HDR streamed nothing and "didn't persist" because build() forced the SudoVDA's
advanced-color state to match the handshake bit_depth on every build — with an
8-bit-negotiated session (the common case: clients advertise no 10-bit cap) that
meant set_advanced_color(false) on every connect, wiping a user's deliberate
Windows HDR toggle on the virtual display.
But the whole pipeline already follows the monitor's REAL HDR state: WGC captures
FP16 when HDR is on, NVENC forces Main10 + BT.2020 PQ from the 10-bit capture
format regardless of the negotiated depth (encode/nvenc.rs), and the client
auto-detects PQ from the HEVC VUI. So the negotiated bit_depth must NOT drive the
monitor's colorspace.
- build(): only ever ENABLE HDR (proactively, for a negotiated 10-bit session);
never force it off. A user-enabled HDR session now persists and flows end-to-end.
- secure-desktop mux: gate the HDR→SDR drop (for the DDA leg) on the monitor's
ACTUAL advanced-color state at switch time, not bit_depth — so an HDR session
with an 8-bit handshake still drops correctly for Winlogon and restores after.
- sudovda: add advanced_color_enabled() reader (DISPLAYCONFIG_GET_ADVANCED_COLOR_INFO).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
af6787c0bd