Minor fix for Irix.

[flightgear.git] / NEWS

New in 0.7.8
* July 13, 2001
* Updated to the latest JSBSim flight dynamics model (http://jsbsim.sf.net)
* First release of a bundled utility: fgjs which assists you in creating
  a joystick/button configuration for your setup.
* Updated airport data file with taxiways at many major airports.
* Better support for using an external browser to view online help
  components.  Windows support for this will be included in the next
  revision.
* Now using plib-1.4.x which supports more than 3 concurrent sounds.
* Most of the README's and documentation has been reviewed and brought
  up to date.
* Support for ultra-hires screen dumps suitable for large scale
  printed output.
* Updated, more flexible binary scenery format.
* Support for using digital axes (i.e. a hat) as a pair of buttons
  which can be mapped to any function a button could be mapped to.
* Added user documentation to the base package
* Added a c172 mini panel.
* Improved c172 panel graphics.
* Added units to configuration files
* Fixed X15 panel
* External view panning fix ups.
* Fixed the segfault on exit bug.
* Lots of property manager tweaks.  Appened units to property name to
  make it explicit, adjusted read/write/archive bits and defaults
* MSVC fixups.
* gcc-3.0 fixups.
* Irix fixups.
* Fixed a potential segfault in radio station lookup/search code.
* Fixed a bug in the audio system intialization order that could cause
  a segfault in some circumstances.
* Fixed a typo in the 2nd tank property name so it's value is now accessible
  from the instrument panel. 
* Fixed a bug when loading the "old" binary scenery which prevented ground
  lighting from being generated.
* Jettison old conditionally compiled plib-1.2.x code, we now require
  plib-1.4.x or higher.
* Eliminated some convoluted that generated a harmless, but confusing
  "*** NO TIMEZONE" error message,
* Fixed doubled bindings for joystick buttons.
* Threading fixups.
* Fixed a bug with the time warping/offset code.  You can again
  startup with a proper time offset if you like.
* Fixed a couple memory problems ... attempting to access/use/write to
  previously freed memory.

New in 0.7.7
* June 20, 2001

* Cleaned up various warning messages
* Various Cygwin fixes.
* Various MSVC fixes.
* Various Irix Mips fixes.

* Check for null panel before passing mouse events to panel object.
* Fixed panel edge artifacts (due to unwanted texture wrapping.)
* Fixed a typo in the base/materials file.
* Various property manager fixes.
* Various property manager lookup optimizations.
* Fixed a bug in the autopilot altitude hold that crept in.

* Converted from hardcoded to configurable keyboard bindings.
* Added an FGSubsystem base class so subsystems can be managed with a
  common api.
* Keyboard commands are now completely remapable.  Removed BFI and
  keyboard in place of remapable inputs.
* Started to impliment a command manager.  This along with the
  property manager will go a long ways toward building infrastructure
  for scripting.
* Started laying infrastructure for creating ultra-high-res tiled
  screen shots suitable for printers.
* Synced with a recent version of JSBSim.
* GUI code split into smaller logical subcomponents.
* FGOptions converted to use property manager directly.
* "delta-t" and fdm interface timing fixes and tweaks.
* Added a sound effect manager class at the FlightGear level.

