is completely free it is removed from the queue.
The amount of time to free the memory for even a single tile can be quite
substantial, especially with the increased overhead of dynamic/random
ground objects. This change allows the system to spread the work of freeing
tile memory out over many frames so you don't get a noticable single frame
hit or stutter.
This is a small fix for what turned out to be a major bug. Ground elevation
was calculated incorrectly when distant from one of the view locations. This
resulted in several problems including bizarre gear trimming, mid air
"crashes" (as in thinking we hit the ground) and so on when close to or on the
ground.
Unfortunately it does require a second ssg traversal when in tower view
(only), but the increased load isn't all that noticable. For the time being
this really is the best solution. In a future update I will be eliminating
the unecessary per frame traversals for the static views (without having to
maintain multiple ssgRoots).
When we go to multiple FDM instances we will perhaps need to put the ssg
traversal and ground elevation queries for the FDMs into an event timer that
updates the FDMs ground elevation in a round robin fashion (maybe every 1/n
seconds where n is the number of FDM instances running).
This is a new improved patch for the previous tile manager fixes.
Rather than building dependencies between FGlocation or the viewer or fdm with
tilemgr what I ended up doing was linking the pieces together in the Mainloop
in main.cxx. You'll see what I mean...it's been commented fairly well. More
than likely we should move that chunk somewhere...just not sure where yet.
The changes seem clean now. As I get more ideas there could be some further
improvement in organizing the update in tilemgr. You'll note that I left an
override in there for the tilemgr::update() function to preserve earlier
functionality if someone needs it (e.g. usage independent of an fdm or
viewer), not to mention there are a few places in flightgear that call it
directly that have not been changed to the new interface (and may not need to be).
The code has been optimized to avoid duplicate traversals and seems to run
generally quite well. Note that there can be a short delay reloading tiles
that have been dropped from static views. We could call the tile scheduler on
a view switch, but it's not a big deal and at the moment I'd like to get this
in so people can try it and comment on it as it is.
Everything has been resycned with CVS tonight and I've included the
description submitted earlier (below).
Best,
Jim
Changes synced with CVS approx 20:30EDT 2002-05-09 (after this evenings updates).
Files:
http://www.spiderbark.com/fgfs/viewer-update-20020516.tar.gz
or
http://www.spiderbark.com/fgfs/viewer-update-20020516.diffs.gz
Description:
In a nutshell, these patches begin to take what was one value for ground
elevation and calculate ground elevation values seperately for the FDM and the
viewer (eye position). Several outstanding view related bugs have been fixed.
With the introduction of the new viewer code a lot of that Flight Gear code
broke related to use of a global variable called "scenery.cur_elev".
Therefore the ground_elevation and other associated items (like the current
tile bucket) is maintained per FDM instance and per View. Each of these has a
"point" or location that can be identified. See changes to FGLocation class
and main.cxx.
Most of the problems related to the new viewer in terms of sky, ground and
runway lights, and tower views are fixed.
There are four minor problems remaining. 1) The sun/moon spins when you pan
the "lookat" tower view only (view #3). 2) Under stress (esp. magic carpet
full speed with max visibility), there is a memory leak in the tile caching
that was not introduced with these changes. 3) I have not tested these
changes or made corrections to the ADA or External FDM interfaces. 4) The
change view function doesn't call the time/light update (not a problem unless
a tower is very far away).
Details:
FDM/flight.cxx, flight.hxx - FGInterface ties to FGAircraftModel so that it's
location data can be accessed for runway (ground elevation under aircraft)
elevation.
FDM/larsim.cxx, larcsim.hxx - gets runway elevation from FGInterface now.
Commented out function that is causing a namespace conflict, hasn't been
called with recent code anyway.
FDM/JSBSim/JSBSim.cxx, YASim/YASim.cxx - gets runway elevation from
FGInterface now.
Scenery/newcache.cxx, newcache.hxx - changed caching scheme to time based
(oldest tiles discard).
