Celestia Revision History
-------------------------

1.00
* Initial public release


1.01
* Added more realistic and aesthetically pleasing ring illumination function
* Made planets project shadows onto their rings (requires multitexturing)
* Detect and use ARB_multitexture extension
* Some configuration parameters now read from a file
* Support for multiple solar system catalog files
* Split solar system files into solarsys.ssc and extrasolar.ssc
* Added Help/License menu
* Added simple camera orbit mode
* Fixed up parsing and printing of catalog numbers--still kludgy though


1.02
* Made Celestia icon appear in corner of window.  Whee.
* Fixed an extremely subtle numerical precision bug which manifested itself in
  a number of ways:  jittering when following small objects, incorrect
  targeting of small objects with goto, occasional flashes when closely
  approaching an object, and probably other things as well.
* Reversed rotation directions when orbiting--it's much more intuitive now
* Added an exponential dolly capability to the camera
* Double-clicking will now center on the selected object
* Fixed bug in elliptical orbit calculation
* When orbits are displayed, the Orbit for the selected object is highlighted
* Incorporated Scott Hudson's asteroid geometry data for Toutatis, Kleopatra,
  and Geographos.
* Fixed problems with disappearing labels and with misplaced labels for
  extrasolar planets
* Eliminated 'sticking' when mouse buttons released outside of Celestia window
* Added Real Time option to Time menu
* Reversed planet rotation direction so it's correct.  Oops.
* Added about a dozen extrasolar systems from Jean Schneider's catalog
* Create two new textures for extrasolar planets
* Moved Selection class outside of Simulation, as it's generally useful


1.03
* Rotating the camera is now more responsive to mouse movement
* 'Infinite mouse' hack allows rotating and dollying without having to pick up
  the mouse and reposition the cursor in the window
* Fixed z ordering for planets and satellites so small that they only appear
  as points.  Small satellites will no longer get obscured by planets they're
  in front of.
* Apparent magnitude calculation for planets now takes into account phase
* At close range, stars are now rendered as textured sphere meshes.
* Choosing stars by catalog number no longer selects a star even when the specified
  star doesn't exist.
* Added labels for stars; the list of labelled stars is read from celestia.cfg
* Cleaned up vecmath.h, added consts and reference parameters where appropriate
* Cleaned up StarNameDatabase


1.04
* Start out at the moon instead of in deep space
* Made picking of planets work properly for planets with disc sizes greater than one
  pixel.
* Added call to glDeleteTextures to Texture class destructor
* Added bump mapping.  Uses DOT3 bump mapping and only works on GeForce cards
  right now.
* Enabled user control of per-pixel lighting.
* Menu checked state for label options synced with renderer state.
* Added a context menu that appears when an object is right clicked.
* Celestia now uses texture coordinates from 3DS files
* Added 3DS model of Eros based on NEAR laser rangefinder data
* Added 3DS models of Deimos, Phobos, and numerous other asteroids and
  small moons based on Phil Stooke's models
* Replaced TriangleList class with much more flexible VertexList
* Introduced support for compressed textures; texture compression is specified
  on a per texture basis in .ssc files.
* Added a reverse time option
* Added an OpenGL Driver Info item to the help menu


1.05
* Made per-pixel lighting work for planets without bump maps too
* Allow user control of magnitude of faintest visible stars
* Added support for PNG textures
* Improved console: enabled backspace, relocated text entry, code cleanup, ...
* Corrected star positions by converting them from equatorial to ecliptical
  coordinates.
* Eliminated case sensitivity when selecting objects by name
* New ring texture for Saturn with separate reflectance and opacity
* Ring textures now specified in .ssc files instead of hardcoded
* Implemented date/time selector dialog box
* Changed the mouse wheel function from zoom to dolly.  Zoom is now controlled by
  shift left-dragging the mouse.  For mice without wheels, control left-dragging
  will dolly.
* Fixed orbit and dolly functions to work in follow mode
* Improved rendering of objects at close range: less clipping, extra sphere LOD.
* Fixed bug that caused irregular objects to be displayed at half their actual size
* ESC now cancels goto and follow instead of exiting app.
* Fixed orbital calculations for planets so their positions are now closer to
  reality.
* Completed extrasolar planets database; it now contains all known planets
  around normal stars
* Mir!
* MeanAnomaly field in .ssc files was incorrectly called TrueAnomaly; this
  is fixed, and solar system parser now also accepts MeanLongitude in orbital
  elements section.
* Epoch can now be specified for orbital elements.  Default is J2000.


1.06
* Made Alt+F4 exit the app.
* Fixed text rendering to be pixel-accurate; labels and console text are now
  crisper and don't have any missing pixels (need to test on more graphics
  chipsets.)
* Updated parser to handle negative numbers.  Big oops.
* Corrected errors and omissions in extrasolar planets catalog.
* Added locations menu for saving and recalling favorite places.
* Added intro message.
* Removed stars without spectral class info from database.
* Included support for cloud maps
* Added extrasolar planets from the ESO's April 4th announcement
* Axial rotation for stars
* Alleviated clipping of very distant stars (Deneb was missing from Earth's
  sky due to this bug.)
* Increased depth buffer precision for planet rendering--this should improve
  the quality of rendering with 16-bit z buffers
* Added option to render constellation diagrams
* Use strips instead of lists for rendering spheres
* Enabled keyboard control of zoom with home and end
* Implemented basics of linear scripting system
* Run a script at startup; the script filename can be set in the config file

Code revisions:
* Converted Simulation class to use Julian days instead of seconds as internal
  time units.
* Eliminated brain damaged observer methods in Simulation
* Cleaned up Console class


1.07
* More corrections to planetary orbital calculations
* Accept LongOfPericenter as well ArgOfPericenter in solar system catalog files
* Updated parser to accept C-style string escapes
* Render the Milky Way and other galaxies
* Added more constellations
* Display constellation names
* Cleaned up render menu
* Added FPS counter
* Implemented basic WWW info feature for planets and stars
* New script commands: renderflags, labels, orbit
* Implemented a scripted demo mode
* Placed ISS in Earth orbit


1.08
* Initial UNIX port
* Created GLUT based front-end
* Created abstract Timer class with Windows and UNIX implementations


1.09
* UNIX port fixes: eliminated friend templates in Quaternion, added -lm to
  configure.in, added missing return type for methods in Console and Overlay


1.0.10
* Fixed problem with ring shadow texture by setting wrap mode to GL_CLAMP_TO_EDGE
* Corrected scale of ring shadow to match size of planet
* Switched to octree based visibility determinination algorithm for
  stars.  The result is better rendering performance, especially when
  many stars are displayed.  The octree algorithm is also lag free, meaning
  that all star "popping" is eliminated.
* Added setvisibilitylimit command for scripting.
* Fonts now selectable in celestia.cfg
* Added more and fewer visible stars options to render menu
* Fixed BigFix precision bug that appeared only with certain compiler versions.
* UNIX version: Enabled arrow keys and home/end in UNIX version
* UNIX version: Implemented frame rate counter
* UNIX version: Added mouse wheel support
* UNIX version: Fixed bug that caused picking to happen while dragging mouse
* UNIX version: Added more compiler optimization flags to Makefile
* UNIX version: Ctrl-Q now exits program
* UNIX version: Fixed vertically flipped textures
* UNIX version: Initial Gtk+ version, with rudimentary GUI


1.1.0
* Added RotationPhase field to solar system bodies; tweaking this makes sure
  that the right part of the planet is dark at a given time.
* Changed axial tilt of Earth so that the North Pole is illuminated in summer,
  not winter.
* Added option to render celestial coordinate sphere
* Added geosynchronous follow mode
* Added synchronous command to enable geosynchronous follow mode
* Fixed disappearing stars when modifying field of view
* Fixed bug reading angle in galaxies file
* Made it possible to select an object by 'path' e.g. Sol/Earth/Moon
* Bound { and } keys to control ambient light level
* Windows version: added solar system browser window
* Windows version: added star browser window
* Windows version: separated update from redraw so animation no longer occurs
  when dragging modal dialogs over the view window
* Windows version: made context menus work when running fullscreen

Code:
* Fixed bug in quaternion to matrix conversion; conversion was returning the
  matrix representation of the conjugate.
* Moved common UI code into CelestiaCore


1.1.1
* Added spectral type field to star browser
* Fixed bug that was causing garbled fonts in some cases
* Added missing minus character to default label font
* Many more options for goto--pick a specific long and lat, set coordinate
  frame, choose up vector
* Changed camera rotation interpolation--now use quaternion slerp
* Constrained parallaxes of stars which are components of multistar systems;
  binary stars now actually close to each other and not just when viewed
  from Earth.
* Fixed another stupid sign problem--north celestial pole is now positive,
  not negative y.  This change should be invisible to a user.
* Replaced welcome message with logo texture

Code:
* Moved selection info code from Simulation to CelestiaCore
* Fixed bug in Texture destructor


