0:45 you saying "stop giggling" actually made me laugh for a few minutes and i had to rewind the video to actually hear what you're talking about

Hello! 2021 Let's Go! - Audio Squeeks and pops we're not on my master upload.... (shakes fist at KZfaq), and do try the real-time, no effort demo! community.onelonecoder.com/members/javidx9/CircleVsRectangle/

Just when I was working with collisions on my game, wow.

One lone coder videos motivated to me to start studying coding on my free time and after start high studies of computing. Today was a bad day at studies. Lot of work, to my expectations low qualifications for great effords, incomprehensible teachers... But, see David coding has make me smile and it has remember me why I'm doing this. Thanks OneLoneCoder for all your work

I really appreciate these videos , thank you

20:24 there's a nasty audio artifact

Your NES series inspired me to try to write a gameboy emulator having no experience

I stopped suffering when interacting with C ++ and loved it thanks to your channel. I wish you prosperity

This is what makes this channel so unique and fun. Smart programming with cool little tricks and clever ideas.

Welcome back, looking forward to hearing more about these PGE updates!

This is so simple and amazingly powerful! I needed to resolve collisions between spheres and bounding boxes... And I remembered the lone coder had some great trick with the clamp function. I come to search this video and I wasn't disappointed! It works just fine in 3d (just add the z axis). I extended it to work with oriented bounding boxes just translating the sphere to be relative to the bounding box origin, and applying the inverted rotation matrix to it. It worked immediately! Thank you!

the corner resolution is so satisfying to watch!

Great stuff - this is the real start of 2021 :)

Just implemented by myself in Java, and it works like a charm. Thanks for explanation and for the great job !!

Yay! I've been looking forward to this. :)

Looking closely at 0:00 you can see that the video actually starts

Hello, Sorry for the following silly question. Maybe i am wrong here: In the picture at 11:21 N represent the nearest point on the rectangle. So the lengh of N is the lengh between the world origin and this point N. I that case |N|

i hope you had a good break! i really love these videos

The absolute mad lad made it run in webGL

Awesome, great video Javidx9!! The Pixel Game Engine is getting better and better.

Man, your channel is ridiculously good, just want to say thanks. Will support when the situation allows for it! (Y)

Awesome how great the Pixel Game Engine has become! Great video Javid.

Another amazing video. Thanks !

Hi Javid, I've been using this algorithm for collisions in my projects for about a year now, and it's worked wonders! I really appreciate you making these videos! That said, I encountered some strange behavior a while ago, and after hours of debugging my own code I finally realized the issue actually in this algorithm. There is an unwanted side effect of sliding along tiles, wherein the circle will round off its position on one axis as if colliding with a corner when moving into an edge where two rectangles meet. This bug can be reproduced in the web demo: - Position the circle just below/to the right of the line dividing any two joined rectangles. - Hold in the axis that moves toward the rectangles and simultaneously tap and release the key that moves negatively in the other axis (left or up). As long as you keep moving in the direction of the rectangles, you should see the circle slide along the other axis when you tap, but then resolve backward as soon as you release until it stops at the point that the other axis would start rounding a corner. I'd love some help with this as I'm struggling to find an elegant solution to this issue. Perhaps there isn't one. Thanks again!

2021 has already been better for me than 2020. I started a new job on January 11 after being unemployed since the beginning of August. I'm a contractor working for GDIT, helping them with a software project they're developing for the US military to help make it easier to avoid friendly fire incidents.

This video saved me hours of work. Thank you!

A good video to start 2021 and happy New Year

Nice to see You. All the best

You are a legend! Thank you for your videos

PGE IN THR BROWSER? Javid, you're a legend

Really nice work! Thinking about using this for my project on MonoGame!

Thanks, this was very helpful.

Very helpful video, as always. Thank you javidx9!

this is a really nice collision check. even though my player is literally a square it's still better than what i had before because of the way it pushes you around objects

Great video! Thank you!

