------------- Version 0.6.0

- completely rewrote STL-export- and OpenGL-display-code, they do now share a
  common base.  With this the following features come:
  - STL export for all grids, including hollow shapes for all grids
  - STL export preview in the STL export window, you see exactly what the STL
    shape looks like
  - for the programmers: it has become simpler to support new grids all polygon
    based grids now can create proper STL output and code for the 3D display
    much easier, grids like the spheres stay complicated, though
  - bigger sensitive click spots for spheres, they also look better
  - in the 3D view you can see the natural color and the color constraint color
- improved STL export window (tooltips, ...)
- STL export displays the exact volume of the generated object
- fix a problem loading puzzle files with complex groups
- add a new way how opjects are rotated in the 3-D viewer
- make cimpilabe with gcc-4.4 and fltk-1.3
- deleting the last shape crashed the program


------------- Version 0.5.2 Oct 2009

- spheres can now be hollow with a hole to the outside (thanks to George Bell)
- new feature in movement browser: push and pull pieces by clicking tonto them
  (thanks to Barry Downes)
- fix an STL export bug resulting in somtimes double face output
- fix a bug in the assembly import that made sphere amost always crash the program

------------- Version 0.5.1 Apr 2009

- fix a rounding bug in sphere transformation resulting in missing solutions
- fix a crash when opening the status windows with sphere grid
- deactivate movement browser when not available
- fix possible crash when minimizing shapes
- fix documentation formatting for legal paper (was still A4)
- slight update of documentation (e.g. movement browser)

------------- Version 0.5.0 Apr 2009

- fix problem in the rotation filter when 2 mirror shapes were assigned to a
  problem with different ranges. In that case some solutions were not found
  when the mirror check was enabled
- new grid: tetrahedra-octahedron
- basic movement analysis for triangle grid allowing to analyse puzzles without
  coordinated motion
- add scrollwheel support for 3D view zoom
- a lot of cleanup in the disassembler functions
- converter from cube to rhombic grid and from cube to tetra-octa grid
- remove 256 piece limitation for disassembler
- add a simple movement browser to analyse the movements of pieces in an
  assembled puzzle
- more memory efficient disassembler, which means you can analyse puzzles with
  more movement without running out of memory
- the command line tool (not in the windows binary distribution) can now print
  some information about a puzzle file
- add lots and lots of code comments in the hope someone may need it, doxygen
  comments for the library are added in many places
- different config file format (the old one is thrown away) this new format
  will allow more easy additions
- faster sorting method for solution sorting
- fix a cursor drawing bug in the rhombic grid
- a new console application that can solve puzzles and actually saves them
  (this application is not included in the windows binary package)
- fix potential symmetry calculation problem with the rhombic grid
- cube disassembly analysis should be a tiny bit faster
- explicitly limit colours to 63, the user could add more but it didn't work in
  older versions
- better compression for XML files, should result in smaller files although not
  that much
- millability and notchability in status window
- rewrite XML loading and writing code, this code is faster and compacter and
  uses much less memory so saving and loading puzzles is much quicker now
- the printable userguide is back download it separately from the burrtools
  website, it is better than ever
- remove windows installer (it was buggy and noone cared to tell me, so now
  only the zip is left, which I can verify)
- add a function to convert assemblies into shapes and add those to the puzzle
  various filters can be applied
- add a new, more CPU intensive but more thorough check for rotated, translated
  solutions, which can be used with the assembly import to get a usable piece
  generator
- status window information calculation is much much faster and will not longer
  get slower with each additional shape

------------- Version 0.4.2 Jan 2009

- Fix a bug in symmetry avoidance algorithm that could result in too few
  solutions found. The problem occurs if you have result shapes that don't have
  a direct mirror (only mirrors + rotations) symmetry
- Fix a crash that happened when selecting a z-layer when no shape is there

------------- Version 0.4.1 May 11 2008

- Fix bug in rhombic grid solver. The solver could not solve the trivial case.
  This could lead to not found solutions with very simple pieces
- Less restrictive 255 piece limitation. Assembly is now allowed again
- Fix some typos

------------- Version 0.4.0 Apr 04 2008

- a new space grid: rhombic tetrahedrons. With this grid it is possible to
  build a lot of the Stewart Coffin puzzles and also puzzles with diagonally
  cut cubes
- STL export improved
  - can now export binary STL files which are much smaller
  - can now export puzzles that use the sphere grid
- shapes can be removed using the status window making it easier to spot
  duplicates and remove them
- a new possibility to export images. It is now possible to export the current
  display within the 3D window into a vector graphic file like SVG
- the help is now available within the program instead of a separate PDF file.
  It includes the complete texts from the UserGuide including all images. For
  those that want to print the texts it is possible to export the help to the
  harddisk.
- a function to fill holes in shapes
- a lot of internal cleanup this also includes a possible speedup for the 3D
  view
- the window position was saved at shutdown of the program but not properly
  restored. Now it is

