If spawned as a custom enemy (createentity entry 56), or spawned outside
of the rooms they spawn in in the main game, they will repeatedly clone
themselves every frame, which profusely leaks memory. In fact it quickly
causes a crash in 2.2 and previous, but 2.3 fixes that crash, so it just
keeps spawning enemies endlessly, which eventually lags the game, and
eventually can out-of-memory your system (bad!).
The problem is those movement types rely on entclass::setenemyroom() to
change their `behave` to be 11 or 13. Else, the new entity created will
still have `behave` 10 or 12, which will create ANOTHER entity in the
same way, and so on, and so forth.
So to fix this, just make it so if an enemy is still `behave` 10 or 12
by the end, then, just set it to -1. That way it'll stay still and won't
cause any harm.
I considered setting the `behave` to 11 or 13 respectively, but, that's
probably going farther than just fixing a memory leak, and anyways, it's
not that much useful for me as a custom level maker, and the entities
spawned aren't really controllable.
Previously, turning glitchrunner mode on essentially locked you to
emulating 2.0, and turning it off just meant normal 2.3 behavior. But
what if you wanted 2.2 behavior instead? Well, that's what I had to ask
when a TAS of mine would desync in 2.3 because of the two-frame delay
fix (glitchrunner off), but would also desync because of 2.0 warp lines
(glitchrunner on).
What I've done is made it so there are three states to glitchrunner mode
now: 2.0 (previously just the "on" state), 2.2 (previously a state you
couldn't use), and "off". Furthermore, I made it an enum, so in case
future versions of the game patch out more glitches, we can add them to
the enum (and the only other thing we have to update is a lookup table
in GlitchrunnerMode.c). Also, 2.2 glitches exist in 2.0, so you'll want
to use GlitchrunnerMode_less_than_or_equal() to check glitchrunner
version.
This fixes a regression that desyncs my Nova TAS after re-removing the
1-frame input delay.
Quick stopping is simply holding left/right but for less than 5 frames.
Viridian doesn't decelerate when you let go and they immediately stop in
place. (The code calls this tapping, but "quick stopping" is a better
name because you can immediately counter-strafe to stop yourself from
decelrating in the first place, and that works because of this same
code.)
So, the sequence of events in 2.2 and previous looks like this:
- gameinput()
- If quick stopping, set vx to 0
- gamerender()
- Change drawframe depending on vx
- gamelogic()
- Use drawframe for collision (whyyyyyyyyyyyyyyyyyyyyyyyyyyy)
And now (ignoring the intermediate period where the whole loop order was
wrong), the sequence of events in 2.3 looks like this:
- gamerenderfixed()
- Change drawframe depending on vx
- gamerender()
- gameinput()
- If quick stopping, set vx to 0
- gamelogic()
- Use drawframe for collision (my mind has become numb to pain)
So, this means that all the player movement stuff is completely the
same. Except their drawframe is going to be different.
Unfortunately, I had overlooked that gameinput() sets vx and that
animateentities() (in gamerenderfixed()) checks vx. Although, to be
fair, it's a pretty dumb decision to make collision detection be based
on the actual sprites' pixels themselves, instead of a hitbox, in the
first place, so you'd expect THAT to be the end of the dumb parade. Or
maybe you shouldn't, I don't know.
So, what's the solution?
What I've done here is added duplicates of framedelay, drawframe, and
walkingframe, for collision use only. They get updated in gamelogic(),
after gameinput(), which is after when vx could be set to 0.
I've kept the original framedelay, drawframe, and walkingframe around,
to keep the same visuals as closely as possible.
However, due to the removal of the input delay, whenever you quick stop,
your sprite will be wrong for just 1 frame - because when you let go of
the direction key, the game will set your vx to 0 and the logical
drawframe will update to reflect that, but the previous frame cannot
know in advance that you'll release the key on the next frame, and so
the visual drawframe will assume that you keep holding the key.
Whereas in 2.2 and below, when you release a direction key, the player's
position will only update to reflect that on the next frame, but the
current frame can immediately recognize that and update the drawframe
now, instead of retconning it later.
Basically the visual drawframe assumes that you keep holding the key,
and if you don't, then it takes on the value of the collision drawframe
anyway, so it's okay. And it's only visual, anyway - the collision
drawframe of the next frame (when you release the key) will be the same
as the drawframe of the frame you release the key in 2.2 and below.
But I really don't care to try and fix this for if you re-enable the
input delay because it's minor and it'd be more complicated.
This fixes one of two desyncs in my Nova TAS.
