With 3 ZUN bugs, this one small function is technically buggier than
the entirety of Kikuri… or at least *as* buggy, with only two of them
being visible in the original game.
Oh well, that's 80% of REIIDEN.EXE RE'd!
Part of P0201, funded by Ember2528 and Yanga.
These could have been nicely separated into per-device translations
(one for GDC, one for EGC, one for regular VRAM accesses)… if their
original order followed that classification.
OK, so let's make it one full `graph_ex.cpp` translation unit… nope,
FUUIN.EXE needs graph_2xscale_byterect_1_to_0_slow() with different
compilation flags. 🤦
Whatever, fuck it, let's go for individual translation units, with
individual headers, so that we at least get predictably organized
source code out of this.
Part of P0196, funded by Yanga.
The one where symmetric birds spawn from the bottom of the playfield,
then fly to the top while shooting bullets at random angles.
Part of P0178, funded by Ember2528.
Actually fairly average, as far as unreasonable decompilations are
concerned. No `goto`, at least! Another place that would benefit from
EGC raster op documentation, though.
Also, got one more padding byte in TH05's MAINE.EXE correct. 🙂
Part of P0126, funded by [Anonymous] and Blue Bolt.
Rather than preferring either the Microsoft/Watcom `(in|out)pw?` style,
or the Borland `(in|out)portb?` style, master.lib had to introduce its
own `(OUT|IN)P[BW]` naming scheme… Insert obligatory xkcd standards
comic.
Part of P0126, funded by [Anonymous] and Blue Bolt.
Well well, the choice between sorting this function mechanically (and
putting it next to the EGC functions) or contextually (and putting it
next to the GDC SCROLL function)… Any choice would eventually turned
out suboptimal, I'm sure. 😅
Part of P0121, funded by Yanga.
Whew, time to look at every `int` variable we ever declared! The best
moment to do this would have been a year ago, but well, better late
than never. No need to communicate that in comments anymore.
These shouldn't be used for widths, heights, or sprite-space
coordinates. Maybe we'll cover that another time, this commit is
already large enough.
Part of P0111, funded by [Anonymous] and Blue Bolt.
ZUN might have gotten the impression that the EGC can *only* work with
multiples of 16 pixels per load or store? Which might explain why…
Part of P0102, funded by Yanga.
Yes, when clipping the start and end points to the screen area, ZUN
uses an integer division to calculate the line slopes, rather than a
floating-point one. Doesn't seem like it actually causes any incorrect
lines to be drawn, though; that case is only hit in the Mima boss
fight, which draws a few lines with a bottom coordinate of 400 rather
than 399. It *might* also restore the wrong pixels at parts of the
YuugenMagan fight, causing weird flickering, but seriously, that's an
issue everywhere you look in this game.
Part of P0069, funded by [Anonymous] and Yanga.
nmlgc