------------- Version 0.3.1 Jul 29 2007

- new edit method. It is now possible to add voxels by clicking into the 3d
  view.
- OpenGl libraries were not properly found on some UNIX systems
- solving a puzzle will trigger save warning when exiting
- fixes in new assembler
  - sometimes it found no solutions even though there were some
  - better work selection heuristic resulting in speedup in some cases
  - fix mirror problem causing calculation abort with some mirror
    constellations
- Joe Becker edited the whole userguide
- fix possible crash with very large grids
- build improvements
  - better crosscompilation possibilities
  - don't build table generators, when tables are up to date
  - NSIS script
- add a missing symmetry for triangles
- fix a crash when having empty sphere grids in problems
- fix crash when animating a solution that has been removed by the ongoing
  solving

------------- Version 0.3.0 Jun 13 2007

- a new assembly algorithm that is much faster with puzzles with many
  multipieces and that has many new possibilities for the future. The old one
  will stay for simple puzzles because it is faster in those situations
- piece ranges. It is now possible to specify a range of pieces to use to solve
  the puzzle
- fix memory leak when counting assemblies
- fix some more problems with certain kind of mirror solutions
- it is now possible to keep mirror solutions, if you wish
- improvements to image export:
  - better layouting of images
  - easier adjustment of zoom level
  - generate assembly and disassembly image sequences
  - fix bug with problem selection

------------- Version 0.2.3 Apr 21 2007

- fix another problem that resulted in too many solutions removed for puzzles
  with mirrors

------------- Version 0.2.2 Apr 15 2007

- fix problems with mirror solution detection that sometimes removed too many
  solutions
- fix compilation on non x86 CPUs, properly use the canonical system name and
  enable assembly functions only when the code works on that CPU
- (hopefully) fix a hanging program that sometimes occured when the prepare
  button was used

------------- Version 0.2.1 Mar 21 2007

- add many new symmetry groups, many thanks to Markus Götz
  - 3 new cube groups added
  - 45+4+16 new sphere added
  - 2 triangle groups removed
- add a red - blue/green/cyan 3D mode
- fix some bugs with sphere puzzles:
  - placement browser didn't work properly
  - shapes are now centred and don't jump around when adding new spheres
  - some puzzles where unsolvable due to internal shortcommings
- add a progress display for the creation of the status window as calculating
  the information in the status window might take quite some time
- show the actual symmetry group number in the status window and "---" when the
  group is unknown
- when status window is open you can no longer do anything else, this is better
  because the status window is not updated when editing
- proper display of the degree symbol in the tooltips for the rotate buttons
- the zoom slider zooms much larger
- huge speedup in preparation time. The program used to do a lot of unnecessary
  checks at the start. Now only the required ones are left
- lots of internal cleanup in the gui code
- add code that comes from FLU into the source. This will make compilation on
  UNIX system easier as FLU is not a standard library available on many systems
- improved build system to install the documentation and leave out the headers
  for the library
- BurrTools now adds a default rule with each added colour and upon creation of
  the problem it adds rules for all defined colours
- fix an assert, when problems contained empty shapes
- the check for mirrored solutions was not always enabled when it was required
  resulting in additional solutions
- the mirror check was not able to correctly handle 2 pieces of identical
  shape. They should not be there but when they are they are now handled right

------------- Version 0.2.0 Feb 11 2007

- write required base for other space grids and partially implement triangular
  prisms (no disassembling right now)
- STL (3D printer format) export. It is now possible to export cubes into a
  file suitable for 3D printer for rapid prototyping
- implement a status window that displays all kinds of useful and not so useful
  information for all the shapes in the puzzle
- new functionality for solver tab:
    - sort solutions in different ways while solving
    - sort after the solving has finished
    - remove single and multiple solutions
    - add and remove disassemblies to save memory
- give pieces a weight so that the disassembler knows which pieces have
  priority when they get moved. This way you can make the box fixed for the
  disassembly animation
- new disassembler, for complex disassemblies it is quite a bit faster and
  consumes less memory. But this will probably not show in most puzzles.
  This disassembler also never moves 2 pieces by different amounts at
  the same time, e.g Piece1 by 1 and Piece2 by 2 units. It is also finds
  now all possibilities to move groups of pieces. The old one used to
  oversee a few chances to move 2 or more pieces at the same time. This
  might slow down the disassembler when many choices exist.
- new data structure for the disassembler. This structure should make the
  disassembler a bit faster
- new disassembly animation. This is used in the image export to produce image
  sequences where the action always takes place in the middle and thus is much
  better visible
- smaller optimisations for preparation and assembly phase (around 10% speed
  improvement)

