A title whose netplay mode draws every seat's view into one frame (so all
peers keep identical guest state) can now ask the present path to show only
this peer's rectangle of the display: psx_netplay_present_local_view(x, y,
w, h), usually picked from psx_netplay_local_slot(). The GL dual-raster
present shows it from the internal-resolution surface, the software present
crops its staged frame, both at 4:3, and the headless present-image ring
records the same rectangle. The request is host-only (never serialized or
guest-visible), lapses PSX_NETPLAY_LOCAL_VIEW_HOLD ticks after its last
renewal so menus fall back to the full frame, survives rollback replays
without moving its stamp backwards, and is ignored offline. It wins over
[netplay] local_viewport.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>