* Support for setting a starting position as and offset distance (and /
  or radial) from your specified starting postition.  This allows you to
  initialize on final x miles out at y altitude.
* Many updates to make a much more realistic single engine and prop model
  with atmospheric and velocity dependencies.  Fuel flow now modeled.
* Straightened out magnetic offset issues with VOR stations so we can
  navigate properly from real avaition charts.
* Added a direct network interface support for the "Atlas" moving map
  program.  (Output radio stack settings so current VOR and OBS can be
  visualized.)
* Autopilot made to work more like a real world autopilot (rather than
  based on perfect values.)  Autopilot wing leveler is slaved off the
  turn coordinator.  Heading hold is slaved from the DG (which drifts).
  Nav and ILS holds slave off the needle position.
* Backcorse ILS needle should move in correct direction now.
* Identing of NAV radios (and individual volume control) now work.
* Don't play DME ident if no colocated DME.
* VOR/ILS/ADF range pickup realistically modeled as per AIM.
* Added support for marker beacons.
* Support for loading and saving the current 'simulator state' using
  an xml formated file.
* Added threaded tile paging for systems with pthread support.
* Added high level support for creating airport taxiway and runway signs.
* Many updates and fixes to the "installation and getting started" manual.
* Support for adding static objects to the scenery.
* Many updates and new features for the xml configurable panel engine.
  Many corresponding improvements to the default instrument panel.
* Support added for incrementally numbering screen snapshots.
* Added support for a new, smaller, faster binary scenery format.
* Added an xml configurable HUD engine.
* Added interface glue to propogate wind values to LaRCsim.

New in 0.7.6
* December 15, 2000
* Added night ground cover lights with user controllable densities on
  a per texture basis.  Lights have a bit of a "fog punch through" effect.
* Support added for "shaped" instrument panels.
* Added support for virtual panels that are larger than the screen
  space which can scroll.
* Added waypoint and route flying support to the autopilot and HUD.
* New highly detailed runway textures with accurate markings.
* Added a basic piston engine model, with support for rpm, egt, cht, mp,
  and mixture.
* Many tweaks and improvements to the c172 instrument panel.
* Corrections and additions to the airport and navaid database.
* Added an external interface to the property manager so you can
  "telnet" into a running copy of FlightGear, cd through the property
  tree and examine and even change values, all from a remote computer.
* Improvements to flight model initialization.
* Fixes and improvements to the save/restore code.
* Added a load/save dialog box for saving/restoring your current flight.
* Program notes max texture size for your card/driver so it can load
  higher resultion textures if they are available and if you can use
  them.
* Added a visibility= command line option for setting intial visibility
  distance.
* Range of tiles loaded and drawn are now directly calculated from the current
  visibility distance so that the ground always blends smoothly into sky.
* Rewrote the tile caching scheme so it is now more flexible, more dynamic,
  simpler, and more robust.
* Updates to the FDM bus.
* Many clean ups with the view code to prepare the way for a greater
  variety of external views.
* MSVC project files now included in the source distribution.
* Fixed a view bug that could make the aircraft model appear rotated
  incorrectly
* Fixed a bug with the autopilot rate of climb hold.
* Internal property manager tweaks.
* Additional materials can be aliased to an existing material to save
  texture space (at the expense of less texture variety)
* MSVC tweaks.
* MacOS tweaks.

New in 0.7.5
* September 18, 2000
* Aircraft now starts at end of runway closest to desired heading.
* Runways now have accurate markings.
* Addition of a completely reconfigurable instrument panel.
* Tons of panel tweaks and fixes.  Gyro now drifts, relocated whisky compass,
  skid ball moves in the right direction, etc.
* Updates and tweaks to network multiplayer code.
* Tweaks to ground steering sensitivity.
* Updates to the UIUC flightmodel and icing research code.
* Fixed the sound problem in the previous version.
* Current scenery normal is now available for use.
* Current load queue size is now available for use.
* Added a configure time check for proper simgear version.
* Explicitely link in -lpthread if it exists.
* Fixed a couple namespace problems.
* MacOS and MSVC tweaks.
* Renamed JSBsim to JSBSim
* Added support in the material library for non-repeating textures.

New in 0.7.4
* July 19, 2000

* VOR reception now scales with altitude.
* Added differential braking support.
* Landing gear modeling code now works in JSBSim
* Overhauled cloud code substantially, new cloud textures.
* Added support for Ray Woodworth's 5 axis motion chair.
* Red light the panel at night and shade based on time of day.

* Fixed autopilot altitude hold increment bug.
* Fixed screen snap shot function.
* Fixed mach number for LaRCsim.
* --start-date-gmt option fixed.
* Fixes to uiuc includes and initializations
* Fixes to periodic scheduler.
* Fixed a tile loading bug if the load queue wasn't empty before a reset or
  teleport.

