With the previous commit in place, we can now simply move some usages of
the previous towerbg to use a separate object instead. That way, we
don't have to mess with a monolithic state, or some better way to phrase
what I just said, and we instead have two separate objects that can
coexist side-by-side.
Previously, the tower background was controlled by a disparate set of
attributes on Graphics and mapclass, and wasn't really encapsulated. (If
that's what that word means, I don't particularly care about
object-oriented lingo.) But now, all relevant things that a tower
background has has been put into a TowerBG struct, so it will be easy to
make multiple copies without having to duplicate the code that handles
it.
These commands now use the INBOUNDS_ARR() macro to convey intent, and to
make sure that if the size of the array changes in the future, that the
bounds check wouldn't end up being wrong. Also fixed some code style for
the flag() and ifcrewlost() commands.
I was investigating a desync in my Nova TAS, and it turns out that
the gravity line collision functions check for the `oldxp` and `oldyp`
of the player, i.e. their position on the previous frame, along with
their position on the current frame. So, if the player either collided
with the gravity line last frame or this frame, then the player collided
with the gravity line this frame.
Except, that's not actually true. It turns out that `oldxp` and `oldyp`
don't necessarily always correspond to the `xp` and `yp` of the player
on the previous frame. It turns out that your `oldyp` will be updated if
you stand on a vertically moving platform, before the gravity line
collision function gets ran. So, if you were colliding with a gravity
line on the previous frame, but you got moved out of there by a
vertically moving platform, then you just don't collide with the gravity
line at all.
However, this behavior changed in 2.3 after my over-30-FPS patch got
merged (#220). That patch took advantage of the existing `oldxp` and
`oldyp` entity attributes, and uses them to interpolate their positions
during rendering to make everything look real smooth.
Previously, `oldxp` and `oldyp` would both be updated in
`entityclass::updateentitylogic()`. However, I moved it in that patch to
update right before `gameinput()` in `main.cpp`.
As a result, `oldyp` no longer gets updated whenever the player stands
on a vertically moving platform. This ends up desyncing my TAS.
As expected, updating `oldyp` in `entityclass::movingplatformfix()` (the
function responsible for moving the player whenever they stand on a
vertically moving platform) makes it so that my TAS syncs, but the
visuals are glitchy when standing on a vertically moving platform. And
as much as I'd like to get rid of gravity lines checking for whether
you've collided with them on the previous frame, doing that desyncs my
TAS, too.
In the end, it seems like I should just leave `oldxp` and `oldyp` alone,
and switch to using dedicated variables that are never used in the
physics of the game. So I'm introducing `lerpoldxp` and `lerpoldyp`, and
replacing all instances of using `oldxp` and `oldyp` that my over-30-FPS
patch added, with `lerpoldxp` and `lerpoldyp` instead.
After doing this, and applying #503 as well, my Nova TAS syncs after
some minor but acceptable fixes with Viridian's walkingframe.
By "unnecessary qualifiers to self", I mean something like using the
'game.' qualifier for a variable on the Game class when you're inside a
function on the Game class itself. This patch is to enforce consistency
as most of the code doesn't have these unnecessary qualifiers.
To prevent further unnecessary qualifiers to self, I made it so the
extern in each header file can be omitted by using a define. That way,
if someone writes something referring to 'game.' on a Game function,
there will be a compile error.
However, if you really need to have a reference to the global name, and
you're within the same .cpp file as the implementation of that object,
you can just do the extern at the function-level. A good example of this
is editorinput()/editorrender()/editorlogic() in editor.cpp. In my
opinion, they should probably be split off into their own separate file
because editor.cpp is getting way too big, but this will do for now.
The entity getters I'm referring to are entityclass::getscm(),
entityclass::getlineat(), entityclass::getcrewman(), and
entityclass::getcustomcrewman().
Even though the player should always exist, and the player should always
be indice 0, I wouldn't want to make that assumption. I've been wrong
before.
Also, these functions returning 0 lull you into a false sense of
security. If you assume that commands using these functions are fine,
you'll forget about the fact that `i` in those commands could be
potentially anything, given an invalid argument. In fact, it's possible
to index createactivityzone(), flipgravity(), and customposition()
out-of-bounds by setting `i` to anything! Well, WAS possible. I fixed it
so now they can't.
