2000 HOUR 2D Game Engine! // Code Review

  Рет қаралды 87,602

The Cherno

The Cherno

Күн бұрын

To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/.... The first 200 of you will get 20% off Brilliant’s annual premium subscription!
Patreon ► / thecherno
Instagram ► / thecherno
Twitter ► / thecherno
Discord ► / discord
Code ► github.com/jka...
Send an email to chernoreview@gmail.com with your source code, a brief explanation, and what you need help with/want me to review and you could be in the next episode of my Code Review series! Also let me know if you would like to remain anonymous.
Hazel ► hazelengine.com
🕹️ Play our latest game FREE (made in Hazel!) ► studiocherno.i...
🌏 Need web hosting? ► hostinger.com/...
💰 Links to stuff I use:
⌨ Keyboard ► geni.us/T2J7
🐭 Mouse ► geni.us/BuY7
💻 Monitors ► geni.us/wZFSwSK
This video is sponsored by Brilliant.

Пікірлер: 242
@TheCherno
@TheCherno 11 ай бұрын
Thanks for watching! Should we continue looking at this 2000-hour 2D Game Engine? Also don't forget you can try everything Brilliant has to offer-free-for a full 30 days! Visit brilliant.org/TheCherno - the first 200 of you will get 20% off Brilliant’s annual premium subscription!
@matin.f139
@matin.f139 11 ай бұрын
do itttttt please!
@dracula5752
@dracula5752 11 ай бұрын
part 2 when
@LovepreetSingh-ye9hd
@LovepreetSingh-ye9hd 11 ай бұрын
Let's dive in please!
@Dr_OmarYaser
@Dr_OmarYaser 11 ай бұрын
very helpful ... continue
@ferdynandkiepski5026
@ferdynandkiepski5026 11 ай бұрын
Yes
@nestor1208
@nestor1208 11 ай бұрын
"I won't roast you too much" *proceeds to making a 30-minute video of roasing the README file alone*
@monad_tcp
@monad_tcp 10 ай бұрын
After reading the README file, I've seen it all
@Renschi.
@Renschi. 11 ай бұрын
At 2:23 Cherno mentioned he doesn't know the tool Rene. This is because it is literally me. The person who created this Engine is one of my friends and I asked him to add me as a tool because I gave some recommendations about the UI of the Engine :)
@NoThing-ec9km
@NoThing-ec9km 11 ай бұрын
Lmao. Loved it😅
@xTriplexS
@xTriplexS 11 ай бұрын
Lol
@blackcitadel37
@blackcitadel37 11 ай бұрын
wait, add you as a... tool? lmfao XD
@and_then_I_whispered
@and_then_I_whispered 11 ай бұрын
you mean the egnine?
@hasankaraman
@hasankaraman 11 ай бұрын
He can now add cherno as well
@y4ni608
@y4ni608 11 ай бұрын
Hello!! Thanks for reviewing my game engine for some reason my previuos commentar got deleted. it looks like im missing a concept about pointers 😅. I did discuss this vector SpriteRepository structure with my teacher (He is a teacher teaching mainly about os's) (Im still in highschool, 2nd grade) and he actually agreed with this structure. It's cool seing different opinions coming together, but i will defenetly value the advice of a professional gameengine dev more. I can't wait to see the part 2! by the way, if you guys got any questions about my game engine feel free to ask here :) 7 month edit: Yo guys, i have finally implemented all the stuff cherno advised, and im happy AF i love the new project structure
@giobbymenta
@giobbymenta 10 ай бұрын
He agreed with your structure cause for an highschool student is really good enough lol. Good job
@ocaly
@ocaly 3 ай бұрын
Congrats bro!
@Berzeger
@Berzeger 2 ай бұрын
Hey, that's amazing on several fronts - that you accepted Cherno's critique as a grown man (and even fixed it according to his suggestions) and also that you're so young and yet managed to write an engine!
@bulentgercek
@bulentgercek 11 ай бұрын
Cherno is a type of guy can do code review without looking the code. :D
@sneed1208
@sneed1208 11 ай бұрын
He does look into the code that is presented in the README though, so that's not true.
@MahmoudSayed-hg8rb
@MahmoudSayed-hg8rb 11 ай бұрын
I haven't finished the video yet, but i think there might be part 2 and maybe more.
@blackcitadel37
@blackcitadel37 11 ай бұрын
senior dev sorcery
@kzone272
@kzone272 11 ай бұрын
This is accurate, except its actually an insult not a compliment.
