game.shouldreturntoeditor was added to fix a frame ordering issue that
was causing a bug where if you started playtesting in a room with a
horizontal/vertical warp background, and exited playtesting in a
different room that also had a horizontal/vertical warp background and
which was different, then the background of the room you exited in would
slowly scroll offscreen, when you re-entered the editor, instead of the
background consisting entirely of the actual background of the room.
Namely, the issue was that the game would render one more frame of
GAMEMODE after graphics.backgrounddrawn got set to false, and re-set it
to true, thus negating the background redraw, so the editor background
would be incorrect.
With defer callbacks, we can now just use a couple lines of code,
instead of having to add an extra kludge variable and putting handling
for it all over the code.
While working on #535, I noticed that editormenuactionpress() still
didn't do the explicit void declaration. Then I ran `rg 'void.*\(\)'`
and found three other functions that I somehow missed in #628. Whoops.
Well, now they no longer are missed.
This is a small quality-of-life tweak that makes it so if you're in the
middle of editing a level, you don't have to save the level, exit to the
menu, change whatever setting you wanted, re-enter the editor, and type
in the level name, just to change one setting. This is the same as
adding Graphic Options and Game Options to the in-game pause menu,
except for the editor, too.
To do this, I'm reusing Game::returntopausemenu() (because all of its
callers are the same callers for returning to editor settings) and
renamed it to returntoingame(), then added a variable named
ingame_editormode to Game. When we're in the options menus but still in
the editor, BOTH ingame_titlemode and ingame_editormode will be true.
This is a small quality-of-life thing that makes it so you don't have to
move your menu selection all the way over to the "return" button in
order to return to the previous menu. You can just press Escape instead
to return to the previous menu. The previous behavior of pressing Escape
was to bring up the 'confirm quit' menu, or if you were in an options
menu in-game, return to the pause menu.
If you're on the main menu (and thus don't have any previous menu) and
press Escape, the game will instead bring up the 'confirm quit' menu.
For consistency, the "quit game" option on the main menu will also bring
up the 'confirm quit' menu as well, instead of immediately closing the
game.
Pressing the controller button mapped to Escape will also work as well.
The only menus that don't have return buttons are the 'countdown' menus
- so the game will not let you press Escape if there's a menu countdown
happening.
Now that pressing Escape in the 'continue' menu will just bring you back
to the 'play' menu, there's no need to specifically put
map.nexttowercolour() first when canceling the 'confirm quit' menu.
This avoids the room name awkwardly moving back up if the cursor is at
the bottom of the screen in a room with a room name, then the user
switches to a room without a room name, then moves the cursor away from
the bottom, then switches to a named room - even though the cursor was
already away from the bottom of the screen.
Conversely, if the user moves their cursor to the bottom of the screen
in an unnamed room, then switches into a named room, the room name will
already have been hidden and they won't need to wait for it to hide.
This fixes the drawer suddenly popping up only to disappear, if the user
leaves a Direct Mode room into a non-Direct Mode room when the drawer
hasn't closed all the way, and then re-enters a Direct Mode room.
Gravity line correction no longer happens on every deltaframe. This
means less CPU time is wasted. Although, there's probably no need to
correct gravity lines on every single frame... hm... well, that's an
optimization for later (there's plenty of other stuff to cache, like
minimap drawing or editor foreground drawing).
There's no need to create an std::string for every single element just
to see if it's a key name.
At least in libstdc++, there's an optimization where std::strings that
are 16 characters or less don't allocate on the heap, and instead use
the internal 16-char buffer directly in the control structure of the
std::string. However, it's not guaranteed that all the element names
we'll get will always be 16 chars or less, and in case the std::string
does end up allocating on the heap, we have no reason for it to allocate
on the heap; so we should just convert these string comparisons to C
strings instead.
Zip files that have been successfully mounted in editorclass::loadZips()
will now be ignored when the game does its second pass over the levels
directory. Otherwise, this would produce a superfluous error message,
because the game would attempt to parse the zip file as a level file
(when it's not a level file and is in fact a binary file).
Otherwise, this would produce a superfluous warning message in the
console. Directories are now ignored and never attempted to be opened;
so now any warning messages printed out are genuine file that something
has genuinely gone wrong with.
Well, there's still a warning message printed if there's a symlink to a
directory; this is rarer, but it's still a false positive.
