vcpkg libigl won't compile seamlessly with the vcpkg imgui integration

[not-magic]

Describe your issue

If you install libigl via vcpkg with imgui + opengl and also install imgui with glfw-binding, it can't find backends/imgui_impl_glfw.h.

vcpkg just installs this in the regular include path and doesn't need to be in the "backends" folder.

libigl should probably do it the vcpkg way and just use #include <imgui_impl_glfw.h> and include the backends folder directly for test projects.

Checklist

• I have read the bug report page
• CMake issue: I have tried with a fresh clone/empty build directory

Platform

• Windows
• macOS Intel
• macOS Arm (e.g., M1, M2)
• Linux