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enricobuehler d39da4bc06 feat(windows): pf-vdisplay — all-Rust IddCx virtual display (replaces SudoVDA)

P1 done: a pure-Rust UMDF2 IddCx driver, drop-in compatible with the host's
existing vdisplay/sudovda.rs control plane (the {e5bcc234} interface + the
SudoVDA IOCTL ABI), so the host drives it unchanged. Validated streaming on
glass at 5120x1440@240 — steady 240 fps, ~2.4 ms encode, clean teardown, full
parity with SudoVDA.

- Vendored wdf-umdf-sys / wdf-umdf bindgen crates (MIT, from virtual-display-rs)
  + the SDK-version build.rs fix that resolves the IddCxStub lib path by the WDK
  version actually containing um\x64\iddcx, not the max base SDK.
- pf-vdisplay crate: entry/callbacks/context/control/monitor/edid/
  swap_chain_processor. Our OWN 128-byte EDID (manufacturer PNK, product
  punktfunk — no SudoVDA bytes), a real swap-chain drain (faithful vdd port,
  required so DWM keeps compositing), the SudoVDA-compatible IOCTL control plane
  (ADD/REMOVE/PING/GET_WATCHDOG/GET_VERSION/SET_RENDER_ADAPTER) + a watchdog that
  tears down orphaned monitors when the host stops pinging.
- deploy-dev.ps1: stage + sign + stampinf (date.time DriverVer) + Inf2Cat +
  install, codifying the "bump DriverVer or pnputil keeps the old binary" gotcha.
- docs/windows-virtual-display-rust-port.md: investigation, the on-glass
  validation, and the two traps that cost time (Session-0 measurement +
  accumulated device-state needing a reboot).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-24 00:36:21 +02:00

3.4 KiB

Raw Blame History

pf-vdisplay — punktfunk Windows virtual display (Rust IddCx)

P1 of replacing the vendored SudoVDA C++ driver with one we own — a pure-Rust UMDF2 IddCx (Indirect Display Driver) virtual display, drop-in compatible with the host's existing vdisplay/sudovda.rs IOCTL control plane. Full rationale + roadmap: docs/windows-virtual-display-rust-port.md.

Layout

vdisplay-driver/
  wdf-umdf-sys/     VENDORED bindgen FFI to WDF + IddCx (links WdfDriverStubUm + IddCxStub)
  wdf-umdf/         VENDORED safe wrappers (IddCx*/Wdf*)
  pf-vdisplay/      OUR driver crate (cdylib) + pf_vdisplay.inx

wdf-umdf-sys / wdf-umdf are vendored from MolotovCherry/virtual-display-rs (MIT — see LICENSE.virtual-display-rs). They're a self-contained bindgen over the WDK, not windows-drivers-rs (which the gamepad drivers use): IddCx functions are direct IddCxStub exports the WDF function-table macro can't reach, so a unified bindgen is the cleaner base. Local fix carried in wdf-umdf-sys/build.rs: resolve the IddCxStub lib path by the SDK version that actually contains um\x64\iddcx\<ver> (a newer base SDK alongside the WDK has um\x64 but no iddcx).

Status

Scaffold builds ✅ — workspace + vendored bindings + pf-vdisplay compile in-tree to pf_vdisplay.dll. The reference (virtual-display-rs) was separately built + installed + loaded (Status OK) on the RTX box, proving the IddCx-in-Rust chain end to end.
Next (P1 driver logic): port the IddCx driver — DriverEntry → IDD_CX_CLIENT_CONFIG (adapter-init / parse-monitor-description / query-target-modes / assign-swapchain) → device + monitor context, generic EDID, no-op swap-chain drain (DDA still captures for P1). Logging via OutputDebugString (no log/driver-logger/tokio).
Then (control plane): the SudoVDA-compatible IOCTL surface on the control device (ADD/REMOVE/PING/GET_WATCHDOG/GET_VERSION/SET_RENDER_ADAPTER, byte-identical structs + the {e5bcc234-…} interface GUID) so vdisplay/sudovda.rs drives it unchanged; a default mode table + the per-ADD client mode injected as preferred; the watchdog.
Later (P2): push swap-chain frames straight to the host (skip DDA); HDR via the IddCx 1.11 D3D12 acquire path.

Build

Needs the WDK (UMDF 2.31 + IddCx stubs), LLVM/clang (LIBCLANG_PATH), and the pinned nightly-2024-07-26 (auto-selected via rust-toolchain.toml). From pf-vdisplay/, inside an MSVC dev shell:

set LIBCLANG_PATH=C:\Program Files\LLVM\bin
cargo build            # -> ../target/x86_64-pc-windows-msvc/debug/pf_vdisplay.dll

Sign + install (same recipe as the gamepad drivers)

(no FORCE_INTEGRITY bit to clear — this crate doesn't set /INTEGRITYCHECK)
signtool sign /fd SHA256 /sha1 <punktfunk-ds-test thumbprint> the renamed pf_vdisplay.dll
stampinf -f pf_vdisplay.inf -d * -a amd64 -u 2.15.0 -v <ver> ; Inf2Cat /driver:<dir> /os:10_X64 ; sign the .cat
pnputil /add-driver pf_vdisplay.inf ; create the root devnode (nefconc --create-device-node --hardware-id root\pf_vdisplay --class-name Display --class-guid {4d36e968-…}, mirroring install-sudovda.ps1)

Bundles into the Inno Setup installer the same way as gamepad-drivers/ once the driver is functional.

3.4 KiB Raw Blame History