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)
The actual unindent is done in a separate commit to minimize noise,
because diffs are terrible at clearly conveying unindents (it should put
all the minus lines together and all the plus lines together, too).
The entirety of the rest of scriptclass::loadcustom() is encased in a
block that first checks if the script with the name even exists. Instead
of indenting the rest of the function, just invert the check and reduce
indentation level.
This commit refactors custom level scripts to no longer be stored in one
giant vector containing not only every single script name, but every
single script's contents as well. More specifically,
scriptclass::customscript has been converted to an std::vector<Script>
scriptclass::customscripts (note the extra S), and a Script is just a
struct with an std::string name and std::vector<std::string> contents.
This is an improvement in both performance and maintainability. The game
no longer has to look through script contents in case they're actually
script names, and then manually extract the script contents from there.
Instead, all it has to do is look for script names only. And the
contents are provided for free. This results in a performance gain.
Also, the old system resulted in lots of boilerplate everywhere anytime
scripts had to be handled or parsed. Now, the boilerplate is only done
when saving or loading a custom level. This makes code quality much,
much better.
To be sure I didn't actually change anything, I tested by first saving
Dimension Open in current 2.3 (because current 2.3 gets rid of the
awful edentity whitespace), and then resaved it on this patch. There is
absolutely no difference between the current-2.3-resave and
this-patch-resave.
This resulted in two bugs:
1. Custom assets would not be unmounted when quitting to the menu.
2. Custom assets would be unmounted when playtesting a level.
The solution is to unmount assets in Game::quittomenu() instead.
Main game would retain custom level assets, now fixed. Also, custom fonts load properly. Finally, levels can be stored as a zip and placed in the levels folder, with the .vvvvvv file at the root of the zip and custom asset folders (graphics, sounds etc) also at the root.
This commit adds bounds checks to those commands in case say()/reply()
asks for more lines than there are left in the all-script-lines buffer
(not just the current script, so in order for it to segfault your script
has to be last in the all-script-lines vector), and in case text() asks
for more lines than there are in the rest of the rest of the parsed
internal script.
For some reason, scriptclass::loadcustom() sometimes refers to
`customscript` as `script.customscript` instead of `customscript`. The
`script.` is unnecessary.
Otherwise, it would end up indexing a vector out-of-bounds, which is UB
and causes a segfault, too. This is used in some constructs like
say(-1)
<internal command>
where the text contents don't matter, only that a text box shows up.
The `speak` command is the exact same as the `speak_active` command,
except without one line of code. So instead of copy-pasting the entire
thing, it's better to just combine them into the same chunk of code.
Resetting game.activeactivity fixes triggering Undefined Behavior if you
quit to the menu while standing inside an activity zone, and then
re-entered the game. Resetting game.act_fade also fixes the activity
zone prompt fadeout that happens once the above segfault is fixed.
Don't worry, other activity-zone like variables such as teleporter
prompts and trophy text are already covered. obj.trophytext is reset in
scriptclass::hardreset(), too, and game.readytotele is reset every time
mapclass::gotoroom() is called, and mapclass::gotoroom() is called every
time a gamemode is started.
Instead of using somewhat-obtuse for-loops to initialize or reset these
vectors, it takes up less lines of code and is clearer if we use
std::vector::resize() and std::vector::clear() instead.
Otherwise, if you died after entering a room with a horizontal or
vertical warp background (but not the all-sides warp background), the
warp background would be the first thing you see when going to the Game
Over screen, and would then start scrolling downwards with the proper
tower background coming in from the top.
This oversight seems to have always been in the game.
Was No Death Mode actually tested? Like, did anyone ever play through
the entire game without dying in the Warp Zone, or even AFTER completing
the Warp Zone, like, ever?
It's less code being copied and pasted, especially since for my
over-30-FPS patch I would have to make a separate function for each if
both of them were still there, but if they're unified into one then I
will only have to make one more function.
And since map.scrolldir is now used outside of GAMEMODE, we'll need to
reset it in hardreset() and when exiting playtesting.
Stringly-typed things are bad, because if you make a typo when typing
out a string, it's not caught at compile-time. And in the case of this
menu system, you'd have to do an excessive amount of testing to uncover
any bugs caused by a typo. Why do that when you can just use an enum and
catch compile-time errors instead?
Also, you can't use switch-case statements on stringly-typed variables.
So every menu name is now in the enum Menu::MenuName, but you can simply
refer to a menu name by just prefixing it with Menu::.
Unfortunately, I've had to change the "continue" menu name to be
"continuemenu", because "continue" is a keyword in C and C++. Also, it
looks like "timetrialcomplete4" is an unused menu name, even though it
was referenced in Render.cpp.
It's treated like a bool anyway, so might as well make it one.
This also necessitates updating every single instance where it or an
element inside it is used, too.
Same principle as removing the separate variable to track number of
collected trinkets. This means it's less error-prone as we're no longer
tracking number of trinkets separately.
In the function that counts the number of trinkets, I would've liked to
have used std::count_if(). However, the most optimal way would require
using a lambda, and lambdas are too new for the C++ standard we're
using. So I just bit the bullet and counted them manually.
game.trinkets is supposed to be correlated with obj.collect, however why
not just count obj.collect directly?
This turns game.trinkets into a function, game.trinkets(), which will
directly count the number of collected trinkets and return it. This will
fix a few corner cases where the number of trinkets can desync with the
actual collection statuses of trinkets.