The problem is that by adding two frames of edge-flipping to vertically
moving platforms, Viridian's framedelay is updated for one extra frame
after they step off of a vertically-moving platform. This then messes up
Viridian's drawframe for the rest of the TAS until they die in a
drawframe-sensitive trick.
The solution here is to only set the visual onroof/onground to 1
instead. The logical onroof/onground is still 2, so players still have
two frames of edge-flipping off of vertically-moving platforms - it just
won't really look like it (not that you could easily tell anyway).
This fixes a bug where the player's y-position would be incorrect if
they loaded a save that was on a conveyor and it was their first time
loading in since the game was opened.
This is because on the first load, the game creates a new player entity,
but on subsequent loads, the game re-uses the player entity. Subsequent
loads use mapclass::resetplayer(), which already has the newxp/newyp
fix, but as for the first time, the game does not set newxp/newyp.
So just set newxp/newyp, like in mapclass::resetplayer().
There is a pattern in the Super Gravitron that is meant to "staircase",
similar to the Gravitron in Intermission 2. Something like:
[]
[]
[]
[] []
[] []
Unfortunately, due to an oversight, this pattern can only ever produce 1
square or 4 squares, which look out of place.
Both gravitrons are state machines (of course). States 20 and 21 in the
Super Gravitron are this staircase pattern (state 20 spawns the squares
on the left, state 21 spawns the squares on the right).
The only way states 20 and 21 can be reached is through state 1, and the
only way state 1 can be reached is through state 3. The only way state 3
can be reached is through states 28, 29, 30, and 31.
In states 20 and 21, the variable used to keep track of the amount of
squares spawned is swnstate4. However, states 28, 29, 30, and 31 all end
up using swnstate4, and at the end of states 28 and 29, swnstate4 will
be 7, and at the end of states 30 and 31, swnstate4 will be 3. This
means if we go to states 20 and 21 after coming from states 28 and 29,
we will only get 1 square, and if we go to states 20 and 21 after coming
from states 30 and 31, we will only get 4 squares.
This can be clearly filed under a failure to reset appropriate state.
What's the solution here? Just reset swnstate4 in state 3, so there will
be 7 squares, as intended. This also fixes the bug for state 22 as well,
which is affected in the same manner.
This is a lot of copy-pasted code, but a little bit of copy-pasting
never hurt anyone...
The keybind to interact with activity zones and teleporters is now
separate from the keybind to open the map, or return to the editor from
in-editor playtesting, or restart a time trial. The keybind is now E,
and the default controller bind is X. No controller button prompts, but
the game didn't have controller button prompts anyways, so whatever.
Doing this now because if people's muscle memory are going to be broken
by not being able to spam the map keybind anymore, at least we can help
a bit by changing the keybind so they can keep spamming it - their
muscle memory is going to be broken anyways.
This option has to be enabled by going to the speedrunner menu options
and selecting "interact button". It is disabled by default.
All prompt text needs to be string-interpolated every time they are
drawn, because it is possible for people to change which interact button
they use in the middle of gameplay, via the in-game options.
Closes#736.
If you have completed No Death Mode, and entered the Master of the
Universe trophy room in the Secret Lab in over-30-FPS mode, it would
appear to start at one position before quickly zipping to another during
the deltaframes.
This is because it updates its position after the initial assignments of
lerpoldxp/lerpoldyp in entityclass::createentity().
Other entities do this too, and what's been done for them is to
copy-paste the lerpoldxp/lerpoldyp updates alongside the xp/yp updates.
However, instead of single-case patching this deltaframe glitch, I've
opted to fix ALL cases by simply moving the lerpoldxp/lerpoldyp
assignments to the end of the function, guaranteeing that all entities
that update their position after the initial assignment in the function
will not have any deltaframe glitches.
Of course, there's still the duplicate lerpoldxp/lerpoldyp updates in
entityclass::updateentities()... I'm not sure what to do about those.
vx/vy mean x-velocity and y-velocity... except here, where it seems like
they're used as extra parameters that do different things depending on
the entity. But it seems like at one point they were actually meant to
be the speed of the entity (this is the case for the unused decorative
particle entities), and then just never got renamed when they weren't.
The custom levels community named these two parameters meta1 and meta2
in the reference list of entities for the createentity() script command,
so that's what I'm naming them here. This will avoid confusion (I know
that some people reading this function have genuinely mistaken the vx/vy
for actually meaning x-velocity and y-velocity, simply because they were
named that way).
I have spelled out each overloaded version instead, and only the
overloads that are actually used - which just happens to be everything
except the 8-argument one. I don't want to deal with callers right now
(there are too many of them), so I'm not going to change the names that
the callers use, nor do I want to change the amount of arguments any
existing callers use right now - but we will have to deal with them in
one way or another when we move to C.