* Some additional MSVC5 portability fixes.
* Tweaks to build with newest gcc under Irix contributed by Erik Hofman.

* Clean out a pile of old junk in the material manager library from the
  pre-ssg days, and majorly overhauled it.
* Complete reengineering of the panel code in preparation for moving the
  configuration out into a data file.
* Lots of hashing around with Joystick support trying to achieve something
  that is flexible enough to handle the zillions of possible configurations
  out there.  Hopefully we are approaching a workable solution.
* Better windows support in our joystick module.
* View code simplifications and optimizations contributed by Norman Vine.

* Added support for $FG_SCENERY and --fg-scenery=path so scenery can have a
  different location from the base package.
* Moved drop in sky module, world time module, ephemeris module, and low
  level communications modules over to simgear.
* Replaced gdbm with metakit
* Added David Megginson's property manager


New in 0.7.3
* May 18, 2000
* Added a radio stack 2 VOR/ILS and an ADF to the instrument panel.
  You can change the frequencies by clicking on the knobs on the
  instrument panels.  You can now navigate with VOR/ADF/DME and fly
  ILS approaches.
* Added a chronometer to the instrument panel.
* Added a "wet" compass to the top of the instrument panel.
* Compass, vsi, and altitute instruments and vacuum system are more
  accurately modeled.
* Added a magnetic variation model.
* Added navaid database management and query code.
* Added magvar offset to VOR radials.
* Heading bug now display magnetic heading rather than true heading.
* Autopilot now has modes to track a VOR and GS.
* Added custom joystick client support so sim can be flown from a
  remote joystick connected to another machine.  This is in support of
  some custom hardware located in the human factors research lab of the
  university of minnesota.
* HUD controls are a bit different "h" toggles through day/night/off
  modes and "H" cycles through brightness levels.
* Norman Vine contributed code to optionally do antialiased hud lines
  on hardware that supports this.  Norman also contributed additional
  hud cleanups and updates.
* Updates to JSBsim flight dynamics code that includes a generic
  reconfigurable flight control system, a initial state trimming routine,
  support for wind and weather, support for flaps, independent trim control,
  config files changes
* Updates to LaRCsim flight dynamcis code contributed by UIUC that
  allows loading aircraft specifications at runtime from config files.
  UIUC is using flightgear as a platform to do icing research.  The UIUC
  aircraft use the c172 gear model for now which causes some weirdness
  on the ground for some of the larger aircraft.
* Flight model no longer has to be chosen at compile time.
* Separated ephemeris code from the actual sky rendering code and gave
  this whole section a big overhaul.  The moon should now consistantly
  have the correct phase.
* Rebuilt the sky dome using ssg.
* Removed dependencies on mat3.h and friends (old srgp support lib)
* Airport lookups now done through gdbm (a light weight embedded database.)
* Converted ssgVTable's to ssgVtxTables which do proper memory
  management and should facilitate use of compiled vertex arrays once
  ssg add support for these.
* Overhauled autopilot internals, separated out the gui controls from
  the actual autopilot code.
* Cygwin32 build fixes
* MSVC++ build fixes
* Mac build fixes