In order to keep save compatibility with previous versions of VVVVVV,
the game will still write the <trinkets> variable. However, it will not
read the <trinkets> variable from a save file.
This removes the variables obj.nentity and obj.nlinecrosskludge, as well
as removing the 'active' attribute from the entity class object. Now
every entity you access is guaranteed to be real and you don't have to
check the 'active' variable.
The biggest part of this is changing createentity() to modify a
newly-created entity object and push it back instead of already
modifying an indice in obj.entities.
As well, removing an entity now uses the new obj.removeentity() function
and removeentity_iter() macro.
Looks like this function was created because editorclass::load() takes
in a string by reference, not by value, and thus mutates it afterwards,
so if you passed a string in when you didn't want it to be mutated, bad
things would happen.
However, a better workaround for the above issue would simply to
duplicate the string and pass that string instead, thus the original
string wouldn't be affected.
This removes global arg passing from all functions on editorclass.
Callers have been updated correspondingly. Additionally, all 'dwgfx' has
been replaced with 'graphics' in editor.cpp.
This commit removes all global args from the parameters of each function
on the scriptclass object, and updates all places they are called
accordingly. It also changes all instances of 'dwgfx' to 'graphics' in
Script.cpp.
Interestingly enough, it looks like editor.h depended on Script.h's
class define of the musicclass. I've temporarily placed the class define
in editor.h, but by the end of this patchset it'll be gone.
This commit removes the global args being passed around from the
function args on the mapclass object, as well as updating all callers in
other files to not have those args. Furthermore, 'dwgfx' has been
renamed to 'graphics' in Map.cpp.
This commit removes all global args from functions on the entityclass
object, and updates the callers of those functions in other files
accordingly (most significantly, the game level files Finalclass.cpp,
Labclass.cpp, Otherlevel.cpp, Spacestation2.cpp, WarpClass.cpp, due to
them using createentity()), as well as renaming all instances of 'dwgfx'
in Entity.cpp to 'graphics'.
I've decided to call dwgfx/game/map/obj/key/help/music the "global args".
Because they're essentially global variables that are being passed
around in args.
This commit removes global args from all functions on the Game class,
and deals with updating the callsites of said functions accordingly. It
also renames all usages of 'dwgfx' in Game.cpp to 'graphics', since the
global variable is called 'graphics' now.
Interesting to note, I was removing the class defines from Game.h, but
it turns out that Graphics.h depends on the mapclass and entityclass
defines from Game.h. And also Graphics.h spelled mapclass wrong (it
forgot the "class") so I just decided to use that existing line instead.
This is only temporary and after all is said and done, at the end of
this pull request those class defines will be gone.
This is a refactor that turns the script-related arrays `ed.sb`, and
`ed.hooklist` into C++ vectors (`script.commands` was already a vector, it was
just misused). The code handling these vectors now looks more like idiomatic
C++ than sloppily-pasted pseudo-ActionScript. This removes the variables
`script.scriptlength`, `ed.sblength`, and `ed.numhooks`, too.
This reduces the amount of code needed to e.g. simply remove something from
any of these vectors. Previously the code had to manually shift the rest of
the elements down one-by-one, and doing it manually is definitely error-prone
and tedious.
But now we can just use fancy functions like `std::vector::erase()` and
`std::remove()` to do it all in one line!
Don't worry, I checked and `std::remove()` is in the C++ standard since at least
1998.
This patch makes it so the `commands` vector gets cleared when
`scriptclass::load()` is ran. Previously, the `commands` vector never actually
properly got cleared, so there could potentially be glitches that rely on the
game indexing past the bounds set by `scriptlength` but still in-bounds in the
eyes of C++, and people could potentially rely on such an exploit...
However, I checked, and I'm pretty sure that no such glitch previously existed
at all, because the only times the vector gets indexed are when `scriptlength`
is either being incremented after starting from 0 (`add()`) or when it's
underneath a `position < scriptlength` conditional.
Furthermore, I'm unaware of anyone who has actually found or used such an
exploit, and I've been in the custom level community for 6 years.
So I think it's fine.
The problem with flipme() was that it WAS properly reflecting
("reflecting" as in mirroring over a given line) the text box over the
line y=120, BUT it forgot to account for the height of the text box.
Thus, the text box position would be off by the length of its own
height. And when the text box got taller, this offset would worsen and
worsen.
The game uses magic values x=-500 and y=-500 to indicate when a text box
should be centered horizontally or vertically. It does this for x=-1
too, but it's buggy because it only looks at the first line of the text
box to center it. In this commit I fix it so that it will look at all of
the lines of the text box to center it instead.
This fixes a bug where if warpdir() was used during in-editor
playtesting, the changed warp direction would persist even when leaving
playtesting.
This would be very annoying to correct back every time you playtested
and warpdir() was used, so I've added some kludge to store the actual
warp direction of each room when entering playtesting, and then set the
warp directions back when leaving playtesting.
This has two benefits:
(1) The game uses less resources when it is asked to gotoroom to the
same room because it is no longer redrawing the warp background
every single frame, which is very wasteful.
(2) The warp background no longer freezes or flickers if the player is
standing inside a gotoroom script box (which calls gotoroom every
frame or every other frame, because every time the gotoroom happens
the script box gets reloaded).
