compatibility with vcpkg

[rfomin]

• Move FindSDL2* to cmake/SDL2 directory, rename targets.

• Add vcpkg.json with dependencies.

The only problem is that the contents of the base directory are not copied to the target directory, not sure why.

[Dasperal]

Last time I tried vcpkg, SDL2 DLL from it caused crush at startup, was it fixed?

[rfomin]

• If vcpkg doesn't provide install rules for DLLs, they must be provided manually, probably in the same /lib/DLL/CMakeLists.txt.

There is an option to provide automatic install, works in Woof:

# X_VCPKG_APPLOCAL_DEPS_INSTALL automatically installs dependencies
# (except SDL_Mixer "plugins"). CMP0077 supress some arcane CMake warning.
set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
set(X_VCPKG_APPLOCAL_DEPS_INSTALL ON)

Last time I tried vcpkg, SDL2 DLL from it caused crush at startup, was it fixed?

It works for me, I use it to test resent PRs.

[rfomin]

@Dasperal Not relevant to this PR, but I found out how to fix slow libsamplerate from vcpkg, see: https://github.com/fabiangreffrath/woof/commit/cde9dd6aeca1c1d91bd6ddee550714d9e8055ee7

[Dasperal]

So, what's left:

• Add copy target to /lib/DLL/CMakeLists.txt for transitive dependencies from vcpkg if they exist (SDL_Mixer "plugins").
• Add install rules for transitive dependencies from vcpkg if they exist (SDL_Mixer "plugins"). Also consider manually adding install rules for direct dependencies from vcpkg as well, because vcpkg install them multiple times, one for each executable, and doesn't print what is installed and where.
• Add guide about using vcpkg to COMPILING.md.

Other questions:

• Do we want to always prioritize configs over find modules?
  • In some cases, user may want to provide his own development libraries using variables like SDL2_DIR that take effect only in find module.
  • The find_package in the config mode doesn't print any information if it managed to find the package. In the module mode, it displays the version of found package.
• Do we want to use miniz from vcpkg? On Fedora Linux, we probably want to use global miniz because it can be shared between packages, and have a newer version than the vendored one. But I am not sure about vcpkg, miniz there is already outdated, and it will be just another DLL for no reason.

[rfomin]

• vcpkg install them multiple times, one for each executable, and doesn't print what is installed and where.

This is not a problem for me, in fact I would like to reduce the number of unnecessary messages. I like it when a program prints only error messages or "done". 😄

• Do we want to always prioritize configs over find modules?

We can make option(CMAKE_FIND_PACKAGE_PREFER_CONFIG On) (I don't remember exact syntax).

• Do we want to use miniz from vcpkg?

Personally, I like single-file libraries because we don't have to manage dependencies.

[JNechaevsky]

Colleagues, is it release-critical? I'm thinking to release a quad-res update today.

[Dasperal]

No, it's not release-critical. Just support for another optional building environment.

[Dasperal]

• I decided that we will prioritize our miniz over one from vcpkg by default (not include it in vcpkg manifest or building guide).
• Exposed CMAKE_FIND_PACKAGE_PREFER_CONFIG as a cmake option.
• Exposed VCPKG_MANIFEST_MODE as a cmake option to let the user choose to operate in manifest mode or classic mode.
• Added guide about compiling with MSVC and vcpkg.
• Added CI builds with MSVC. Temporary disabled to save GitHub Actions time because they are currently not needed for anything.

And while I'm here, update libraries.

I'll leave TODOs for copy target and install rules for now and merge that already done. I probably file a feature request to vcpkg about automatic copy and install of transitive dependencies.

[Dasperal]

TODOs about SDL2_mixer "plugins" fixed themselves with SDL2_mixer package update in vcpkg