New in 0.7.2
* February 17, 2000
* Lots of code reorganizations
* Build requires plib-1.1.x
* Build requires SimGear-0.0.x
* LaRCsim/c172 is now the default aircraft model.
* Added flaps support to control model.
* Lots of updates and tweaks for the LaRCsim/c172 model.
* Use a more standard texture/blend mode combination for sun/moon halos to
  avoid render path that's not supported by all cards/drivers.
* Change reported speed on hud from V_equiv_kts to V_calibrated_kts
* Instrument panel rewrite by David Megginson.  This isn't quite as flashy
  as the first pass, but is much more functional, plays much better with 
  opengl, and it should be relatively easy for someone with graphical skills
  to make it look more spiffy.
* MacOS fixes contributed by Darrell Walisser.
* Many JSBsim updates.
* Added a screen snapshot facility (F3).
* Added a load/save state function contributed by David Megginson.
* Added support for various I/O protocols and channels so that flightgear
  can communicate with itself and other programs through a variety of means.
* Bug fix:  The aircraft model used for external views was being included in 
  the height above terrain check so when the view position and the aircraft
  model collided the current altitude kept getting pushed up to compensate,
  but of course the aircraft model would get pushed up as well because it
  tracks the current aircraft position and orientation.  Thus you had a never
  ending cycle ...
* Oliver's multiplayer network code now moved to his own subdirectory:
  NetworkOLK
* Added simulated cloud puffs as we pass through the cloud layer.
* Cleaned up some memory leaks occuring between ssg and flightgear.
* Update to Christian's weather data base code.

New in 0.7.1
* Durk Talsma added a nifty cloud layer.
* Default to Christian Mayer's new weather system.
* Added routines to do screen printing contributed by Mark Vallevand.
* Added routines to do screen shots to ppm graphics file (all platforms)
  contributed Rich Kaszeta.
* Added a magic carpet (aka slew) mode.
* Added a hot air balloon simulator mode. (alpha)
* Added a simple (direct lincage) autocoordation feature.
* Added a mode to control view (side to side and up and down) with the mouse.
* Fixed a DEM decoding problem which caused most of the terrain to be 256
  meter too high (and regenerated the world scenery with proper elevations.)
* Updates to JSBsim.
* Added support for a pilot view offset from the center of gravity.
* Various platform portability fixes.
* Updated time-offset/syncing command line options.
* Updated the FDM <==> Flight Gear interface to be more object oriented.
  This should hopefully pave the way for being able to simulate several
  concurrent entities.
* Removed unimplemented menu entries.
* Various scenery tools changes and enhancements in preparation for adding
  runways (hopefully for the next release.)

New in 0.7.0
* Autopilot can now fly great circle routes.
* Incorporated a first stab at some networking code contributed by Oliver
  Delise.
* Added Christian Mayer's new weather subsystem.
* Started adding support for "external" views ... still needs some work.
* Added a flight model acceleration funtion.
* Added support for mouse yoke control contributed by David Megginson.
* FDM model hertz now definable from the command line.
* Added initial timezone support so the user can have better control and more 
  options for setting the starting time of the sim.
* We now draw nonexistant tiles as ocean which means we only have to create
  and distribute tiles that contain some sort of land mass.

* Replaced basic render engine with plib's ssg (simple scene graph).
* Now expect plib to be installed in it's one true and official location.
* Added support for timegm() if it exists which explicitely expects GMT input.
* A bit of your basic code reorganization and shuffling.

* Removed tools dependency on libgfc.  Functionality is now covered by 
  shapelib which has been added into the Tools tree.
* Added support for the wonderful GSHHS global land mass data set.
* Removed dependecy on process-dem.pl script.
* Created a new distributed/parallel tile build system ... hmmm kind of super
  computer or beowulf style stuff for getting large chunks of scenery built
  as fast as possible.
* Only generate tiles that have land mass data since the sim can recreate pure
  ocean tiles on the fly.
* First stab at a water flattening scheme to prevent oceans, lakes, and rivers
  from running up and down the sides of hills.
* Changed the default "Work/" subdirectory layout.
* Updates to better handle segment boundaries in preparation for real airport
  runway and lighting modeling.
* Updates and enhancements to my polygon management class.

* Updates to JSBsim.
* Updates to Tony's c172 model.
* Updated getting started guide from Micheal Basler.

* FreeBSD portability tweaks.
* MACos portability tweaks.
* Borland C++ tweaks.
* MSVC++ tweaks.