------------- Version 0.1.9 May 06 2006

- the fade out of pieces that are removed in the assembly animation can be
  turned on and off
- Add possibility to GUI to edit the comment included in a puzzle
- another 3 symmetry groups were missing
- fix: don't try to disassemble 1 piece puzzles
- properly exit when pressing the close x in the window header
- fix crash when removing the last colour
- the marker in the block lists is better visible
- drawing modes from PuzzleSolver3D
- ticks for the z layer selector in the grid editor
- better cursor in 3D view
- disassembler improvements (better move generation, merge, when x pieces move
  the same amount in the same direction, unmerge, when they move a different
  amount
- lots interface changes with icons from Ronald Kint-Bruynseels and many new
  functions to ease the drawing of puzzles
- independent zoom levels for the 3 tabs
- when making the piece numbers start with 1 I missed a few places
- plug a memory leak that hit when having a lot of assemblies
- make it possible to exchange shapes, problems and positions of shapes inside
  problems without destroying found solutions
- shapes can be named. If they have a name it is used in most places, where the
  name is useful. If no name is given shapes keep the numbers as usual. If you
  want the remove a given name just enter an empty text Problems are treated
  the same way. They don't need to have a name.
- huge speed improvement for the assembling of puzzles with many identical
  pieces. The time for JayCube, for example, dropped on my machine from 2.5
  hours to 7 minutes. The disadvantage is that you can not continue old saved
  puzzles.
- Implement "Automatic Clumps". The idea is taken from an article by Frans in
  the CFF 69. It comes from Bill Cutlers puzzle programs. The idea is to join
  cubes that always have the same state: meaning they are always all empty or
  all contain piece x or all contain piece y and so on.  Instead of treating
  them one by one, they are now joined.
- Huge speed improvement in the preparation phase. This is especially visible
  to puzzle where many "false" placements of pieces are possible when you just
  look at the result shape and the piece. A "false" placement is a placement
  like the middle position in a 6 piece burr that can never result in a proper
  solution. These false placements can now be removed much more efficiently
  before the more expensive check starts resulting in less work for the
  expensive checks and in speedup.
- handwritten machine level code for time important functions giving another
  20% speed gain for calculation intensive assemblies
- pieces are no longer minimised when a puzzle is solved. This has been in the
  program only because the program couldn't handle that properly
- fixed bug in rotation suppression. Sometimes the program would find rotated
  solutions. Even worse, that was dependent on the orientation of the pieces
- improvements to 3D view: no wideangle distortion when viewing big puzzles, no
  colour changes when zooming objects, slightly transparent pieces no longer
  "hide" some pieces behind them
- image export to create images of shapes, problems or solutions with complete
  assembly instructions with a few options to influence the resulting image(s).
  More development is going to come here.
- sometime loading of saved assembly states failed making a resume impossible,
  the saving was ok, there was an error when reading the data. So if you have
  files like that that didn't load properly you can give it a new try with this
  version

------------- Version 0.1.8b Nov 27 2005

- Fix Bug found by Markus Götz that made the program crash, when all piece
  were cubes
- Fix a bug found by Primitivo Familiar Ramos. The problem- slider on the solve
  tab didn't work
- also implement some suggestions by Primitivo: start counting from 1, unify
  tool tips, fix some spelling errors
- empty status bar when activating solve tab, as the information got stale
  (found by Peter Knoppers)