Hi David +1 as usual .. it's took me a lot of time to recognize the central point of mathematic ;-)

cannot wait for the next video

Yeah! Finally :D

20:25 That pop scared the shit out of me

Awesome. Missed you mate.

dope vid

Hi Javid, Ian here. Nice to have you back. Also, I see that Pi 400 in the background. :D I hope you are well rested after the break, seemed like you were fairly bust throughout the second half of last year.

You're my role model!

welcome back!

This is also known as a Signed Distance Field. So you can easily collide a circle and any of the shapes there are analytical SDF function for, such as the ones provided on Inigo Quilez's pages. :)

Simple but effective

I hope your friends gifted you algorithms on Christmas :D

nice!

nice one

I have watched the little talk from 4:46 several times. the "come to think of it, that is how everyone defines a circle" makes me laugh every time.

30:32 Isn't there still a bug where if a potential position lies on the nearest point your position goes to NaN? I don't think checking fOverlap for NaN does actually anything. Reasoning: The mag() -function is internally: sqrt(x * x + y * y). No division. On the other hand norm() returns vector / mag(vector) which can be NaN. Line 107: If vRayToNearest magnitude is 0, then fOverlap = r - 0 > 0. Line 111: The check passes. Line 113 vRayToNearest.norm() divides by zero and returns NaN. vPotentialPosition.xy = NaN. This NaN quickly cascades to all values, including fOverlap, but by this time it's too late to fix; your position is already NaN. I'm not sure what could be a potential fix. Immediately one thinks of checking if (fOverlap > 0 && vRayToNearest.mag() != 0), but that feels wrong intuitively (since that's a collision but it's not registered). Maybe if mag() == 0, you should push vPotentialPosition just a little bit forward or backward on the ray to ensure a non-zero number.

So nobody else noticed the maths at 11:23 is not correct? Javid forgot to substract the balls position from N to get another vector, lets call it D, and this vectors magnitude should be compared to the radius of the ball! In the final code it is done correctly however :).

All your BASS are belong to us!

Balls colliding with balls, stop *giggling* .. - One lone coder 2021

You Said The Chanel is Back

Nice 🙂

4:10 Fun fact: Super Mario 64 actually did something similar, except with polygons instead. It worked well because it was a geometrically simple game.

Vimto product placement!

Is the video about "Changing the state of the procedurally generated universe" still planned? It's honestly the most interesting thing to me. I'd be sooo happy, if you'd revisit the topic :D

Compiles into WebGL now? Wow. That just turned it up to 11 :-)

Got missing you, absent for some weeks.

What do you do if the speed is high enough to put the center of the circle inside the rectangle?

Hi Javid, I dont know if you would reply but I have a quick question and wanted to know your opinion because its often straight to the point. In one video you mentioned that you work somewhere at the development of robots, is c++ a valuable language in robotics because at my university they only teach us matlab mainly for those things but I know that that is not used by a lot of companies, and im interested in programming and want to learn c++ anyway but that way I kind of have more motivation to learn in a faster pace. Btw, your videos have been great to learn programming by thinking outside of the box and simple and elegant solutions so please continue what you do, its really entertaining and helpfull.

now apply to raycasting and you have signed distance field raymarching / sphere marching

I see...greate material to build platform for mobile robot simulator.. ;-)

hi javidx9, nice video as always, i was wondering wich would be the best way to update the velocity after colliding with a wall, it can't be set to zero cause the character could be sliding along the wall, the length of the velocity is often used to handle animations

I desperately need rectangle vs rectangle collision response for years now, when they hit in different angle and then rotate..Like when a rectangle falls on the ground in non-zero angle, you know , Box2D stuff ;)

There is some problem with the source code link. Always very interesting video.

Who knew TV stood for transform view, makes so much sense now, apart from my TV licence... ? (Great video many thanks :)

Welcome back! Is it just me or does your voice sound a bit muffled (for the lack of a better term) during the segments when you are on camera? As if there was a high frequency attenuation effect applied to the audio.

But the question is when quaternions?

