Please have cmake variables to use external packages

[yurivict]

On FreeBSD I have every bundled package already available. I don't want want to install them again and again with new ports. Bundling is also obviously unscaleable because if all dependencies are bundled in all software, deep dependencies would be installed exponentially many times and would fill up the disk. It would also be impossible to fix security problems when they are found, because these problems would need to be fixed in exponentially many places.

For exach bundled package please add the variable USE_EXTERNAL_xx so that the users would be able to use external packages.

Thank you,
Yuri

[doug-moen]

You can submit a PR with the changes that you are requesting. Or, you can point me at another project that defines these USE_EXTERNAL_xx variables using the same coding pattern that you are requesting me to use.

[yurivict]

The aseprite project does this using USE_SHARED_xx variables, see here https://github.com/aseprite/aseprite/blob/master/CMakeLists.txt#L61