I had misread this line in #629 and thought that it was just clearing
the entire surface, when really it was filling the surface with opaque
black. ClearSurface() would instead make it transparent, which would
mean when it got drawn, it would get drawn against blue, and not black.
Whoops.
I don't know why this is here; it's unused. I don't know why the
compiler doesn't warn about this being unused either - maybe it's
secretly being used? That also means I'm not sure if the compiler is
optimizing this away or not. Anyway, this is getting removed.
The STL here cannot be completely eliminated (because the custom entity
object uses std::string), but at least we can avoid unnecessarily making
std::strings until the very end.
There's not really any reason for this function to use heap-allocated
strings. So I've refactored it to not do that.
I would've used SDL_strrstr(), if it existed. It does not appear to
exist. But that's okay.
ClearSurface() is less verbose than doing it the old way, and also
conveys intent clearer. Plus, some of these FillRect()s had hardcoded
width and height values, whereas ClearSurface() doesn't - meaning this
change also has better future-proofing, in case the widths and heights
of the surfaces involved change in the future.
Apparently in C, if you have `void test();`, it's completely okay to do
`test(2);`. The function will take in the argument, but just discard it
and throw it away. It's like a trash can, and a rude one at that. If you
declare it like `void test(void);`, this is prevented.
This is not a problem in C++ - doing `void test();` and `test(2);` is
guaranteed to result in a compile error (this also means that right now,
at least in all `.cpp` files, nobody is ever calling a void parameter
function with arguments and having their arguments be thrown away).
However, we may not be using C++ in the future, so I just want to lay
down the precedent that if a function takes in no arguments, you must
explicitly declare it as such.
I would've added `-Wstrict-prototypes`, but it produces an annoying
warning message saying it doesn't work in C++ mode if you're compiling
in C++ mode. So it can be added later.
One of these days, I need to get around to running Include What You Use
on this codebase. Until then, while I was working on #624, I noticed
these; I'm removing them now.
Note that level dir listing still uses plenty of STL (including the end
product - the `LevelMetaData` struct - which, for the purposes of 2.3,
is okay enough (2.4 should remove STL usage entirely)); it's just that
the initial act of iterating over the levels directory no longer takes
four or SIX(!!!) heap allocations (not counting reallocations and other
heap allocations this patch does not remove), and no longer does any
data marshalling.
Like text splitting, and binary blob extra indice grabbing, the current
approach that FILESYSTEM_getLevelDirFileNames() uses is a temporary
std::vector of std::strings as a middleman to store all the filenames,
and the game iterates over that std::vector to grab each level metadata.
Except, it's even worse in this case, because PHYSFS_enumerateFiles()
ALREADY does a heap allocation. Oh, and
FILESYSTEM_getLevelDirFileNames() gets called two or three times. Yeah,
let me explain:
1. FILESYSTEM_getLevelDirFileNames() calls PHYSFS_enumerateFiles().
2. PHYSFS_enumerateFiles() allocates an array of pointers to arrays of
chars on the heap. For each filename, it will:
a. Allocate an array of chars for the filename.
b. Reallocate the array of pointers to add the pointer to the above
char array.
(In this step, it also inserts the filename in alphabetically -
without any further allocations, as far as I know - but this is a
COMPLETELY unnecessary step, because we are going to sort the list
of levels by ourselves via the metadata title in the end anyways.)
3. FILESYSTEM_getLevelDirFileNames() iterates over the PhysFS list, and
allocates an std::vector on the heap to shove the list into. Then,
for each filename, it will:
a. Allocate an std::string, initialized to "levels/".
b. Append the filename to the std::string above. This will most
likely require a re-allocation.
c. Duplicate the std::string - which requires allocating more memory
again - to put it into the std::vector.
(Compared to the PhysFS list above, the std::vector does less
reallocations; it however will still end up reallocating a certain
amount of times in the end.)
4. FILESYSTEM_getLevelDirFileNames() will free the PhysFS list.
5. Then to get the std::vector<std::string> back to the caller, we end
up having to reallocate the std::vector again - reallocating every
single std::string inside it, too - to give it back to the caller.
And to top it all off, FILESYSTEM_getLevelDirFileNames() is guaranteed
to either be called two times, or three times. This is because
editorclass::getDirectoryData() will call editorclass::loadZips(), which
will unconditionally call FILESYSTEM_getLevelDirFileNames(), then call
it AGAIN if a zip was found. Then once the function returns,
getDirectoryData() will still unconditionally call
FILESYSTEM_getLevelDirFileNames(). This smells like someone bolting
something on without regard for the whole picture of the system, but
whatever; I can clean up their mess just fine.
