The guard was a 420px bubble around the fleet, which is smaller than the
window - so a rock could and did materialise in plain sight, several hundred
pixels away but well inside the view. "Not on the fleet" was never the rule
the player notices; "not in view" is.
The keep-out area is now the visible world rect, grown by a margin so a rock
placed just outside does not drift into view on the frame it was created.
The old bubble survives as a FLOOR under it: what to use when the viewport
cannot be measured - no camera yet on a scene's first frame, or a headless
run with no window - and for a heavily zoomed-in view where the screen is
narrower than the distance a rock needs to be safe.
Candidates inside are pushed out through the nearest edge rather than
dropped, so the field keeps its density around the fleet instead of thinning
out exactly where the player is looking.
Measured: keep-out 2200x2200 over a 1920 screen, nearest asteroid 1899 units
out where it used to be allowed at 420.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>