@bulentgercek
@bulentgercek 10 ай бұрын
@@kzone272 This is only a joke. This is an internet meme. It's not an insult or anything. Cherno has an important place in my life.
@jadrop0037
@jadrop0037 11 ай бұрын
Please continue the review on a future video. I’m really curious to see the engine running!
@marctse3556
@marctse3556 11 ай бұрын
Please continue with this engine. This is super informational! I also like the high level design aspect of this review
@felixp535
@felixp535 11 ай бұрын
Yeah I really enjoy these kinds of videos, learning about how game engines work and are usually structured, and especially WHY it's done this way. It feels like this developer was trying to reinvent the wheel, but to be fair, how do you know you're reinventing the wheel if you don't even know how a wheel looks like and how it works? I started my own game engine a while ago, following Yan's amazing Game Engine series (except I was doing it in a language called Jai). I managed to render simple images, but I stopped following the series when it got to the ECS stuff, as I didn't want to have that in my engine. I just wanted to continue working on the rendering, but most of the stuff was being off-screened, so I really felt stuck when trying to actually create the structure for the rendering system. It's soooo complex, there's just sooooo much to think about. In various projects I've tried to explore there's RenderingContexts, RenderingConfigurations, all sorts of Buffers and Passes, rendering on separate threads, making all of this mess API-agnostic... I just gave up. I would love a series of videos explaining how all of that stuff works, explained with simple text and drawings just like in this video.
@y4ni608
@y4ni608 11 ай бұрын
@@felixp535 Hello, yeah i kinda wanted to try something new, but i can see what issues i have here, i really didnt think that much about it
@NathanHedglin
@NathanHedglin 11 ай бұрын
​@@felixp535exactly. JAI?! You got access? How do you like it?
@gelis07
@gelis07 11 ай бұрын
12:24 that literally can become the best bell curve programming meme ever.
@Diventurer
@Diventurer 11 ай бұрын
That raw pointer confidence chart is way too relatable. I can't believe how much I trusted myself with them before.
@LightTheMars
@LightTheMars 11 ай бұрын
Instead of UUIDs for referencing entities during runtime you can also use generational indices. Keeps the index simple and small and takes care of validity.
@HairyPixels
@HairyPixels 11 ай бұрын
UUIDs are extremely slow to generate too.
@funns7uf
@funns7uf 11 ай бұрын
@@HairyPixels how so? UUID v4 is just a random 128-bit number with a couple of the bits set to specific values
@HairyPixels
@HairyPixels 11 ай бұрын
@@funns7uf it's how the numbers are generated I guess. Maybe for sprites it's no so bad but if you start making them real time it's measurable.
@jonforhan9196
@jonforhan9196 11 ай бұрын
@@HairyPixelscreate them in batches and utilize the mm registers maybe
@dealloc
@dealloc 11 ай бұрын
@@HairyPixels Extremely slow to generate? What are you on an Amiga? Also, you don't need to generate UUIDs every single frame. You generate them only when you create the instances. It doesn't have to be generate UUIDs from a cryptographically secure random number generator either.
@verminology9999
@verminology9999 11 ай бұрын
In my opinion, this was one of your best code reviews, and you didn't even open the project yet. The way you explained everything visually was very cool and extremely informative. I would love to see a part two!
@donsk324
@donsk324 11 ай бұрын
12:40 Can releate haha. At first I used to avoid dynamic memory management, then I started to embrace pointers after I got the hang of them and considered smart pointers 'pointless', that is after attaching address sanitizer and spending approximately an hour trying to fix memory leaks and memory corruption on a small sized project and later realized how important ownership is and how raw pointers laked ownership.
@hullukana214
@hullukana214 11 ай бұрын
Please make another video about this engine. I'm sure a deeper look into the engine would reveal many more memory management related issues for you to get stuck on for half an hour.
@TopConductor
@TopConductor 11 ай бұрын
I like the code review without even looking at code directly xd It was very interesting to hear this UUID idea. I also was writing some small projects, and came up with the idea of storing the integer instead of the ptr myself, but it always felt awkward for me, and kind of unpreffessional, idk. thanks for the great video
@sigxfs
@sigxfs 11 ай бұрын
currently making my own 3d engine and this is the exact design problem i was thinking about
@CatzHoek
@CatzHoek 11 ай бұрын
This project really seems to have some meat to it so i love that you can really talk about stuff. Would love to see that disected even more in other videos.