New in 0.6.0
* Tons of improvements with scenery creation.  Inter-tile gaps have been
  fixed, distorted textures have been fixed, real coastlines have been added,
  and many other subtle improvements.
* Tools for parallelizing the scenery building tasks.  For instance by using
  20 machines in parallel, scenery for the entire USA can be regenerated in
  just over 4 hours vs. 70+ hours on a single machine.
* Texture scale can be specified (and changed)( in the materials file.  The
  sim must be rerun for the change to take effect.
* Windows now uses plib joystick code so rudder pedals should now work.
* Now builds against Steve Baker's plib (portable game devel library) 
  distributed separately (www.woodsoup.org/~sbaker/plib/)
* Many source code changes for the MacOS port contributed by Darrell
  Walisser (the port isn't quite there yet ...)
* Source code changes for better compiling with the Borland compiler.
* Source code changes for better compiling with the native Irix compilers.
* Fixed a bug so you can now fly across the international date line (or
  more precisely the division between longitude = +/-180.
* Tweaks to the Astro section contributed by Durk Talsma.
* Autopilot improvements contributed by Norman Vine.
* Fonts/characters now drawn with texture maps for increased speed.
* Instrument panel can be toggled on and off with "P".
* GUI interface for tweaking some autopilot parameters.
* HUD appearance and layout changes contributed by Norman Vine, includes
  faster font drawing for much better performance.
* Reset function added to reset you to your starting conditions.
* GUI function to enter a new airport id (and be transported there)
* Added serial output support for an "in-development" full motion cockpit.
* "Just in time" texture loading to reduce initial sim loading time.


New in 0.59 (This is an intermediate/stepping stone release.  Skip this 
             release if you are interested in stability.)
* IRIX portability changes and support for native SGI compilers.
* Solaris portability tweaks
* Incorporated some MacOS portability changes (although the port is not
  yet complete.)
* Changes to allow adjustment of the autopilot settings while it is
  activated.
* Began complete overhaul of scenery generation tools.
* Fixed a view frustum culling bug.
* separated lib GPC (generic polygon clipper.)  GPC is not "freeware" and
  the author has explicitely refused our request to distribute source code
  for this library with Flight Gear.
* updated installation and getting started guide
* switched to a simpler, lighter weight frame rate calculation method.
* new tile division scheme.
* GPS serial *output* fixes.
* Added a nifty halo to both the sun and moon.  Preparation for allowing
  subtle moon lighting effects at night.
* Incorporated Jon Berndt's new C++ flight model rewrite.
* Autopilot settings can be adjusted while active.
* Updates to the instrument panel.
* Fixed AOA reading on the HUD.
* Added random splash screens.
* Modified scenery loader to accept tri-fans.
* Other non-backwards compatible changes to scenery file format and tile
  layout.


New in 0.58
* Added JSBsim alpha code ... this is Jon S. Berndts alpha FDM rewrite.
  Still lots to do, but you can watch a balistic flight for a short time.
* Renamed Simulator/Flight to Simulator/FDM
* Tweaks to assist building FGFS on solaris platforms.
* Moved Lib/DEM to Tools/DEM
* Started preparations for scenery generation tools overhaul.
* More MSVC++ support.
* Removed code that made the sun bigger at the horizon since this is just
  an optical illusion in real life.
* Bug fixed so that the sim can start out at an airport below sea level.

New in 0.57
* Converted to a simpler frame rate counting method.
* Fixed the AOA reading on the HUD.
* Removed gpc from the Lib section of distribution by request of the
  gpc Author.  The gpc license is unfortunately not compatible with
  the GPL.  I may look for an alternative library, or just require
  that developers download this library separately.
* First slew of changes from the MacOS porting effort contributed by
 "Robert Puyol" <puyol@abvent.fr>.
* Support for an arbitrary number of serial ports + additional serial port 
  output tweaks.
* Serial output tweaks to make things more robust and act more like a GPS.
* Portability enhancements for Borland, Solaris, and SGI.
* Some internal class renaming and reorganizations.  fgFLIGHT becomes FGState.
  fgCONTROLS becomes FGControls.
* Started work on an "external" flight model so the sim can be driven from
  external input (serial port, network, file, etc.)
* Fixed a problem that creeped in with setting the initial startup altitude.
  This could cause an unrecoverable bounce and you'd end up flipped on your
  back.  Should be fixed now.
* Sun now appears to grow in size as it gets very low in the horizon.
* Fixed a view frustum culling bug where the scene was not accurately culled
  when your view was anything other than straight forward.

