High Performance JS heatmaps | Hacker News Reader

High Performance JS heatmaps

codeflow.org

99 pointsmariuz13 comments

Interesting. I'd be interested to see a version that uses WebSockets to transfer the data points and draw it on another screen (e.g. analytics, see how users interact in realtime).

there's no need for that to be part of the library though or am i missing things?

Nope. That's the idea. The library gives you a high performance drawing engine. What you feed it is up to the respective use-case.

It only works for me once after I refresh the page. If I click overlay the data stops persisting. A hard refresh allows it to work again. Ubuntu 12.10 Firefox 18.0.1

That's an interesting bug.

- Does it work in chrome? (please state chrome version)

- Do you have any error on the javascript console (ctrl+shift+k in firefox, ctrl+shift+j in chrome).

- What GPU/driver are you using?

- Please paste the content of about:gpu in chrome, and about:support (the graphics section) in Firefox

Hi, I can't test it in chrome as WebGL isn't supported.

Firefox graphics: http://pastebin.com/XVdypYVq

Relevant error messages: http://pastebin.com/PvKVwWFi (These are repeated. I missed them the first time round because they were actually warnings rather than errors.

Hardware: http://pastebin.com/x7Jh025T

What version of chrome are you using?

  Google Chrome – WebGL has been enabled on all platforms that have a capable graphics card with updated drivers since version 9.[14] Google Chrome 13.0 and newer versions use Cross-origin resource sharing (CORS) to control all WebGL cross-domain textures.[15]

Source: http://en.wikipedia.org/wiki/WebGL

>>> "capable graphics card with updated drivers"

I think that's the issue with this version of Ubuntu. It's a strange hybrid graphics setup.

Right, got it. That was a small error in the auto update on addPoint check, index off by 1: https://github.com/pyalot/webgl-heatmap/commit/8d04627cba4a3...

Example/blog post is updated. Let me know if that fixes the issue for you.

I'm afraid not, same behaviour as before. The javascript warnings have gone now though.

Can you shoot me an email to pyalot@gmail.com I'm probably gonna write a conformance test for it eventually, but since it works on my 3 platforms (mbp, ubuntu 12.04, win7) I'll need some help figuring out how to write one that reproduces it.

I had the same issue in chrome

I get the same red "hotspot" from moving my mouse around, or scrolling with my cursor in one place. Is there a way to tell the difference with this?

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