The script command createentity() is always an int. But not only that,
every time createentity() is used, its arguments are always treated like
ints. Always. I knew that vx/vy were floats because of the int casts in
the function, but I didn't even realize that xp/yp were floats, too,
until I checked just now! That's how much they're treated like ints.
All int casts in createentity() have also been removed, due to being
unnecessary (either because of us suppressing MSVC implicit conversion
warnings, or because there are now no longer any conversions happening).
During the final stretch, after Viridian turns off the Dimensional
Stability Generator, the map goes all psychedelic and changes colors
every 40 frames. Entities change their colors too, including conveyors,
moving platforms, and disappearing platforms.
But play around with the disappearing platforms for a bit and you'll
notice they seem a bit glitchy. If you run on them at the right time,
the tile they use while disappearing seems to abruptly change whenever
the color of the room changes. If there's a color change while they're
reappearing (when you die and respawn in the same room as them), they'll
have the wrong tile and look like a conveyor. And even if you've never
interacted with them at all, dying and respawning in the same room as
them will change their tile to something wrong and also look like a
conveyor.
So, what's the problem? Well, first off, the tile of every untouched
disappearing platform changing into a conveyor after you die and respawn
in the same room is caused by a block of code in gamelogic() that gets
run on each entity whenever you die. This block of code is the exact
same block of code that gets ran on a disappearing platform if it's in
the middle of disappearing.
As a quick primer, every entity in the game has a state, which is just a
number. You can view each entity's state in
entityclass::updateentities().
State 0 of disappearing platforms is doing nothing, and they start with
an onentity of 1, which means they turn to state 1 when they get
touched. State 1 moves to state 2. State 2 does some decrementing, then
moves to state 3 and sets the onentity to 4. State 3 also does nothing.
After being touched, state 4 makes the platform reappear and move to
state 5, but state 5 does the actual reappearing; state 5 then sets the
state back to 0 and onentity back to 1.
So, back to the copy-pasted block of code. The block of code was
originally intended to fast-forward disappearing platforms if they were
in the middle of disappearing, so the player respawn code would properly
respawn the disappearing platform, instead of leaving it disappeared.
What it does is keep updating the entity, while the state of the entity
is 2, until it is no longer in state 2, then sets it to state 4.
Crucially, the original block of code only ran if the disappearing
platform was in state 2. But the other block of code, which was
copy-pasted with slight modifications, runs on ALL disappearing
platforms in final stretch, regardless of if they are in state 2 or not.
Thus, all untouched platforms will be set to state 4, and state 4 will
do the animation of the platform reappearing, which is invalid given
that the platform never disappeared in the first place. So that's why
dying and respawning in the same room as some disappearing platforms
during final stretch will change their tiles to be conveyors.
It seems to me that doing anything with death is wrong, here. The root
cause is that map.changefinalcol() "resets" the tile of every
disappearing platform, which is a function that gets called on every
color change. The color change has nothing to do with dying, so why
fiddle with the death code?
Thus, I've deleted that entire block of code.
What I've done to fix the issue is to make it so the tile of
disappearing platforms aren't manually controlled. You see, unlike other
entities in the game, the tile of disappearing platforms gets manually
modified whenever it disappears or reappears. Other entities use the
tile as a base and store their tile offset in the separate walkingframe
attribute, which will be added to the tile attribute to produce the
drawframe, which is the final thing that gets rendered - but for
disappearing platforms, their tile gets directly incremented or
decremented whenever they disappear or reappear, so when
map.changefinalcol() gets ran to update the tile of every platform and
conveyor, it basically discards the tile offset that was manually added
in.
Instead, what I've done is make it so disappearing platforms now use
walkingframe, and thus their final drawframe will be their tile plus
their walkingframe. Whenever map.changefinalcol() gets called, it is now
free to modify the tile of disappearing platforms accordingly - after
all, the tile offset is now stored in walkingframe, so no weird
glitchiness can happen there.
Custom levels can have warp lines. If you have a warp line and a warping
background in the same room, the warp line takes precedence over the
warp background.
However, whenever you enter a room with a warp line and warp background,
any entities on the warping edges will be drawn with screenwrapping for
one frame, even though they never wrapped at all.
This is due to frame ordering: when the warp line gets created,
obj.customwarpmode gets set to true. Then when the screen edges and
warping logic gets ran, the very first thing that gets checked is this
exact variable, and map.warpx/map.warpy get set appropriately - so
there's no way the entity could legitimately screenwrap.