@irfanjames6551
@irfanjames6551 11 ай бұрын
31:31 Yes... Yan. This is a beautiful format. Can't wait for future reviews. Also, the PacMan Game you were going to build yourself. Would really appreciate it, if you can manage to take some time.
@thygrrr
@thygrrr 11 ай бұрын
Many (Generation-X and older) Germans call the "Strg" key the "String" key, and it really grinds my gears. :D
@K.R.O1875
@K.R.O1875 11 ай бұрын
You should do a follow up on this. There was still plenty for people to learn from here. But the kid states at the very start of the documentation that it may be outdated. It would be cool to have a look at the actual code and engine and offer some advice on that.
@exosupesu
@exosupesu 11 ай бұрын
This guy roasted the whole engine without even seeing the source code
@parabalani
@parabalani 11 ай бұрын
Which is questionable
@Mitch_Crane
@Mitch_Crane 11 ай бұрын
Isn't that what everyone does
@topg3067
@topg3067 11 ай бұрын
He just needs ad revenue and relevancy, and took the easiest part to pick on. He ran out of libraries to use in his own engine lmao
@JavedAlam-ce4mu
@JavedAlam-ce4mu 3 ай бұрын
@@topg3067 you can't say it wasn't educational
@yieldjedimaster1040
@yieldjedimaster1040 11 ай бұрын
Yes, it's really helpful, let's continue!
@simiuciacia
@simiuciacia 11 ай бұрын
I was expecting something more of a "continue we shall" with that pfp
@ParticalStudios
@ParticalStudios 11 ай бұрын
Cherno, with the video content you create, you are very inspiring for people like me who want to become a game engine developer in the future. Thank you for that, keep that great work up!
@briumphbimbles
@briumphbimbles 11 ай бұрын
1:41 how can you build a game engine and not know about relative paths?
@sub-harmonik
@sub-harmonik 11 ай бұрын
As someone who isn't a game dev but is peripherally interested, I really liked the conceptual overviews, thanks. This kind of thing is still relevant to other areas of system design.
@thewelder3538
@thewelder3538 3 ай бұрын
But Cherno... The reality is that under the hood, std::vector is very much like std::vector. Whether you push_back the sprite or the pointer, they're still both going to be heap allocated unless you've got your own allocator. The difference being that with operator new(), your sprites aren't going to be contiguous, but your pointers will be and you've got to to destroy them yourself. The vector iterator is still just a pointer.
@turner7777
@turner7777 11 ай бұрын
Would be cool if you did a vid on how to properly design a project
@aryanbhatia4872
@aryanbhatia4872 11 ай бұрын
loved your review of this, please cover more of this.
@natanaelrabello
@natanaelrabello 11 ай бұрын
Please keep roasting this engine. I feel like amazing lessons could come out of it. Thanks :)
@hayabusa1x
@hayabusa1x 10 ай бұрын
Very helpful explanation on pointers vs identifiers. Would love to see you review the rest of this code base.
@adamrushford
@adamrushford 11 ай бұрын
Thank you Yan that was very helpful and appreciated as always can't wait for more!
@mikael8276
@mikael8276 11 ай бұрын
Whoa, I didn't know that pushing a new element into a vector would invalidate all earlier references.
@fappylp2574
@fappylp2574 10 ай бұрын
Most of the lines of code I have ever written in C++ have turned out to be undefined behaviour... It's astonishing what you can miss without formal training!
@JavedAlam-ce4mu
@JavedAlam-ce4mu 3 ай бұрын
That's only if you're either pushing from the front, or pushing from the back, but the memory size isn't enough, so it has to make a new vector and copy those items to another location. But it's also specifically only when you are referencing data in the vector, e.g.: pointer* = &vectorName[1] or reference& = vectorName[1] Which really isn't that common. It isn't true for vectors of pointers, e.g. vector Pushing elements to these doesn't invalidate their addresses because they point elsewhere.
@jakubgiesler6150
@jakubgiesler6150 8 ай бұрын
My first line was written around 2009 in Java (i was 11 btw), and when I learned pointers and c++ around 2015 I felt super smart and used them everywhere, and now it's 2024, and I rarely use pointers, so yeah the statement is true.
@defter6800
@defter6800 11 ай бұрын
You can also introduce some typed ID (for different types of objects) by using syntax sugar of C++ and allocate this ID by increment atomic int variable (or even non atomic). Only downside if too many threads do this frequently with atomic variable, but there is always way to pre-allocate N ID's very fast and unroll some loops or make like ranged limited local ID allocator that use ID ranges from global ect.
