Reason: That switch statement. How should we even?
Well, the code *is* fairly good. After looking very deep into it, and
spending 35% of that function on blank lines (for logical grouping) and
explanatory comments, that is…
Part of P0152, funded by -Tom- and [Anonymous].
Deciding whether to decompile this one or not seemed to be a tough
choice. Should we *really* introduce two more translation units just
for the sake of decompiling another function that's identical to its
TH04 counterpart anyway?
Well, turns out it actually isn't: TH05 does in fact *not* immediately
clip bullets that are spawned on top of the player. Which might sound
like it has a notably different effect on gameplay… except that it
doesn't.
So yeah, good we've decompiled it, and got to show that more clearly.
Part of P0152, funded by -Tom- and [Anonymous].
Reason: Self-modifying. -.- And saving SI and DI on the stack way too
late.
Luckily, it's mostly identical to TH04's version I decompiled earlier,
only (thankfully) combining regular and special bullets into one
function, and integrating TH05-specific improvements.
Part of P0152, funded by -Tom- and [Anonymous].
Only used for the revenge bullets fired from Stage 3 Alice's barrier.
Not worth creating a separate translation unit, especially since the
function above is undecompilable as well…
Part of P0152, funded by -Tom- and [Anonymous].
Spent 4 pushes on the basic types and constants in 2020, still ended up
up getting this wrong and documenting the opposite of what TH05 actually
does…
Part of P0152, funded by -Tom- and [Anonymous].
… (24 + (difficulty * 8) + rank) in TH04, and (42 + (difficulty * 8))
in TH05. Also, TH05 only doesn't have TH04's bullet zap animation
because ZUN didn't consistently use constants…
Completes P0151, funded by Blue Bolt and -Tom-.
First place to confirm the hitbox of both the 8×8 pellets and the 16×16
sprite bullets!
Well, "hitbox". It's really more of a kill delta of 8×8 pixels between
the center points of a bullet and the player. You can distribute these
pixels to any combination of bullet and player "hitboxes" that make up
8×8. 4×4 around both the player and bullets? 1×1 for bullets, and 8×8
for the player? All equally valid… or perhaps none of them, once you
keep in mind that other entity types might have different kill deltas,
which turns the concept of a "hitbox" into just a confusing abstraction.
Part of P0150, funded by Blue Bolt.
TH05's version, which we saw way back in ac7e6bc, is almost identical
and can be used for any speed, whereas this one is hardcoded to modify
only the speed in the bullet template.
Part of P0150, funded by Blue Bolt.
`switch` statements compiling to binary searches if the range of values
is nasty enough? That's so cool. Apart from a few places in TH02,
this is the only place in PC-98 Touhou to show off that Turbo C++
optimization.
That code's still unexpectedly janky for what you'd expect from the 4th
game in the series, though.
Part of P0150, funded by Blue Bolt.
Still way premature to say things like "the base speed of a bullet
aroup is not affected by difficulty, only by rank". (Which also would
be a way less meaningful statement than you might think it is.)
Part of P0150, funded by Blue Bolt.
Too bad that it would have made no sense to call them "goofy bullets".
"Regular" is also a better name than "normal" (which is a difficulty!).
Completes P0149, funded by Blue Bolt, Ember2528, and -Tom-.
motion_t is also used for certain animations in MAINE.EXE, so not all
instances refer to entities in playfield space. Explicitly specifying
the latter now allows us to gain…
Part of P0149, funded by Blue Bolt, Ember2528, and -Tom-.
Well. The more random bullets at constrained angles are added to a
bullet group, the closer that group will invariably approximate a
spread shape. That's why it probably appeared as a "spread" to me in
2020. But the implementation for this group type
• neither uses any of the spread code,
• nor does it ensure a consistent angle between the bullets (which a
hypothetical "random angle spread" group type would probably do).
Also, look at its number within the enum! How could I ever get that
confused?!
Part of P0149, funded by Blue Bolt, Ember2528, and -Tom-.
And actually document them correctly.
Clear: Custom duration, awards constant points per bullet during the
entire duration, plays a decay animation
Zap: Fixed duration, awards a semi-exponential bonus for all bullets
alive on the first frame, plays a, um, "zapping" animation… in
TH04, because it's bugged in TH05 :zunpet:
Part of P0149, funded by Blue Bolt, Ember2528, and -Tom-.
We're going to need some name for the longer, boss-specific danmaku
animations. Turns out that these are exactly called "patterns" in
Sparen's glossary:
https://sparen.github.io/ph3tutorials/ddsg0.html#sub4
So what we called a "pattern" is actually called a "group". Whoops!
Part of P0142, funded by Yanga.
Originally just a workaround to remove angles from the PI counter, but
having the sign indicate the Y direction also makes them a lot nicer to
read in C land.
(Maintenance mode commit)
Making sure that we don't ever have to iterate over the 8×8 pellet part
of the bullet array during rendering… sure, but why not give the same
optimization treatment to the 16×16 bullets?
Part of P0112, funded by [Anonymous] and Blue Bolt.
… and this one, while I'm at it. I've been using pretty much every
possible type for VRAM offset variables, depending on my mood that day,
since signedness apparently never matters for those.
Except that it does. And so, just like with most of our high-level
types, we also have to account for ZUN's little signedness
inconsistencies here. Oh well, at least it's now only one of two types,
and there's no need to choose between `int` or `unsigned int` or
`short` or `unsigned short` or `int16_t` or `uint16_t` or `size_t` or…
Part of P0111, funded by [Anonymous] and Blue Bolt.
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.
The kind of minor copy-pasting mistake that should have been caught by
a proper type system… which ReC98 can only simulate to an extent.
Part of P0110, funded by [Anonymous] and Blue Bolt.
Because pretty much all of TH05's bullet spawn code is micro-optimized
and undecompilable ASM, we'll unfortunately have to keep those ASM
versions around forever 😕
Well, the TH05 ones at least.
Part of P0109, funded by [Anonymous] and Blue Bolt.
Adding op/, main/, and end/ directories does nicely cover a great
majority of the "not really further classifiable slices" implied in
d56bd45.
Part of P0086, funded by [Anonymous] and Blue Bolt.
nmlgc