[vtkusers] CMake best practice for using VTK?

[Ben Boeckel]

On Mon, Jun 27, 2016 at 21:44:14 +0200, Elvis Stansvik wrote:
> 1. The shear amount of libraries that are linked against. Are all these
> really necessary, or is it possible to more selective somehow? Is there
> something like Qt's CMake system, where you can pull in just a certain Qt
> module with target_link_libraries(myapp Qt5::Widgets) ?

Use find_package(VTK REQUIRED COMPONENTS ${libraries_you_want}). Then
link using ${vtkModuleName_LIBRARIES}. The way you are finding VTK gets
all libraries.

You may also be interested in the VTK_ENABLE_KITS option which reduces
the number of libraries VTK creates.

> 2. How come the .so files are specified directly as inputs, with their full
> paths? Isn't the common method to just add the appropriate -l (and possibly
> -L if needed) flags?

CMake prefers full paths. The example is when you have this:

    /path/A/libA.so
    /path/A/libB.so
    /path/B/libB.so

and you want to link /path/A/libA.so and /path/B/libB.so. Getting -L and
-l right is finicky and hard to get right, so just using full paths is
safer and easier. This usually occurs with setups where you want a newer
version of A from Homebrew/Macports, but the system B where
Homebrew/Macports just happens to also have a copy of B.

--Ben