CheckSpriteAvailability writes $ff into the image index of a sprite
outside its window, and state::npcs reports what is drawn. From the
Pewter Gym's doormat that is the guide alone, already talked to, so the
rung's list was empty: GO OBJECTIVE had nothing to aim at and GO OUT,
withheld only while the rung's person is in the room, was the pad.
Outside, GO OBJECTIVE walked back in. BROCK was twelve rows up.
state::offscreen_npcs reports the sprites the cartridge hides only for
being outside the window, read from bytes the seam already has, and
objective_targets reads them for a person. Nothing else does: a sprite
out of the window may be a toggleable object switched off, and GO NPC,
TALK and objects keep what is drawn.
Facing any of the rung's people is the arrival: with three in a gym,
leaving out only the one ahead walked GO OBJECTIVE between the leader
and the trainer.
route and frontier ask for the grid once per plan and fall back to the window
when there is none. With it: one plan crosses a whole map, GO WARP / GO OUT /
GO ROUTE route to their warp or connection tile rather than to the nearest tile
of an edge that reads Unknown, a tile-pair wall is planned around instead of
being learned by walking into it, and the frontier is the nearest unstood
walkable tile anywhere on the map instead of the nearest one on screen.