1.1.2
* Replaced single catalog number with separate entries for HD and HIP numbers
* Expanded star name database and rewrote star name code to be less strict
  when matching names.
* Added track mode
* Changed displayed units of distance and velocity
* Fixed picking of stars so it works properly at close distances
* Fixed bug that caused solar systems not to be displayed when another star
  was nearby (this made it impossible to visit the planets of Gliese 876)
* Fixed inverted bump maps
* Now use exponential interpolation during goto movement.
* New Jupiter texture based on Cassini images
* Added a tour guide feature
* Added more constellation diagrams
* Windows version: save and restore window size settings in registry
* Windows version: added toggle between GMT and local time
* Windows version: added keyboard command mnemonics to menus
* Windows version: InstallShield setup
* Windows version: added controls help dialog
* UNIX version: implemented find object and about dialogs (Gnome/Gtk only)
	
Code:
* Moved star browser and solar system browser code into separate modules
* Fixed DPRINTF macro so it's not broken in g++


1.1.3
* Added city light map for night side of Earth
* Specular reflections for Earth's oceans
* Haze effects for planets and moons with atmospheres
* Optimized star rendering--faster, uses substantially less memory
  when many stars visible
* Changed minimum limiting magnitude from 8.0 to 12.0
* Support for nVidia vertex programs
* Eliminated 'seams' in normalization cube maps used for lighting
* View frustum culling of planets and nearby stars
* Fixed clipping that occurred when close to planets
* Fixed depth buffer precision problems (most apparent with spacecraft)
* Tidied up display of speed, distance, and star/planet statistics.
* Changed how modes work--goto won't break follow and sync follow modes
  any more
* Fixed underlit planets on GL implementations without EXT_rescale_normal
* Type K, M, R, S, and N stars now cast a red tinted light on their planets
* New Earth texture
* Print less debugging spew on startup
* Integrated Colin Walters endianness fixes
* Windows version: info about max texture size and number of simultaneous
  textures added to OpenGL Info dialog.
* New objects: Comet Borrelly, the giant Kuiper Belt object 2001 KX76,
  and the Hubble Space Telescope
	
Code:
* Rewrote texture and model managers
* Cleaned up simulation.cpp to use frames of reference and eliminated a lot
  of special case code for the different 'modes'
* Stopped using the Intel JPEG library on Windows; instead, the Independent
  JPEG Group's library is now used on all platforms.


1.1.4
* Fixed text rendering problems that appeared on Matrox cards
* Windows version: fixed bug that broke web info for stars
* Windows version: improved web info feature so that it doesn't launch a new
  instance of IE every time.
* Added eight new extrasolar planets announced 15 Oct
* Fixed goto command so that it doesn't ever place you inside a planet
* Allow navigation with number pad
* Much greater resolution in planet meshes
* Implemented atmospheric effects
* Modified center so it does not change the frame of reference--will prevent
  suddenly leaving the ground when used on the surface of a planet.
* Changed rendering order so star and constellation labels are obscured by
  planets.
* Corrected satellite obliquities--they should have been relative to their
  planets equatorial plane.
* Eliminated premature clipping of irregular bodies at close range
* Fixed problem with lighting on S3 Savage4
* Fixed clipping bug with fields of view greater than 45 degrees
* Introduced support for custom orbital calculations
* Much more accurate orbital calculations for Earth and Moon; eclipses now
  occur at the correct time.  Also, introduced accurate calculations for
  other solar system planets except Pluto.
* Require solar system catalog files have orbital elements in an
  EllipticalOrbit group.
* Added four more asteroids with models by Scott Hudson: KY26, Castalia,
  Bacchus, and Golevka
* Added keyboard commands to toggle night side lights (Ctrl+L) and
  atmospheres (Ctrl+A)
* Added a 'Goto Object' dialog box, which lets you specify an object name
  and distance, longitude, and latitude.
* Implemented a screen capture feature
* Windows version: added a star browser option to display just those stars
  with planetary systems.
* Windows version: fixed bug in Set Time dialog that wouldn't allow setting
  both the date and the time of day.
* Windows version: added basic joystick support.
* Windows version: fixed 'jumping' that occurred when using Goto or Follow
  from popup menu.
* Windows version: added 'Set to Current Time' button in Set Time dialog
* Windows version: fixed selection of planetary satellites via context menu
* Windows version: made tab, return, and escape work properly in modeless
  dialogs
* Unix version: created installer (Deon Ramsey)

Code:
* Rewrote texture font code; texfont.cpp is gone, everything now in
  texturefont.cpp


1.2.0
* Fixed problem with image capture function that saved skewed images for some
  windows widths.
* Changed field of view display to use minutes and seconds
* Fixed display of time scale when time is reversed
* Fixed jittering labels for stars distant from the sun
* Fixed depth ordering problem that caused satellites to appear in front of
  the horizon when viewed from the surface of Earth
* Made the correct hemisphere of the Moon face Earth
* Fixed Earth's rotation so that sunrise and sunset times are correct
* Fixed picking so that clicking on a distant planet will never select one of
  its satellites.
* Improved orbit calculation code to properly compute eccentric anomaly
* Render orbit outlines behind planets instead of in front of them
* Made it possible for clouds to move relative to the ground
* Eliminated star haloes that were visible in daylight
* Added Uranus's ring system
* Added Shrox's Mars Global Surveyor and Mars Odyssey models
* Windows: save rendering and label settings
* Windows: added movie capture feature
* Windows: fixed disappearing mouse cursor bug
* Windows: added slider for controlling number of stars displayed by
  star browser.
* Windows: vastly improved full screen support
* Windows: fixed non-functioning Fewer Stars menu option
* Unix: fixed problems with '--enable-debug' under automake (dramsey)
* Unix: Enhanced autoconfigure to enable automated distribution build, as well
        as building the buildstardb program used to create stars.dat (dramsey)
* Unix: Fixed Problem with --enable-debug=no acting as if --enable-debug=yes
        had been given. (dramsey)
* Unix: Changed --enable-gtk into --with-gtk, and made it automatic if Gtk+ and
        GtkGLArea is present. (dramsey)
* Unix: Inserted testing code for GtkGLArea into configure.in (dramsey)
* Unix: Integrated a current gnome macros package. (dramsey)
* Removed many errors and compiler warnings (dramsey)
* Label Galaxies option. (dramsey)
* Unix Gtk : Added several menu options already present in the windows version.
             (dramsey)
* Unix Gtk : Fixed problem where giving keyboard commands wasn't updating
	     the toggle menu gadgets. (dramsey)
* Unix : Handle timezones correctly. (dramsey)
* Fixed constellation typo: Cyngi -> Cygni
* Much better Data analysis and Correction for the buildstardb program
  leading to better data in stars.dat . Verbosity of the buildstardb program
  may now be controlled by commandline argument. (dramsey)
* Improved solar system catalog file format so it's easier to install add-ons
* Scan extras directory for solar system catalog files
* Fixed pixel shader rendering path so it uses star light color
* Added support for textures in 3DS models
* Fixed locations menu
* Improved locations menu so that position and frame of reference are saved
  and restored.
* Fixed broken script commands: setposition, setorientation, and move
* Display the names of tracked and followed objects
* Windows: replaced proliferating render and label options in menu with
  a single modeless dialog.
* Fixed period and rotation of Phoebe

	
1.2.1
* Unix: configure.in changes to better find OpenGL libraries by Bruckner.
* Added accurate orbital calculations for Galilean satellites.
* Added tolerance parameter for picking to make picking objects in a narrow
  narrow field of view work better.
* New texture for Miranda courtesy of Bruckner.
* Windows: Fixed bug that caused a crash when canceling the view options dialog
* Windows: Fixed crash that occurred when recalling a location with
  no selection

	
1.2.2
* Improved find algorithm for starnames, and combined names from hdnames.dat
  into starnames.dat. Also added several additional names and variant spellings
  from my Star Atlas into starnames.dat (whose format has been completely
  revamped). (dramsey)
* Unix GTK: Got Ctrl-Q to exit the Program properly. (dramsey)
* Unix GTK: Capture Filenames now starts up with a proper filename, remembers
            the last directory, and complains about bad filenames. (dramsey)
* Added 'verbose' option, and supressed most non-error type messages unless
  verbose is set. (dramsey)
* Made picking exact for oblate planets
* Optimized rendering of planet meshes
* Switched to high levels of details when camera is near surface of a planet
* Improved the appearance of the corona around stars
* Fixed specular lighting for 3DS meshes, but correcting the mapping of 3DS
  shininess to OpenGL specular exponents.
* Multi Resolution Texturing. (dramsey)
* Unix: Much improved recognition of missing packages in configure. (dramsey)
* Added rendering of eclipse shadows
* Implemented longitude of axis for planet rotation elements
* Corrected inclinations of Saturn (now rings appear at proper tilt when viewed
  from Earth), Uranus, and Neptune.
* Added accurate orbital calculations for the eight largest moons of Saturn
* Textures for Ariel, Umbriel, Titania, and Umbriel from Bruckner.
* Improved planet labeling: less clutter, plus labels are displayed for distant
  objects at high zoom levels.
* Fixed rendering of ring systems so that planets with both rings and
  a cloud layer are rendered correctly.
* Added accurate orbital calculations for the five largest moons of Uranus
* Added option to render stars as points (for a less fuzzy appearance)
* Corrected sizing of planets' shadows on their ring systems
* Enabled used of extremely high resolution textures through splitting into
  subtextures.
* Corrected orbital elements for Ceres, Pallas, Juno, and Vesta.
* Added Ikeya-Zhang to solar system
* Fixed position calculation for orbits with 0.98 < e < 1
* Enabled rendering of 3DS meshes with transparent parts
* Unix Gtk: New Renderer Options
* Fixed colors on the Hubble model
* Fixed some clipping problems with 3DS meshes caused by bad center calculation
* Enhanced Locations menu to support full manipulation and categorization of
  saved locations.