@MotionLive
@MotionLive 11 ай бұрын
Really helpful video, thank you !
@cpaulicka
@cpaulicka 11 ай бұрын
This was fun but…very little discussion of abstraction at the very end. Also, discuss user of software vs developer of software (which often have different priorities). Instead you kind of jump into details (charmingly so, yes). API design before implementation helps; you could do that with the implied api here and clean it up, and then walk through possible implementation details afterwards. ;-)
@NathanHedglin
@NathanHedglin 11 ай бұрын
Please continue! This is a great breakdown
@mldy1
@mldy1 10 ай бұрын
25:48 probability would be 1 in 2^64, or 1 in ~18 quintillion or 1 in ~18 billion billion so probably more likely a cosmic ray would case the program to crash
@Mirage_3253
@Mirage_3253 2 ай бұрын
bro gave the entire CODE review without looking at the the Code 😂😂😂❤
@spidermanlift4527
@spidermanlift4527 11 ай бұрын
I wanna see more of this engine
@TehHeiks
@TehHeiks 10 ай бұрын
That sprite stunlock truly is something
@the_gobbo
@the_gobbo 10 ай бұрын
1:59 Boy was he right about this being a ride lol 🤣
@loiphin
@loiphin 11 ай бұрын
You sounded so excited whilst reading your Brilliant sponsor script... hahaha
@austinbachurski7906
@austinbachurski7906 11 ай бұрын
I'd really like to hear more about this UUID storage works. I don't believe I'm properly grasping it, obviously (I assume) you're not using the id as the index of the vector or whatever container you're using right? Would like to hear more if possible, and please continue the code review if you have time. Thanks.
@anispinner
@anispinner 11 ай бұрын
Basically a 30 minute sprite review
@ludologian
@ludologian 11 ай бұрын
I'm c# developer, and I consider myself something between beginner & intermediate lvl but generally I can follow up with you.. please stay with this format
@markp1634
@markp1634 11 ай бұрын
Please keep going!
@not_herobrine3752
@not_herobrine3752 11 ай бұрын
i wonder if thecherno would review a c styled rust codebase
@JavedAlam-ce4mu
@JavedAlam-ce4mu 3 ай бұрын
I'm confused, if you used a 64-bit UUID wouldn't the vector size be huge? Or are you saying to use a map instead?
@-lolus-
@-lolus- 11 ай бұрын
i'd love to se another part about this engine
@nicksdrumsticks
@nicksdrumsticks 11 ай бұрын
7:04 - What the hell? That pronunciation was so accurate
@NeuroScientician
@NeuroScientician 11 ай бұрын
What is a good way to track hours spent in VSCode/Game Engine? Something bit more automatic that just stopwatch and a spreadsheet?
@notlekrut
@notlekrut 11 ай бұрын
You can use apps/sites that have extensions for IDEs, like Wakatime, there's several others. There's also some apps that track OS windows and window titles to figure out what you're working on and then you can categorize, but I only know specific ones for mac(ie. Timing), but I'm sure there's similar ones for Windows.
@InfiniteCoder01
@InfiniteCoder01 11 ай бұрын
Wakatime
@grigoriy_hacker
@grigoriy_hacker 2 ай бұрын
Nice egnine, I love it
@y4ni608
@y4ni608 2 ай бұрын
Thanks :D
@px2059
@px2059 11 ай бұрын
Most of the times engines have to move objects around in the heap to fill the holes created by freed memory. If you access pointers directly, you either can't move objects or you can't use memory efficiently.
@EmilyGraceSeville7cf
@EmilyGraceSeville7cf 11 ай бұрын
I love your content, keep going😄
@leshommesdupilly
@leshommesdupilly 4 ай бұрын
I liked spending hundreds of hours coding games, engines, applications.. It was really fun and I was satisfied of the speed. And then, I learned about the cache, cpu optimizations, ram latency, and now, all I can see is wasted performance and spaghetti code 😂
@tbc1880
@tbc1880 7 ай бұрын
As someone in a similar spot as the guy here, (not 2k hrs deep but grinding through my own engine as basically a higher level novice) I want to shoot two questions I have into the void in hopes I may finally get answers. For my scenes I have the main loop run their update function and every now and then a different one for a transition that may send data over to the new scene (like if I move to the main menu from settings I keep the music playing vs from title screen which has it's own music.) The main just gets a pointer to the new scene while the old one clears itself of all objects and such. Main then runs and creates the new scene. While memory usage is still low I wonder if this is okay due to a not exactly memory leak I am seeing. Basically if I move between scene 1 and 2 the memory use will rise but will stop after a bit. Move to scene 3 and the cap rises. Scene 4 and so on. I have no clue what maybe causing this as I am deleting everything and if it were a true leak would it not continue indefinitely? Is it just my computer managing data in that way or an actual issue with my code.
