Tower backgrounds have a bypos and bscroll. bypos is just the y-position
of the background, and bscroll is the amount of pixels to scroll the
background by on each frame, which is used to scroll it (if it's not
being redrawn) and for linear interpolation.
For the tower background (and not the title background), bypos is
map.ypos / 2, and bscroll is (map.ypos - map.oldypos) / 2. However,
usually bscroll gets assigned at the same time bypos is incremented or
decremented, so you never see that calculation explicitly - except in
the previous commit, where I worked out the calculation because the
change in y-position isn't a known constant.
Having to do all these calculations every time introduces the
possibility of errors where you forget to do it, or you do it wrongly.
But that's not even the worst; you could cause a linear interpolation
glitch if you decide to overwrite bscroll without taking into account
map.oldypos and map.ypos.
So that's why I'm adding a function that automatically updates the tower
background, using the values of map.oldypos and map.ypos, that is used
every time map.ypos is assigned. That way, we have to write less code,
you can be sure that there's no place where we forget to do the
calculations (or at least it will be glaringly obvious) or we do it
wrongly, and it plays nicely with linear interpolation. This also
replaces every instance where the manual calculations are done with the
new function.
If you have invincibility enabled and push the camera, the background
would smear. This is because the game doesn't calculate the proper
bscroll and bypos of the tower background, and also doesn't end up
redrawing it.
We do both these things now, so this is fixed.
To exclude gravitron squares, the game excluded all entities whose
`size` was 12 or higher. The `size` of the player when they transform
into VVVVVV-Man is 13.
We have already inadvertently fixed VVVVVV-Man not warping vertically in
2.2. This was done with the previous room transition/warping code
refactors; the gravitron square conditionals were simply excluded from
the vertical warp code, because there's no situation where there would
ever be a gravitron square outside the screen vertically.
As with making rescuable crewmates warpable, I have yet to ever see
people use VVVVVV-Man in a custom level. It's not like they would want
to use it anyway; VVVVVV-Man is really, really buggy. And it's probably
better to make it less buggy, starting with this commit.
That being said, VVVVVV-Man's collision when warping horizontally is
really janky, so I still wouldn't use it.
The game excluded every entity whose `type` was 50 or higher. The `type`
of rescuable crewmates is 55.
Could some levels be broken by this behavior? Unlikely; without warping,
the crewmates would end up falling out of the room and would become
unrescuable. So this is more likely to fix than to break.
But more importantly, *no one knows that rescuable crewmates don't
warp*. If anyone would know, it would be me, because I've been in the
custom levels community for over 7 years - and yet, during that time, I
have not seen anyone run into this corner case. If they did, I would
remember! This implies that people simply have never thought about
putting rescuable crewmates in places where they would warp - or they
have, ran into this issue, and worked around it.
With those two reasons, I'm comfortable fixing this inconsistency.
This saves one indentation level. I also fixed the comments a bit
(multiline instead of single-line, "gravitron squares" instead of "SWN
enemies", also commented the player exclusion from horizontal wrapping
in vertically-wrapping rooms).
edteleportent is a global variable that gets assigned whenever the
player collides with a warp token, and gets read from later down the
line in gamelogic(). While I don't know of any way to cause anything bad
with this (and I did try), storing a temporary indexing variable like
this is only bound to be a liability in the future - so we might as well
prevent badness now by adding a bounds check here.
Otherwise, if the timer ticked up past the par (via using the unfocus
pause or pause menu), it would result in the sad squeak being played
every frame because the game would constantly be setting
timetrialparlost, then moving to the code block below, assuming that
since timetrialparlost that we haven't lost the par already, and playing
the squeak.
timetrialparlost gets reset in hardreset() and startgamemode() anyways,
so there's no need to be constantly resetting this variable.
Fixes#699.
This fixes being unable to use teleporters while the "- Press ACTION to
advance text -" prompt is up, which is used to perform credits warp.
In 2.2 and 2.0, this advancetext check was only in gamerender() for
rendering the "- Press ENTER to Teleport -" prompt and didn't affect any
logic. In 2.3, I moved the check (and the rest of the conditional it was
in) to gamelogic() - same as the activity zone prompt conditionals - so
if you gained control while being in a prompt zone, the prompt wouldn't
suddenly appear[1].
