There were a couple of places where the configure scripts did not add
either includes to VTKm_INCLUDE_DIRS or libraries to VTKm_LIBRARIES.
The biggest offender was when the examples used find_package to load the
VTK-m configuration it needed. find_package cleared out the includes and
libraries, but it did not clear out the VTKm_<COMPONENT>_FOUND
variables. Normally, these variables would not be set before
find_package is called, but in this case the examples were called after
some partial configuration. I got around this issue by clearing out all
the *_FOUND variables in VTKmConfig.cmake.
The examples are now written so they can be copied out of the vtk-m
source and still build properly. This will help new users / developers
learn how to build projects that use VTK-m.
The GLEW library is optional, but without it you cannot do OpenGL
interop. The hello_world example uses OpenGL interop, but did not check
that GLEW was available. It tried to use GLEW and an error occured.
For header files, this only adds the file to IDE file lists, which is
convenient but not critical. However, the test did find a ligit error in
the hello_world example where the TBB build was actually using the
serial device adapter.
This is needed as it allows the policies specified in the root of
vtk-m to propagate properly to the examples. When CMake
sees a cmake_minimum_required command it resets all policy flags.
Based on the work of Tyson Neuroth and Huu Tan Nguyen at the VTK-m code
sprint.
Shows how to invoke a simple worklet to generate coordinates and colors,
and than use opengl interop to display it to the screen.
