This VM has no display but does have a real GPU -- Vulkan 1.4 through
Venus and GL 4.6 through virgl, onto the host's card -- so the only thing
missing for a winit window is a compositor. Same trick `emu` uses for the
Android emulator: a headless sway, with grim for the picture.
It starts its own compositor rather than joining `emu`'s. sway tiles, so
adding a window to the one an emulator sits in resizes that emulator, and
a peer session's `emu up` could join at any moment. Xwayland is off here
because winit speaks Wayland; `emu` forces it on only because the Android
emulator's renderer speaks GLX.
It waits for the window to be mapped rather than sleeping a fixed time:
the first version's fixed sleep captured an all-black screen when sway
had started in the same invocation, which is indistinguishable from an
app that draws nothing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