1.2.3
* Fixed bug in texturefont.cpp that produce an error with some STL
  implementations (VS.NET, HPUX)
* Added elapsed time counter to movie recording UI
* Added support for orbits interpolated from sampled positions
* Fixed 'crosshair' appearance of eclipse shadows on some cards
* Enforced power of two texture size requirement--eliminates texture loading
  crashes on some systems
* UNIX: Modified GL extension handling code to make it possible to compile
  against Mesa 4 headers.


1.2.4
* Fixed bug that caused alpha blending to always be enabled for 3DS meshes
* Fixed sign error in that caused some orbits to be retrograde
* Fixed rendering of night lights to ignore ambient color (keeps night lights
  from being visible on lit side of planet.)
* Improved precision to eliminate position drifting because of rounding errors
  (was apparent when orbiting within 1km of an object)
* Replaced perfectly spherical Comet Halley with an irregular model
* Added object classifications and label coloring based on them
* Created new 'phase-lock' coordinate system
* Created new 'chase' coordinate system
* Unix Gtk: removed bug in Text enter mode. (dramsey)
* Unix Gtk: Menus for new Labels. (dramsey)
* Unix Gtk: Star Browser Body Types. (dramsey)
* Unix Gtk: Correct Underlines for Menus. (dramsey)
* Guess Body Types more accurately. (dramsey)
* Support hyperbolic orbits
* Improved algorithm for calculating positions on highly eccentric orbits
* Added setambientlight scripting command
* Enabled rendering of satellite orbits
* Windows: added open script option to file menu
* Changed orbit and dolly functions so they operate with respect to the
  current reference object instead of the selection.
* Made Goto command automatically switch to follow mode
* Fixed customorbit.cpp to compile on HP/UX
* Fixed appearance of galaxies when viewed from inside an atmosphere
* Removed duplicate entry for Iota Horologii (HR 810) in exoplanet catalog
* Unix: fixed GL extension code so it's possible to compile with Mesa 4 headers
* Unix: fixed byte swapping code
* Fixed bug that caused distant stars to disappear when viewed at some angles
* Unix Gtk: removed problem preventing ShowClouds from working. (dramsey)
* Unix Gtk: Options Dialog. (dramsey)
* Celestia Watcher extended. (dramsey)
* Unix Glut: Keyboard handling corrected. (dramsey)
* Galaxy labels were being placed incorrectly. (dramsey)
* Fixed slowdown while rendering shadows on TNT, Rage Pro cards
* Model precession of rotation axis
* New script commands: set, gotoloc, chase, lock
* Fixed orbits of major planets so that they don't get wacky far into the
  future or past
* Windows: fixed image capture in Windows so it doesn't screw up texture loading
* Display time to arrival when travelling
* Added preloadtex command for scripting
* Enforce a maximum time rate of 1e15 times normal


1.2.5
* Implemented text-based auxilliary star catalogs
* Added orientation property for planets
* Corrected rotation of Toutatis
* Improved specular highlights on planets (use local viewer model)
* Added constellation boundaries
* Fixed z fighting when cloud layers are used with vertex shaders
* Added Christopher Andre's eclipse finder for windows
* Fixed writing of locations file so locations still work after restarting
* Comets
* Added newly discovered extrasolar planets
* Added InfoURL field for objects in .ssc files
* Numerous Gtk UI fixes (details?)
* Fixed 'squareness' of planets and moons viewed at a distance
* Middle mouse button toggles between 45 degree and last field of view
* Added FOV to set command, so scripts can set the field of view.
* Made ring shadows optional
* Added distance filtering for stars
* Encode/decode Tycho catalog numbers, to support extended star database
* Fixed Moon's orbit so it doesn't crash into the Earth far in the future
* Improved vertex shader illumination for planetary rings
* Better text display from .cel scripts
* Added text "flash" messages for many keyboard commands
* Fixed Windows Solar System Browser to allow arbitrary depth tree
* Added shadows cast by rings onto planets
* Fixed lots of bugs with sampled orbits (.xyz files)
* Added RotateAcceleration field to config file; allows adjustment of
  navigation control sensitivity
* Improved accuracy of orbital calculations; VSOP87 series for all planets
* Added beginning/ending fields to definitions in .ssc files; allows
  setting finite lifespans for objects
* Made galaxies pickable
* Added view frustum culling of galaxies, for much improved performance
* Allow date strings Beginning, Ending, and Epoch fields of .ssc files
* Fixed incorrect occlusion of small satellites orbiting close to planets
* New set of constellation figures
* Sync'd mouse functions in Windows and Linux versions of Celestia
* Linux: fixed dialing ranges in set time dialog
* Fixed texture lookup to use higher res textures if a low res one isn't
  available
* Made steering keys on keypad turn the camera at a rate proportional to the
  field of view
* Added 'automag' option to automatically adjust the limiting magnitude based
  on the field of view (i.e. fainter stars become visible when the fov is
  decreased)
* Fixed haloes around bright stars so they're fixed in size regardless of
  field of view
* New colors for celestial grid and constellation figures
* Tuning of Gnome GUI: underlined key accelerators, enabled operation of all
  dialogs and menus with ALT <key>, arrow keys, and Tab
* Linux: GUI now synced with current state of pixel/vertex shaders 
* New keyboard bindings:
  Ctrl+Y    : automag toggle
  Ctrl+T    : toggle display of comet tails
  Ctrl+B    : constellation boundaries toggle
  !         : use current time
  Backspace : clear selection
* Reversed more/fewer stars keys ([ and ]) to be consistent with more/less
  ambient light keys
* Added support for multiple extras directories
* Reduced minimum field of view down to 3 arcsec
* Fixed glitch with center command that appeared under Linux and on Windows
  when building with VS.NET
* Cleaned up OpenGL extension initialization
* Significantly improved the reliability of object selection via mouse
  click, notably for small fields of view in the arcsec range. 
* Fixed the 'move' script command
* New script commands: setfaintestautomag45deg {magnitude float}, 
  lookback {} 
* [,] keys now adjust the limiting magnitude at 45 degrees 
  field of view, if automag is ON. Values displayed via flash messages  
* Associated the 'looking back' operation  with the '*' key shortcut
* Fixed bug in orbits of Galilean moons
* Corrected equatorial planes and rotation offsets for the major planets
* Linux: Added KDE interface, all features of the GTK interface are 
  available (except for the Tour Guide), new features include:
   - Bookmarks / URLs;
   - History navigation;* Improved drag and drop of cel:// URLs on Windows
   - Configurable shortcuts and tool bar;
   - Contextual menus;
   - Saved Settings and Preferences.
  Integration with KDE:
   - New Mime Type application/x-celestia-script for *.cel files;
   - *.cel files and cel:// URLs are associated with Celestia, if no instance
     of Celestia is running when the file or URL is activated it will be
     started and the script will be run or the location set to that of the URL.
     If an instance is already running the script will be run in that instance
     or that instance's location will be changed to match the URL.
* Added drag and drop and copy to clipboard for cel:// URLs on Windows
* Improved drag and drop of cel:// URLs on Windows

1.3.0
* Integrated more of Grant Hutchinson's corrections for the orientations of
  solar system bodies
* Updates for asteroids and comets from Grant Hutchinson:
   - Added Phil Stooke's textures for the asteroids Ida and Gaspra
   - Fixed mirror-reversal of Ida and Gaspra meshes (Grant Hutchinson)
   - Use orbital elements valid for the Galileo encounters of Ida and Gaspra
   - Corrected rotation parameters
* Made name matching for galaxies case-insensitive
* Corrected orbits of Uranians satellites Miranda, Ariel, Umbriel, Titania and
  Oberon.
* cel:// URL fixes
   - Added support for relative URLs
   - Improved drag and drop support on Windows
   - Browser integration on Windows: clicking on a cel:// URL launches Celestia
   - Better time precision
* Added new keyboard commands for dealing with light time delay
   - ? : show light time delay between current position and selected object
   - - (minus) : compensate for light time : subtract light travel time to
     selected object from the current time
* KDE interface: add subtract light time button to Set Time dialog
* Added cubic interpolation option for sampled trajectories (.xyz files)
* Added NormalMap field for .ssc files
* Prevent crashing when CompressTexture true is specified for an already compressed texture.
* KDE: Implement eclipse finder
   - Eclipse finder code separated into UI and platform-independent parts
* Added basic support for rendering nebula as 3ds meshes.
* Modified format of galaxies file to handle other deep sky objects as well
* Added OpenCluster objects
* Implemented 'markers'
   - Selection is highlighted with a marker
   - Markers may also be set on objects using the right-click context menu
   - Added mark/unmark commands for scripts
   - Bound Ctrl+K to toggle display of markers
   - Added flash messages indicating on|off status of markers 
   - Implemented markers into KDE interface	
* Added triangle-accurate picking of mesh objects
* Multiview
   - Ctrl+R : split view vertically
   - Ctrl+U : split view horizontally
   - TAB    : cycle active view
   - DEL    : delete active view
   - Ctrl+D : delete all views except active one
   - Views may be resized by dragging on borders
   - Multview functions also available in the view menu
* Eliminated eclipse shadows appearing on wrong side of planet
* Added support for specular and bump map effects across a wider range
  of graphics hardware.
   - Introduced notion of a render path
   - Ctrl+V changed to cycle render path instead of toggle vertex shader
   - Added IgnoreGLExtensions directive for celestia.cfg
* Added track command for script
* Fixed eclipse shadow z-fighting artifacts
* Fixed vertical mirroring of textures on 3DS models
* Fixed problems with bump mapping
* Enabled loading of .cel scripts through the Windows or KDE shell
* New directory structure for add-ons; meshes, textures, and other media
  may now be located withing an add-on subdirectory.
* Added texture for Eros
* Added separate cloud and surface textures for Venus
* New "invisible" class for solar system objects
* Fixed crashes that occurred when viewing ringed planets on older hardware
* Got rid of three zeros after decimal point when displaying time rate
* Updated configuration files for new versions of autoconf

