This is such good info thank you! I should definitely do a follow-up!

I'd love to see a Langton's Ant Part 2! After I saw the video about it on Numberphile, I made it on my graphing calculator lol.

I made a video of Langton's ants "fighting", it's on my channel if anyone's interested :)

if an ant enters an ant tile add another ant!

Cool suggestion!

This is a very elaborate comment. Can you do it and just show us the result

Nice improvement!

Normalize a value

:0 I never though you could do that ..thanks for the trick!

Yay!

I discovered Processing at the same time I heard Support for Java is ending...

Chris Hawker lol

When I made it, I did the same, but I used a 4 number array representing the amount to change the ant's index (As I had it represented by a position in a 1d array of the grid), and had a variable that would range from 0 to 3 representing the direction. When the ant would move, it would use the direction as an index for the aforementioned array, and that would be the amount it changes it's position by. For turning, I had an array of +1 and -1 representing right and left respectively, and using the value of the cell the ant moves into (post-step) as an index for this array, I would change the direction variable. So it would either increase by 1, or decrease by 1. Before assigning it, I would perform a bitwise AND operation on it with 0b11 (3) so that if it became -1, it would change to 3. My goal was to write it in JS while optimizing the absolute hell out of it, to the best of my ability, so that it would run as fast as possible in a webpage. With just JS, I got it to 80 million steps/second (Capped by Chrome), and with WebAssembly, I got it to 200 million/second. With WebAssembly: www.jdoodle.com/h/1Yw With pure JS: www.jdoodle.com/h/1ZM I had to reconstruct the pure JS version from a slightly older one because I didn't save the version that I made just before shifting to WASM. I'm pretty sure that I had it at just about 60 million/second, but it's running closer to 50 million/second. Maybe I missed something small, idk. (Note: The arrays are saved as Int32Array as a performance optimization) Test settings (10 million/frame): Rules: L Delay: 0 Steps: 10000000 Width: 2 Height: 2

I made it check the pixel's color, and then put a little rectangle to replace the color that the ant was just on.

same, my code is PVector pos, move; int spacing = 25; color white = color(255); color black = color(0); void setup(){ size(1000,1000, P2D); rectMode(CENTER); background(255); noStroke(); pos = new PVector(width/2,height/2); move = new PVector(0, -spacing); } void draw(){ color c = get(floor(pos.x), floor(pos.y)); if (c == white){ move.rotate(-HALF_PI); fill(black); rect(pos.x,pos.y,spacing, spacing); pos.add(move); } if (c == black){ move.rotate(HALF_PI); fill(white); rect(pos.x,pos.y,spacing,spacing); pos.add(move); } }

Yes, I had meant to mention this is an exercise for the user to try but somehow forgot. Thanks for the comment I'm going to pin it! (And yes, I should follow up on this too.)

Sean Franklin Admittedly, this is intended more to get people interested in coding and show them how it works then to be highly professional; accessibility is high priority here. Just look at the number of comments on pretty much any of his videos saying that so-and-so doesn’t know programming but enjoys watching him anyways, or that somebody became interested in programming because of him; that aspect of reaching out to laymen would be gone. I’ll admit he is pretty all over the place in this one, but I can forgive him for that.

Yes, a good point, thanks for the tip!

Please suggest here! github.com/CodingTrain/Rainbow-Topics/issues

@@TheCodingTrain Hey... Hey I made an issue on GitHub after commenting here... Waiting...

Nice work! You can submit a link to the coding train website if you like! github.com/CodingTrain/website/wiki/Community-Contributions-Guide

whatt dou?? this is magic man... i can't even seem to realize what he's doing.

Part of the video is giving the viewer the opportunity to learn how to do things better.

Yes, a great improvement!

Unfortunately Java implements modulo funnily, if you take the modulo of a negative number it returns the same number. For example: -5%10 = -5 Whereas in other languages it would be 5. js also does it in the funny way too.

you could just take the absolute of the mod then

Thanatos 12321 Or not use 0,1,2,3. Have the directions start at anything above 0 modulo (weird Java modulo) should work then, right?

Yep, you did find it later on. Good job man! These challenges are super cool to watch!

Thanks for this suggestion!

Yes, a switch statement is just concise syntax for a certain kind of if statement, but the result is exactly the same!

​@@TheCodingTrain Actually, it is not. Logically, it may seem the same, but there is a difference between if/else and switch-case. The instruction for performing a conditional jump takes 2 machine cycles if the condition is not met, and 3 if it is met. An if-else statement will jump to the end of each body if the condition is not met, while a switch-case will jump to a body if the condition is met. For example, let's say it were the 4th condition that was met (I will exclude the comparison, and only count the conditional jump instruction's time) if-else: 3 3 3 2 switch-case: 2 2 2 3 And when a switch-case doesn't test each condition, it uses an array of addresses for each condition, and jumps to one of these by index. This is especially efficient if the switch-case uses consecutive conditions, for example, [0, 1, 2, 3, 4, 5, 6...], but make no mistake, a switch-case and if-else are NOT the same. Switch-case is just slightly faster.

Because you have a fill(255) so every rect is going to be white. If you want to fill black put a fill(0) inside the if (x>255)

oh mistyped, imagine if x were in the place of that 255

I used Atom, using the p5/javascript version of processing.

yes yes i know this comment is a yer old but i dont care hes coding in java not js

Thanks for these great suggestions!

Sam DeLong Go Wikipedia, search for "AI", click around.

Yes, a good point! I tend to be informal about these sorts of things and refactor later.

:(

Also TMW your code was more complicated than his

Who is Dan?

@@KnakuanaRka Dan is Dan Shiffman... the guy in the video

I wrote this in p5 and after a while it will eventually just fill the screen (I just counted, and it took 3 million moves to fill the 400x400 screen) It only takes a minute and a half to do that, with output to screen every 10,000 moves.

You hatred my thing cool

People suggest here! github.com/CodingTrain/Rainbow-Topics/issues

He's using Processing, which makes it really easy to make graphical applications by abstracting a lot of the boilerplate of java. Processing doesn't need a main method, it uses setup and draw methods instead

Thanks! I scratched my head around for a bit on that one.

No problem! I'd highly recommend checking out processing, it's super useful and really easy to use

I love this idea!

If you know which way to turn (-1 for left, +1 for right) you could do this: dir = (dir + turn) % 4;

I think you'd have to say: dir = (dir + 4 + turn) % 4; Otherwise it won't work with dir = 0 and turn = -1.

The Coding Train Thanks for pointing that out! You are right, forgot how modulus works in Java :)

@@danielgrunkin8705 Or, you can use "& 0b11" instead of % 4 to avoid that problem. Then you could ditch the + 4

You'll find it here! thecodingtrain.com/CodingChallenges/089-langtonsant.html

The direction the ant will move in diagonally depends on which direction it is facing initially (north, south, east, or west).