So, what do I do about this? Well, just like I did with text splitting
and binary blob extras, make the final for-loop - the one that does the
actual metadata parsing - more immediate.
So how do I do that? Well, PhysFS has a function named
PHYSFS_enumerate(). PHYSFS_enumerateFiles(), in fact, uses this function
internally, and is basically just a wrapper with some allocation and
alphabetization.
PHYSFS_enumerate() takes in a pointer to a function, which it will call
for every single entry that it iterates over. It also lets you pass in
another arbitrary pointer that it leaves alone, which I use to pass
through a function pointer that is the actual callback.
So to clarify, there are two callbacks - one callback is passed through
into another callback that gets passed through to PHYSFS_enumerate().
The callback that gets passed to PHYSFS_enumerate() is always the same,
but the callback that gets passed through the callback can be different
(if you look at the calling code, you can see that one caller passes
through a normal level metadata callback; the other passes through a zip
file callback).
Furthermore, I've also cleaned it up so that if editorclass::loadZips()
finds a zip file, it won't iterate over all the files in the levels
directory a third time. Instead, the level directory only gets iterated
over twice - once to check for zips, and another to load every level
plus all zips; the second time is when all the heap allocations happen.
And with that, level list loading now uses less STL templated stuff and
much less heap allocations.
Also, ed.directoryList basically has no reason to exist other than being
a temporary std::vector, so I've removed it. This further decreases
memory usage, depending on how many levels you have in your levels
folder (I know that I usually have a lot and don't really ever clean it
up, lol).
Lastly, in the callback passed to PhysFS, `builtLocation` is actually no
longer hardcoded to just the `levels` directory, since instead we now
use the `origdir` variable that PhysFS passes us. So that's good, too.
If PHYSFS_mountHandle() failed to mount a zip file, we would print
PhysFS's error message straight, without any surrounding context. This
seems a little weird, and doesn't maximize understanding for readers;
I've made it so now the error message is "Could not mount <zip file>:
<PhysFS error>".
The current way "arrays" from XML files are loaded (before this commit
is applied) goes something like this:
1. Read the buffer of the contents of the tag using TinyXML-2.
2. Allocate a buffer on the heap of the same size, and copy the
existing buffer to it. (This is what the statement `std::string
TextString = pText;` does.)
3. For each delimiter in the heap-allocated buffer...
a. Allocate another buffer on the heap, and copy the characters from
the previous delimiter to the delimiter you just hit.
b. Then allocate the buffer AGAIN, to copy it into an std::vector.
4. Then re-allocate every single buffer YET AGAIN, because you need to
make a copy of the std::vector in split() to return it to the caller.
As you can see, the existing way uses a lot of memory allocations and
data marshalling, just to split some text.
The problem here is mostly making a temporary std::vector of split text,
before doing any actual useful work (most likely, putting it into an
array or ANOTHER std::vector - if the latter, then that's yet another
memory allocation on top of the memory allocation you already did; this
memory allocation is unavoidable, unlike the ones mentioned earlier,
which should be removed).
So I noticed that since we're iterating over the entire string once
(just to shove its contents into a temporary std::vector), and then
basically iterating over it again - why can't the whole thing just be
more immediate, and just be iterated over once?
So that's what I've done here. I've axed the split() function (both of
them, actually), and made next_split() and next_split_s().
next_split() will take an existing string and a starting index, and it
will find the next occurrence of the given delimiter in the string. Once
it does so, it will return the length from the previous starting index,
and modify your starting index as well. The price for immediateness is
that you're supposed to handle keeping the index of the previous
starting index around in order to be able to use the function; updating
it after each iteration is also your responsibility.
(By the way, next_split() doesn't use SDL_strchr(), because we can't get
the length of the substring for the last substring. We could handle this
special case specifically, but it'd be uglier; it also introduces
iterating over the last substring twice, when we only need to do it
once.)
next_split_s() does the same thing as next_split(), except it will copy
the resulting substring into a buffer that you provide (along with its
size). Useful if you don't particularly care about the length of the
substring.