1.3.1
* Improved inclusion of light travel delay, also in KDE time setting dialog 
* Fixed lookback command for subsequent changes of target speed
* Allow wildcard character * inplace of extension for texture filenames
* Fix bump mapping (again)
* Use standard normal maps instead of x-reversed ones
* Compute the radii of stars more accurately by using bolometric magnitudes
* Permit star names to be defined within .stc files
* Fixed near clipping of small deep sky objects
* Windows: added auto magnitude toggle to render menu
* KDE: added popup error notifications
* Allow oblate planets to have atmospheres
* Corrected specular highlights; abrupt cutoff near terminator eliminated
* Fixed 'hole in the sky' bug
* Allow sunset color to be specified in .ssc files
* Improved rendering of objects in daytime skies
* Bound Ctrl+P to mark/unmark selection
* Implemented tab completion of star, planet, and deep sky object names
* Implemented new, scientifically accurate Pluto-Charon textures
* Windows: bound Ctrl+C to copy cel:// URL to clipboard
* Modified the way field of view works: compute the field of view based
  on distance to screen, monitor resolution, and view size; don't attempt
  to maintain a constant vertical FOV when splitting views.
* Implemented alternate surfaces for planets
* Added overlay textures that are applied on top of other surface maps
* Bound + to toggle limit of knowledge maps
* Improved estimates for stellar rotation period; previously all stars
  were assigned the same rotation rate as the sun.
* Added locations--labels of planetary surface features
* Bound & to toggle display of location labels
* Added a locations dialog for controlling the display of locations
* Allow orbit paths to be turned on independently for all object classes
* Added a 'scaled disc' style for rendering stars
* Bound shift+arrow keys to orbit reference object
* Added unmarkall command for scripting
* Added missing render flags for script commands: automag, atmospheres, grid
* Added a MeshCenter field for properly position and rotation of 3DS meshes
* Implemented virtual textures, for ultra-high resolution texture mapping of
  planets.
* Added textures for Hyperion and Proteus
* Made cancel script command stop motion, tracking, and any object-relative
  coordinate system.
* Adjusted estimates for radii and rotation periods of extrasolar planets;
  rotation rates account (somewhat) for the effects of tidal despinning. 
* Fixed a bug that was causing precision loss in orientation values; this fixes
  some of the jerkiness apparent at very low fields of view.
* Corrected radii of Uranus's rings
* Added ring system for Neptune
* Corrected errors in Callisto's orbit
* Modify the right-drag rotation rate based on the distance between the
  camera and the selection.
* Made ambient light work for bump mapped objects in the vertex program/DOT3
  render path.
* Bound Shift+C to center/orbit.  This places the selection in middle of
  the view while keeping the reference object at the same point in the view.
* Added locations-labels of all world capitals (240) with importance
  weights calculated from their numbers of inhabitants
* Added solar system location labels

1.3.2
* Added support for extended character sets (most of WGL4) and UTF-8 encoded
  strings
* Updated info display to show apparent size of selected object
* Enable tab completion of location names
* Introduced support for JPL ephemeris files
* Fixed crash in Windows star browser that occurred after changing the number
  of stars and pressing return.
* Fixed bug that made stars and galaxies appear square when certain nebulae
  were in view.
* Made the delete button in the Windows bookmarks organizer actually work
* Updated orbits for Amalthea and Phoebe
* Fixed seams in Jupiter and Phobos textures
* Spacecraft orbit paths adaptively sampled for smoother results
* Eliminated obscuring of location labels that occurred low view aspect ratios
* Added models of comet Halley and the small moons Pandora and Larissa
* Added limit of knowledge masks for the Galilean moons
* Changed spectral class of carbon stars to C, which supercedes and combines
  R and N
* Lua scripting additions
  * View management commands
  * Image capture commands
  * Made setrenderflags and setlabelflags accept a table
  * Orbit and locations settings
  * observer:cancelgoto
* Made the cursor shape change to the resize icon when positioned over view
  borders
* Added a new 3D file format: cmod, the Celestia model format
* Documented the fields in celestia.cfg with extensive comments
* Added newly discovered extrasolar planet HD 330075 b
* Added Cassini and Huygens models and trajectories
* Fixed crashing bug in the eclipse finder
* Changed default start location to Earth
* Revised some erroneous spectral classes in star catalog
* Made solar system objects occlude labels of more distant objects
* Implemented an algorithm for importance weights to avoid overlapping or
  too crowded location labels for Mars, Venus and the Moon
* Added new textures for Titan based on recent imaging from the Cassini
  mission 
* Improved depth sorting so that hidden surface removal works properly for
  overlapping objects
* Added theoretical estimates of oblateness and rotation rate for extrasolar
  planets
* Replaced old Io and Europa textures with improved versions
* Added disposition modifier for ssc objects to control what happens when
  an object with the same name and parent already exists.  The three possible
  behaviors are Add (the default), Replace, and Modify.
* WINDOWS: Limited CPU usage when main window is minimized
* WINDOWS: Changed preferred z-buffer depth from 16 to 24 bits to reduce
  z-fight artifacts.
* Fixed labels and info text so it looks crisp when multisample antialiasing
  is enabled.
* Eliminated flickering of location labels
* WINDOWS: Save texture resolution setting between sessions