As a side effect, this ended up aligning rendering and logic together,
so if you couldn't see the teleporter prompt, you weren't able to
teleport - whereas in 2.2 and 2.0, you could still use the teleporter
even though the prompt wasn't up.
So by removing the advancetext check, you are now able to use the
teleporter again, AND the "- Press ENTER to Teleport -" prompt will also
show up as well.
Habeechee reported this regression on the VVVVVV speedrunning Discord
server.
[1]: f07a8d2143, PR #421
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.
This reintroduces 2-frame edge-flipping after the 1-frame input delay
got removed. This is because along with processing input and moving
Viridian, logical onground/onroof assignments need to processed in the
same between-render sequence as well - otherwise Viridian only gets 1
frame of edge-flipping due to frame ordering.
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.
The previous location of this loop was placed there because it happened
just after the end of the render function. Now that the loop order is
fixed, the first thing that happens after the render function is the
start of gamelogic(), so this loop should go there now, else entity
positions won't be interpolated.
Also it now preincrements instead of postincrements because I like
preincrements.
To do this, I've added Graphics::setbars(), to make sure
oldcutscenebarspos always gets assigned when cutscenebarspos is. This
fixes potential deltaframe rendering issues if these two mismatch.
If you stood in two activity zones at once, you'll automatically select
the one that got created first. And when you activated it, the activity
zone prompt would switch to fading out the prompt of the OTHER activity
zone, the one you didn't activate.
This wasn't a problem in 2.2 and previous, because the fading animation
was simply bugged and defaulted to being solid black. However, in 2.3,
the fading animation is fixed, so this is possible.
Also, this really only happens in the main game. Since there's only one
type of useful activity zone in custom levels - namely the terminal
activity zone - if two activity zones did happen to overlap, activating
one of them wouldn't result in visibly fading out a different activity
zone (because they both look the same); furthermore custom level makers
are careful to not overlap terminal activity zones, lest this result in
player confusion; furthermore the placed activity zones only cover a
small area, whereas in the main game, crewmates' activity zones are
pretty big.
(Technically, you CAN create main game activity zones in custom levels,
but those are hardcoded to call main game scripts, and basically nobody
uses them.)
So what's the solution? Simply adding game.hascontrol and script.running
checks to the updating of game.activity_last[prompt|r|g|b].
Why not add those checks to the assignment of game.activeactivity, just
above? Because that would introduce a frame ordering issue (that
would NOT be (automatically) fixed by #535) where the eligibility of
pressing Enter on an activity zone now checks if you were standing in an
activity zone LAST frame, and not THIS frame. (I tested this with
libTAS.) Better to fiddle with the rendering code than fiddle with the
actual physics code.
The specific spot I used to test this was standing in Violet's activity
zone and the activity zone of the ship radio terminals (the three
terminals on the ground in her room); the ship radio terminals are
first-placed, so if you're testing this (and you should!), make that the
prompt is of the ship radio activity zone before activation.
This probably should've been moved to RenderFixed a while ago, because
it's unnecessary to run this on every single deltaframe.
The only minor wrinkle here is that this means rendering of activity
zone fades will be delayed for 1 frame, but #535 will fix that.
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 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.
This reverts commit 942217f871.
This fix (of a regression of a fix) has a regression where immediately
flipping off of horizontally-moving platforms or conveyors will no
longer provide you with a "boost" given certain vertical pixel
alignments.
The regression that this fix fixed will be fixed another way.
Fixes#606.
This does the same thing as the last commit, but for No Death Mode
instead of Time Trials. Whenever you die in No Death Mode, or complete
it, all the relevant variables get copied to variables prefixed with
'ndmresult' that never get reset by script.hardreset(), and these
variables are what titlerender() use, instead of the "live" ones.
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
When I did #567, I didn't test it. And I should have tested it, because
it made the player invisible. This is because map.resetplayer() also
sets the invis attribute of the player to true as well, and I only undid
it setting game.lifeseq to 10.
