In which our typedefs mercilessly reveal ZUN's original sloppiness, and
the unncessary sign extension taking place here. Also, ❎ unused…
Completes P0069, funded by [Anonymous] and Yanga.
TH01's (original) version also replicates the PC-98 text RAM's reverse
and underline attributes. Which was removed in later games,
interestingly and inconsistently enough.
Part of P0068, funded by Yanga.
Including the longest function present in more than one game among all
of PC-98 Touhou, and #23 on the list of longest functions overall,
which draws a 1-pixel line between two arbitrary pixels.
Completes P0067, funded by Splashman.
Semi-unused, that is, the one use of this function doesn't actually
move the rectangle to a different position. Ironically, the non-moving
back-to-front function immediately above *is* unused…
Also, too bad that stack order is the only reason we can't use structs
to combine all plane variables into a single object.
Part of P0067, funded by Splashman.
nmlgc