However, that happens in gamelogic(). gamelogic() is also the one
responsible for creating entities upon room load, but that happens after
the obj.customwarpmode check - so when the game gets around to rendering
in gamerender(), it sees that map.warpx or map.warpy is on, and draws
the screenwrapping, even though map.warpx/map.warpy aren't really on at
all. Only when gamelogic() is called in the frame later do map.warpx and
map.warpy finally get set to false.
To fix this, just set map.warpx and map.warpy to false when creating
warp lines.
I just spotted this one - if vy isn't bounds-checked, this causes bogus
input from the createentity() script command to commit Undefined
Behavior. Should've spotted this one when I was adding bounds checks to
the rest of createentity() earlier, but at least it's fixed now.
This replaces all raw ed.level accesses with new setter and getter
funcs, which makes it easier to add bounds checks later. And I've also
removed all the manually-written bounds checks, since they will go into
the new getter and setter.
To get the room properties of a specific room, you use
editorclass::getroomprop(), which returns a pointer to the room
properties - then you just read off of that pointer. To set a room
property, you use editorclass::setroom<PROP>(), where <PROP> is the name
of the property. These are maintained using X macros to avoid
copy-pasting. editorclass::getroompropidx() is a helper function and
shouldn't be used directly.
I will need to separate these into two different variables because I
will need to move logical onground/onroof assignments to the start of
gamelogic() - if I kept them together, however, that would change the
visuals of onground/onroof, which I want to keep consistent with 2.2.
This once again fixes the facing directions of crewmates upon room load,
except now it covers more cases.
So, here is the saga so far:
- 2.0 (presumably) to 2.2: crewmate direction fix is special-cased at
the end of mapclass::loadlevel(). Only covers crewmates created during
the room load, does not cover crewmates created from scripts, only
covers state 18 of crewmates.
- 2.3 currently (after #220): crewmate direction fix is moved to
entityclass::createentity(), which covers every avenue of crewmate
creation (including from scripts), but still only covers state 18.
- This commit: crewmate direction fix now covers every possible state of
the crewmate, also does not copy-paste any code.
What I've done instead is to make it so createentity() will immediately
call updateentities() on the pushed-back entity. This is kludge-y, but
is completely okay to do, because unlike other entities, crewmate
entities never change their state or have any side-effects from
double-evaluation, meaning calling updateentities() on them is
idempotent and it's okay to call their updateentities() more than once.
This does have the slight danger that if the states of crewmates were to
change in the future to no longer be idempotent, this would end up
resulting in a somewhat hard-to-track-down double-evaluation bug, but
it's worth taking that risk.
This fix is not applied to entity 14 (the supercrewmate) because it is
possible that calling updateentities() on it will immediately remove the
entity, which is not idempotent (it's changing the state of something
outside the object). Supercrewmates are a bit difficult to work with
outside of the main game anyways, and if you spawn them you could
probably just use the changedir() script command to fix their direction,
so I'm not inclined to fix this for them anyway.
This copy-pasted code only existed because the previous loop order was
incorrect and rendered entities before they would get properly updated
by the fixed render function. Now, the fixed render function is
guaranteed to be called before the render function, so we can rely on
that to update the drawframe and realcol of entities instead of
duplicating the code ourselves in createentity().
The drawframe assignment is still kept to fix the case where dying while
completestop is active (i.e. during a trinket or crewmate rescue
cutscene) and respawning in a different room won't turn everything into
Viridian sprites.
These float attributes are assigned to, and then never read again. The
coordinate systems of blocks are a bit of a mess - some use xp/yp, some
use xp/yp and rect.x/rect.y - but I can confidently say that these are
never used, because it compiles fine if I remove the attributes from the
class, plus remove all assignments to it.
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.
This fixes a regression where moving platforms had no collision. Because
their width and height would be maintained, but their type would be -1.
(Also because I didn't test enough.)
In #565, I decided to set blocks' types to -1 when disabling them, to be
a bit safer in case there was some code that used block types but not
their width and heights. However, this means that when blocks get
disabled and re-created in the platform update loops, their types get
set to -1, which effectively also disables their collision.
In the end, I'll just have to compromise and remove setting blocks to
type -1. Because in a better world, we shouldn't be destroying and
creating blocks constantly just to move some platforms - however, fixing
such a fundamental problem is beyond the scope of at least 2.3 (there's
also the fact that this problem also results in some bugs that are a
part of compatibility, whether we like it or not). So I'll just remove
the -1.
This patch restores some 2.2 behavior, fixing a regression caused by the
refactor of properly using std::vectors.
