The cursor channel excluded the host pointer from the video for the
whole session, but the client only draws it under the DESKTOP mouse
model — flipping ⌃⌥⇧M to capture mid-stream left the session
pointer-blind (user-found). The fix makes render ownership LIVE state:
- wire: CursorRenderMode 0x51 (client→host, control stream) —
client_draws: true = desktop model (host excludes + forwards),
false = capture model / released (host composites, full fidelity —
DWM on Windows incl. real XOR inversion, encoder blend on Linux).
Sessions start client_draws=true (the pre-message behavior).
- host: control task stores the flag; the encode loop edge-detects it —
forwarding + frame.cursor strip while the client draws, quiet
forwarder + overlay-into-blend while composited. SessionPlan now
grants blend CAPABILITY wherever the capture has a pointer (dropping
the !cursor_forward gate) so the composite side needs no encoder
rebuild; per-tick frame.cursor decides what is drawn.
- Windows: Capturer::set_cursor_forward → retained
IOCTL_SET_CURSOR_FORWARD sender (proto v6) → driver (un)declares the
IddCx hardware cursor on the LIVE monitor. Un-declare re-issues the
setup with EMPTY caps (candidate mechanism — the DDI has no
documented un-setup); resetup-on-commit is skipped while off, so a
mode commit's software-cursor default is the fallback path. Failure
against a pre-v6 driver logs and keeps declared-at-ADD behavior.
- SDL client: one edge-detected reconciler at the cursor pump site —
desktop-active = client draws; capture model or released = host
composites. Covers the chord, the M3 auto-flip, and engage/release.
- C ABI v12: punktfunk_connection_set_cursor_render (additive; wire
version unchanged — pre-§8 hosts ignore the unknown message type).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>