optimize geojson writer

Conversion from double value to char representation
is killing performance. This change replaces ostreams
with string appends to speed it up.

Change-Id: Ice0e8694deeb8898340dd7c989689aa4511c7fb4
more optimization of geojson writer

Move from strings to sprintfs to be faster still.
Requires manual buffer management of course.

From here we have to move to bson and then to
more compact representations.

Change-Id: I043fe5e4b3308449ac30092fa7128c7475ff47d8
Fix bug in picking of invisible props in an assembly.

This bug was described in
http://paraview.org/Bug/print_bug_page.php?bug_id=9459
When a actor in an assembly is hidden it may happen that it can
be picked anyway. To fix that we make sure the prop is
visible and pickable before performing the pick rendering pass for it.

Change-Id: I0c546d68ffe41cce956f7a59e8c8b4defeddb0c0
First pass at a new render widget

Still not complete, using GLEW for OpenGL extensions, and an X
implementation that uses more recent API to create OpenGL contexts
including OpenGL 3/4 if the required extension is present. This also
used XLibs directly for interaction, rather than going through Xt.

It needs a little more work to actually hook up something that will
render to the context, but it shows a great black window right now!

Change-Id: Ida0be9f2e9dc11ba3253ffd18cffa2e983ec954e
Implement a basic VBO based poly data mapper

This makes use of the code developed for the scene, but ports it to
a more direct use of VBOs in the derived poly data mapper.

Change-Id: Idb0db244abbb0e6857818589b20aae22e10abd53
Basic support for color from property

Change-Id: I3c62b6ce39afcb3f1abe59811f89e9064b23456d
ENH: Rename nodes to points in vtkStructuredData

Modified the function names in vtkStructuredData to use "points"
instead of "nodes" in order to be consistent with the rest of VTK.
Further, updated all affected code that is using vtkStructuredData
to reflect this change.

Change-Id: Iad0a876b49e0b5439e47b963c73885c2ade3c0d6
Add the find module for Eigen 3

Change-Id: I1399f62495478622892247f8f1f9c6351c28cbba
Added a hack to override OpenGL overrides with GL2

This adds VTK_REPLACE_OPENGL_OVERRIDES (off by default) as a build
option, if enabled the vtkRenderingOpenGL module will be modified to
depend on vtkRenderingOpenGL2 (privately) and its overrides modified
so that we can replace existing implementations piece by piece while
running the full suite of regression tests (and seeing how close the
drop in replacement classes are).

Change-Id: I6decb741bde86270c43578e1b24dca4058de6781
fix potential segmentation fault

If one table and one tree were requested as output from
vtkRCalculatorFilter, its output would be a vtkTable or vtkTree.
It actually needs to be a vtkMultiPieceDataSet to contain both
objects though, and this would result in a segmentation fault
shortly thereafter.  This commit fixes this degenerate case
and adds a test for it.

Change-Id: I53e468bba2e2d336dc7a4a7f9fb53fdcb64f98b6
some rough changes to the VBO polydata mapper
some more cleanup
added light override
BUGFIX: Fix issue with unigrid enzo datasets

Fixed issued with unigrid enzo datasets. The reader
was calculating number of levels to be 0, which was
leading to a segfault. Added code to detect unigrid
datasets and fixed the issue by setting the number
of levels to 1.

Change-Id: Ie9f1fbe8c3c38c69e5761b357256be9531ed10f3
compute cam matrix, add posiitonal light in progress
updates to support positional lights
Filters/Geometry: Remove some unused functions from tests

Change-Id: Ic1ae3928ee171531136d42630fec6484eb0a9cbd
Filters/Geometry: Hide WriteGrid if ENABLE_IO isn't on

It is unused otherwise.

Change-Id: Ic13a1e15ae2dd121b0122e7b520551184da57e2c
Roughly mapping the colors/scalars, updates to shaders

Attempt to map the colors/scalars, and adjust the shader according
to whether color is a uniform or an attribute. Added some logic to
deal with building normals as the painters do, but error out for
now. This is also not even close to dealing with cell colors and/or
properties.

Change-Id: If584570b71dca4db3e9fd6c4ad95af58c00dea32
Clean up vtkMedicalImageProperties PrintSelf.

Change-Id: I721d91a75a04f485a34aeed9fa04b154d892b1f8