Furthermore, in the game.scmmoveme block in gamelogic(), obj.getplayer()
wasn't even checked, even though it's been checked in all other places.
I only caught it just now because I wanted to bounds-check all usages of
obj.getscm(), too, and that game.scmmove block also used obj.getscm()
without bounds-checking it as well.
When this is done, there is potential for a mistake to occur when
writing out the bounds check, which is eliminated when using the macro
instead. Luckily, this doesn't seem to have happened, but what's even
worse is I hardcoded 400 instead of using SDL_arraysize(ed.level), so if
the size of ed.level the bounds checks would all be wrong, which
wouldn't be good. But that's fixed now, too.
This is because if they are manually written out, they are more likely
to contain mistakes.
In fact, after further review, there are several functions with
incorrect manually-written bounds checks:
* entityclass::entitycollide()
* entityclass::removeentity()
* entityclass::removeblock()
* entityclass::copylinecross()
* entityclass::revertlinecross()
All of those functions forgot to do 'greater than or equal to' instead
of 'greater than' when comparing against the size of the vector. So they
were erroneous. But they are now fixed.
It's better to do INBOUNDS_VEC(i, obj.entities) instead of 'i > -1'.
'i > -1' is used in cases like obj.getplayer(), which COULD return a
sentinel value of -1 and so correct code will have to check that value.
However, I am now of the opinion that INBOUNDS_VEC() should be used and
isn't unnecessary.
Consider the case of the face() script command: it's not enough to check
i > -1, you should read the routine carefully. Because if you look
closely, you'll see that it's not guaranteed that 'i' will be initialized
at all in that command. Indeed, if you call face() with invalid
arguments, it won't be. And so, 'i' could be something like 215, and
that would index out-of-bounds, and that wouldn't be good. Therefore,
it's better to have the full bounds check instead of checking only one
bounds. Many commands are like this, after some searching I can also
name position(), changemood(), changetile(), changegravity(), etc.
It also makes the code more explicit. Now you don't have to wonder what
-1 means or why it's being checked, you can just read the 'INBOUNDS' and
go "oh, that checks if it's actually inbounds or not".
In 2.0, 2.1, and 2.2, calling flipgravity() on an entity that wasn't
rule 6 would change it to rule 7. In 2.3 currently, doing this will only
change it to rule 7 if it's already rule 6, starting with the
introduction of the change where if an entity was rule 7 it would be
changed to rule 6.
The crewmate conversion trick has been restored, but converting an
entity to a crewmate will change its rule to 6, not 7 like in pre-2.3.
If you want it to be changed to rule 7 instead of 6, you'd have to call
flipgravity() twice in 2.3 and only once in pre-2.3, which would make
maintaining compatibility between versions a bit harder.
So to fix this, I'm inverting it so that if you call flipgravity() on an
entity that isn't rule 7, it will be converted to rule 7, and only if
it's rule 7 will it be converted to rule 6.
This is a followup to b7cf6855b0 and
10ed0058fd.
In 2.2, if you had a duplicate player entity, there'd be no way to get
rid of it. Except for the recently-discovered Arbitrary Entity
Manipulation glitch, where you set `i` to the indice of the entity and
call flipgravity() on it, turning its rule to 7 and making it no longer
a player entity.
However, I patched this useful mechanic out when I made it so that you'd
no longer be able to convert entities with rule 0 to rule 6
(10ed0058fd, upheld in
b7cf6855b0), because doing so would mean
being able to softlock the game by not having any player entity.
So, in this patch, I'm making it so that you CAN convert duplicate
player entities to crewmates (and thus basically destroy them), but you
can't do that to the TRUE player entity (i.e. the first entity indice
that has rule 0, which is basically always indice 0).
So there's this trick that I recently discovered, since many script
commands don't initialize `i` it's possible to use them to manipulate
arbitrary entities by specifying their indice.
This means in 2.2 you can convert entities to pseudo-crewmates by
changing their rule to 6. Except in 2.3, this was fixed when I fixed the
command to work on flipped crewmates as well. So I'm restoring this
functionality, but I recognize the protection that my previous change to
the command did in preventing levels from destroying the player entity
by changing the player's rule to something nonzero, so instead of
removing the if-conditional entirely, I'm making it so that it will only
set the rule if the entity's rule isn't 0.
