processing / processing/p5.js

WebGL `setAttributes` causes image interpolation to default to LINEAR

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Area:WebGL Bug
Dominant language
JavaScript
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Description

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

1.11

Web browser and version

129.0.6668.58 & 115.15.0esr

Operating system

Debian 12

Steps to reproduce this
Steps:
  1. Call setAttributes
  2. setInterpolation on a texture to NEAREST
  3. Render the texture and watch it not work

Example (working sketch located at https://editor.p5js.org/PotatoBoy/sketches/tFXOSAnZV):

let img;
let canvas;

function preload() {
  img = loadImage('test.png');
}

function setup() {
  canvas = createCanvas(400, 400, WEBGL);
  setAttributes({ alpha: true });

  canvas.getTexture(img).setInterpolation(NEAREST, NEAREST);
}

function draw() {
  background(0);
  image(img, -width / 2, -height / 2, width, height);
}

Result:
image
Expected Result:
image

Note: Related to https://github.com/processing/p5.js/issues/6325 which is encompassed by this issue

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the linked reproduction and trace the WebGL paths for setAttributes and setInterpolation. Verify the texture setup before and after setAttributes, then confirm the fix by rerunning the sketch and checking that NEAREST interpolation remains effective when the texture is rendered.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
computer-graphics
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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