D161 - egui, chosen for the shape of what it has to draw

decided · 2026-08-20

orbistoun-gui is an immediate-mode application on egui, via eframe with the wgpu backend.

The panels this shell exists to show are a ranked import list, an ordered call tail, a register dump and a progress verdict. All of them are replaced wholesale when a run finishes rather than edited field by field, which is exactly what immediate mode draws well - a retained widget tree would spend its effort syncing against state that is thrown away and rebuilt.

wgpu rather than glow because phase 6 has to present a guest frame eventually, and that path is clearer through wgpu than through a webview or a GL wrapper. Not built now - there is no frame - but the toolkit choice is the one part of this that is expensive to revisit.

Considered and not taken: Tauri, which is familiar from other work here, but drags a webview in and makes raw framebuffer presentation awkward later; and iced, which is tidier for conventional app layouts and more ceremony for dense diagnostic tables.

The window is checked for worker mode before it is created. WorkerHandle::spawn_self re-executes the same binary with a flag, so a shim that cannot serve the protocol cannot run a guest at all - and reaching the window code in a worker process would open a second window on every launch.