@unkgames-abdullahali4048
@unkgames-abdullahali4048 11 ай бұрын
Another video of this engine
@kelvinpoetra
@kelvinpoetra Ай бұрын
Hi Cherno, I want to ask what steps are needed to create a game engine?
@SquidSnipes
@SquidSnipes 11 ай бұрын
Please continue with this
@olegallito5742
@olegallito5742 11 ай бұрын
Minute 9 is when I started asking myself like "where the fuck is the engine" rather than a few classes and a half (that aren't even handy to use). It's pretty much like making a game from scratch, but using some questionable libraries.
@rafaelmateodev
@rafaelmateodev 11 ай бұрын
I hope they make the changes, this seems imperative.
@simiuciacia
@simiuciacia 11 ай бұрын
People should pay for content like this, this is my kind of videos really, thx again
@alastairtheduke
@alastairtheduke 9 ай бұрын
great video
@Griffin12536
@Griffin12536 2 ай бұрын
That was some incredible insight to how a programmer thinks.
@topg3067
@topg3067 11 ай бұрын
Back to the engine.
@Brolexios
@Brolexios 10 ай бұрын
@TheCherno, what do you use to draw on the screen and whiteboard these webpages?
@BrainStroming1789
@BrainStroming1789 3 ай бұрын
Si j'avais à faire une revue, déjà je commencerais par poser une question majeur. Est-ce de la responsabilité de l'objet Game de savoir comment créer un sprite et comment manager sa persistance ?! non. Un objet SpriteManager capable de créer des sprites transitant ou persisté serait plus optim. Conception SOLID et le code deviendra plus simple et logique. Ensuite sur le "new", pourquoi sur-utiliser la stl ? qu'il était doux le temps ou nous savions faire la part des choses et ne pas utiliser une class inutile quand elle n'est pas nécessaire.
@SiltyWheat7
@SiltyWheat7 11 ай бұрын
I'm not sure I interpreted this correctly. How would you use a random GUID or UUID as an index for a vector? Wouldn't these IDs potentially be massive (i.e. 0 to 2^64 - 1) meaning the vector would have a ridiculous number of elements?
@tardistrailers
@tardistrailers 11 ай бұрын
You could use a hashmap instead of a vector in that case.
@fappylp2574
@fappylp2574 10 ай бұрын
Lol, just buy more ram...
@fappylp2574
@fappylp2574 10 ай бұрын
@@tardistrailers But how do you get around losing the contiguous memory? Does it make sense to store a map of (UUID -> Index) and keep that updated somehow? The whole point of this contiguous allocation is better performance during iteration (ECS etc.).
@loctite417
@loctite417 11 ай бұрын
Thank you for extremely helpful video especially since I recently made a sprite rendering system with a c style array of size 2048 storing pointer to sprites lmao
@weirddan455
@weirddan455 11 ай бұрын
"Code Review" - Never even looks at the code. He just saw the new keyword and went off on a tangent about entity component systems...
@ZeroUm_
@ZeroUm_ 11 ай бұрын
Architecture review is code review. It's way more important to catch wrong assumptions about how stuff works than nitpicking variable names or any easily refactorizable code.
@NathanHedglin
@NathanHedglin 11 ай бұрын
If you don't get the architecture correct, the code basically doesn't matter
@anispinner
@anispinner 11 ай бұрын
00:18 Ah, looks like a typo for "Egg nine"
@niallrussell7184
@niallrussell7184 11 ай бұрын
I expected this to be about optimizing drawcalls or something.. didn't even get that far! 🤣
@ScibbieGames
@ScibbieGames 11 ай бұрын
Structure of arrays enthusiasts unite
@lucasgaming4793
@lucasgaming4793 11 ай бұрын
i would like to see more
@TheMrTka4
@TheMrTka4 11 ай бұрын
I expected some code in code review :D But that was useful anyway! I would like to see a continuation about this engine. I miss code reviews from you!
@ari-mcbrown
@ari-mcbrown 8 ай бұрын
Here's some actionable advice: ... set your autofocus to a fixed setting.... pls. :'(
@maximiliannowak7860
@maximiliannowak7860 11 ай бұрын
Man, all this talking about sprites made me thirsty
@y4ni608
@y4ni608 11 ай бұрын
Hahaha
@xXCheapTofuXx
@xXCheapTofuXx Ай бұрын
i bet he didn't even realize he wrote "u" instead of "you" just automatic.