It's trivially easy to send the scripting system into an infinite loop
on the same frame (i.e. without any script delay in between, i.e. within
the same execution of script.run()). Just take a look at these two
scripts:
a:
iftrinkets(0,b)
#
b:
iftrinkets(0,a)
#
The hashes are to prevent the scripting system from parsing iftrinkets()
using the internal version instead of the simplified version, because
after doing a simplified iftrinkets(), the parser will (to oversimplify)
execute the last line of the script as internal.
Anyway, sending the game into an infinite loop like this will cause the
Not Responding dialog on Windows.
So to prevent this from happening, I've added an execution counter to
scriptclass::run(). If it gets too high, we're in an infinite loop and
so we stop running the script.
Fixes#402 (Violet appearing 1 frame after the Ship teleporter room
appears).
The root cause of this bug is due to the game loop order changes made
with the over-30-FPS patch. 2.2's game loop order was gameinput(),
gamerender(), then gamelogic(). In 2.3, gamerender() was moved to the end
as it required special code to render more than 30 frames a second. So
2.3's game loop order is gameinput(), gamelogic(), then gamerender().
In hindsight, I could have preserved the game loop order, but this would
require some more complex code in the game loop than what is there
currently. Fixing it now would fix rendering glitches such as this one
(along with being able to remove script.dontrunnextframe with the
two-frame-delay fix), but it could also introduce new rendering glitches
we don't yet know about. After discussing this in Discord DMs with
flibit, we agreed that the game loop order should be fixed in 2.4
instead.
When the game teleports you, gamelogic() runs script.teleport(). This
function will gotoroom to the teleporter destination, then it loads the
teleport script. Some teleport scripts (such as levelonecomplete, which
creates Violet) expect that their entities will be created, and more
generally that their script will be ran, on the same frame that the
gotoroom happens, i.e. by the time that the next gamerender() happens,
i.e. script.run() should be ran before the next gamerender() happens.
This would be true on the old game loop order, but with the new game
loop order, gamerender() gets ran directly after gamelogic() with no
script.run() in between.
To fix this, I did the same thing I did with the two-frame-delay fix
(#317), where I ran the script for that frame, but in order to prevent
running it twice I set script.dontrunnextframe to true.
This fixes the bug where Viridian would appear to "zip" when they would
be teleported to the position of the teleporter before being flung out
of it.
As discussed in #393, I've also set the oldxp/oldyp when Viridian is
temporarily positioned in the center of the room, even though at this
point they should already be invisible. This is just to be safe.
Fixes#393.
Okay, so basically here's the include layout that this game now
consistently uses:
[The "main" header file, if any (e.g. Graphics.h for Graphics.cpp)]
[blank line]
[All system includes, such as tinyxml2/physfs/utfcpp/SDL]
[blank line]
[All project includes, such as Game.h/Entity.h/etc.]
And if applicable, another blank line, and then some special-case
include screwy stuff (take a look at editor.cpp or FileSystemUtils.cpp,
for example, they have ifdefs and defines with their includes).
Including a header file inside another header file means a bunch of
files are going to be unnecessarily recompiled whenever that inner
header file is changed. So I minimized the amount of header files
included in a header file, and only included the ones that were
necessary (system includes don't count, I'm only talking about includes
from within this project). Then the includes are only in the .cpp files
themselves.
This also minimizes problems such as a NO_CUSTOM_LEVELS build failing
because some file depended on an include that got included in editor.h,
which is another benefit of removing unnecessary includes from header
files.
graphics.textbox.clear() should be used instead of
graphics.textboxremove() or graphics.textboxremovefast(), because even
with graphics.textboxremovefast(), you'll still have to process at least
one frame of GAMEMODE logic before the text boxes are actually properly
removed, and this caused a 1-frame glitch when exiting playtesting with
text boxes on-screen and then re-entering playtesting.
Technically I could've only fixed it in Game::returntoeditor(), but I
wanted to be safe, so I also fixed it in scriptclass::hardreset(), too.
When I moved duplicate player entity removal to
scriptclass::hardreset(), I also inadvertently made it so all non-player
entities got removed as well, even though this wasn't my intent. And
thus, pressing Enter to restart a time trial removes every entity except
the player, since it calls script.hardreset().
The time trial script.hardreset() is bad for other reasons (see #367),
however it's still a good idea to reset only what's needed in
script.hardreset().
