processing/p5.js

large webGL canvases draw at unpredictable locations

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#5,156 opened on Apr 3, 2021

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Area:WebGLBugHelp Wanted

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Description

Most appropriate sub-area of p5.js?

  • Accessibility (Web Accessibility)
  • Build tools and processes
  • Color
  • Core/Environment/Rendering
  • Data
  • DOM
  • Events
  • Friendly error system
  • Image
  • IO (Input/Output)
  • Localization
  • Math
  • Unit Testing
  • Typography
  • Utilities
  • WebGL
  • Other (specify if possible)

Details about the bug:

I noticed that when trying to draw very large graphics objects to the canvas, it doesn't seem to be drawing in the correct location. I noticed this happening yesterday when using a couple canvases around 5000px, and today again when using canvases > 6000px.

They seem to be drawing down and to the left for some reason. I'm attaching a sketch showing the issue and a screenshot here as well.

https://editor.p5js.org/aferriss/sketches/aMrQqoKF2

  • p5.js version: 1.3.1
  • Web browser and version: Chrome
  • Operating System: Mac OSX
  • Steps to reproduce this:
  1. Create a large graphics object (>6000px)
  2. Draw some things into that graphics object
  3. Try to draw that object at the origin.

Contributor guide

Research direction
Investigate the WebGL rendering pipeline for large canvases, specifically the coordinate transformation or buffer allocation.
Tech stack
javascript
Domain
frontend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65