All callers have been updated accordingly. This new system does not make
ANY heap allocations at all; at worst, it allocates a temporary buffer
on the stack, but that's only if you use next_split_s(); plus, it'd be a
fixed-size buffer, and stack allocations are negligible anyway.
This improves performance when loading any sort of XML file, especially
loading custom levels - which, on my system at least, I can noticeably
tell (there's less of a freeze when I load in to a custom level with
lots of scripts). It also decreases memory usage, because the heap isn't
being used just to iterate over some delimiters when XML files are
loaded.
Contents and scripts should be reset in editorclass::reset(); there's no
reason to reset them again right before you load them from an XML file
in editorclass::load().
Additionally, the resets now consistently use SDL_zeroa() (for contents)
and scriptclass::clearcustom() (for scripts).
I'm partial to slash-asterisk-style comments, so I'll use those here.
Also, having a space after the start of comments is good. I've also
removed the "Add the script if we have a preceding header" comments
since it can be inferred by reading the surrounding code.
Instead of checking the length() of an std::string, just check if
pText[0] is equal to '\0'.
This will have to be done anyway, because I'm going to get rid of the
std::string allocation here, and I noticed this inefficiency in the
indentation, so I'm going to remove it.
The actual unindent will be done in the next commit.
Even if split() didn't use the STL, using this function here is a bit
unnecessary, because a simple SDL_strchr() suffices. Refactoring split()
to not use the STL will break this caller anyway, so I might as well
just refactor this to not use split() in the first place.
This refactor also properly checks if the inputs are valid integers. And
since split() is no longer used, it also rejects inputs ending with a
trailing comma as being invalid, too; this didn't happen previously.
It's intentional that I used is_number() here instead of
is_positive_num(), thus accepting negative numbers; in the future it
might be possible to have negative room coordinates.
This fixes memory leaking every single time a file gets loaded(!) when
the list of custom levels gets loaded(!!!), which Valgrind reports. This
memory leak is completely my bad; 2.2 properly frees the loaded file,
and VCE uses an std::unique_ptr - which I decided to ignore and not
think about why it would be there.
It's safe to do this free after uMem gets copied into std::string;
although, in the future, I *am* thinking about refactoring this function
(and the tag finder function) to not use std::strings, and I'll have to
be careful to make sure that the memory management with the file is
correct when I do so.
MSVC complains about these, doesn't seem like GCC does. These can be
safely removed because they're unreachable, and they always follow a
case-switch or similar that has a default case which this code is a
duplicate of anyway. (Unless it isn't, in which case all the better to
remove it, becausee otherwise it looks misleading or confusing to casual
glances at the code.)
find_tag() would commit out-of-bounds indexing if someone made a level
file with malformed XML entity encodings in the metadata tags.
This would happen if the end of the string followed immediately after an
ampersand and hash, or if there wasn't a semicolon ending an XML entity.
Valgrind complains about these, so I've fixed it.
The previous person who wrote this (a girl named Misa) clearly didn't
understand the reason why you couldn't compare line[line.length()-1]
directly to a string literal. It's because the former is a char, and the
latter is a pointer to a char. Both are ints, so it compiles fine, but
it doesn't do what you want it to.
Why not just make the latter a char instead of a string literal? Well,
because you can, but also I clearly didn't think this through earlier,
so that's why I didn't do it in the first place.
But this is fixed now.
Retextured checkpoints have always been in the game, but clicking on
them in the editor would lead to them losing their retextured-ness. So,
checkpoints should be left alone if their p1 isn't either 0 or 1. Also,
they don't show up properly in the editor, so that's fixed, too.
Retextured and flipped terminals were added in 2.3, and show up properly
in-game, but don't properly show up in the editor, either. So now they
show up in the editor. Additionally, clicking on them will flip the
terminal as well, but only if its p1 is 0 or 1, just like checkpoints
now do.
There are multiple different exit paths to the main menu. In 2.2, they
all had a bunch of copy-pasted code. In 2.3 currently, most of them use
game.quittomenu(), but there are some stragglers that still use
hand-copied code.
This is a bit of a problem, because all exit paths should consistently
have FILESYSTEM_unmountassets(), as part of the 2.3 feature of per-level
custom assets. Furthermore, most (but not all) of the paths call
script.hardreset() too, and some of the stragglers don't. So there could
be something persisting through to the title screen (like a really long
flash/shake timer) that could only persist if exiting to the title
screen through those paths.
