Some optimizations regarding embedded compilation

[fluolite]

How can this be achieved?
If only skia soft rendering and slint soft rendering are enabled, and gl feature is no longer enabled, then libgbm can be avoided.
Because libgbm still needs to compile the EGL of mesa3d

[tronical]

For just the Slint software renderer, this is already implemented AFAICS. If you disable default features and enable just the compat-1-2, backend-linuxkms, and the renderer-software features, you should not see a gbm dependency.

However, this is not implemented for Skia. It's possible to implement this by means of introducing a new renderer-skia-software Cargo feature.

[fluolite]

Yes, this is exactly what I think is feasible.