Live-validated Mac <-> RTX 4090 at the display's native 5120x1440@240:
- Resolution: set_active_mode enumerates the IDD's advertised modes and sets the
requested resolution at the best supported refresh (keeps 5120x1440@240; no more
silent fallback to the 1080p OS default when an exact mode is briefly unavailable).
- Bitrate auto-cap: NVENC init probes and steps the average bitrate down to the GPU's
codec-level max so a high client bitrate connects (matches the Linux host; we do not
split NVENC sessions).
- Mouse cursor: DXGI duplication excludes the HW cursor; capture the pointer
shape/position (GetFramePointerShape) and GPU-composite it before NVENC. Color cursors
alpha-blend; masked-color (the text I-beam) uses an INV_DEST_COLOR inversion blend so
the caret inverts the screen and shows on any background (no black box); monochrome
handled too.
- Secure desktop (lock / login / UAC): run as SYSTEM in the interactive session, follow
the input desktop via SetThreadDesktop, and on the WinSta switch recreate the D3D11
device and re-resolve the virtual output's GDI name from the stable SudoVDA target id
(the name changes across the topology rebuild; the old failure hunted the stale
\\.\DISPLAYn and dropped). ACCESS_LOST / INVALID_CALL / device-removed are recoverable,
and a mid-stream resolution change is followed (capturer + NVENC re-init at the new
size). isolate_displays detaches other monitors so Winlogon renders to the virtual
output. One real session recovered 1012 desktop switches and completed cleanly.
Windows-only backends; Linux/macOS unaffected. Builds clean on x86_64-pc-windows-msvc.
Deployment (windowless SYSTEM launch via PsExec + hidden VBScript) documented in
docs/windows-host.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
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