Put glfw under subrepo about vookoo

[FunMiles]

I have created a first basic version with glfw clone into the external directory.
Can you check it out on windows, @lhog ? I have checked it also works on my Linux box.
https://github.com/FunMiles/Vookoo. Branch glfw-subrepo

The changes also address #16

[andy-thomason]

Bear in mind that GLFW only exists to run the examples and is not a dependency of Vookoo itself (vku.hpp) which is dependant only on the Vulkan headers. However, we need an example framework to get us started - if only to create windows on three disparate platforms. I am not averse to using subrepos however, but we must document them carefully so that a new user who wants to run the examples will know how.

[FunMiles]

@andy-thomason So far, my CMakeLists.txt in the main directory only supports the building of the examples. I intend to add an install capability, but perhaps as a separate pull request, as to keep issues well separated. In the install capability, it will create cmake files. The cmake file would allow to use find_package(vookoo) and they could have two components, the base one for vku.hpp and the framework one for vku_framework.hpp. The first one would add no dependency, but the second could carry with it the glfw dependency. Maybe we can have a discussion about this in a separate issue about installation. I can also amend the README.md to cover the subject of the examples. It already does say clearly that it is an include-only library.

In the mean time, do you think the building of the examples should be under a CMake option? Should it be on or off by default?

[lhog]

Didn't work for me out of the box:

[FunMiles]

@lhog, I rebooted my linux machine under windows and it works without trouble. Did you, by any chance, keep your build to point to the example as the CMake root directory? You need to select the main directory as the location of the CMakeLists.

[lhog]

@FunMiles yep, apologies, I missed the fact you added another CMakeLists.
Works for me now too.

[FunMiles]

Great. I'm creating the pull request.

[FunMiles]

The PR has been merged. I'm closing this issue.