1.4.0
* New stars.dat format with HD catalog numbers and parallax errors omitted
* Added catalog cross indexes for HD and SAO catalogs
* Fixed bugs in parsing catalog numbers
* Added white dwarf temperatures and  spectral types DA, DB, DC, DO, DQ, and DZ
* Added handling for partial spectral types where one or both of the subclass
  and luminosity class are unknown
* Permit extended star attributes in .stc files: mesh, texture, rotation
  elements, semiaxes
* Support multiple star systems of any complexity with orbits and barycenters
* Changed .stc loader so that a star definition with a duplicate catalog
  number replaces the previous definition
* Made catalog numbers optional in .stc files; stars can be defined without
  having to create fake catalog numbers
* Star colors now chosen based on temperature; either 'classic' and black body
  colors may be selected
* Bound % key to toggle between star color tables
* Fixed black holes: infinite radius bug gone, rendered just as a plain black
  sphere
* Added comprehensive catalog of all knows stars within 25 light years of the
  Sun, including orbits for multiple star systems
* Created new command line tools for building binary star databases
* Removed limitation that two or more solar systems couldn't be shown
  simultaneously
* Show light from multiple nearby stars illuminating planets
* Implemented new GLSL render path; NVIDIA combiners and GeForceFX paths
  deprecated.
* Display UTF-8 superscript digits in some star names
* Updated the Titan texture. It accomodates all published high resolution 
  imaging from the Cassini mission until and including the flyby of 03/31/05. 
* Updated the Iapetus texture. It accomodates all published high resolution
  imaging from the Cassini mission, including also a unique hires photo taken 
  in "Saturn shine". 
* Added catalogs of 163 visual and 39 spectroscopic binary orbits,
  respectively, (S�erhjelm 1999, Pourbaix 2000) with known primary/secondary
  mass ratios.
* Added an extended and precise data base of 942 galaxies 
  (Steinicke's rev. NGC/IC, 2005) with a magnitude cutoff Bmag < 12. 
* Included the commented PERL scripts used to extract and adapt the binary
  orbit and  galaxy data from published professional catalogs.
* Added --extrasdir command line option for specifying additional directories
  to search for add-ons
* Allowed time scale to be modified while simulation is paused
* Replaced Windows date picker with a custom one that can be used to set dates
  prior to 1752.
* Fixed a bug in the Windows time picker that was causing the set time to be
  off by however many seconds the dialog was active.
* Added parent field for stars in celx scripting's getinfo command
* GTK+ front-end overhaul
   - source split into multiple files
   - performance work to minimize number of preference resyncs
   - redesigned interface to use GtkActions and GtkUIManager (XML)
   - added preference saving to file
   - commented heavily
   - new about dialog
   - made non-modal: GoTo, View Options, Tour Guide, Browsers, EclipseFinder
   - changes to allow for compilation on Windows
   - greek letters in Star Browser names
   - added tab-completion support in overlay entry
   - replaced deprecated widgets in several dialogs
   - new GTK save/open dialog
   - added "copy" and "open" url functions
   - updated GConf schema with new options
   - fixed automake bug where GConf schema would always install
   - removed linking against glut for no reason
* Implemented complete precision catalog (Steinicke's revised NGC/IC, 2005) of
  10610 galaxies with 
   - distance information from  four catalogs ( 6 methods ), 
   - <= 4 alternate names, 
   - info-URLs, 
   - absolute magnitudes and 
   - correct sizes & orientations in space, as calculated from catalog
     parameters. 
* Included well commented Perl script (deepsky.pl) as documentation. The used distance determination method is indicated in catalog for each galaxy.
* Updated binary star data base (visualbins.stc, spectbins.dsc) and respective
  PERL catalog extraction scripts (visualbins.pl, spectbins.pl), such as to eliminate double occurences wrto nearstars.stc (, which remained unaffected).
* Added much improved galaxy templates.
* Implemented galaxy coloration based on hue profiles from true color
  photographic imaging. Being older than spirals, elliptical galaxies have a somewhat redder coloration.
* Implemented a realistic relative apparent brightness display scheme for
  galaxies.
* Added apparent magnitude display as function of distance on canvas.
* Added display of DSO Type (Galaxy,...) and Hubble subtype in case of
  galaxies.
* Changed the galaxy label color from yellow to blue-green for better
  visibility.
* Did extensive octree rebuilding. Culling of deep sky objects is logarithmic
  now, enabling support for very large catalogs with little performance expenses.
* Performed optimized tuning of octree parameters that practically recovers
  the "pre-galactic" performance, despite a large data base of 10610 galaxies.
* Added support for multiple names of deep sky objects and implemented
  non linear keyboard selection of names with corresponding tab completion, etc., like with the rest of the celestial bodies.
* Replaced deep sky catalog class with a more complex database, following the
  original star database layout. This allows for more sophisticated and fast treatment of massive catalogs.
* Enabled very fast search of close-to-viewer deep sky objects.
* Implemented brightness corrections involving the angle between 1-2 surface
  normals and the viewing angle, such that the brightness distribution
  gets ~ uniform  for all galaxy orientations and Hubble types. This also
  avoids excessive, unnatural brightness effects in edge-on views.
* Galaxies get brighter with decreasing observer distance according to
  realistic human eye sensitivity profile.
* Brightness display optionally coupled with Automag scheme.
* Enabled very fast picking of deep sky objects.
* Placed galaxy templates in 'models/' directory.
* Added various crucial fixes in galaxy.cpp,
   - factor 2 was missing in the 'size' definition via the radius such that
     distances among DSO's were grossly incorrect;
   - fixed correct ordering of (non-commuting) operations in matrix m.
     This gave incorrect galaxy orientations;
   - To save space and to improve display: generate neat spherical E0
     template from S0 disk template via rescaling by (1.0f, 3.8f, 1.0f);
   - fixed wrong x,y alignment of elliptical rescaling.
* Added code to ease compilation with newer Xcode versions (Macintosh).
* Updated src/celengine/Makefile.am for Linux building. 
* Introduced a new cel function => renderflags {set "nebulae"}.
* Reduced the default value of 'faintestAutoMag45deg' from 8.5 to 7.0.
* Fixed the visibility of the Milky Way during day-time and the abrupt
  appearance or disappearance of galaxies near the day-night border.
* Enabled "geosynchronous Follow" (key 'Y') also for selected DSO's
  (yet it does not seem to be very useful...).
* Moved render flag check in the code such that labels can be drawn even if
  e.g. renderGalaxy flag is turned off.
* Suppressed apparent magnitude display for galaxy add-ons, lacking
  specification of an absolute magnitude (absMag) input value.
* Deleted various source code files that became superfluous.
* Improved comet display. Introduced a neat scheme implementing comet tail
  fading (between 4 and 6 AU for Sol). Systems with several suns and
  luminosities different from the solar one are accounted for. 
* Implemented a new, simple scheme avoiding overcrowded galaxy labels.  
  Their "importance"  is sorted according to apparent magnitude! Thus the
  labels of the brightest galaxies pop up first upon zooming in... 
* Fixes/workarounds for OpenGL 2.0 render paths on both nVidia and ATI cards.


1.4.1
* Windows: Added time zone selection to set time dialog
* Windows: Fixed hard to read text in set time dialog (bug was only present for
  certain Windows shell appearance settings.)
* Changed maximum number of eclipse shadows in OpenGL 2.0 path from two to
  three; if max is exceeded, clamp to three rather than not rendering the
  shadows at all.
* Corrected a bad calculation in ring shadow shaders that caused ring shadows
  to be drawn in the wrong place.
* Windows: Fixed the minimum feature size slider in the locations dialog so it
  updates in response to all the standard controls.
* Added a correct InfoURL for the Moon
* Windows: added splash screen with a progress indicator
* KDE: fixed some AMD64 bugs
* GTK: added splash screen with a progress indicator
* GTK: Added configure options to enable or disable Cairo support for splash
* Corrected a local flashing of the Milky Way brightness.
* Now the distance to the galaxy center is displayed, if the observer is
  located inside the galaxy (Milky Way...).
* Eliminated various incorrect Hubble type acronyms in deepsky.dsc that had
  penetrated the PERL filter.
* Add the corrected PERL script deepsky.pl.     
* Mac: Universal binary - runs natively on Intel and PPC
* Mac: OpenGL 2.0 render path should now work on many configurations
  (requires OS X 10.4.3 or later)
* Mac: Offer option to disable vertex programs automatically when ATI Radeon
  9200 renderer is detected (avoids hard crash)
* Mac: Progress message and version number displayed on splash screen
* Mac: Couple of French translation fixes
* Mac: Changed wording of "Subtract Light Travel Delay" menu item to
  "Add/Subtract Light Travel Delay" to more accurately reflect its function
* Mac: More sensible default values for preferences
* Mac: Bug fixes to favorites, InfoURL handling
* Mac: Full screen mode pauses when various panels are shown
* Mac: Fixed crash when LANG or LC environment variables are set
* Mac: Added bona fide English and French help menu
* Mac: Cleaned up README in general
* Added Phoebe textures in medres and lores directories from recent published 
  Ciclops cylindrical maps
* Updated  Titan and Iapetus textures in lores directory
* Windows: save and restore the last used GL render path
* Removed the GeForce FX render path; GLSL path is preferred
* Added lunar elevation map, using Clementine laser altimeter data, merged
  in the polar regions, with topographic data  from Clementine 750 nm
  oblique and nadir images.
* KDE: Reverted mouse wheel action to be compatible with the other interfaces.
* KDE: New configurable splash screen
    (http://celestia.teyssier.org/splash_spec.html)
* Updated/added Tethys textures in lores, medres and hires directories. 
* Added locations on Phoebe in satmoons2.ssc, as extracted from USGS/IAU
  official data.
* Added Mesh for Phoebe texture.      
* Updated Iapetus texture.
* Moved locations files from extras into data directory for inclusion in
  standard package.
* Fixed bug where displayed time scale differed from actual time scale after
  clicking a cel URL.
* Removed several files from installation on Linux and MacOS, saving ~5M
  compressed.