But, actually, it seems like there's a good reason for some of those to
not call script.hardreset() - namely, dying or completing No Death Mode
and completing a Time Trial presents some information onscreen that
would get reset by script.hardreset(), so I'll fix that in a later
commit.
So what I've done for this commit is found every exit path that didn't
already use game.quittomenu(), and made them use game.quittomenu(). As
well, some of them had special handling that existed on top of them
already having a corresponding entry in game.quittomenu() (but the path
would take the special handling because it never did game.quittomenu()),
so I removed that special handling as well (e.g. exiting from a custom
level used returntomenu(Menu::levellist) when quittomenu() already had
that same returntomenu()).
The menu that exiting from the level editor returns to is now handled in
game.quittomenu() as well, where the map.custommode branch now also
checks for map.custommodeforreal. Unfortunately, it seems like entering
the level editor doesn't properly initialize map.custommode, so entering
the level editor now initializes map.custommode, too.
I've also taken the music.play(6) out of game.quittomenu(), because not
all exit paths immediately play Presenting VVVVVV, so all exit paths
that DO immediately play Presenting VVVVVV now have music.play(6)
special-cased for them, which is fine enough for me.
Here is the list of all exit paths to the menu:
- Exiting through the pause menu (without glitchrunner mode)
- Exiting through the pause menu (with glitchrunner mode)
- Completing a custom level
- Completing a Time Trial
- Dying in No Death Mode
- Completing No Death Mode
- Completing an Intermission replay
- Exiting from the level editor
- Completing the main game
During 2.3 development, there's been a gradual shift to using SDL stdlib
functions instead of libc functions, but there are still some libc
functions (or the same libc function but from the STL) in the code.
Well, this patch replaces all the rest of them in one fell swoop.
SDL's stdlib can replace most of these, but its SDL_min() and SDL_max()
are inadequate - they aren't really functions, they're more like macros
with a nasty penchant for double-evaluation. So I just made my own
VVV_min() and VVV_max() functions and placed them in Maths.h instead,
then replaced all the previous usages of min(), max(), std::min(),
std::max(), SDL_min(), and SDL_max() with VVV_min() and VVV_max().
Additionally, there's no SDL_isxdigit(), so I just implemented my own
VVV_isxdigit().
SDL has SDL_malloc() and SDL_free(), but they have some refcounting
built in to them, so in order to use them with LodePNG, I have to
replace the malloc() and free() that LodePNG uses. Which isn't too hard,
I did it in a new file called ThirdPartyDeps.c, and LodePNG is now
compiled with the LODEPNG_NO_COMPILE_ALLOCATORS definition.
Lastly, I also refactored the awful strcpy() and strcat() usages in
PLATFORM_migrateSaveData() to use SDL_snprintf() instead. I know save
migration is getting axed in 2.4, but it still bothers me to have
something like that in the codebase otherwise.
Without further ado, here is the full list of functions that the
codebase now uses:
- SDL_strlcpy() instead of strcpy()
- SDL_strlcat() instead of strcat()
- SDL_snprintf() instead of sprintf(), strcpy(), or strcat() (see above)
- VVV_min() instead of min(), std::min(), or SDL_min()
- VVV_max() instead of max(), std::max(), or SDL_max()
- VVV_isxdigit() instead of isxdigit()
- SDL_strcmp() instead of strcmp()
- SDL_strcasecmp() instead of strcasecmp() or Win32 strcmpi()
- SDL_strstr() instead of strstr()
- SDL_strlen() instead of strlen()
- SDL_sscanf() instead of sscanf()
- SDL_getenv() instead of getenv()
- SDL_malloc() instead of malloc() (replacing in LodePNG as well)
- SDL_free() instead of free() (replacing in LodePNG as well)
This patch de-duplicates the tool drawing code a bit in the menu that
gets brought up when you press Space in the level editor, as well as
fixes several bugs related to the fact that the original author(s) of
the code decided to copy-paste everything. (It was most likely Terry,
judging by the distinct lack of whitespace between tokens in the code.)
There are two "pages" of tools that get shown when you open the tool
menu, according to your currently-selected tool.
1. On the first page, your currently-selected tool gets a brighter
outline. However, on the second page, the code to draw the outline over
your currently-selected tool is missing. So I've fixed that.