Scenery/tileentry.cxx, tileentry.hxx - added place to record time, changed
rendering to reference viewer altitude in order to fix a problem with ground
and runway lights.
Scenery/tilemgr.cxx, tilemgr.hxx - Modified update() to accept values for
multiple locations. Refresh function added in order to periodically make
the tiles current for a non-moving view (like a tower).
Main/fg_init.cxx - register event for making tiles current in a non-moving
view (like a tower).
Main/location.hxx - added support for current ground elevation data.
Main/main.cxx - added second tilemgr call for fdm, fixed places where viewer
position data was required for correct sky rendering.
Main/options.cxx - fixed segfault reported by Curtis when using --view-offset
command line parameter.
Main/viewer.cxx, viewer.hxx - removed fudging of view position. Fixed numerous
bugs that were causing eye and target values to get mixed up.
- changed FGSubsystem::update(int) to
FGSubsystem::update(delta_time_sec); the argument is now delta time
in seconds rather than milliseconds
- added FGSubsystem::suspend(), FGSubsystem::suspend(bool),
FGSubsystem::resume(), and FGSubsystem::is_suspended(), all with
default implementations; is_suspended takes account of the master
freeze as well as the subsystem's individual suspended state
- the FDMs now use the delta time argument the same as the rest of
FlightGear; formerly, main.cxx made a special case and passed a
multiloop argument
- FDMs now calculate multiloop internally instead of relying on
main.cxx
There are probably some problems -- I've done basic testing with the
major FDMs and subsystems, but we'll probably need a few weeks to
sniff out bugs.
graph as the terrain, except for internal cockpit view. The SSG
scene-graph variables (except for the lighting root -- I'll get that
later) are now held in globals.hxx.
FGModelMgr::draw() is obsolete; I'll remove it in a future revision.
Description:
This update includes the new viewer interface as proposed by David M. and
a first pass at cleaning up the viewer/view manager code by Jim W.
Note that I have dropped Main/viewer_lookat.?xx and Main/viewer_rph.?xx and
modified the Makefile.am accordingly.
Detail of work:
Overall:
The code reads a little easier. There are still some unnecessary bits in
there and I'd like to supplement the comments in the viewer.hxx with a tiny
bit on each interface group and what the groupings mean (similar but briefer
than what you emailed me the other day). I tried not to mess up the style,
but there is an occasional inconsistency. In general I wouldn't call it done
(especially since there's no tower yet! :)), but I'd like to get this out
there so others can comment, and test.
In Viewer:
The interface as you suggested has been implemented. Basically everything
seems to work as it did visually. There is no difference that I can see in
performance, although some things might be a tiny bit faster.
I've merged the lookat and rph (pilot view) code into the recalc for the
viewer. There is still some redundancy between the two, but a lot has been
removed. In some cases I've taken some code that we'd likely want to inline
anyway and left it in there in duplicate. You'll see that the code for both
looks a little cleaner. I need to take a closer look at the rotations in
particular. I've cleaned up a little there, but I suspect more can be done
to streamline this.
The external declaration to the Quat_mat in mouse.cxx has been removed. IMHO
the quat doesn't serve any intrinsic purpose in mouse.cxx, but I'm not about
to rip it out. It would seem that there more conventional ways to get
spherical data that are just as fast. In any case all the viewer was pulling
from the quat matrix was the pitch value so I modified mouse.cxx to output to
our pitchOffset input and that works fine.
I've changed the native values to degrees from radians where appropriate.
This required a conversion from degrees to radians in a couple modules that
access the interface. Perhaps we should add interface calls that do the
conversion, e.g. a getHeadingOffset_rad() to go along with the
getHeadingOffset_deg().
On the view_offset (now headingOffset) thing there are two entry points
because of the ability to instantly switch views or to scroll to a new view
angle (by hitting the numeric keys for example). This leaves an anomaly in
the interface which should be resolved by adding "goal" settings to the
interface, e.g. a setGoalHeadingOffset_deg(), setGoalPitchOffset_deg(), etc.