So you get a trophy and achievement for completing the game in Flip
Mode. Which begs the question, how does the game know that you've played
through the game in Flip Mode the entire way, and haven't switched it
off at any point? It looks like if you play normally all the way up
until the checkpoint in V, and then turn on Flip Mode, the game won't
give you the trophy. What gives?
Well, actually, what happens is that every time you press Enter on a
teleporter, the game will set flag 73 to true if you're NOT in Flip
Mode. Then when Game Complete runs, the game will check if flag 73 is
off, and then give you the achievement and trophy accordingly.
However, what this means is that you could just save your game before
pressing Enter on a teleporter, then quit and go into options, turn on
Flip Mode, use the teleporter, then save your game (it's automatically
saved since you just used a teleporter), quit and go into options, and
turn it off. Then you'd get the Flip Mode trophy even though you haven't
actually played the entire game in Flip Mode.
Furthermore, in 2.3 you can bring up the pause menu to toggle Flip Mode,
so you don't even have to quit to circumvent this detection.
To fix both of these exploits, I moved the turning on of flag 73 to
starting a new game, loading a quicksave, and loading a telesave (cases
0, 1, and 2 respectively in scriptclass::startgamemode()). I also added
a Flip Mode check to the routine that runs whenever you exit an options
menu back to the pause menu, so you can't circumvent the detection that
way, either.
For some reason, there were just exact duplicates of the talkgreen_2
script and alarmon/alarmoff commands. I have no idea why, but cppcheck
identified them.
There's no need to use a template here. Just manually call SDL_tolower()
or SDL_toupper() as needed.
Oh yeah, and use SDL_tolower() and SDL_toupper() instead of libc
tolower() and toupper().
They're always fixed-size anyways, there's no need for them to be
vectors.
Also used the new INBOUNDS_ARR() macro for the map.explored bounds
checks in Script.cpp, and made map.explored a proper bool array instead
of an int array.
Since they're always fixed-size, they don't need to be dynamically-sized
vectors.
entityclass::customcrewmoods is now a proper bool instead of an int now,
and I replaced the hardcoded constant 6 with a static const int Game
attribute to make it easier to change.
It could index the `words` array out-of-bounds if there were more than
40 arguments in a command. Not like that would ever happen, but it's
still good to be sure.
This was caused by the fact that not all unlocks were done through the
Game::unlocknum() function. Some just set the unlock number directly.
But it's fixed now.
For whatever reason, not all arguments of createentity() are exposed in
the command.
We have to keep in mind that (1) unspecified arguments default to 0
(instead of the 320 and 240 for argument 8 and 9 that createentity()
usually defaults to), and that (2) arguments persist across commands.
(Why not get rid of argument persistence, you say? Unfortunately, some
levels rely on argument persistence to call gotoposition() without
specifying the third argument, even though you're supposed to specify
all three arguments.)
To add these arguments without breaking levels, I re-added the
createentity() defaults of 320 and 240 for args 8 and 9, and then I
reset the new arguments afterwards when I'm done. Technically this could
be bad if other commands used those higher arguments, but none of them
really do. (Except createcrewman(), but it only sets argument 6 to 0
sometimes anyway, but argument 6 is already supposed to default to 0.)
This patch is very kludge-y, but at least it fixes a semi-noticeable
visual issue in custom levels that use internal scripts to spawn
entities when loading a room.
Basically, the problem here is that when the game checks for script
boxes and sets newscript, newscript has already been processed for that
frame, and when the game does load a script, script.run() has already
been processed for that frame.
That issue can be fixed, but it turns out that due to my over-30-FPS
game loop changes, there's now ANOTHER visible frame of delay between
room load and entity creation, because the render function gets called
in between the script being loaded at the end of gamelogic() and the
script actually getting run.
So... I have to temporary move script.run() to the end of gamelogic()
(in map.twoframedelayfix()), and make sure it doesn't get run next
frame, because double-evaluations are bad. To do that, I have to
introduce the kludge variable script.dontrunnextframe, which does
exactly as it says.
And with all that work, the two-frame (now three-frame) delay is fixed.
Ironically enough, resetting more variables in script.hardreset() makes
the glitchy fadeout system even more glitchy. Resetting map.towermode,
for example, makes it so that if you're in towers when you quit to the
menu, script.hardreset() makes it so that the game thinks you're no
longer inbounds (because it no longer thinks you're in a tower and thus
considers coordinates in the space of 40x30 tiles to be inbounds instead
of 40x700 or 40x100 tiles to be inbounds), calls map.gotoroom(), which
resets the gamestate to 0. So if we're using the old system, it's better
to reset only as much as needed.