@y4ni608
@y4ni608 Ай бұрын
hell yeah xD
@marcelbarbosa281
@marcelbarbosa281 11 ай бұрын
Yes, i want sir.
@hawns3212
@hawns3212 11 ай бұрын
25:45 The odds of two random 64 bit numbers colliding is 2.916x10^-39% AKA 0.0000000000000000000000000000000000000002196% With more decimals after, of course, but roughly that It is a chance of 1 in 340,282,366,920,938,463,463,374,607,431,768,211,456 chance or a 1 in 2^128 chance or a 1 in 340.2 undecillion chance. Very very unlikely. If this ever happens to you, go buy a lottery ticket. You're likely to win the lottery 11,645,529,300,000,000,000,000,000,000 times more likely to win the lottery than get two 64 bit integers being the same Edit: I made a mistake, its not 1 in 2^127, but 2^128
@HiHi-ur3on
@HiHi-ur3on 11 ай бұрын
That doesn't make sense. Shouldn't the chance of two random 64 bit numbers be a straight up 1 in 2^64? Since the second number has to be exactly the first number and can be any of 2^64 numbers?
@felixp535
@felixp535 11 ай бұрын
How can it be a 1 in 2^127 when there's only 64 bits? This makes no sense. If we both pick a number between 1 and 10, the chance we pick the same number is 1/10 (the number you pick doesn't matter, the only thing that matters is that I pick the same). Following the same logic, the chance for a computer to pick two identical numbers between 1 and 2^64 is 1 in 2^64.
@hawns3212
@hawns3212 11 ай бұрын
@@felixp535 Lets make it a bit simpler. Imagine you have two dice and you want them both to roll 6s. Each die has a 1 in 6 chance of landing 6, so dice A has 1/6 chance, and dice 2 has 1/6 chance. These are statistically independent events, therefore to calculate the odds of them both happening we multiply them, therefore both dice have a 1/6 chance. This is called taking the intersection of the probabilities, when two events happen together. The odds of having one number from a 64 bit integer is 1 in 2^64. Assuming perfect randomness in the generation we multiply it (aka square it) just like the dice. 2^64 squared is 2^128, therefore we have odds of 1 in 2^128.
@Rizza257
@Rizza257 11 ай бұрын
@@felixp535 this is a common misconception. The probability of person 1 picking does not affect the probability of person 2. This means they are independent events. The probability for independent events is calculated P = P(A) * P(B). So in your example the probability of both picking the same number out of ten is 1/10 * 1/10 = 1/100. This is because you have to consider every combination they can pick the same number.
@felixp535
@felixp535 11 ай бұрын
​@@Rizza257 You made me doubt so I double checked using Excel. The probability of both picking the same number is indeed 1/10 and not 1/100 as you mention. The number chosen by A doesn't matter. The only thing that matters is that B also chooses the same one, which has a 1/10 chance to happen. The events are dependant because B must pick the same number as A. When you think about it, A does not have to pick the same number as B, so P(A) is the probability that A picks any number, which is 1.
@TheViperZed
@TheViperZed 11 ай бұрын
wow this was basic, anyway what this is really missing is a decent description on pointer arithmetic and why that is a very inexpensive operation. This is of course assuming that all the sprite objects have an equal, known, size at compile time and no further de-referencing to other data on the heap happens, cause then the original method of just storing pointers is actually more efficient when drawing the sprite. If you have to explain this to someone, this really should really include an in depth discussion of stack and heap allocations and what that actually means, as that is the underlying optimization issue.
@dejoma.
@dejoma. 11 ай бұрын
When somebody writes "You can give the pointer an address by calling ..." you know that this person does not understand how memory allocation works in C++. Which is absurd after 2000 hours :D
@y4ni608
@y4ni608 11 ай бұрын
I apolozige for any confusion in the Readme file, to put it simply my english is just very bad. i meant with this line "You can give the Sprite ptr a address by calling the s2d::Sprite::getSpriteByName("name"); " that well since s2d::Sprite* my_ptr is a nullptr on start you are assigning the nullptr a adress i dont really know how to put it in good english for you. So thats what i meant, and yeah i do agree that it sounds wierd when you say "Give the pointer a adress" but i dont know how to say it better, sorry.