1.5.0
* New translations: Ukrainian, Russian, Arabic, Dutch, Chinese, Korean,
  Bulgarian
* Updated translations
* Separate i18n domain for constellation names
* Windows: Added support for i18n
* Fixed bugs with UTF-8 in object name completion
* Enabled new star rendering path: uses point sprite extension, new Gaussian
  glare textures
* Added dynamic star labeling
* Added support for non-power-of-two textures (newer graphics cards only;
  on older cards the textures will be automatically rescaled to the nearest
  power of two.)
* Mac: i18n improvements and bug fixes
* Mac: enabled support for hardware antialiasing
* Fixed crashes that occurred when Lua script errors were reported
* Made overlay textures work in GLSL path
* KDE: accept relative dir/files in --conf, --dir, and --extrasdir command
  line options
* KDE: fixed by ing deep sky objects info url where the default url was
  always used.
* Implemented event handlers for celx scripts
* Localized planet labels
* New extrasolar planets:
  - XO-1
  - HD 69830 system
  - HD 164922 b, HD 66428 b, HD 99109 b, HD 107148 b, HIP 14810 b
  - HIP 14810 c, HD 185269 b, Gliese 849 b
  - Mu Ara e
  - Gliese 581 c & d, HD 175541 b, HD 210702 b, HD192699 b
  - HD 47536 c, XO-2 b, HD 147506 (HAT-P-2), HD 17092 b  
* Revised orbits of many extrasolar planets to reflect new data
* Added stars for new extrasolar planets: GSC 92941-01657
* Mac: Show menu bar when moving mouse to top of screen in full screen
* Mac: added Japanese translation
* Fixed bug in cmod loader that caused binary cmod files to be read
  incorrectly on 64-bit machines.
* KDE: removed a dependency on STL support in Qt
* Mac: added missing 'Hide Others' menu option
* Fixed some depth sorting problems: coalescing of depth buckets was failing
  when a merged object was clipped to the new plane.
* Mac: cursor now changes on draggable view boundaries
* Added Plutonian satellite names: S/2005 P1 -> Hydra, S/2005 P2 -> Nix
* Fixed bug that caused time scale in celestiacore and simulation to get out
  of sync.
* Improved rendering of meshes in OpenGL 2.0 render path:
  - Switched to local viewer model for better quality specular highlights
  - Added support for specular and normal maps for meshes
  - Enable rendering of eclipse shadows cast onto meshes
* Added a ReverseMouseWheel option for configuration file
* Enabled per-pixel specular lighting in OpenGL 2.0 path
* Made specular lighting work properly with normal maps
* Enabled separate specular color when rendering models in pre OpenGL 2.0
  render paths
* Fixed gcc 4.1.1 build errors caused by bad constructor declarations in Star
  and CommandGotoLongLat classes
* Fixed bad calculation of specular exponent when converting materials from
  3DS files.
* Implemented cloud shadows
* Changed eclipse shadow shaders to use a single interpolant for all
  shadows instead of one per shadow
* Made relative InfoURL relative to current add-on directory instead of main
  data directory.
* KDE and GTK: added ogg/theora video capture
* Fixed bug in eclipse shadow test; objects close to the surface of the lit
  side of a planet were incorrectly rendered with shadows
* Made OpenGL 2.0 render path respect the ring shadow render flag setting
* Replaced Hubble Space Telescope made with Cham's much improved version
* New RECONS data added to nearstars.stc
* Windows: generate an accelerate command only when the 'a' key is pressed
  without any modifiers.
* Improved atmosphere rendering in OpenGL 2.0 path; uses new ssc parameters
  to specify scattering and absorption coefficients
* Added Lunar-Lambert photometric model (linear combination of Lambert and
  Lommel-Seeliger) for much more realistic appearing dusty objects
  (e.g. the Moon)
* Modified eclipse finder dialog for i18n
* Display a '?' when glyph is not found in a font texture
* Fixed a bug in the octree culling code that was causing star culling errors
* Fixed ambient light in OpenGL 2.0 render path to match other render paths
* Updates to parser:
  - Allow leading + (no effect, just symmetry with - )
  - Allow numbers to begin with a decimal point (e.g. accept .12 as well
    as 0.12)
* KDE: improvements to popup menu
  - orbiting bodies are now sorted by type
  - filtered out invisible objects and barycenters
  - added new marker shapes
* KDE: CelestialBrowser improvements:
  - Show satellites of satellites
  - Don't display barycenters and invisible objects
  - Added new body classifications: small body and dwarf planet
* Added cmodsphere, a utility for producing cmod meshes from height samples
  regularly spaced in longitude and latitude.
* COPYING, controls.txt, start script, and guide can all be localized
* cel and celx scripting: 
  - added openclusters and cloudshadows render flags
  - added location, nebulae, openclusers, and i18nconsteallations label flags
* Established Barycentric Dynamical Time (TDB) as the time scale used
  internally by Celestia
  - Convert to UTC when displaying the time
  - Modified Set Time dialog to convert from UTC to TDB
* Added normal maps for cloud layers
* Allow smaller objects to cast eclipse shadows (e.g. can now see eclipse
  shadows from Miranda on Uranus)
* Added support for compressed normal maps (DXT5nm)
* Added new solar system object type ReferencePoint, for defining reference
  frame centers.
* Added generalized reference frames for positioning and orienting bodies
* Implemented a new depth sorting algorithm that fixes many depth sorting
  bugs.
* Rewrote orbit path rendering; orbits are now properly depth sorted
* Mac: middle mouse button implemented (option-click on one button mice)
* Mac: show nearest and brightest stars properly sorted in star browser
* Added spectrum2rgb tool for generating RGB asteroid colors from SMASS
  spectra
* Made star orbit paths visible
* galaxies:
  -changed galaxy template format to standard (grayscale) PNG 
  -allow a custom template for each galaxy in deepsky.dsc
  -new approach to thickness of galaxy (arms): assumed proportional to read-in
   brightness values 
  -emulate dust lanes around galactic plane (y=0)
  -considerable improvement of Milky Way appearance as seen from Earth 
  -implement galaxy labels of transparency increasing with distance, thus
   providing a neat 3d effect
* galaxy templates:
  -designed an entirely new set of PNG templates using a uniform multi-layer
   technique
  -provided a custom Milky Way template including all known arms with correct
   location of the Sun. Supply adapted deepsky.dsc
* Moved origin of coordinate system to the solar system barycenter
* Added VSOP87 CustomOrbit for the Sun about the solar system barycenter
* Improved custom orbits based on JPL ephemerides:
  - Support big endian platforms
  - Fixed Moon orbit
  - Added orbits for Earth-Moon barycenter and sun
  - Added heliocentric and solar system barycentric orbits
  - Added Moon and Earth orbits relative to Earth-Moon barycenter
  - Guarded against crash when the JPL ephemeris file can't be found
* Generalized rotations
  - Clear syntax for ssc files
  - UniformRotation 
  - PrecessingOrientation
  - SampledOrientation - interpolated sequence of quaternion key frames
* Scripting improvements	
  - New celx scripting commands:
    - utctotdb and tdbtoutc
    - gl commands
    - celestia:getdsocount, celestia:getdsocount
    - iterators: celestia:stars and celestia:dsos
    - get/setaltazimuthmode
  - Lua hooks for script extensions to Celestia
  - Script interfaces for orbits and rotation models (ScriptedOrbit and 
    ScriptedRotation)
  - Support Lua 5.1 (5.0 compatibility retained)
  - Made celestia:loadtexture use relative file names
  - new properties for object:getinfo: catalogNUmber, hubbleType, and
    absoluteMagnitude
* Accelerated loading of large catalog files with an improved name index
  (over 100x performance increase for 100k+ object catalogs)
* Fixed bug that causes locations to work improperly in multi-star systems
* Improved vecToVec rotation and quaternion-to-matrix functions
* Added moons Daphnis, Perdita, Mab, and Cupid to numberedmoons.ssc
* Added FixedPosition trajectory type for making an object stationary within
  its reference frame
* Added FixedRotation rotation model
* Added logging of mesh statistics
* Improved load time mesh conditioning: eliminated duplicate materials and
  sort submeshes by material to reduce graphics state changes.
* Switched to improved version of Cassini model from Cham
* Added SpiceOrbit interface to trajectories defined in SPICE kernel files
* Added asteroid RGB colors integrated from spectra
* Corrected kilometers per light year constant
* Added various improvements to the MilkyWay & other galaxy template display.
* Added E0.png galaxy template that allows for better En, n=1..7 elliptical
  shapes.  
* Fixed sizes of irregular galaxies (factor of 2!).
* Prevented galaxy code from crashing if a template is missing.
* Improved selection of galaxies by taking into account their 3d shape
* Added new parameter set for Mie atmosphere display of Titan.
* Added handling zero duration goto object commands
* Fixed too aggressive rounding in time rate display
* Changed Windows solar system browser to ignore invisible objects
* Fixed precision problems in code to display location labels (that were
  causing jittering and disappearing labels.)
* Improved precision of LongLat object locations
* Made selection only work for currently visible (enabled) objects
* Windows: Fixed crash that occurred when star browser was closed
* Fixed bug that made moons disappear as a planet approached stellar transit
* Added a major update of the galaxy database such that close to 100% of the
  galaxies now involve distance measurements 
* Included the complete local group of galaxies 
* Added varying label transparency also for stars
* Added the PERL scripts used for extraction of galaxy and binary orbit data
  from scientific sources. They both are useful tools and a concise 
  documentation of Celestia's data
* updated binary orbit data (visualbins.stc and spectbins.stc) along with
  respective PERL scripts (visualbins.pl and spectbins.pl)
* Defined a lighting model to use for models that don't have normals (also
  prevents crash on Mac OS X version)
* Fade out orbits labels as their onscreen size shrinks
* Changed color of moon orbits
* cmod mesh format enhancements:
  - added point sprite primitive type (currently OpenGL 2.0 only)
  - added blend mode for materials
  - eliminated bug that caused a crash when loading submeshes with no primitive
    groups
* Improved conformance of generated GLSL shaders
* Mac OS X: star browser is now refreshed when it beomes active
* Fixed bug that limited virtual texture resolution on ringed planets
* Fixed bug with PNG image capture
* Minor moons:
  - Added new numbered Saturnian satellites
  - New IAU names for small satellites of Jupiter, Saturn, and Neptune
- Updated rotation rate of Nereid based on photometry
- Added new IAU names for features on Titan, Enceladus, Mars, and Venus;
  revisions to Mercury features
- Enabled line smoothing for markers
- Switched to double precision for rotation and precession periods--keeps
  synchronous rotations from drifting out of sync
* Celx scripts:
  - Added script for marking & red-shift coloring all 10000+ galaxies
  - Added script for marking all member galaxies of the local group
* Fixed crash when deepsky.dsc was empty
* Increased max draw distance to 100 Gly
* Modified the visualbin and spectbin databases to allow selection of the
  barycenters throughout. Commented out a number of binaries in spectbins that
  were also included in visualbins
* Mac: implemented tabbed browser interface
* Mac: fixed crash at startup on multicore machines with Lua edu tools
* Mac: fixed cmd+arrow infinite spin
* Mac: made DSOs localizeable
* Mac: fixed a crash when app is hidden at splash screen on multicore configs
* Mac: added multibyte console input
* Mac: minor fix for favorites bug
* Mac: removed Show Clusters menu item
* Mac: fixed crash on text enter after exiting full screen
* Added Orion's belt to constellation diagrams
* Orbit determination for Dysnomia
* Updated Ceres rotation period from Icarus 2007, 188(2):451
* New names for Saturnian satellites: Greip, Jarnsaxa, Tarqeq
* Switched to equatorial coordinates for Charon and Pluto orbits, to match Nix
  and Hydra
* New extrasolar planets: HAT-P-4 b, HAT-P-5 b, HAT-P-6 b, HS 16175 b,
 HD 167042 b, HD 74156 d, HD 285968 b, V391 Peg b,
 HD 132406 b, HD 43691 b, NGC 2423 3 b, Gliese 317 b & c,
 TrES-3, HD 155358 b&c, HD 5319 b, HD 75898 b, OGLE-TR-182 b, WASP-3 b,
 55 Cnc f, Lupus-TR-3 b, OGLE-TR-211 b, HD 156846 b, HD 4113 b, Kap CrB b, 
 GD 66 b, XO-3 b, WASP-4 b TW Hya b
 removed HD 33636 b
* Set up transit of Gliese 436
* Added setradius method for solar system objects to celx
* Added script commands to set label and line colors
* Added get/setgalaxylightgain functions for celx scripting
* Added gl.LineWidth function
* Eliminated 0.1 second delay in script startup, allowing scripts to run before
  first frame is rendered.
* Rewrote orbit cache for efficiency
  - Avoid unnecessary recaclulation of orbits
  - Prevents thrashing with multiple views
  - Added function to invalidate orbit cache
* Improved celestial grid
  - More meridians and labels shown
  - Better label formatting
* cel: URL fixes:
  - Added support for location selections
  - Fixed omission of star name in path for some objects
* Fixed small FOV bug when using Shift+Left button to zoom
* Display ambient light level when adjusted with { or }
* Improved star radius display
* Don't show irrelevant text for invisible objects
* Implemented adaptive tesselation for comet tails based on the size on screen;
  makes comet tails appear smooth when seen up close
* New label and line colors
* Fixed depth sorting problem for stars that covered less than a pixel
  in the view
* Fixed bug with bookmarks when selection is a DSO
* Centered constellation labels
* Added checkbox for star orbit rendering (all platforms)
* Added Scripts menu to quick launch scripts in the scripts directory
* Fixed index out of bounds error in SampledOrbit, SampledRotation
  (crashing bug)
* Added adaptive sampling for rendering elliptical orbits (more samples in
  regions of high curvature)
* Windows: fixed movie recording rate
* Windows: fixed unitialized variable that could cause wrong
translations to be used
* Changed pick code to select barycenter of distant star systems
* Windows: Fixed bug in popup menu and solar system browser with objects with
  empty name strings
* Windows: Fixed bug in 'Set current time' action for Windows Set Time dialog;   UTC to TDB correction was not being applied.
* KDE: Fixed cel URL handler to avoid opening of empty tab in Konqueror
* KDE: Fixed window being resized when URL is activated by another app
* Mac: Added more info to OpenGL Info window
* Mac: Added satellites submenu to context menu
* Added Julian date setting to Set Time dialog
* Bound Shift+K and Shift+L key combinations to adjust time by factor of 2
* Fixed pause behavior with cel URLs and bookmarks (non-Windows platforms)
* Include star system barycenters in cel URL paths
* Switched to double precision arithmetic for orbits to avoid rendering
  artifacts
* Use cubic interpolation for orbits paths to eliminate sharp angles when
  rendering them
* Removed fractional part in the display of galaxy light gain
* Fixed bug in calendar date calculation for negative Julian dates and
  dates far in the past or future.
* Changed quaternion slerp so shortest path is taken when interpolating
  orientations. Prevents extra spinning when using SampledOrientation.
* Implemented SampledTrajectory, a new trajectory type similar to
  SampledOrbit except with properties to control interpolation and precision.
* Fixed bug with showing labels of objects with empty name strings
* Replaced month number with name abbreviation in date display
* Fixed inconsistent operation of mouse wheel reverse flag
* Fixed some memory leaks
* Fixed depth sorting of labels for solar system objects
* Added capability to set default star textures via celestia.cfg
* Added RA/Dec to selection information (using observer centered coordinate
 system)
* Removed hardcoded limit on max number of nearby solar systems when rendering
  (fixes a crashing bug.)
* Added untranslated "Sun" name so that scripts and add-ons using that name
  aren't broken on non-English versions
* Added translation for "Milky Way"
* Perf: Rearranged some galaxy rendering code to increase performance
* Perf: Added code to skip deep sky object octree traversal when all deep sky
  objects are disabled.
* Updated stc parser to handle catalog numbers for OrbitBarycenter
* Added fade effect for constellation labels and lines when viewer leaves
  vicinity of Solar System
* Added support for showing reference vectors: frame axes, body axes, velocity,
  sun direction
* Implemented labels for markers
* Clamped simulation time to +/- two billion years
* Added hires textures to distribution
* New date/time formatting; date format setting added to config dialog
* Added child lists for stars
* Changed goto distance for stellar barycenters so that all child stars fit
  in view
* Fixed bug that caused solar system browser to come up empty if the observer
  was close to a star without a solar system.
* Fixed incorrect shadow count assert
* Fixed inappropriate Greek letter substitution in some object names
* Added definition for RingSystemSectinos to celestia.cfg
* Updated Great Red Spot longitude
* Updated Nix and Hydra orbits (new data from Tholen et al)
* IAU naming changes: Erriapo -> Erriapus, new spelling of Hyrrokkin
* Added new IAU names for features on Mars, Io, Europa, Titan, Venus
* New IAU name for Saturnian ring feature: Roche division
* Updated crater sizes for Gaspra
* Applied brown dwarf textures to type M brown dwarfs RECONS 2 and LP 944-20
* Mac: Ignore bodies with empty names in solar system browser
* Mac: Fixed POSIX locales by setting LANG at startup
* KDE: Star type saved in config file
* KDE: Save texture resolution setting to config file
* KDE: Added texture resolution setting to config dialog
* Windows: Removed unused Mark Features checkbox from Locations dialog
* Windows: Prevent crash on switch to fullscreen mode when graphics card or driver is
  changed between program runs.
* Windows: Automatically enable markers when 'Mark Object' is chosen from selection
  popup menu.
* Changed default rotation model to FixedRotation for objects without
  periodic orbits.
* Core: Default to the GLSL/OpenGL 2.0 render path if possible
* GTK: Save star rendering limit distance
* GTK: Add texture resolution setting to preferences and save value


