wgpu-hal creates every swapchain with `preTransform = IDENTITY` (#3345).
On a tablet whose panel is mounted landscape, a portrait window then
hands Android an unrotated buffer: SurfaceFlinger falls back to rotating
it on the GPU (composition CLIENT), and on this device those frames tear.
That is why Android draws with Skia over OpenGL today, and why the
develop view pays a readback (TD-1).
The field cannot just be set to `currentTransform` inside wgpu. It is a
promise that the image is already drawn rotated and sized in the panel's
orientation, and only the renderer above wgpu can keep it. So the patch
is the smallest thing that lets that renderer ask:
`vulkan::Surface::current_transform` reads the surface's transform, and
`set_pre_transform` makes the next swapchain use it. The default stays
IDENTITY, so desktop and any caller that does not opt in behave exactly
as upstream.
The Android develop view reads its frame back through memory (TD-1)
because wgpu's Vulkan swapchain never pre-rotates, and a portrait window
on this tablet's landscape panel then tears. The fix is a small patch to
each of these two crates, and this commit is only the ground it lands on:
both are byte-for-byte the crates.io sources the lockfile already
resolved, so the commits that follow are the patch and nothing else.
third_party/ is excluded from the workspace, or every path dependency
under the root would become a member and `--workspace` would test and
lint upstream code as ours. The README says how to carry the patches
across a Slint or wgpu bump, which matters because a stale version here
does not fail the build — cargo just warns and uses the unpatched crate.
dtourolle