And furthermore, we shouldn't be relying on script.hardreset() to
initialize variables for us. That should be done at the class
constructor level. So I've gone ahead and initialized the variables in
class constructors, too.
This is the second part of what is necessary for credits warp to work.
The speedrunners call this "text storage". You need to get the
advancetext prompt up without a text box in order to be able to
increment the gamestate without bound. In 2.0, script.hardreset() reset
the text boxes, but not the prompt.
It seems like they were unfinished. This commit makes them properly
work.
When a track is stopped with stopmusic() or musicfadeout(),
resumemusic() will resume from where the track stopped. musicfadein()
does the same but does it with a gradual fade instead of suddenly
playing it at full volume.
I changed several interfaces around for this. First, setting currentsong
to -1 when music is stopped is handled in the hook callback that gets
called by SDL_mixer whenever the music stops. Otherwise, it'd be
problematic if currentsong was set to -1 when the song starts fading out
instead of when the song actually ends.
Also, music.play() has a few optional arguments now, to reduce the
copying-and-pasting of music code.
Lastly, we have to roll our own tracker of music length by using
SDL_GetPerformanceCounter(), because there's no way to get the music
position if a song fades out. (We could implicitly keep the music
position if we abruptly stopped the song using Mix_PauseMusic(), and
resume it using Mix_ResumeMusic(), but ignoring the fact that those two
functions are also used on the unfocus-pause (which, as it turns out, is
basically a non-issue because the unfocus-pause can use some other
functions), there's no equivalent for fading out, i.e. there's no
"fade out and pause when it fully fades out" function in SDL_mixer.) And
then we have to account for the unfocus-pause in our manual tracker.
Other than that, these commands are now fully functional.
Now it's really, really smooth. Except for like the last frame when it
goes down, which I sometimes didn't notice (but maybe it didn't happen
every time due to being lucky on the delta timesteps or something,
whatevs.)
Looks like duplicate player entities persisting across rooms is a
semi-useful feature used by some levels. Still, though, it's a bit of a
nuisance to have duplicate player entities persisting across game
sessions. And levels can't rely on this persistence anyway, anyone could
just close the game and re-open it to get rid of the duplicate entities
regardless.
Continuing from #280, another potential source of out-of-bounds indexing
(and thus, Undefined Behavior badness) comes from script commands. A
majority of them don't do any input validation at all, which means the
potential for out-of-bounds indexing and segfaulting in custom levels.
So it's always good to add bounds checks to them.
Interesting note, the only existing command that has bounds checks is
the flag() command. That means you can't turn out-of-bounds flags on or
off. But there's no bounds checks for ifflag(), or customifflag(), which
means you CAN index out-of-bounds with those commands! That's a bit bad
to do, so.
Also, I decided to add the bounds checks for playef() at the
musicclass::playef() level, instead of just the level of the playef()
command. I don't know of any other cases outside of the command where
musicclass::playef() will index out of bounds, but musicclass is the one
containing the indexed vector anyway, I wanted to cover more cases, and
it's better to be safe than sorry.
obj.getplayer() can return -1, which can cause out-of-bounds indexing of
obj.entities, which is really bad. This was by far the most changes, as
obj.getplayer() is the most used entity-getting function that returns
-1, as well as the most-used function whose sentinel value goes
unchecked.
To deal with the usage of obj.getplayer() in mapclass::warpto(), I just
added general bounds checks inside that function instead of changing all
the callers.
A few months ago, I added ghosts to the VVVVVV: Community Edition editor. I was told recently I should think
about upstreaming it, and with Terry saying go ahead I finally ported them into VVVVVV. There's one slight
difference however--you can choose whether you have them or not in the editor's settings menu. They're off by
default, and this is saved to the save file.
Anyway, when you're playtesting, the game saves the players position, color, room coordinates and sprite every 3
frames. The max is 100, where if it tries to add more, the oldest one gets removed.
When you exit playtesting, the saved positions appear one at a time, and you can use the Z key to speed it up.
[Here's a video of them in action.](https://o.lol-sa.me/4H21zCv.mp4)