In 2.2, the game allocated 200 items in obj.entities, but used a system
where each entity had an `active` attribute to signify if the entity
actually existed or not. When dealing with entities, you would have to
check this `active` flag, or else you'd be dealing with an entity that
didn't actually exist. (By the way, what I'm saying applies to blocks
and obj.blocks as well, except for some small differing details like the
game allocating 500 block slots versus obj.entities's 200.)
As a consequence, the game had to use a separate tracking variable,
obj.nentity, because obj.entities.size() would just report 200, instead
of the actual amount of entities. Needless to say, having to check for
`active` and use `obj.nentity` is a bit error-prone, and it's messier
than simply using the std::vector the way it was intended. Also, this
resulted in a hard limit of 200 entities, which custom level makers ran
into surprisingly quite often.
2.3 comes along, and removes the whole system. Now, std::vectors are
properly being used, and obj.entities.size() reports the actual number
of entities in the vector; you no longer have to check for `active` when
dealing with entities of any sort.
But there was one previous behavior of 2.2 that this system kind of
forgets about - namely, the ability to have holes in between entities.
You see, when an entity got disabled in 2.2 (which just meant turning
its `active` off), the indices of all other entities stayed the same;
the indice of the entity that got disabled stays there as a hole in the
array. But when an entity gets removed in 2.3 (previous to this patch),
the indices of every entity afterwards in the array get shifted down by
one. std::vector isn't really meant to be able to contain holes.
Do the indices of entities and blocks matter? Yes; they determine the
order in which entities and blocks get evaluated (the highest indice
gets evaluated first), and I had to fix some block evaluation order
stuff in previous PRs.
And in the case of entities, they matter hugely when using the
recently-discovered Arbitrary Entity Manipulation glitch (where crewmate
script commands are used on arbitrary entities by setting the `i`
attribute of `scriptclass` and passing invalid crewmate identifiers to
the commands). If you use Arbitrary Entity Manipulation after destroying
some entities, there is a chance that your script won't work between 2.2
and 2.3.
The indices also still determine the rendering order of entities
(highest indice gets drawn first, which means lowest indice gets drawn
in front of other entities). As an example: let's say we have the player
at 0, a gravity line at 1, and a checkpoint at 2; then we destroy the
gravity line and create a crewmate (let's do Violet).
If we're able to have holes, then after removing the gravity line, none
of the other indices shift. Then Violet will be created at indice 1, and
will be drawn in front of the checkpoint.
But if we can't have holes, then removing the gravity line results in
the indice of the checkpoint shifting down to indice 1. Then Violet is
created at indice 2, and gets drawn behind the checkpoint! This is a
clear illustration of changing the behavior that existed in 2.2.
However, I also don't want to go back to the `active` system of having
to check an attribute before operating on an entity. So... what do we
do to restore the holes?
Well, we don't need to have an `active` attribute, or modify any
existing code that operates on entities. Instead, we can just set the
attributes of the entities so that they naturally get ignored by
everything that comes into contact with it. For entities, we set their
invis to true, and their size, type, and rule to -1 (the game never uses
a size, type, or rule of -1 anywhere); for blocks, we set their type to
-1, and their width and height to 0.
obj.entities.size() will no longer necessarily equal the amount of
entities in the room; rather, it will be the amount of entity SLOTS that
have been allocated. But nothing that uses obj.entities.size() needs to
actually know the amount of entities; it's mostly used for iterating
over every entity in the vector.
Excess entity slots get cleaned up upon every call of
mapclass::gotoroom(), which will now deallocate entity slots starting
from the end until it hits a player, at which point it will switch to
disabling entity slots instead of removing them entirely.
The entclass::clear() and blockclass::clear() functions have been
restored because we need to call their initialization functions when
reusing a block/entity slot; it's possible to create an entity with an
invalid type number (it creates a glitchy Viridian), and without calling
the initialization function again, it would simply not create anything.
After this patch is applied, entity and block indices will be restored
to how they behaved in 2.2.
Ever since 2.0, the colors of some of the Time Trial trophies in the
Secret Lab don't correspond to the crewmate of the given level. The
trophy for the Tower uses Victoria's color, and the Lab trophy uses
Vermilion's color. The Space Station 2 trophy uses Viridian's color, and
the Final Level trophy uses Vitellary's color.
This doesn't appear to be intentional, and it would be odd if it was,
since this game matches the colors everywhere else (each zone on the map
is colored with their respective crewmate in mind, for instance). Also,
the Lab trophy has the sad expression, which is Victoria's trait - it
would be weird if this was intended for Vermilion instead.
But the biggest piece of evidence that this was unintentional is the
corresponding comment for each color in Graphics::setcol(). It mislabels
yellow as cyan, cyan as yellow, blue as red, and red as blue.