So instead, I'll just add a flag to map.resetplayer() that by default
doesn't set game.lifeseq or the player's invis attribute. And I tested
it this time, and it works fine. I tested both respawning after death
and exiting to the menu and loading in the game again.
In order to be able to fix the bug #556, I'm planning on adding
ScreenSettings* to the settings.vvv write function. However, that
entails adding another argument to Game::savesettings(), which is going
to be really messy given the default argument of Game::savestats().
That, combined with the fact that the code comment at the site of the
implementation of Game::savestats() being wrong (!!!), leads me to
believe that using default function arguments here isn't worth it.
Instead, what I've done is made it so callers are explicit about whether
or not they're calling savestats(), savesettings(), or both at the same
time. If they are calling both at the same time, then they will be using
a new function named savestatsandsettings().
In short, these are the interface changes:
* bool Game::savestats(bool) has been removed
* bool Game::savestatsandsettings() has been added
* void Game::savestats_menu() has been renamed to
void Game::savestatsandsettings_menu()
* All previous callers of bool Game::savestats() are now using bool
Game::savestatsandsettings()
* The one caller of bool Game::savestats(bool) is now using bool
Game::savestats()
As part of fixing #464, I'll need to move these pieces of code around
easily. In #220 I just kind of shoved them awkwardly in whatever
fixed function would be last called in the gamestate loop, which I
shouldn't have done as I've now had to make formal fixed-render
functions anyway. Because these fixed functions need to be called
directly before a render function, and I'm fixing the order to put
render functions in their proper place, so I need to be able to move
these around easily, and making them function calls instead of inlined
makes them easier to manipulate.
Today, I saw a video posted by Chelito on the VVVVVV speedrunning
Discord where he died inside a gravitron square over and over after the
Gravitron in Intermission 2 ended.
https://cdn.discordapp.com/attachments/234787368522088448/779074864660480020/What.mp4
This is caused by the fact that after the Gravitron ends, the game no
longer considers you to be inside swnmode, so it won't move the enemies
offscreen when you die.
To fix this, after the Gravitron ends, the game will switch to swngame
8, where it will keep you inside swnmode until all gravitron squares are
offscreen. This means that gravitron squares that are onscreen after the
Gravitron ends will be moved offscreen if you die, preventing the above
death loop from happening.
...you die and the platform's x-coordinate is to the left of x=152.
Which means if you die and the platform isn't completely clear of the
space of its adjacent disappearing platform.
The block needs to be updated accordingly with calls to
obj.nocollisionat() and obj.moveblockto(), else the block will simply be
left behind and the platform will no longer have any collision. This is
in contrast to 2.2 behavior, where the platform would simply
unconditionally create a new block, which would actually end up with a
duplicate block since the previous block didn't get cleaned up, but this
didn't cause any problems because the room was carefully designed so you
would never be able to touch that previous block after you died and
respawned at the checkpoint. But it's still there.
I also added comments to document what this kludge code did, because
otherwise it would be mysterious to readers who are unfamiliar with it.
Fixes#543.
Originally this function was made because it needed to be exported to
gameinput(), but this piece of code is actually also used in
gamecompletelogic(). So it's good to de-duplicate it here, too.
This kludge variable was used to re-set the warp background after coming
back from the in-game settings menus. But since #522 got merged, this
has no longer been necessary.
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.
There is this issue with conveyors where if you collide with them, your
intended next y-position doesn't get updated to the position of the
conveyor, and then your y-position gets set to your intended next
y-position. This also applies to horizontally moving platforms.
This bug used to not produce any problems, if at all, until #502 got
merged. Since then, respawning from checkpoints that are on conveyors
would sometimes not update your y-position at all, making it possible to
get stuck inside a death loop that would require you to exit the game
and re-enter it.
But you can always reliably create this bug simply by going into the
editor and placing down a conveyor and checkpoint on top of each other.
Then enter and exit playtesting a bunch of times, and you'll notice the
glitchy y-position Viridian keeps taking on.
The root cause of this is how the game moves the player whenever they
stand on the top or bottom of a conveyor (or a horizontally moving
platform). The game sets their intended next x-position (newxp), then
calls obj.entitymapcollision() on them. This would be okay, except their
intended next y-position (newyp) doesn't get set along with their newxp,
so entitymapcollision() will use the wrong newyp, then find that there
is nothing that will collide with the player at that given newyp, then
update the yp of the player to the wrong newyp.
