Using OpenProcessing

p5.js Project Guidance
1

If you use OpenProcessing I am hoping you can answer some questions for me …

  1. Is there a forum or contact to get support using OP?
  2. Anyone know how to get OP to use web workers?
  3. Is it possible to specify a p5js version to use with a sketch? OP is currently using 1.11.9 but I have sketches using earlier versions that I want to upload.
2

I can’t help with 1 and 2, but you can choose the version in the settings – upper right corner, click on the icon with the 3 sliders, then to the right of the word MODE is a barely visible red on black version number that you can click to choose your p5 version.

To the web designers: NEVER use pure red text on a black background. Around 1/12 of men are at least slightly red colorblind and red on black is just not visible to us. That includes especially red error messages in the black Processing IDE console. If you want red, add in some green and blue to make it bright enough to stand out.

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3

If we choose the HTML/CSS/JS mode, we’re free to get any JS library of any version!

We just need to edit its “index.html” file for it!

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4

Thanks @scudly and @GoToLoop for your suggestions I will try them both out.

When software used to come with printed manuals I once bought some software and the manual was red text on black paper (actually might have been black text on red paper doesn’t matter) to prevent it being photocopied, it was a pain in the backside.

So this red/black issue is well known.

5

Here’s a screen recording for reference:

2025-08-31 09.52.52

Note that this option appears in P5js mode only.

If you are using HTML/CSS/JS mode, you can set the p5.js version by editing the script tag in index.html:

<script src="https://cdn.jsdelivr.net/npm/p5@1.11.9/lib/p5.js"></script>

Replace 1.11.9 with the version of p5.js you want to use.

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6

Thanks @sableraph for your visual I think it reinforces the need to avoid low contrast text. :grin:

7

Thanks again for all your help. Just to let you know I have found a solution to using Web Workers in OpenProcesing.

  1. This the web worker code file should be a code tab rather than imported into files
  2. Mark all code tabs as javascript by adding the .js extension. This includes web worker file
  3. choose the HTML/CSS/JS mode.
  4. in index,html add script tags for all your code files except the web worker.
  5. in index.html add script tags for p5js and any third party libraries used.

I have used this in my “Train Tracks” sketch (see below) which uses a web worker to create new puzzles.

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