As described in
https://github.com/yuzu-emu/yuzu/pull/9395#discussion_r1047456172
checking for PKG_CONFIG_FOUND before calling pkg_search_module() is
unneeded, and some find modules (like FindFFmpeg.cmake) don't do this
already. Consequently, this patch removes these checks.
Uses find_package_handle_standard_args to handle the find_package call
from the root CMakeLists. Removes all the unnecessary logic after the
find_package and just sets it to REQUIRED.
With this patch I've deleted a few find modules that are now unused
since the vcpkg transition, as the CMake code now forces CONFIG mode for
Catch2, fmt and nlohmann_json.
I've then simplified the lz4, opus, and zstd modules by exclusively
using pkg-config. They were using it already, but were ignoring the
result. Also, I believe that manually looking for libraries was required
for Conan to work, and it is thus not needed anymore.
Lastly, I believe that there is no platform that ships these system libs
without pkg-config/pkgconf, so requiring it should be fine.
[REUSE] is a specification that aims at making file copyright
information consistent, so that it can be both human and machine
readable. It basically requires that all files have a header containing
copyright and licensing information. When this isn't possible, like
when dealing with binary assets, generated files or embedded third-party
dependencies, it is permitted to insert copyright information in the
`.reuse/dep5` file.
Oh, and it also requires that all the licenses used in the project are
present in the `LICENSES` folder, that's why the diff is so huge.
This can be done automatically with `reuse download --all`.
The `reuse` tool also contains a handy subcommand that analyzes the
project and tells whether or not the project is (still) compliant,
`reuse lint`.
Following REUSE has a few advantages over the current approach:
- Copyright information is easy to access for users / downstream
- Files like `dist/license.md` do not need to exist anymore, as
`.reuse/dep5` is used instead
- `reuse lint` makes it easy to ensure that copyright information of
files like binary assets / images is always accurate and up to date
To add copyright information of files that didn't have it I looked up
who committed what and when, for each file. As yuzu contributors do not
have to sign a CLA or similar I couldn't assume that copyright ownership
was of the "yuzu Emulator Project", so I used the name and/or email of
the commit author instead.
[REUSE]: https://reuse.software
Follow-up to b2eb103829