@maltaparkhelp
@maltaparkhelp 11 ай бұрын
The downside to a vector of objects is that when the vector resizes, the all the objects need to be moved, instead of just the pointers. Depending on the size of the objects, this could make a big difference.
@mjthebest7294
@mjthebest7294 11 ай бұрын
Traversing the vector is usually done muuuuch more frequently than vector resizing, so optimizing that is a priority. If resizing is happening so frequently that is slows you down, you have an architectural design issue
@edmunns8825
@edmunns8825 11 ай бұрын
An egnine is three short of a dozen, but just enough for 2 dosen and an egnine
@gyorgyreisch440
@gyorgyreisch440 11 ай бұрын
I don't understand why is better to storing the objects in that vector than storing pointers to them?! I can imagine one reason: if ALL of the stored object are the same type (aka same size in memory)? (Ok, I haven't program any game engine yet, but in the other programming tasks I experienced that storing pointers [of course unique, shared or weak] is the solution.)
@machimanta
@machimanta 11 ай бұрын
If you store all the objects in a vector directly, you are guaranteed that they are contiguous in memory. If you store pointers, you have no guarantee that the pointed-to addresses (where the object data would be) are spatially local in memory. This has huge implications because accessing memory is SIGNIFICANTLY slower for a CPU than arithmetic/logical operations. CPU architecture attempts to solve this problem by having "cache." Every time you access a memory location, the CPU first checks whether it has that memory in its cache. If it is, great! (That's called a "cache hit" and is very fast.) If not, it must fall back to RAM and grab it (called a "cache miss" and is very slow). Contiguous memory is important because when CPU has a cache miss and fetches the memory from RAM, it grabs more than just the memory you requested. It actually grabs larger block determined by the size of the "cache line." The size of the cache line depends on the CPU & cache level, but its typically ~64 bytes for the closest (fastest) cache. So if I linearly access a vector of 4 byte integers, the first access would be a slow cache miss and then the next 15 integers would be very fast since they were put in cache by the initial miss. In practice it gets a bit more complicated (i.e. the CPU has ways to predict cache misses and compensate for them and compilers can do clever tricks to optimize code around cache access) but the takeaway is that linear, contiguous memory accesses are fast and random accesses are slow.
@y4ni608
@y4ni608 11 ай бұрын
​@@machimanta Hi i didnt quite get your explanation, so what advantage do i actually have when i store the objects as objects and not pointers? So do i like always have my sprites in cache to access them always with a cache hit when i store them as object, and when i store them as pointers i just need to go back to memory because i have the pointers in the cache and do a cache miss?
@machimanta
@machimanta 11 ай бұрын
@@y4ni608 In order to have an object, it has to be kept /somewhere/ in memory. So storing the objects directly within the vector (rather than having a vector of pointers to objects) is the most efficient way to do it from the eyes of the CPU. If you're currently storing pointers to objects, then you're likely allocating them individually with calls to new/make_shared/make_unique/malloc/etc. (pick your poison). Doing so means they are more-or-less stored "randomly" in memory. That's bad since it means the CPU will stall a lot trying to find their data (cache miss penalty). Computers are good at doing predictable things, so having to randomly jump around in memory from object-to-object is not ideal
@kplays_6000
@kplays_6000 11 ай бұрын
This was helpful by all means, but this isn't a code review to me. There was no analysis or explanation of actual code, which is what you've brought us to expect from your code reviews - you could have at least gone into the code and made the exact same analysis from within the code rather than the github readme. Regardless, I'd be interested to see more
@brianewing1428
@brianewing1428 11 ай бұрын
He says at the start - "This isn't a code review. Instead, it's an email review"
@kplays_6000
@kplays_6000 11 ай бұрын
@@brianewing1428 and then proceeds to title the video afterwards as "Code Review"
@brianewing1428
@brianewing1428 11 ай бұрын
@@kplays_6000 To draw people in, knowing the twist is explained in the first 2 minutes
@parabalani
@parabalani 11 ай бұрын
This was weird. You didn't even look at the code and instead reviewed a description and pseudocode. Also, giving a concrete demonstration on how to rewrite his code without using pointers would be helpful.
@owdoogames
@owdoogames 11 ай бұрын
2000 hours? Them’s rookie numbers. I’ve probably spent twice that trying to learn Godot and trying to make a crappy Metroidvania and failing miserably. Off to write my own game egnine instead.
