Module render_thread 

UI render worker thread.

Moves scene encode, swapchain acquire, blit, submit, present, and poll off the main winit thread onto a dedicated ui-render worker. Main keeps the widget tree + scene encoding; the worker owns the wgpu RenderContext, RenderSurface<'static>, and vello::Renderer.

Three channels: render_tx/rx (capacity 1 — blocks main until the worker drains the previous frame) moves an encoded Scene + dims + base colour; pool_tx/buffers (worker → main, capacity 2, pre-seeded) recycles each Scene and damage vector as one atomic pair; outcome_tx/frame_complete (capacity 8) reports per-frame outcomes so main can re-request a redraw on Outdated/Suboptimal/Occluded/Timeout.

The worker resizes the surface itself — main never touches it after handing it off at spawn — so wgpu state never crosses threads.

On exiting, the App sends RenderRequest::Shutdown and join()s the worker, which drops its RenderSurface<'static> before the Window is dropped — required or wgpu panics on a surface outliving its window. On suspended the worker drops only the surface and hands its context and renderer back (RenderThreadHandle::shutdown_keeping_renderer), so the next surface does not open a device and compile pipelines again.

Structs

RenderThreadHandle

Enums

FrameOutcome

RenderRequest

Type Aliases

PresentHook

Runs on the render thread once a frame is presented.