Other than these two issues, the next step here will be to look at some
further optimizations, and to write support code for a tower view. That
should be fairly simple at this point. I was considering creating a
"simulated tower view" or "pedestrian view" that defaulted to a position off
to the right of whereever the plane is at the moment you switch to the tower
view. This could be a fall back when we don't have an actual tower location
at hand (as would be the case with rural airports).
ViewManager:
Basically all I did here was neaten things up by ripping out excess crap and
made it compatible as is with the new interface.
The result is that viewmanager is now ready to be developed. The two
preexisting views are still hardcoded into the view manager. The next step
would be to design configuration xml (eg /sim/view[x]/config/blahblah) that
could be used to set up as many views as we want. If we want to take the easy
way out, we might want to insist that view[0] be a pilot-view and have
viewmanager check for that.
and fixes a 'potential bug' if the FGFS View code were to change
I also consolidated the specialized IntersectLeaf()
as they really didn't gain us much outside of their having
'more direct access into the SSG controlled data'
I would like to see the fgCurrentElevation functions moved
out of hitlist.cxx.
The one obstacle is their being dependent on my PLib
auxillary functions
ssgGetEntityTransform()
ssgGetCurrentBSphere()
code has been run through astyle with the default options
separate header file. This change will help integrate properties into
JSBSim.
Also, I (David Megginson) removed most of the SimGear include
statements from globals.hxx, reducing the amount of recompilation
every time SimGear changes. This required making minor changes to a
lot of files that were depending on the side-effects of the inclusions
in globals.hxx.
Added two new properties:
/environment/temperature-sea-level-degc
/environment/pressure-sea-level-inhg
These are now supported in FGEnvironment as well, though they always
have the same value for now. They need to be hooked up to the FDMs.
different locations, and hitched it into FGGlobals. FGEnvironmentMgr
has taken over as the subsystem, while FGEnvironment is simple the
information that it returns. I've removed current_environment
completely -- everything now uses properties or goes through
FGGlobals. FGGlobals itself has a couple of useful methods:
const FGEnvironment * get_environment ();
const FGEnvironment * get_environment (double lat, double lon, double alt);
The first one returns the environment data for the plane's current
position, while the second returns the environment data for any
arbitrary location. Currently, they both return the same information,
but that will change soon.
properties have been renamed from wind-(north|east|down)-fps to
wind-from-(north|east|down)-fps, and the FDMs modified appropriately.
No other changes should be visible unless FG_OLD_WEATHER is defined.
are being driven from an external data source.)
Akso found and fixed a bug in the simgear that caused the time to go goofy
temporarily while scenery was being loaded.
/sim/freeze/master (implimented)
/sim/freeze/fuel (implimented)
/sim/freeze/position (not implimented)
/sim/freeze/time-of-day (not implimented)
/sim/freeze/master is bound to the 'p' key via keyboard.xml, however,
/sim/freeze/fuel is not bound to anything at the moment so you must
change it via the external property interface, or specify an initial
value on the command line.
- automake-1.4 sets default values for INCLUDES which we can't
overwrite.
- automake-1.5 renames this to DEFAULT_INCLUDES and leaves INCLUDES
open for the developer to use.
Thus for automake-1.4 we are forced to 'append' to INCLUDES and in
automake-1.5 we can just set the value to whatever we like.
Unfortunately, the behaviors of the two versions are mutually
incompatible.
The solution I am committing now works for both versions but
automake-1.5 generates a lot of spurious warning messages that are
annoying, but not fatal.
(i.e. multiloop). Most subsystems currently ignore the parameter, but
eventually, it will allow all subsystems to update by time rather than
by framerate.
Here's an unusual patch for FlightGear -- I've created .cvsignore
files for every source directory, to make CVS output more informative.