New in 0.56
* Changed default HUD units to the more standard feet units.  You can still
  use meters by specifying the command line option "--units-meters".
* Added some initial joystick support using Steve's joystick interface class.
  This works great under Linux, but Steve's class now needs to be ported to
  Windoze and other platforms.
* Also added a fall back to the GLUT joystick routines for windows (until
  we can find better joystick support.)
* Added some initial serial port support for acting like gps and outputing 
  nmea data such that could be fed into a flight map software package.
* Miscellaneous code clean ups, portability improvements, and optimizations.
* Switched to a streams based error/debug logging system that can be
  completely stripped out for a release build (./configure --without-logging)
* Support for cygwin32 b20 compiler (latest release)
* Continued progress on instrument panel
* Support for starting fgfs at higher resolutions.

New in 0.55
* New version of gpc (generic polygon clipping library) from 
  http://www.cs.man.ac.uk/aig/staff/alan/software/
* Brakes (use "b" to toggle)
* Added an altitude hold module to the autopilot.  Lock your current altitude
  with "ctrl-a", "cntr-a" again will deactivate.  (Also lock your current 
  heading with "ctrl-h", and again to deactivate.)
* Added a terrain following module ... "ctrl-t" to activate.
* Added an autothrottle ... "ctrl-s" to activate.
* Fixes so that terrain tools will work in windoze.
* More STL & Compiler compatibility fixes.
* Changes to use a Point3 class.
* Fixed win95/98 time problem that limited fps to about 18.3

New in 0.54
* Implimented audio envelopes so that pitch of engine changes with throttle
* Textured moon, and rewritten/restructured Astro code.
* More optimizations and code cleanups.  (Norman Vine, Bernie Bright, Charlie
  Hotchkiss.)
* Bug fixed that was causing odd display artifacts due to a degenerate
  fragment being created for every tile.
* Bug fixed that caused scenery generation to go bad (misplaced fclose on an
  invalid file descriptor.)
* Code changes to support g++ 2.7 STL (from Bernie Bright)

New in 0.53
* Some initial "GameGLUT" support contributed by Gary R. Van Sickle
  (tiberius@braemarinc.com)
* Tracked down and eliminated some memory access type bugs that were
  causing segfaults on some platforms, with some compilers using various
  optimization flags.
* Assorted code optimizations submitted by Norman Vine.
* Renamed fg -> fgfs
* Shuffled files.  
  - Created a new directory Simulator/Airports/ to handle airport data 
    specific tasks 
  - Created Simulator/Object/ to handle basic rendering objects
* Panel code update from Friedemann Reinhard (use --enable-panel to activate)
* Contributions from Bernie Bright
  - Created some new classes to enable pointers-to-functions and
    pointers-to-class-methods to be treated like objects.  These objects
    can be registered with fgEVENT_MGR.
  - File "Include/fg_callback.hxx" contains the callback class defns.
  - Modified fgEVENT and fgEVENT_MGR to use the callback classes.  Also
    some minor tweaks to STL usage.
  - Added file "Include/fg_stl_config.h" to deal with STL portability
    issues.  Added an initial config for egcs (and probably gcc-2.8.x).
    Don't have access to Visual C++ so I've left that for someone else.
  - This file is influenced by the stl_config.h file delivered with egcs.
  - Added "Include/auto_ptr.hxx" which contains an implementation of the
    STL auto_ptr class which is not provided in all STL implementations
    and is needed to use the callback classes.
  - Deleted fgLightUpdate() which was just a wrapper to call
    fgLIGHT::Update().
  - Modified fg_init.cxx to register two method callbacks in place of the
    old wrapper functions.
  - The new classes in libmisc.tgz define a stream interface into zlib.       
    I've put these in a new directory, Lib/Misc.  Feel free to rename it      
    to something more appropriate.  However you'll have to change the         
    include directives in all the other files.  Additionally you'll have      
    add the library to Lib/Makefile.am and Simulator/Main/Makefile.am.        
                                                                              