2. On the first page, the glyph indicator next to the tool icon also
gets brighter when you have that tool selected. However, on the
second page, the code that drew the brighter-colored indicator got
ran before the code that drew the normal-colored indicator, so this
was never shown. This is also fixed.
3. The glyph indicator of the gravity line tool didn't get brighter when
you had it selected, due to its special-cased copy-pasted code
drawing its brighter color before drawing its normal color. This has
also been fixed.
4. Lastly, the tool menu no longer draws the brighter-colored glyphs on
top of the normal-colored glyphs. Instead, the menu will simply draw
the brighter-colored glyphs and will not draw the normal-colored
glyphs in the first place. This is because double-drawing text like
this will look bad if the user has a custom font.png that has
translucent pixels, like I do.
All of these bugs have been fixed by paying off the technical debt of
copy-pasting code.
2.3's per-level assets feature also added a hotkey to reload the custom
assets of the level you're currently editing in the editor, so you
wouldn't have to re-load the level yourself. This hotkey is F9, but
however, it hasn't been documented in the hotkey list brought up by
pressing Shift, until now.
This patch cleans up unnecessary exports from header files (there were
only a few), as well as adds the static keyword to all symbols that
aren't exported and are specific to a file. This helps the linker out in
not doing any unnecessary work, speeding it up and avoiding silent
symbol conflicts (otherwise two symbols with the same name (and
type/signature in C++) would quietly resolve as okay by the linker).
There is a certain ordering of which corners you click on to place enemy
and platform boundaries, and script boxes. You must first click on the
top-left corner, then click on the bottom-right corner. The visual box
that is drawn after you've first clicked on the top-left corner clearly
shows this intended way of doing things.
However, it seems like despite the visuals, the game didn't properly
prevent you from clicking on the corners in the wrong way. If you placed
it from top-right to bottom-left, or bottom-left to top-right, then the
game would place the boxes accordingly, and they would have a weird
shape where two of its opposite sides would just be missing. But,
placing them from bottom-right to top-left is prevented accordingly.
The bug comes down to a simple use of "or", instead of the correct
"and". This isn't the first time the wrong conjunction was used in a
conditional... (8260bb2696, #136)
Since the code block that the if-statement guards is the code that will
execute if the corners placed were correct, the if-statement thus should
be written in the positive case and use a more restrictive "and",
instead of the negative case, which would use a more looser "or". There
are less cases that are correct than cases which are incorrect - in this
case, there is only 1 correct way of doing things (top-left to
bottom-right), compared to 3 incorrect ways of doing things (top-right
to bottom-left, bottom-left to top-right, bottom-right to top-left) - so
when thinking of positive cases, you should be using "and".
Or, you can always just test it. This bug has been in the game since
2.0, so it seems like no one just tested that incorrect input actually
didn't work.
So... it looks like being able to switch through tilesets backwards has
been in 2.3 for a while, guess no one just uses 2.3 or the level editor
that much. It seems like it's always been broken, too.
If you were on the Space Station tileset (tileset 0), pressing Shift+F1
would keep you on the Space Station tileset instead of switching to the
Ship (tileset 4).
It looks like the problem here was mixing size_t and int together - so
the modulus operation promoted the left-hand side to size_t, which is
unsigned, so the -1 turned into SIZE_MAX, which is 18446744073709551615
on my system. You'll note that that ends in a 5, so the number is
divisible by 5, meaning taking it modulo 5 leads to 0. So the tileset
would be kept at 0.
At least unsigned integer underflow/overflow is properly defined, so
there's no UB here. Just careless type mixing going on.
The solution is to make the modulus an int instead of a size_t. This
introduces an implicit conversion, but I don't care because my compiler
doesn't warn about it, and implicit conversion warnings ought to be
disabled on MSVC anyway.
This fixes a bug where if you entered a tower before watching the
credits sequence, the credits sequence would have mismatched text and
background colors.
This bug happened because entering a tower modified the r/g/b attributes
of mapclass, and updated graphics.towerbg, without updating
graphics.titlebg too. Then gamecompleterender() uses the r/g/b
attributes of mapclass.
The solution is to put the r/g/b attributes on TowerBG instead. That
way, entering a tower will only modify the r/g/b attributes used to
render towers, and won't affect the r/g/b attributes used to render the
credits sequence.
Additionally, I also de-duplicated the case-switch that updated the
r/g/b attributes based off of the current colstate, because it got
copy-pasted twice, leading to three instances of one piece of code.
