Optimize cmake targets

[xiaozhuai]

Allow the following usage

find_package(glm CONFIG REQUIRED)
target_link_libraries(main PRIVATE glm::glm)

# Or use the header-only version
find_package(glm CONFIG REQUIRED)
target_link_libraries(main PRIVATE glm::glm-header-only)

Like most header-only library did. Such as fmt and spdlog.

[christophe-lunarg]

Nice!
I was hoping to add CMake find_package. Great! :)

[xiaozhuai]

Nice!
I was hoping to add CMake find_package. Great! :)

Yeah, I'm so happy you approve of this change.

The following will use shared/static library

find_package(glm CONFIG REQUIRED)
target_link_libraries(main PRIVATE glm::glm)

And the following will use header-only version

find_package(glm CONFIG REQUIRED)
target_link_libraries(main PRIVATE glm::glm-header-only)

[christophe-lunarg]

find_package(glm CONFIG REQUIRED)
target_link_libraries(main PRIVATE glm::glm)

one thing that I don't understand or that is important with this. Can we choose to link with GLM as a static library xor dynamic library with this change? If yes, how?

It's specifically important because :

• static library are annoying with compiler options that may be imcompatible with the project that links with this static library.
• dynamic libraries are annoying because they imply distributing a .so or .dll.

So developers will want to choose across all these posibilities, even if the header only is in most cases the most convenient.

I would also enjoy feedback from other people because all these install stuff, is beyond my understanding.

Thanks!

[xiaozhuai]

Can we choose to link with GLM as a static library xor dynamic library with this change? If yes, how?

Yes.
target_link_libraries(main PRIVATE glm::glm) will use static or dynamic library.
It is up to the user to choose to compile a static or dynamic library at compile time.
If user choose to build static glm via cmake -DBUILD_SHARED_LIBS=OFF ..., it will link to static glm library.
If user choose to build dynamic glm via cmake -DBUILD_SHARED_LIBS=ON ..., it will link to dynamic glm library.

target_link_libraries(main PRIVATE glm::glm-header-only) will use header-only library. It is always available.

[xiaozhuai]

And I add an option GLM_BUILD_LIBRARY just now.
When set it to ON, both glm::glm and glm::glm-header-only are available.
When set it to OFF, only glm::glm-header-only is available, and glm::glm also works as an alias of glm::glm-header-only.

[xiaozhuai]

I hope this PR can be merged before 1.0.0 is released.
Because under a lot of package management, such as vcpkg, it will work better.

[christophe-lunarg]

cmake -DBUILD_STATIC_LIBRARY=TRUE

But in the PR, BUILD_SHARED_LIBS and BUILD_STATIC_LIBS were removed? BUILD_STATIC_LIBRARY and BUILD_SHARED_LIBRARY don't look like a CMake built-in variable.

[xiaozhuai]

But in the PR, BUILD_SHARED_LIBS and BUILD_STATIC_LIBS were removed? BUILD_STATIC_LIBRARY and BUILD_SHARED_LIBRARY don't look like a CMake built-in variable.

It's built-in variable.

See https://cmake.org/cmake/help/latest/command/add_library.html

If no type is given explicitly the type is STATIC or SHARED based on whether the current value of the variable BUILD_SHARED_LIBS is ON.

---

Sorry, I have typo on my previous comments. It should be BUILD_SHARED_LIBS, not BUILD_STATIC_LIBRARY and BUILD_SHARED_LIBRARY

[christophe-lunarg]

oh, ok, all good then! :)

Would you mind to add a section on readme.md to explain how to use the GLM with CMake, find_package and building with BUILD_SHARED_LIBS and BUILD_STATIC_LIBS?

I bet other people don't know about this...

[xiaozhuai]

Would you mind to add a section on readme.md to explain how to...

Done~
I also add usage for vcpkg users.

[christophe-lunarg]

Thanks for contributing!