1.5.1
* Added fonts for Russian, Chinese, and Japanese
* Updated translations
* Fixed date formatting for non-UTF8 locales
* Fixed crash for dates prior to JD -1.5 when local format is used
* Fixed star rendering for Macs with ATI graphics hardware (worked around
  a driver bug in point sprite support.)
* Fixed star glare clipping bug
* Fixed bug that caused some stars to be drawn untextured
* Fixed faster/slower options in the Windows time menu to adjust time by
  10x instead of 2x
* Fixed translation of time acronyms DST and STD
* Use localized versions of start script, guide, demo, license, and controls
  file from locale directory
* Fixed Windows 98/ME input problem; most keyboard commands weren't working on
  the OSes.
* Made Lua os functions available from celx scripts when access policy is "ask"


1.6.0
Bug fixes
* Fix to admit absolute directory notation in VT ImageDirectory
* Implemented encoding of special characters when saving cel URLs
* Fixed flickering of models with missing texture coordinates
* Fixed appearance non-ellipsoid star geometry in pre-OGL2 render paths
* Improved appearance of point stars when multisample antialiasing is enabled
* Fix for crash when viewing a star barycenter in an empty system
* Fixed off by one error assertion testing for number of lights used by shaders
* Windows: fixed UTF8 bugs in tour guide, star browser, and context menu
* Fixed crash bug that was triggerred by xyz and xyzv files with duplicate
  times
* Fixed bug that caused dim stars in orbits distant from the primary to not
  be drawn.
* Fixed strange appearance of cloud textures at times in the distant
  past/future.
* Fixed memory leak in multiview handling
* Fixed ambient light in the ARB shader path
* Fixed bugs in comet rendering (corrects overbright coma)
* Fixed code to compile without errors with gcc 4.3; fixed some warnings
* Fixed g++ compier errors in cmodfix tool
* Fixed search path for Lua scripts
* Fixed numerous bugs that occurred when an object's orbit center was different
* Fixed a bug in the celx function celestia:getscreendimension
* Fixed bug with returning Hubble type for galaxies 
* Eliminated error-prone min/max macros; use STL functions instead
* Fixed discrepancy between apparent magnitudes shown in the 3D view and
  the star browser.
* Change "Day Length" string to the correct and more general term "Rotation
  Period"
* Show 'planetary companions' message for stellar barycenters (instead of
  just stars.)
* Improved location drawing so that location labels can be occluded by
  foreground objects.

