Exposed isContextLost from animation loop

[igorDykhta]

For visgl/deck.gl#5399

Background

Required to add better context lost state handling.

Change List

• added isContextLost to AnimationLoop which returns the current state of the used WebGL context
• AnimationLoop.redraw function exits early in case of a lost context

[ibgreen]

Do we want an onContextLost callback on the animation loop?

Note: There is a WebGL extension to simulate context lost for testing purposes.

https://developer.mozilla.org/en-US/docs/Web/API/WEBGL_lose_context

It is supported on Chrome https://webglreport.com/

[igorDykhta]

Do we want an onContextLost callback on the animation loop?

Xiaoji proposed to move this check to anim-loop.

Note: There is a WebGL extension to simulate context lost for testing purposes.
https://developer.mozilla.org/en-US/docs/Web/API/WEBGL_lose_context
It is supported on Chrome https://webglreport.com/

Yes, I'm using it to simulate a context lost event, and test luma > deck > kepler

[igorDykhta]

@ibgreen @Pessimistress Any idea why coverage has decreased here? Do we have invalid context during tests?

[Pessimistress]

Do we want an onContextLost callback on the animation loop?

Added by #1441

Any idea why coverage has decreased here? Do we have invalid context during tests?

Test coverage fluctuates sometimes. It's not necessarily caused by your change.

[ibgreen]

Do we want an onContextLost callback on the animation loop?

Added by #1441

I was referring to adding it to AnimationLoop