Feature request: -Duse_system_imgui

[Atemu]

Hi there, we at Nixpkgs currently need to hackily insert the imgui source into the build but we actually have it packaged natively.

Could you add a -Duse_system_imgui option like there is for spdlog? Thanks.

[Atemu]

On a second thought, it seems like imgui isn't discoverable by pkgconfig etc.

I really don't know enough about meson but I'd like to declare where a pre-built imgui can be found.

[eli-schwartz]

It looks like this nixpkgs recipe merely copies some *.cpp (as well as *.h) files to {includedir}, I wonder how that's supposed to work at all?

[flightlessmango]

Is this still relevant?

[Atemu]

We need to hack deps into place anyhow, so this doesn't present much complexity.

Header/source deps need to be streamlined in general though. Any sane packaging process restricts internet access during the build and that means we all need to get these sources in through other means beforehand.