[p5.js 2.0 Bug Report]: [p5.strands] Shared variable breaks when vertex and fragment shader strands are both present.

[nbogie]

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

2.2.2

Web browser and version

145.0.7632.117 (Official Build) (arm64)

Operating system

Mac OS 14.6.1 (23G93)

Steps to reproduce this

Steps:

1. Visit https://editor.p5js.org/neill0/sketches/ZmBjlLngO
2. Observe sketch fails with

ERROR: 0:313: 'assign' : l-value required (can't modify an input "myVar")

Snippet:

  let myVar = sharedVec2();

  // Adding objectInputs block crashes it
  objectInputs.begin();
  objectInputs.position += [0, 0, 0];
  objectInputs.end();

  pixelInputs.begin();
  myVar = pixelInputs.texCoord;
  pixelInputs.end();

  finalColor.begin();
  finalColor.set([myVar.r, myVar.g, 0, 1]);
  finalColor.end();

Use case

• Displaced terrain vertices - needs objectInputs
• The terrain is coloured in finalColor based on, say, a texCoord that has to be saved from before finalColor, using a shared variable set in, say, pixelInputs.

Link to discord discussion