@Svatko
@Svatko 11 ай бұрын
xd
@rudolfbouzek6944
@rudolfbouzek6944 11 ай бұрын
eh :D so pro :D im looking at basic c++ videos... it was 6 years ago... this is like level: GOD :D
@Fly_The_Sky
@Fly_The_Sky 11 ай бұрын
32 minutes on 4 lines of pseudo code. That is pretty good! I am a Programmer but not a game engine developer, keep more videos coming about this egnine!
@y4ni608
@y4ni608 11 ай бұрын
Haha
@AldoInza
@AldoInza 11 ай бұрын
this looks like a primative egten
@parabalani
@parabalani 11 ай бұрын
I don't think tying a sprite to a scene is great, because the same sprite can be used in multiple scenes. There needs to be some other way. Please continue with this review
@TundeEszlari
@TundeEszlari 11 ай бұрын
You are a very good KZbinr.
@kurt7020
@kurt7020 11 ай бұрын
Dive into the actual code. You can do it! Teach, inspire, help lift others.
@soheibmemes2594
@soheibmemes2594 11 ай бұрын
hi
@puncherinokripperino2500
@puncherinokripperino2500 11 ай бұрын
cherno complains so much about pointer invalidation as if there is no way to solve this problem, like pointer preserving structures, a list of buckets for example, or just a list -_-
@trampflips101
@trampflips101 11 ай бұрын
Lists are, as a general rule of thumb, slower than vectors. Even the theoretical ideal use cases for lists usually end up faster with vectors. This is because lists have very bad spatial locality in memory and therefore very poor cache utilisation.
@t3v727
@t3v727 11 ай бұрын
@@trampflips101 my last engine project used lists for the 3D and the 2D entities but it was written in C and I really enjoyed using them, since I started to finally understand them with that project. The next engine will use C++ tho :D
@anon1963
@anon1963 11 ай бұрын
lists are too slow
@anon1963
@anon1963 11 ай бұрын
@@t3v727 it's not magic, double linked list, each element points to the next element and previous element. single linked list, each element points to the next element
@puncherinokripperino2500
@puncherinokripperino2500 11 ай бұрын
@@trampflips101 good point about lists, but lists of buckets have good memory locality while still preserving pointers
@oguzhantopaloglu9442
@oguzhantopaloglu9442 11 ай бұрын
Bro made a video about a 2k hour game engine without running it once 💀💀💀💀💀
@blackcitadel37
@blackcitadel37 11 ай бұрын
"me make gaem enginen on c++ make shmups game with engien move player ship shoot bullet, bullet moves enemy shipe dies program crashes me happy" me as game dev
@gsestream
@gsestream 11 ай бұрын
only 2000? take 7 years off duty. 2000h is one year 8 hours a day of work every day, which should be given instead of self-attempt, of any kind.
@hardee8742
@hardee8742 11 ай бұрын
this is cursed...
Game Engine Architecture 101 // Code Review
16:19
The Cherno
Рет қаралды 55 М.
I made it FASTER // Code Review
38:46
The Cherno
Рет қаралды 539 М.
Самое неинтересное видео
00:32
Miracle
Рет қаралды 2,9 МЛН
Help Me Celebrate! 😍🙏
00:35
Alan Chikin Chow
Рет қаралды 10 МЛН
The joker favorite#joker  #shorts
00:15
Untitled Joker
Рет қаралды 30 МЛН
Minecraft Creeper Family is back! #minecraft #funny #memes
00:26
Performance Bottlenecks in My Game Engine
22:45
The Cherno
Рет қаралды 42 М.
Don't Make This Mistake! // Code Review
29:21
The Cherno
Рет қаралды 53 М.
The Importance of Scalable Code // Code Review
32:10
The Cherno
Рет қаралды 140 М.
I HAD to fix this immediately // Code Review
31:47
The Cherno
Рет қаралды 30 М.
Optimizing my Game so it Runs on a Potato
19:02
Blargis
Рет қаралды 588 М.
I Optimised My Game Engine Up To 12000 FPS
11:58
Vercidium
Рет қаралды 676 М.
The Ultimate Tier Programming Tier List | Prime Reacts
26:57
ThePrimeTime
Рет қаралды 422 М.
BETTER Header Files and Preprocessor Debugging
24:26
The Cherno
Рет қаралды 71 М.
Harder Drive: Hard drives we didn't want or need
36:47
suckerpinch
Рет қаралды 1,7 МЛН
Hazel - My Game Engine // Code Review
40:59
The Cherno
Рет қаралды 116 М.
Самое неинтересное видео
00:32
Miracle
Рет қаралды 2,9 МЛН