I don't know about "could be used as a reference for good practices", but here's a CMake file for a game project I've worked on if you're interested looking at how someone might use CMake for a smaller codebase (everything large I've used it for has been a work for hire unfortunately). It compiles on Linux with GCC, Mac OS X with Apple Clang, and Windows with MSVC, and supports multiple platform backends (currently SDL2 and SDL3). I've done development work on it with CLion, Xcode, and Visual Studio.
> But I've never read a CMake script and thought what a clean solution, it's always a bit gnarly.
I think using CMake for a cross-platform project that supports multiple compilers will always be a bit gnarly, mainly due to the differences between Windows and Unix-like platforms. MSVC is configured very differently to GCC and Clang so you have to list all your compiler flags twice, and there's no good option for doing system-wide installation of libraries (there's vcpkg, but a lot of stuff on there is missing or outdated) so you have to support both system-wide libraries on Unix-like platforms and user-provided DLLs on Windows.
https://github.com/nfroggy/openmadoola/blob/master/CMakeList...
> But I've never read a CMake script and thought what a clean solution, it's always a bit gnarly.
I think using CMake for a cross-platform project that supports multiple compilers will always be a bit gnarly, mainly due to the differences between Windows and Unix-like platforms. MSVC is configured very differently to GCC and Clang so you have to list all your compiler flags twice, and there's no good option for doing system-wide installation of libraries (there's vcpkg, but a lot of stuff on there is missing or outdated) so you have to support both system-wide libraries on Unix-like platforms and user-provided DLLs on Windows.