To fix this, I simply have to set the correct color for each trophy in
case 25 of entityclass::createentity(). I could fix it in
Graphics::setcol() itself, but custom levels might depend on those
certain colors being the way they are, so it's a safer bet to just fix
it in the trophy creation case itself.
The diff of this might look weird. Even though all I'm doing is changing
some value assignments around, it looks like the "patience" algorithm
thinks I'm moving a whole case of the trophy switch-case around.
This prevents issues when calling std::abs with a float on some older
compilers. While it would normally be promoted to an int, std::abs is
special due to being overloaded despite being a C function. This can
cause errors due to the compiler being unable to find a float overload.
SDL_abs doesn't have this problem, since it's a normal C function.
This check is clearly meant for destroying the factory clouds in the
room "Level Complete!" in the main game, but it covers all rooms on row
8, instead of only (13,8). Adding an x-room check restricts this
behavior to only (13,8).
Trinket9 reported that this weird behavior of destroying specifically
above y-position 60 was undesirable, since they were creating an enemy
with this `behave` in a room on row 8 and it kept disappearing
instantly.
cppcheck said: "Logical disjunction always evaluates to true".
Yes. Yes it does. Whoops. I learned how to specify ranges like this in
high school math and still screw it up...
Scripting crewmates apparently have a specific hardcoded rule in their
follow-player code that makes it so if they're in (10,5) and are to the
left of the line x=155, they will refuse to continue following the
player. This was clearly done to make it so Vitellary in the main game
wouldn't overlap the teleporter, and that was clearly done to make it so
it wouldn't look like he would go behind the teleporter, which would
look weird (I also noticed this in #513).
I stumbled across this code and thought that just like other weird
main-game code that shouldn't apply in custom levels (#136, #137, #144),
this should be fixed, too.
While my previous commit fixes the glitchy y-position when you get stuck
inside a conveyor, I noticed that getting inside a conveyor seems to
always push the player out, despite conveyors sharing the same code with
moving platforms, which has code to temporarily disable their own
collision when the player gets stuck inside them, so that the player
DOESN'T get pushed out.
Well, it turns out that the reason this happens is because conveyors in
a room that get placed during mapclass::loadlevel() get tile 1 placed
underneath them. This is mostly so moving platforms will collide with
them, because otherwise platforms don't collide with other platforms,
and a conveyor is considered a platform.
This means that a conveyor without any tiles behind it will simply get
the player stuck if they get inside it, and the player won't be pushed
out. This is bad, because conveyors don't move, so they'll be stuck
there forever until they press R (or save, quit, and load). This
situation doesn't come up in the main game, but it COULD come up in
custom levels that use the internal createentity() command to create
conveyors that don't have any tiles behind them.
It seems good to fix this as well, while we're at it fixing conveyor
physics, so I'm fixing this as well.
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.
This commit restores the evaluation order of moving platforms and conveyors to
be what it was in 2.2. The evaluation order changed in 2.3 after the patchset
to improve the handling of the `obj.entities` and `obj.blocks` vectors (#191).
By evaluation order, I'm talking about the order in which platforms and
conveyors will be evaluated (and thus will take priority) if Viridian stands
on both a conveyor or platform at once, and they either have different speeds
or are pointing in different directions. Nowhere in the main game is there a
place where you can stand on two different conveyors/platforms at once, so
this is solely within the territory of custom levels, which is my specialty.
So what caused this evaluation order to change? Well, every moving platform
and conveyor in the game is actually made up of two objects: an entity, and a
block. The entity is the part that moves around, and the block is the part
that actually has the collision.
But if the entity is the part that moves around, and entities and blocks are
in entirely separate vectors, how is the block part going to move along with
it? Well, maybe you'd guess some sort of unique ID system, but spend some time
digging around the code and you won't find any trace of any (there's no
attribute on an entity to store such an ID, for starters).
Instead, what the game does is actually remove all blocks that coincide with
the exact top-left corner of the entity, and then create a new one. Destroying
and creating blocks like this all the time is hugely wasteful, but hey, it
worked.
So why did the evaluation order change in 2.3? Well, to understand that,
you'll need to understand 2.2's `active` system. Instead of having an object
be real simply by virtue of it existing, 2.2 had this system where the object
was only real if it had its `active` attribute set to true. In other words,
you would be looking at a fake object that didn't actually exist if its
`active` attribute was false.
On the surface, this doesn't seem that bad. But this can lead to "holes" in a
given vector of objects. A hole is simply an inactive object neighbored by
active objects (or the inactive object could be the first one in the vector,
but then have an active object immediately following it).