    The StopWatch class in Lib/Misc requires a HAVE_GETRUSAGE autoconf        
    test so I've included the required changes in config.tgz.                 
                                                                              
    There are a fair few changes to Simulator/Objects as I've moved           
    things around.  Loading tiles is quicker but thats not where the delay    
    is.  Tile loading takes a few tenths of a second per file on a P200       
    but it seems to be the post-processing that leads to a noticeable         
    blip in framerate.  I suppose its time to start profiling to see where    
    the delays are.                                                           
                                                                              
    I've included a brief description of each archives contents.              
                                                                              
    Lib/Misc/
      zfstream.cxx
      zfstream.hxx
        C++ stream interface into zlib.
        Taken from zlib-1.1.3/contrib/iostream/.
        Minor mods for STL compatibility.
        There's no copyright associated with these so I assume they're
        covered by zlib's.

      fgstream.cxx
      fgstream.hxx
        FlightGear input stream using gz_ifstream.  Tries to open the
        given filename.  If that fails then filename is examined and a
        ".gz" suffix is removed or appended and that file is opened.

      stopwatch.hxx
        A simple timer for benchmarking.  Not used in production code.
        Taken from the Blitz++ project.  Covered by GPL.

      strutils.cxx
      strutils.hxx
        Some simple string manipulation routines.

    Simulator/Airports/
      Load airports database using fgstream.
      Changed fgAIRPORTS to use set<> instead of map<>.
      Added bool fgAIRPORTS::search() as a neater way doing the lookup.
      Returns true if found.

    Simulator/Astro/
      Modified fgStarsInit() to load stars database using fgstream.

    Simulator/Objects/
      Modified fgObjLoad() to use fgstream.
      Modified fgMATERIAL_MGR::load_lib() to use fgstream.
      Many changes to fgMATERIAL.
      Some changes to fgFRAGMENT but I forget what!

New in 0.52
* Stars added in 8 stages as sky gets darker for a smoother more realistic
  transition.
* rewrote star loader to significantly improve load times.
* Tweaked sky brightness and dawn/dusk colors.
* Fixed a small problem with moon rendering.
* Fog color tries to track the sky color at the center of view in sunrise
  and sunset situations.
* Optimizations from Norman Vine
* Code fixes and tweaks from Charlie Hotchkiss.
* Added an --enable/disable-sound option.
* Added a pause key "p"
* Added command line options to specify initial position and orientation.
* Added command line option to start in paused or unpaused state.

New in 0.51
* Translucent menus
* Various HUD intensities so you can find something that is readable for the
  current conditions and lighting.
* Tie visibility to far clip plane & view frustum culling so reducting
  visibility can increase frame rates by increasing what is culled.
* Fixed stupid bug with misplaced initial position.
* Hopefully fixed a bug when parsing system.fgfsrc on windoze.

New in 0.50
* HUD updates from Charlie Hotchkiss (ladder number rotate w/ ladder, control
  position indicators are back)
* Only draw the PUI cursor if Mesa/Glide/Fullscreen.
* Added mipmapping.
* Calculate the model view transformation matrix once per tile per iteration.
  Then glLoadMatrixd() it for each fragment rather than calling push(), 
  translate(), pop().
* Added a basic splash screen.
* Added support for switching between fullscreen and window mode for 
  Mesa/3dfx/glide.
* added an enable/disable splash screen option
* added an enable/disable intro music option
* added an enable/disable instrument panel option
* added an enable/disable mouse pointer option
* Ground collision detection.  You can now land or test for collision with
  any scenery surface.
* Converted angle of attack scale into a radio altimeter.