Hi, this algorithm is awesome, but I wonder is there a way to adapt it to stop the ball as soon as it hits the wall?

hmm, personally I think linked triangles at the bottom level (the generated triangles for each shape) would provide a catch all solution which is ultimately more useful when passed off to a GPU

There used to be a website (5-10yrs ago), green and white, slightly outdated layout, with all possible collissions for shapes and objects. It was something like collisiondetectionalgorithms.com, but I haven't found it for a long time..

Once you start talking about Vectors and Radiuses, my brain goes to single core mode.

This is so simple.. I feel ashamed of much of code I have written in the past

hey awesome video!!! learned a lot! i found a problem when implementing it myself, if the velocity is too much, the potential position will land straight inside the square and the clamp will make "nearest" to point towards inside it instead of the wall. i had to scale the potential vector to be the player radius - [really small value], but that will have weird effects on diferent machines. i cconsidered dividing the movement vector by (int)(vec_len / radius) and adding up/checking collisions at each pass but it seems like a waste, any ideas? (i probably implemented mine wrong to start with, thanks)

There is a bug in this. A rectangle consumes X + W - 1 and Y + H - 1 pixels. So X + W is atually 1 pixel beyond the right side and Y + H is one row past the bottom. For examplem, a 1 pixel wide by 1 pixel high rectangle only has 1 pixel, not 4 pixels.

Can you do a video on triangle collisions? Preferably with collisions to circle and rectangles :D

What IDE are using for coding and compiler? I searched in your video library for a video on how to get started in coding, but couldn't find one.

"This will be a nice and quick video because this technique is simple" *32 minutes later* I have no idea how this works

Nice! But if the rectangle isn't axis-aligned, it gets more complicated. Or am I missing something?

30:27 I ran into a bug implementing this today. When you call norm() it calls mag() so it can also give you undefined values. I was spawning my circles inside the rectangle they collide with and the collision pushes them out - only you get a location that's undefined so they don't exist anywhere sensible. oddly this didnt cause any crashes anywhere else (drawing them each frame, updating their AI to move them, ect) and they just 'didnt exist'.

Shouldn't the resolved position of the collision lie along the initial velocity vector? I may have missed something, but the collision is resolved here by finding the position of collision and displacing the next position along the normal such that there is no overlap. However the origin of the circle in this new position does not seem to lie along the trajectory the ball would have traveled otherwise, which does not make much sense to me. Maybe I am misunderstanding something or at small enough time deltas it doesn't matter but nevertheless excellent video as always!

I have a question. It is not concerning now the content of this video, but can you explain the concept of async a bit more? I am a bit familiar with c++, and since a couple of months I am diving a bit deeper into it. But the topic of threading I did not touch in C++ yet. But as I am a vb.net developer, there is this concept of async functions which are not really threads. Those can be executed in parallel, and if you await them, the GUI for example will stay responsive, so the program feels more snappy. But I don't know how this works... How can it be executed in parallel when it is not a thread? In my understanding to have code running asynchronous there needs to be another thread beside the main thread... So I am a bit confused what's going on there.

I'm a little confused about 11:00, wouldnt shifting the rectangle and point to the right increase the magnitude of N without changing the collision?

I'll just go with using Voronoi regions

can be imported to wasm?

And with a few lines of code, suddenly every homebrew Pac-Man clone becomes more playable and less annoying.

hi, how do i calculate the velocity after a collision?

distance field to check where is the closest object

do another video on Embedding Lua in C++

Can you do it without the square root?

What the hell, I subbed a long time ago, enabled the bell and everything yet KZfaq still didn't show me this video. Is the whole KZfaq broken because everyone is spamming the poll exploit or what.

17:08 What's that sound?

4:49 LMAO)

would you ever attempt to make a chess engine?

Hi, OLC! how about Networking part 3 source codes?)

Litterally thinking all the video "And what about letter collision"? How would a "d" minus letter collide with a rectangle. And then, I thought that would make a totally different video subject. And then I thought "who would ever collide a minus d with a rectangle?". :(

Balls colliding with other balls