generalized Plugin(Extract) so that we can also create vector views

better docs

quick generalization of Plugin(Extract): we can now extract arbitrary
combinations of the field's components

small tweaks

missed those files in my previous commit

- added hacked version of the GNU matheval library to evaluate parsed
  functions efficiently ("a la getdp", but faster): I added a new
  directory (gmsh/MathEval) with that code, as well as a new configure
  option and a new define (HAVE_MATH_EVAL)

- generalized the plugin option code to accept arbitrary string options

- new plugin Plugin(Evaluate) that can evaluate arbitrary functions on
  scalar views (useful for example to create background meshes)

PS: Everything (octree + function evaluation) is now in place to write
a general plugin that can make any operation between arbitrary
views...

added comment about unknown origin of the code

pretty print

pretty print

pretty print

pretty print

pretty print

- cleaned up the octree code (renamed some files, added copyright
  notices, indented everything)

- backported JF's doc from the texinfo file into the c++ code (the
  documentation is actually generated automatically by Gmsh with
  "gmsh -doc"!)

- replaced nPoints with nPointsU and nPointsV in CutGrid

- fixed a couple of printfs + removed some unused variables

- Fixed second order mesh generation in 3D (on simplices only at the moment).

- In prevision of the extension to hexas, prisms and pyramids, all elements
are now derived from a new Element base class, which will be used in the
generalization of Edge/EdgesContainer in the future.

missing return in case of error

pretty print

Added automatic documentation generation for plugins

- better file names for views created by plugins
- use the file name as a guess for view_save_{ascii,binary}

forgot to remove debug printf

make depend

typo

New plugin "Plugin(Extract)" to extract the i-th component of a field

-D_BIG_ENDIAN conflicts on SunOS -> changed our last -D_XXX definitions to
-DHAVE_XXX

Update copyright notice

Fixed (or added a FIXME comment) when a post.list reallocation
could lead to problems

small changes to copy the time values (instead of relying on EndView
to just add the time step number)

Following a discussion with Laurent, we can now combine multiple views
(under certain conditions) into multi time step ones. This permits e.g.
to output separate .pos files for each time step, and still have a real
time evolution in gmsh. Pretty neat :-)

Fixed race condition for RemoveView

Fixed bug in DecomposeInSimplex (need to set deleted non-simplex lists
to NULL)

Fixed missing exception handling for PluginManager::action() (this led to
a crash when General.DefaultPlugins==0).

- new DecomposeInSimplex plugin
- new "Combine Views" command in the parser
- cleaned up View::tranform and View::smooth (+small bug fix for SLs)
- better check for transparency sorting
- make depend
- new View.AlphaChannel option to change the transparency
  globally for a given view (instead of having to change the colormap
  by hand every time)

With all the above, we can now generate very nice (and correct)
transparent iso-surfaces:

Merge "../tutorial/view3.pos";

minIso = 0;
maxIso = 2;
nbIso = 7;

Plugin(CutMap).iView = 0;

For i In {1:nbIso}
  Plugin(CutMap).A = (maxIso-minIso)/nbIso * i;
  Plugin(CutMap).Run;
EndFor

Delete View[0];
Combine Views;

For i In {1:nbIso}
  Delete View[0];
EndFor

Plugin(DecomposeInSimplex).iView = 0;
Plugin(DecomposeInSimplex).Run;

View[0].AlphaChannel = 0.6;

Make Skin a little bit more efficient by allocating/copying the values
only if the face is not found in the tree