Data file updates
* Implemented data base globulars.dsc with all known 150 globulars around the Milky Way
* Renamed galaxy database deepsky.dsc into galaxies.dsc
* Implemented SIMBAD compatible cross-listing for globular clusters
* Updated Iapetus texture based on a new Ciclops map from Oct 2008
* Significant update of the database on binary orbits, including SIMBAD
  compatibility of barycenter nomenclature and alternative names
* Updated the near stars catalog
* Updated texture for Mercury; includes imagery from MESSENGER
* Updated textures for some Saturnian moons: Tethys, Dione, Mimas,
  Enceladus, and Rhea
* Added CHARM2 catalog of measured stellar radii
* Added model of asteroid Itokawa
* Regenerated star catalog using the new reduction of the HIPPARCOS data
* Cassini updates:
  - Updated Cassini trajectory to include extended mission
  - Switched to using xyz+velocity files for a more accurate trajectory
  - Separated Cassini mission into cruise and orbital phases
  - Improved appearance of Huygens separation from Cassini
* Added IAU rotational elements for most major solar system bodies
* Made visible the orbit and label for Pluto-Charon barycenter
* Correctly centered Galileo spacecraft
* Rebuilt cross-indices from SIMBAD data
* Added alternative names for many solar system bodies (e.g. preliminary
  designations for asteroids in addition to proper names.)
* Updated extrasolar planet catalog with discoveries made up to Apr 2009
* Changed class of Pluto, Ceres, Eris, ... to dwarf planet
* Changed class of small outer planet moons to minormoon
* Included new and updated solar system body features from the IAU
* Added provisional rotation period for Eris
	
Tools
* Added Perl script globulars.pl used to extract the globular data from scientific publications and as documentation 
* Added spice2xyzv tool for extracting xyzv files from a pool of SPICE kernels
* Added Perl script to build cross-indices
* Added Perl script to generate CHARM2 catalog
* Added Perl script to build star database

Platform-specific changes
* Mac OS X: Fixed rerun script menu item
* Mac OS X: fixed issue with some checkbox settings not getting saved properly
* Mac OS X: Fixed potential crash in eclipse finder if the user specified
  an object that wasn't a planet or moon
* Mac OS X: Fixed keyboard shortcuts not working when GL window not frontmost
* Mac OS X: eliminated beep when clicking splash screen on multi-core machines
* Mac OS X: fixed compiler warnings, removed -fpermissive flag
* Mac OS X: Refactored Mac disk image build into separate target, made default
  builds more efficient.
* Mac OS X: Fixed bug where time zone was ignored when setting time zone
* Mac OS X: look for user config file in ~/.celestia.cfg
* Mac OS X: Fixed blank names for location bookmarks
* Mac OS X & Windows: Added texture resolution setting to GUI
* BSD: Fixed tm_zone handling
* Linux: Install scripts at during "make install"
* Linux: Added workaround for broken include_x11 define from acinclude.m4
* Linux: Updated admin directory to KDE 3.5.10, regenerated acinclude.m4
* Linux: Added the missing menu entries related to globulars for KDE version
* Linux: Added globular and grid selection options in GTK interface

Internationalization
* Added Polish translation
* Added Lithuanian translation
* Added Romanian translation of constellation names
* Mac OS X: Japanese localation of eclipse finder added
* Added Chinese localization
* Localize surface names in alternate surfaces menu
* Prevented English name 'Milky Way' from being displayed when a translated
  version is present.
* Extended localization to DSO and star names

Features
* Added light from secondary sources (i.e. "planetshine")
* Implemented depth sorting for markers so that they are correctly occluded
  by foreground objects.
* Implemented code package rendering globular clusters
* Implemented new cel URL version with observer position and orientation stored
  in frame coordinates (for forward compatibility)
* Added a long term (+-5000 centuries) precession model for Earth based on
  work by Jan Vondrak
* Improved celestial coordinate grids:
  - Added new grid types: ecliptic, horizontal, and galactic
  - Made grid resolution adapt to the field of view
  - Positioned coordinate labels at edges of field of view
* Added animated selection indicator
  - Switches to direction pointer when the selection is off screen
  - Changes color when the selected object is occluded
* Implemented more flexible system for reference marks and added new
  reference marks:
  - Planetographic grid
  - Terminator
  - VisibleRegion
* Enabled display of the phase angle for the currently selected object
* Improved eclipse rendering: correctly calculate depth and umbra radius
  for eclipses.
* Improved star handling code so that stars can be placed more than 16k light
  years from Earth.
* Switched to using sd prefix for hot subdwarfs per arXiv:0805.2567v1
* Added symbols for locations

Add-on features:
* Added SemiAxes property for ssc objects, which allows triaxial ellipsoid
  geometry for solar system objects like Haumea and Mimas.
* Added new boolean properties for ssc/stc/dsc objects: Visible and Clickable
* Added new classes for solar system objects: dwarfplanet, minormoon,
  surfacefeature, component, and diffuse
* Implemented Modify and Replace dispositions for star catalogs
* Added SPICE rotation model, allowing the orientation of an ssc object to
  be controlled by a SPICE frame.
* SPICE orbit improvements:
  - Allow multiple kernels to be specified for a SPICE orbit
  - Automatically calculate start and end times when possible
* Added Timeline, which allows multiple frame, trajectory, and rotation
  models for a single ssc object.
* Implemented CustomRotation, the rotation model analogue of CustomOrbit
* Added support for InfoURL for stars (already exists for deep sky objects and
  solar system objects)
* Improved SampledTrajectory to handle files with positions and velocities
* Added LabelColor property for locations
* Implemented new Topocentric frame (a simplified two vector frame for placing
  objects on the surface of a planet.)
* Added support for premultiplied alpha blend mode in cmod files
* Extended FixedPosition to support spherical coordinates as well as
  cartesian coordinates.
* Added FixedAttitude rotation model, with more intuitive paramters for
  orientation
* Added new SurfaceObject type for ssc files--like an ordinary body except
  with different default frames that make it easy to position an object on
  the surface of a planet.
* Added CloudShadowDepth property for atmospheres
* Improved control over mesh scaling with NormalizeMesh and MeshScale
  properties for ssc objects.
* Added new locations types: eruptive center, insula (islands), and
  tholus (domical hills and mountains)
* Added support for comment headers in xyz and xyzv files

Code optimization and reorganization
* Reimplemented observer frames in terms of Celestia 1.5.0 frames
* Improved performance of complex frames by caching last calculated orientation
* Added velocity method for all classes derived from Orbit
* Added angularVelocity method for rotation models
* Optimized solar system rendering by maintaining a bounding sphere hierarchy
* Switched to using 2 64-bit integers for storing high precision coordinates;
  simplifies code and improves performance of operations using high precision
  coordinates (dramatically on 64-bit systems)
* Optimized creation of render lists

Scripting
* Celx scripting functions:
  - object:addreferencemark, object:removereferencemark
  - object:visible, object:setvisible, object:catalognumber
  - object:setorbitcolor, object:orbitcoloroverridden, object:setorbitcoloroverridden
  - object:orbitvisibility, object:setorbitvisibility
  - object:locations (returns an iterator over all the locations associated with an object)
  - new phase object type (for timeline phases)
  - permit any X11 color name
  - observer:makeactiveview
  - showconstellations, hideconstellations, setconstellationcolor
  - getlabelcolor, getlinecolor
  - getsystemtime, ispaused
  - gettextureresolution, settextureresolution
  - windowbordersvisible, setwindowbordersvisible
* Split celx scripting support into several modules
* Cel scripting
  - splitview, deleteview, singleview, setactiveview 
  - setgalaxylightgain
  - setradius
  - setlinecolor
  - setlabelcolor
  - settextureresolution
* Made the package library (except loadlib) available for celx scripting
  regardless of the ScriptSystemAccessPolicy setting
* Added an "AddonPath" value that is available to a ScriptedOrbit or
  ScriptedRotation when it is created.
* Pass control modifier to Lua keyboard handlingfunctions

Miscellaneous:
* Bound P and M keys to toggle dwarf planet and minor moon labels
* Bound U and E keys to toggle globular clusters and globular cluster labels
* Group reference mark menu items in a separate submenu
* Changed star name lookup priority in stc parser: check proper names before
  cross indices.
* Eliminated R and Shift+R key bindings for changing texture resolution
* Added new leap second 31-Dec-2008 23:59:60

Cleanup:
* Removed obsolete 'LabelledStars' section from standard celestia.cfg
* Updated README: removed obsolete sections, reorganized credits, added
  information application to 1.6.0
* Purged out of date controls documentation
* Reorganized spacecraft add-ons in standard package
