[p5.js 2.0 Bug Report]: ellipse() with negative detail crashes in WEBGL

[shuklaaryan367-byte]

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

2.2.0

Web browser and version

Google chrome Version 144.0.7559.133

Operating system

Windows 11

Steps to reproduce this

Steps:

1. Create WEBGL canvas
2. Call ellipse()
3. Pass a negative detail value

Snippet:

function setup() {
  createCanvas(200, 200, WEBGL);
  noLoop();
}

function draw() {
  ellipse(0, 0, 100, 100, -10);
}

Observed Behaviour:

Sketch crashes when ellipse() is called with negative detail.
Renderer stops and runtime exception occurs.

Expected Behaviour:

Negative detail values should not crash the renderer.

Possible alternatives:
• Clamp to minimum valid value
• Ignore invalid input
• Throw friendly error

Additional Note
Tested with:

• ellipse(..., -1)
• ellipse(..., -10)
• ellipse(..., -100)

All resulted in crash.

I'm willing to implement a fix if this gets approved.

[saurabh24thakur]

Hey! I’ve reproduced this on v2.2.0 and traced the crash to the vertex logic in primitive_algorithms.js. I'd love to submit a PR to add some validation/clamping for the detail parameter—mind if I take this on?

[shivamsrc]

Hi @davepagurek ! I was reading through this issue and trying to understand how negative detail values are handled in WebGL mode. It seems crashes can occur when invalid values are passed, so I was wondering whether adding validation for the detail parameter (for ex- clamping it to a minimum valid value) would be a good way to prevent crashes caused by invalid input.
Would this be a reasonable direction to explore? If so, I’d be happy to work on a PR. I’d appreciate any guidance on the preferred approach before I start.