So, the platform logic simply doesn't set the player's newyp. Why does
the player have the wrong newyp? It's because moving platforms (and
conveyors) are updated first before all other entities are, and this
includes the code that checks the player for collisions with moving
platforms. That's right: the moving platform collision code gets ran
before the player properly gets updated. This means that the game will
use the newyp of the previous frame, which could be anything, really,
but it most likely just means the intended next y-position of the player
gets canceled, leaving the player with the same y-position they had
before.
Okay, but this bug only seems to happen when you put a checkpoint inside
a conveyor (or a moving platform that hasn't started moving yet) and
start playtesting from it, so why doesn't this bug happen more often,
then? Well, it's probably because of luck and coincidence. Most of the
time, if you're colliding with a conveyor or horizontally moving
platform, you probably have a correct newyp from the previous frame of
the game, so there'd be no problems. And before #502 got merged, this
previous frame would be provided by the player having to fall to the
surface due to the y-offset of their savepoint. However, if you make it
so that you immediately teleport on to a conveyor (because you died),
then this bug will rear its ugly head.
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.
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.
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.
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".
Instead of having two separate functions to move entities along vertical
moving platforms, one for the player and one for the supercrewmate, they
have been consolidated into one function.
So, I was staring at VVVVVV code one day, as I usually do, and I noticed
that warp lines had this curious code in entityclass::updateentities()
that set their statedelay to 2, and I thought, hm, maybe the pre-2.1
warp line bypass is caused by this statedelay. And, it doesn't seem like
this is the primary code used to detect if the player collides with warp
lines, the actual code is commented with "Rewritten system for mobile
update" and bolted-on in gamelogic() instead of properly being in
entityclass::entitycollisioncheck().
So, after getting tripped up on the misleading indentation of that
"Rewritten system" block, I removed the rewritten system, re-added
collision detection for rule 7 (horizontal warp lines), and after
checking the resulting behavior, it appears to be nearly identical to
that of warp lines in 2.0.
You see, if you use warp lines to flip up from the top of the screen
onto the bottom of the screen, close to the edge of the bottom of the
screen, Viridian's head will display on the top of the screen in 2.0. In
2.1 and later, this doesn't happen, confirming that my theory is
correct. I also performed warp line bypass multiple times in 2.0 and
with my restored code, and it is pretty much the exact same behavior.
So now, the pre-2.1 warp line bypass glitch has been re-enabled in
glitchrunner mode.
This misleading indentation makes it really easy to misanalyze this
block as only containing the statements up to obj.customwarplinecheck(),
when in reality it contains everything up to the modifying of
map.warpx/map.warpy. I have made this misanalysis just now in my attempt
to figure out the pre-2.1 warp line bypass glitch, and I don't like it.
So I'm fixing this indentation now.
This moves the teleporter, activity prompt, and trophy text "don't draw"
conditionals to the part where the game checks collision with them,
instead of whenever the game draws them.
This makes it so that the game smoothly does the fade-in/fade-out
animation instead of suddenly stopping rendering them whenever their
"don't draw" conditions apply. Now, the "Press ENTER to activate
terminal" prompt will no longer suddenly disappear whenever you activate
one, and the "- Press ENTER to Teleport -" prompt will smoothly fade
back in after teleporting, instead of suddenly popping in on screen.
Achievements could be unlocked in custom levels/make and play, so this adds the wrapper function `game.unlockAchievement` which calls `NETWORK_unlockAchievement` if `map.custommode` is false.
Also, this function and `Game::unlocknum` have both been `ifdef`ed to be empty if MAKEANDPLAY is defined.
Otherwise, this would cause immense slowdown during the New Record
animation that plays when you die, as the game would be writing
unlock.vvv every frame.
To fix this, I just put it under the same if-guard as the
music.playef(), since the sound effect also only plays once. But I have
to watch out for frame ordering and make sure the record is actually set
before I call game.savestats(), and then of course I have to move
game.swnmessage = 1 over because that's the variable being checked in
the conditional.
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.
