Highlights one exit path of the room-map view: walks the (invisibly drawn) wall glyphs from the room's anchor point, painting each visited attribute cell cyan (attr 5), until it reaches a grille or junction node. Per cell it reads the grid under RoomCellCursor, looks the glyph up in CellDrawTable (32934) and patches the handler into the CALL below (self-modifying). Straight segments keep the heading, corner glyphs 128-131 turn it, and node glyphs (125/142/143) end the walk via ArmEndNode (which pops the return address). The stride pair RoomAttrStep/RoomCellStep encodes the heading: attr +32/-32/+1/-1 = south/north/east/west (grid steps +20/-20/+1/-1 in lockstep, the grid being 20 cells wide).