If you have a vector of 3 objects, all of them active, then removing the
second one will result in the vector containing an active object, followed by
an inactive object, followed by an active one. However, since the switch to
more properly use vectors instead of relying on this `active` system, there's
no longer any way for holes to exist in a vector. Properly removing an object
from a vector will just shift the rest of the objects down, so if we remove
the second object after the vector fix, then this will simply move the third
object into the slot of where the second object used to be.
So, what happens if you destroy a block and then create a new one in the
`active` system? Let's say that your `obj.blocks` looks like this, and here
I'm denoting each block by writing out its coordinates:
[30,60] [70,90] [80,100]
and that you want to update the position of the second one, because the entity
that that blocks belongs to has been updated. Okay, so, you delete that block,
which then makes things look like this:
[30,60] [-] [80,100]
and then afterwards, you create a new block with the updated position,
resulting in this:
[30,60] [74,90] [80,100]
Since `entityclass::createblock()` will find the first block slot that has a
false `active` attribute, it puts the new object in the same slot as the old
one. What has been essentially done here is that the slot of the block has
basically been reserved for the new block with the new position. Here, the
evaluation order of each block will stay the same.
But then 2.3 comes along and changes things up. So we start with an
`obj.blocks` like this again:
[30,60] [70,90] [80,100]
and we want to update the second block, like before. So we remove the second
block, resulting in this:
[30,60] [80,100]
It should be obvious that unlike before, where the third block stayed in the
third slot, the third block has now been moved to the second slot. But
continuing on; we are now going to create the new block with its updated
position, resulting in this:
[30,60] [80,100] [70,90]
At this point, we can see that the evaluation order of these blocks has been
changed due to the fact that the third block has now been moved to the slot
that was previously the slot of the second block.
So what can we do about this? Well, we can basically emulate what VVVVVV did
in 2.2, which is disable a block without actually removing it - except I'm not
going to reintroduce an `active` attribute or anything. I'll disable the
collision of all blocks at a certain position by setting their widths and
heights to 0, and then re-enable them later by finding the first block at that
same position, updating its position, and re-assigning its width and height
again.
The former is what `entityclass::nocollisionat()` does; the latter is what
`entityclass::moveblockto()` does. The former mimicks turning off the `active`
attribute of all blocks sharing a certain top-left corner; the latter mimicks
creating a new block - and it will only do this for one block, because
`entityclass::createblock()` in 2.2 only looked for the first block with a
false `active` attribute.
Now, some quirks relied on the previous behavior of destroying and creating
blocks, but all of these quirks have been preserved with the way I implemented
this fix.
The first quirk is that platforms passing through 0,0 will destroy all spike
hitboxes, script boxes, activity zones, and one-way hitboxes in the room. The
hitboxes of moving platforms, disappearing platforms, 1x1 quicksand, and
conveyors will not be affected.
This is a consequence of the fact that the former group uses the `x` and `y`
of their `rect`, while the latter group uses the `xp` and `yp` attributes. So
the `xp` and `yp` of the former are both 0. Meaning, a platform passing
through 0,0 destroys them all.
Having these separate coordinates seems like an artifact from the Flash days.
(And furthermore, there's an unused `x` and `y` attribute on all blocks,
making for technically three separate sets of coordinates! This should
probably be cleaned up, except for what I'm about to say...) But actually, if
you merge both sets of coordinates into one, this lets moving platforms
destroy script boxes and activity zones if it passes through the top-left
corner of them, which is probably far worse than the destruction being
localized to a specific coordinate that would never likely be reached
normally.
This quirk is preserved just fine without any special-casing, because instead
of destroying all blocks at 0,0, they just get disabled, which does the same
job. This quirk seems trivial to fix if I made it so that the position of a
platform's block was updated instantaneously instead of having one step to
disable it and another step to re-enable it, but I aim to preserve as much
quirks as possible.
The second quirk is that a moving platform passing through the top-left corner
of a disappearing platform or 1x1 quicksand will destroy the block of that
disappearing platform. This is because, again, when a moving platform updates,
it destroys all blocks at its previous position, not just only one block. This
is automatically preserved because this commit just disables the block of the
disappearing platform instead of removing it. Just like the last one, this
quirk seems extremely trivial to fix, and this time by simply making it so
`entityclass::nocollisionat()` would have a `break` statement, i.e. only
disabling the first block it finds instead of all blocks it finds, but I want
to keep all quirks that are possible to keep.