This is especially nice when using cvs-examine from (X)Emacs to look
for changes.
What was happening was that we screwed up and scheduled tiles for
(lon,lon) rather than (lon,lat) ... note the typo. This generated
bogus tile id's which the system happily accepted, put into the tile
cache system, and attempted to load. The problem was that these bogus
tile id's were negative where as all valid tile id's should be >= 0.
These negative tile id's up the logic used to remove tiles from the
cache. When identifying tiles for removal, we look for the furthest
tile away from us by starting out the furthest id at -1 and if we find
something further, we update the furthest tile id. Then at the end we
check if the furthest tile id >= 0 to see if we found anything we
could remove. However, the furthest tile id was these bogus tiles
with negative tile id's so the system always assumed there was nothing
appropriate for removal. This made it impossible to ever remove a
tile from the cache meaning it quickly filled up and no more tiles
could be loaded.
I fixed the one instance of scheduling tiles for a bogus location, and
added a sanity check so if it ever happens again we'll bomb with an
appropriate error message.
fix startup sequence problems where we initialize the FDM before we know
the desired starting altitude.
These changes delay fdm initialization until the local tile has been loaded
and we can do a real intersection and find the true ground elevation.
In order to do this, I depend more on the property manager as glue, rather
than the FGInterface.
There are some glitches still when switching to a new airport or reseting
the sim. I will work on addressing these, but I need to commit the changes
so far to keep in sync with other developers.
but no entries qualify for removal. It will keep trying to schedule the
tile(s) until an entry frees up. Entries in the cache do not qualify for
removal if they are in the process of being loaded.
a crash when relocating to a new airport. Pending work from the old
area is now just completed as normal, rather than trying to empty the various
queues in their various stages when can lead to many problems in a threaded
environment.
to have attached an ssg loaded object to this branch, then plib will remove
it and all it's states (and textures) which will call opengl api commands
which will crash the program if run from a separate thread from the main render
thread.
- model loading deferred to primary thread
- tile removal deferred to paging thread
- other tweaks and rearrangments.
Airport signs
- first stab at some support for adding taxiway and runway signs. This
is non-optimal, but I'm under the gun for a demo.
a newly loaded tile to the scene graph. Instead it puts it in a queue
for the tile manager. I've used your counter_hack to check the loaded
queue and add any tiles to the scene graph. I was playing around with
the counter_hack so there might be some commented out code, etc. I also
changed some SG_DEBUGs to SG_INFOs so I could track the tile loading.
He writes:
Here are the final changes to add threads to the tile loading. All the
thread related code is in the new FGTileLoader class.
./configure.in
./acconfig.h
Added --with-threads option and corresponding ENABLE_THREADS
definition. The default is no threads.
./src/Scenery/tilemgr
Removed load_queue and associated references. This has been replaced by
a new class FGTileLoader in FGNewCache.
Made the global variable global_tile_cache a member.
schedule_needed(): removed global_tile_cache.exists() tests since
sched_tile() effectively repeats the test.
initialize_queue(): removed code that loads tiles since this is now
performed by FGTileLoader.
update(): ditto
./src/Scenery/newcache
Added new class FGTileLoader to manage tile queuing and loading.
tile_map typedefs are private.
exists() is a const member function.
fill_in(): deleted
load_tile(): added.
./src/Scenery/FGTileLoader
The new threaded tile loader. Maintains a queue of tiles waiting to be
loaded and an array of one or more threads to load the tiles. Currently
only a single thread is created. The queue is guarded by a mutex to
synchronize access. A condition variable signals the thread when the
queue is non-empty.
CLO: I made a few tweaks to address a couple issues, hopefully what we
have is solid, but now we kick it out to the general public to see. :-)
tile has been loaded. Since this flag can be set by another thread I've
declared it "volatile bool".
Also cleaned up delete vs delete[] usage. Gcc is happy with delete[],
which is the correct usage.
