feat: tell the ground a map covers from the window it is drawn through

A map's bounds are the window cut from the tile pyramid to draw it, and
several sheets are drawn inside a printed border, a title panel, or a wide
margin of nothing: Zion Canyon and Tunic sit in the middle of a full-world
window, and Pokémon's Kanto shares its sheet with a Charizard. Anything that
divides a map up was dividing that window, so the geohash grid spent most of
its thirty-two named cells on blank paper -- b naming nothing while m carried
what b should have held.

Every variant now names its surface as well as its bounds: the ground the map
covers, measured from the map's own contents. Where its locations are, and the
ground its regions outline, is the archive answering for each map rather than
a list of maps to treat specially, and it says the same thing about a border
whether that border is solid or patterned. Anything drawn outside the window
is left out of the reckoning -- three of Marathon's eighty locations sit off
the sheet entirely, and one of those would stretch the ground back over
everything it had just excluded.

A piece cut from a sheet already knew its ground, and keeps it. That ground is
also what the crop must contain: pieces are grown into the space around them
so a title drawn beside one is not sliced in half, and then eased apart where
they overlap. The easing was free to cut into the ground itself, which is what
took the bottom border off the Camp McCarran panel -- the crop stopped inside
the frame the panel is drawn with. Only the growth is given back now. Where
two pieces genuinely cover the same ground they are left overlapping, because
that is the sheet saying so rather than the crop.

commit

43d5ab4d97f2cca50fb0f350cb80c0e45452d36d

parent

474415c9c6081fe6171c91f213e7742585dfccf1

author

Dami <dami.etoile@gmail.com>