------------- Version 0.1.8a Nov 13 2005

- when the program crashes it tries to show some information and it also tries
  to save the current puzzle into __rescue.xmpuzzle. Please follow the
  instructions in this window and send me the information.
- when reducing show the piece that is worked on to show that something is
  going on
- Placement browser lets you see at what positions a certain piece fits into
  the resulting shape. Attention, read the documentation about this
- Documentation updates. Some of the internals are described. I was also able
  to bundle some puzzle designs with the program so that you have something to
  play with right after installing the program.  Many thanks to the designers
  for allowing me to include their designs.
- Suppression of rotated and mirrored solutions. The program now wont find
  rotated and mirrored solutions any longer (at least I hope that it does
- configuration file. The position of the window is saved, you can also toggle
  tooltips and switch off the light in 3D view resulting in a completely even
  and very light colours for the pieces
- better groupings. It is not possible to assign multiple groups with a count
  to each (set of) pieces. The meaning is defined like this. There can be UP TO
  the specified number of pieces in this group. This is not required, but when
  needed it is used. This may be useful if you don't know which pieces belong
  to which group. Say you have a puzzle of n identical pieces and all you know
  is that it can be disassembled into 2 groups but you don't know how large
  these groups are. Then you simply assign 2 groups to the pieces and in each
  of these 2 groups can go n-1 pieces.
- add possibility to swap 3D view and edit grid in the shape edit tab.  This
  gives you a bigger grid to edit bigger puzzles
- reverse meaning of the slider in the grid editor
- fix bug in minimise causing crash when executed on empty shapes
- solution selector can take the focus, so you can use the cursor keys to go
  through solutions
- more clean design for the grid editor, no more left and right mouse clicking
- some key-shortcuts: F4 toggles 3d and grid view, + and - change edit layer,
  F2 saves and F3 loads a file
- sort solutions by number of moves required the completely disassemble
- show the complete number of moves required to disassembler, and the level of
  the puzzle
- cursor for 3D-View
- Variable cubes are now normal sized cubes with a black square
- remove a colour deletion problem
- when the tab was dragged so that the 3D-view became invisible (0 pixel width)
  the programm abborted

------------- Version 0.1.7 Aug 19 2005

- last version missed the placement optimisations for pieces resulting in an
  eternal solving time for some more complex puzzles like Bill Cutlers SM or
  Lovley18. This version switches the optimisations back on, that makes some
  puzzles a bit slower but on the other hand the solving time for some complex
  puzzles drops down considerable (from years to hours)
- huge speedup for the disassembler for puzzles that have lots of assemblies
  for EasyLiving for example only 25% of the time is left (time dropped from 24
  to 6 seconds) and also for complex puzzles like Pelikan Burr time dropped to
  66% (from 5.5 to 3.6 seconds)
- new editing possibilities: drag to fill rectangles and a button that makes
  your changes not just to the current layer but to all
- add possibility to load PuzzleSolver3D filed (this can be done with the
  "Import" entry in the main menu
- add function to make it possible to not completely disassemble the puzzles.
  This is done by putting pieces into groups. All pieces that are in the same
  group can stay together and the puzzle is still considered as disassembled.
    Group 0 is different. All pieces in group 0 need to be taken apart until
  single. You can set the group for each piece with the G+ and G- buttons in
  the problem tab
- when puzzles where saved before a result shape was defined the program
  refused to load the file. This works now. Old filed can be loaded as well
- small correction to the 3d view. Cubes besides variable cubes had missing
  faces

------------- Version 0.1.6 Jul 10 2005

- add button to change colour
- documentation update
- add a lot of comments
- make "just count" work
- enable time display and estimation
- thread fix for win 9x
- load of bad files no longer aborts program but show message

------------- Version 0.1.5 Jul 10 2005

- no editing of problem while solving
- assembler status in file contains version
- error message, when failed to load
- remove solutions when editing
- variable cubes are not allowed in piece shapes
- memory leaks, uninitialized variables, other misc. valgrind messages
- update interface when solution has anded and reenable everything

------------- Version 0.1.4 Jul 6 2005

- more aggressive reduce, may take a bit longer but still faster than the
  original one that took ages for some puzzles
- valgrind fixes for memory frees and uninitialized memory
- the assembly state can now be saved and resumed so you can top the
  calculation save and resume where you left off the next day
- new disassembly engine that is much faster for complex puzzles but a bit
  slower for simple to disassemble puzzles
- faster disassembler preparation making the disassembling for simple problems
  much faster
- better voxel space drawing, including all edges
- voxel space can now also draw the constraint colours besides the shape colour
- add toggle button on a status bar to toggle between piece and constraint
  colour
- separator text size was sometimes calculates wrong
- add web address to about dialogue
- populate the status line with some information

------------- Version 0.1.3 Jun 26 2005

- buttons use up frame now
- doc update
- make it possible to stop while preparing the assembler, you just have to wait
  for it to finish. Before that the stop button was ignored while in
  preparation
- piece fit test speedup. This should improve preparation speed
- when selecting a shape in the list that lists the piece and the piece count
  for the current problem, the corresponding piece gets selected
- about box
- problem renaming
- when something is not right with the puzzle a message box appears now instead
  of a hang in the GUI
- set the z-layer of the shape editor to 0 on new shape
- bugfixes

------------- Version 0.1.2 Jun 21 2005

old versions