The last quirk is that, apparently, in order to prevent pushing the player
vertically out of a moving platform if they get inside of one, the game
destroys the block of the moving platform. If I had missed this edge case,
then the block would've been destroyed, leaving the moving platform with no
collision. But I caught it in my testing, so the block gets disabled instead
of destroyed. Also, it seems obtuse for those who don't understand why a
platform's block gets destroyed or disabled whenever the player collides with
it in `entityclass::collisioncheck()`, so I've put up a comment documenting it
as well.
The different platform evaluation order desyncs my Nova TAS, but after
applying this patchset and #504, my TAS syncs fine (save for the different
walkingframe from starting immediately on the ground instead of in the air
(#502), but that's minor and can be easily fixed).
I've attached a test level to the pull request for this commit (#503) to
demonstrate that this patchset not only fixes platform evaluation order, but
preserves some bugs and quirks with the existing block system.
The first room demonstrates the fixed platform evaluation order, by stepping
on the conveyors that both point into each other. In 2.2, Viridian will move
to the right of the background pillar, but in 2.3, Viridian will move to the
left of the pillar. However, after applying this patch, Viridian will now move
to the right of the pillar once again.
The second room demonstrates that the platform-passing-through-0,0 trick still
works (as explained above).
The last room demonstrates that platforms passing through the top-left corners
of disappearing platforms or 1x1 quicksand will remove the blocks of those
entities, causing Viridian to immediately pass through them. This trick is
still preserved after my patchset is applied.
It seems like the start point of a custom level and all checkpoints in
the game end up putting your spawn point one pixel away from the surface
it touches, which seems like an oversight. I'm going to enforce some
consistency here and make it so that all spawn points, whenever you
start from a start point or a checkpoint, will always be correctly
positioned flush with the surface they're standing on, and not one pixel
more or less than that.
So, 77a636509b fixed the fact that you
only got 1 frame of onground/onroof when standing on a vertical moving
platform, but removing those lines entirely means that it takes 1 frame
before the onground/onroof of 2 actually takes effect. This desyncs my
Nova TAS, so it seems important to fix.
The onroof/onground attributes are used to determine if the player is
standing on a surface and is eligible to flip. Most notably, it is an
integer and not a boolean, and it starts at 2, giving the player 2
frames to edge-flip, i.e. they can still flip 2 frames after walking off
an edge.
However, these attributes are unnecessarily reassigned in
movingplatformfix() (which is the function that deals exclusively with
vertically-moving platforms; horizontal moving platforms get their own
hormovingplatformfix()). Whoever wrote this misunderstood what
onroof/onground meant; they thought that they were booleans, and so set
them to true, instead of the proper value of 2. This ends up setting
onroof/onground to 1 instead of 2, causing a discrepancy with vertical
moving platforms and the rest of the surfaces in the game.
The bigger mistake here is duplicating code that never needed to be
duplicated. The onroof/onground assignment in gamelogic() works
perfectly fine for vertical moving platforms. Indeed, after testing it
with libTAS, I can confirm that removing the duplicate assignments
restores being able to edge-flip off of moving platforms with 2 frames
of leeway, instead of only 1 frame. It also doesn't change how long it
takes for the onroof/onground to get set when the player is recognized
as standing on a vertically-moving platform, either.
And so, it's better to not duplicate this code, because when you
duplicate it you run the risk of making a mistake, as I just
demonstrated.
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.
This is a refactor that simply moves all temporary variables off of
entityclass, and makes it so they are no longer global variables. This
makes the resulting code easier to understand as it is less entangled
with global state.
These attributes were:
- colpoint1
- colpoint2
- tempx
- tempy
- tempw
- temph
- temp
- temp2
- tpx1
- tpy1
- tpx2
- tpy2
- temprect
- temprect2
- x (actually unused)
- dx
- dy
- dr
- px
- py
- linetemp
- activetrigger
- skipblocks
- skipdirblocks
Most of these attributes were assigned before any of the times they were
used, so it's easy to prove that ungloballing them won't change any
behaviors. However, dx, dy, dr, and skipblocks are a bit more tricky to
analyze. They relate to blocks, with dx, dy, and dr more specifically
relating to one-way tiles. So after some testing with the quirks of
one-way tiles, it seems that the jankiness of one-way tiles haven't
changed at all, either.
Unfortunately, the attribute k is clearly used without being assigned
beforehand, so I can't move it off of entityclass. It's the same story
with the attribute k that Graphics has, too.
For some reason, the variable `k` is on entityclass and gets mutated in
createentity() and createblock(). Then updateentities() uses it without
checking if it's valid, because either `k` or the size of `entities`
could have changed in the meantime. To fix any potential undefined
behavior, these bounds checks should be added.
