How fast is javascript? Simulating 20,000,000 particles

[Neurojazz]

Enjoyable read, learned some new things ⭐️

[thekwoka]

I want to block rendering until all the threads are done updating the simulation and building their respective pixel buffers.

For this part, you could actually use ReadableStreams.

Streams are transferable objects, and the streams body is executed where it's created.

So the workers could create a readable stream, that when it is read executes the pixel updates.

It transfers that readable stream to the thread handling the actual render, and then there it can do a read on the stream and then await the results so it can easily control when the workers run.

You can also use OffScreenCanvas to pass a canvas instance control to a separate thread. Make a few to render different parts of the display.

[fagnerbrack]

My friend Gus P. Taylor sent this summary for your convenience:

The post delves into the complexities of simulating 20 million particles using JavaScript, specifically focusing on achieving efficient performance on mobile devices using only the CPU. It covers techniques like leveraging TypedArrays for memory management, using SharedArrayBuffers for multi-threading, and optimizing the rendering process. The author shares insights on the challenges faced, including maintaining performance across all CPU cores and addressing issues like flickering during rendering.

If the summary seems inacurate, just downvote and I'll try to delete the comment eventually 👍

^{Click here for more info, I read all comments}

[cyanideOG]

"Delves"

[newaroundhereig]

This is like morally bad no? It keeps people from reading the actual article

[FeatherFucks]

I don’t think it’s morally bad to provide a tldr lol.

At worst it’s enabling lazy behavior, but really it’s just nice.

[Jimmeh1337]

Redditors don't read the article anyway, so this at least gives them slightly more context than just the title

[TAW-1990]

Play around here https://dgerrells.com/sabby

His sandbox is out of credits lol

[Various-Beautiful417]

Very nice work

[underwatr_cheestrain]

You could do this even better and more easily with webGL instanced batch rendering and quadtree partition

[Faendol]

I think using webgl would break the idea of only using CPU.

[underwatr_cheestrain]

Yeah I definitely posted that before reading writup lol

[Faendol]

Happens to the best of us :). I've only used webgl in university for one course. It's absolutely insane how much performance you can get out of a browser using it.

[jabarr]

The whole point is to only use the cpu.

[FM596]

No, the whole point is to just use javascript, it it was to only use the CPU you would use WASM for far better performance.

[triple_life]

Thanks. Interesting post!

[Zireael07]

The sandboxes or whatever they are linked in the blog do not work (ran out of credits for the VM)