Bug 264684 – "context lost" when getting WebGL context

• Component: WebGL
• Status: RESOLVED FIXED

[Andre-John Mas]

We are no longer able to get the WebGL context on iOS or iPadOS using release 17, with a "context lost" error being logged.

The issues was discovered using Three.JS, but further investigation reveals this impacts all WebGL applications (those I have tested with).

The following code is enough to cause the issue:

```
  function initWebGL () {
	const canvas = document.querySelector('#canvas');
	canvas.width = window.innerWidth;
	canvas.height = window.innerHeight;

	const glOptions = {
	  // antialias: false,
	  // alpha: false,
	  // premultipliedAlpha: false
	};

	const gl = canvas.getContext('webgl2', glOptions)
	  || canvas.getContext('webgl', glOptions)
	  || canvas.getContext('experimental-webgl', glOptions);
  }

  initWebGL();
```

Note, this does not impact Safari (17.0 (19616.1.27.211.1)) on MacOS X 14.

Tested with: iOS 17.0.3, iPadOS 17.0.3 and MacOSX 14 (Safari).

Note, discussion in the Three.JS forum: https://discourse.threejs.org/t/three-js-broken-on-ios-17-with-context-lost/58025

[Andre-John Mas]

I was just reminded there was updates for iPadOS and iOS.

Confirm this is no longer an issue with iPadOS 17.1.1 or 17.1.1

I'll close this ticket.

[Ahmad Saleem]

*** Bug 264683 has been marked as a duplicate of this bug. ***

[zakyn]

We are still experiencing this issue on iOS 17.1.2 phones

[Andre-John Mas]

@zakyn can you provide some code that illustrates the issue and at what line you are seeing this occur. Thanks