New in 0.49
* Managment of multiple textures
* Incorporated Friedemann Reinhard's initial panel code.
* Fog mode is now GL_FOG_EXP2 instead of GL_FOG_LINEAR
* Build the non-shared pieces of the FG sim as static libs.

New in 0.48
* Incorporated Steve Baker's PUI user interface library written
  entirely on top of OpenGL
* Incorporated Steve Baker's Audio library which currently only
  supports Linux, but a win32 port is very close to being done.
* Sort object fragments by material property before rendering.  This
  will be a big help to performance when we start including objects
  with a wide variety of material properties and textures.
* Overlapped scenery tiles to reduce the chance of an occasional
  floating point precission induced gaps.
* Fixed a bug in zlib exposed by Borland Win32 compiler.
* Impose a maximum triangle area during scenery generation so even
  very flat areas will get split into a few smaller sub triangles.
* Fine grained (fragment level) view frustum culling.
* view transformation optimizations -- Norman Vine.
* Fixed polygon winding problem in scenery generation, so all
  tri-strips are wound counter clockwise (opengl default).

New in 0.47
* Course (per tile) view frustum culling.
* Added a command line option to specify --fg-root which will override
  $FG_ROOT
* Hard coded default locations for FG_ROOT for situations when nothing
  is specified.  Unix = /usr/local/lib/FlightGear  Win32 = \FlightGear
* Restructured the command line processing code so that it can process
  these sames comands (one per line) out of a config file.
* Added a command line option to specify field of view.  This is
  adjustable at run time using "X / x".  Supporting code contributed
  by Norman Vine.

New in 0.46:
* Complete C++ re-write of the HUD section.
* Miscellaneous bug fixes and tweaks.

New in 0.45:
* Added an option to enable/disable wireframe rendering.
* Added an option to enable/disable fog/haze.
* Added an option to enable/disable sky blending.
* Added an option to select smooth/flat polygon shading.
* Added an option to enable full-screen mode.
* Added a visual frame rate counter on the HUD.  (Contributed by Durk Talsma)
* Autopilot updates (Jeff Goeke-Smith)
* Added an option to control the number of neighboring tiles that are drawn

New in 0.44: 
* Fixed a horible bug that cause the time to be *WAY* off when
  compiling with the CygWin32 compiler.
* Wrap up zlib so we can conditionally compile back in normal behavior
  on systems that have trouble building zlib.
* Minor adjustment to texture coordinate generation to reduce texture
  swimming.
* Added a command line option to enable/disable texture maps
* Minor transformation adjustments to try to keep scenery tiles closer
  to (0, 0, 0) GLfloats run out of precision at the distances we need
  to model the earth, but we can do a bunch of pre-transformations
  using double floats and then cast to GLfloat once everything is
  close in where we have less precision problems.
* command line option to set starting position by airport ID
* Cleaned up initialization sequence to eliminate interdependencies
  between sun position, lighting, and view position.  This creates a
  valid single pass initialization path.
* use already calculated LaRCsim values to create the roll/pitch/yaw
  transformation matrix

New in 0.43:
* material properties bug fixed when rendering terrain.
* bug in sky color generation fixed.
* bug in fog color generation fixed.
* zlib on the fly decompression/compression support.
* more code reorganization and clean ups.
* a fixed up 30 arcsec DEM file preprocessor.  World wide DEM's are 
  available in this format.

New in 0.42:
* Simple autopilot heading hold contributed by 
  Jeff Goeke-Smith <jgoeke@voyager.net>
* More code reorganization and clean ups.

New in 0.41:
* Many autoconf cleanups and tweaks
* make and make install work in unix
* make works for cygnus win32 (but not install yet)
* make dist now works
* added the Tools directory into the main source tree

New in 0.40:
* Gnu automake/autoconf/libtool make system
* Initial texture support
* Bug fixes