CMake 3.12 introduces a `...<max>` syntax in the version given to
`cmake_minimum_required` to automatically set policies to NEW up
to that version.  Use it to avoid listing policies explicitly.

The syntax is compatible with older versions of CMake such that they use
the extended version string for the `CMAKE_MINIMUM_REQUIRED_VERSION`
variable (which we don't use) but otherwise ignore it.

With VTK new version, find_package cannot find VTK_RENDERING_BACKEND
properly. The solution is to call find_package(VTK REQUIRED) first, then
use vtk_module_config to load the needed modules. Some typos are also fixed.
For Statistics example, the SetInput function is replaced by SetInputDta
function(See vtkTableAlgorithm class).

Code extracted from:

    https://gitlab.kitware.com/third-party/proj.git

at commit 41bdf05361007f8c5186f3df9944d86bb273ed13 (for/vtk).

Change-Id: I5eadbc3da480bb19db9b99f5c648ff1d3fe2316c

This makes VTK's configure much faster.

Change-Id: I879b52ec0caa569375661cdb21c51dacd4859575

Change-Id: I10a54acbd076e055d8071414f2fff1ebafe1653d

CMake 3.0 introduces these policies to improve default behavior on OS X.
Set them explicitly in VTK to avoid policy warnings.  VTK already works
with the NEW behavior.

Policy CMP0025 affects the project() command when the Apple Clang
compiler is used so we need to set it in all the Examples.  Policy
CMP0042 affects shared libraries on OS X, enabling MACOSX_RPATH by
default.  Set it in directories where we create libraries.  Also tell
KWSys to enable MACOSX_RPATH explicitly instead of setting the policy.

Change-Id: I543b60ee1b8f629adb150e01ee83d99dddb66f46

This approach demonstrates good programming practice by only
linking to the needed modules.
It also removed the need to set CMP0020 to NEW in all cases
except those examples that link to Qt.

The include(${VTK_USE_FILE}) has been removed from the
top-level CMakeLists.txt file as it is unnecessary.

The solution presented here will work with the Examples built
as a stand-alone folder or within the VTK tree or with the
individual examples.

They have been tested on Linux, Windows VS2012 Express,
Mac OS-X 10.9 using Qt5.1.1.

Change-Id: I0572a395b2ebc6630db8c1407f410a584f668a85
Signed-off-by: Andrew Maclean <andrew.amaclean@gmail.com>

If VTK is built with Qt5 and CMake >= 2.8.11 CMP0020 warnings are generated
 in these examples. Setting CMP0020 to new eliminates these warnings.

This warning happens because the examples link to ${VTK_LIBRARIES}
which, inside the VTK build tree, is all libraries built including
those that use Qt.  The policy is set as a workaround in these cases.

A future submission will modify these and other examples to just
use the needed libraries.

Change-Id: Iea460773065ed55880b198eeaeec3da3b711c258
Signed-off-by: Andrew Maclean <andrew.amaclean@gmail.com>

With BUILD_EXAMPLES:ON and BUILD_TESTING:OFF, the Examples should
compile.

To configure VTK with BUILD_EXAMPLES:ON and BUILD_TESTING:OFF, from an
empty build tree,

cmake  -DBUILD_TESTING:BOOL=OFF -DCMAKE_BUILD_TYPE:STRING=Release vtk_src_tree

NOTE: If you have already configured VTK with default settings, you
must clean the build tree and rerun cmake with the above
setting. Otherwise, bogus tests will remain.

Conflicts:
	Examples/IO/Cxx/CMakeLists.txt
	Examples/ImageProcessing/Cxx/CMakeLists.txt
	Examples/Medical/Cxx/CMakeLists.txt
	Examples/Modelling/Cxx/CMakeLists.txt
	Examples/VisualizationAlgorithms/Cxx/CMakeLists.txt
	Examples/Widgets/Cxx/CMakeLists.txt

Change-Id: I996065a30aab43cca630a369b39d748de728039b

Add to the Testing/Data directory ExternalData content links mirroring
the content and layout we use from the VTKData/Data directory.

Add a CMake/vtkLegacyData.cmake module, included from CMakeLists.txt and
Testing/External/CMakeLists.txt, to call ExternalData_Expand_Arguments
for all data directories added from VTKData/Data.  This will bulk-fetch
all test input data currently used by tests of any module, enabled or
not.  We can make the DATA{} references more granular later.

Add a VTK_TEST_DATA_DIR variable to refer to the directory we tell the
ExternalData module to populate the real data files.  Replace references
to VTK_DATA_ROOT in test command lines (after -D) with references to
VTK_TEST_DATA_DIR.  Drop the VTK_DATA_ROOT CMake option and stop using
the VTKData repository.

Remove the TESTING_DATA option from the vtk_add_test_cxx API and remove
the VTK_DATA_ROOT option from the vtk_add_test_mpi API since all test
input data are now handled through ExternalData and Testing/Data content
links.

Change-Id: Id02490b76ea2e161b9038188264a4830485039d8

With BUILD_EXAMPLES:ON and BUILD_TESTING:OFF, the Examples should
compile.

To configure VTK with BUILD_EXAMPLES:ON and BUILD_TESTING:OFF, from an
empty build tree,

cmake  -DBUILD_TESTING:BOOL=OFF -DCMAKE_BUILD_TYPE:STRING=Release vtk_src_tree

NOTE: If you have already configured VTK with default settings, you
must clean the build tree and rerun cmake with the above
setting. Otherwise, bogus tests will remain.

Change-Id: I2035e49c7df4ba6f3d88447ea1b768ec63b87ee7

Teach vtk_add_test_cxx and vtk_test_cxx_executable to work in
Examples/*/Cxx directories when variable "vtk-example" is set and
"vtk-module" is not set.  Convert Examples/*/Cxx/CMakeLists.txt to use
these functions.  Populate Examples/*/Cxx/Baseline/ directories with
ExternalData content links for example baseline images.

Change-Id: Ic7d847a4561f5ed882b35e80c3ce98aa578ef7d3

This makes it easier for external applications attempting to use
vtkTestingObjectFactory since they don't require the
vtkTestingRendering_SOURCE_DIR to set anymore (which won't even when the
vtkTestingRendering module has been successfully imported.

Change-Id: I14795bbe0f9d71d41da14c970ba49bdb8e11a913

1) Add Find_Package(VTK COMPONENTS) for each example dir
2) Add MAC app support
3) Use ${VTK_LIBRARIES} for target_link_libraries
4) Use new signature for add_test

Each set of examples can be built within the VTK bin tree or as
stand-alone examples.

Change-Id: I6daa126bcc2ed44d827b50954d27f90f394ad4f2

Change-Id: I087c80d66752263176af2457c4463f359a9d376a

ENH: New testing objects, vtkTestingObjectFactory and vtkTestingInteractor facilitate consistent regression testing of VTK Cxx Tests and Examples. The changes in VTK/Examples permit the building of examples within the VTK build tree and externally.

ENH: Setting up build of examples to always be an outside project.  An in-tree build will produce a custom target that builds it as an outside project using ctest --build-and-test.  Once VTK is built the examples will be built.  The output paths are setup to put the examples in the VTK bin directory so DLL builds will work out of the box.