Prevent unnecessary texture upload on image source updates

[karimnaaji]

Fixes a regression introduced by #11564.

The reason texture.update was added was mentioned as the following in the original PR:

also uses texture.update rather than always creating a new texture when the source's image is updated

But this introduced another regression since the check did not account whether the image changed at all making it run most frames, where it was running previously only when the texture had to be created.

Launch Checklist

• briefly describe the changes in this PR
• manually test the debug page
• apply changelog label ('bug', 'feature', 'docs', etc) or use the label 'skip changelog'
• add an entry inside this element for inclusion in the mapbox-gl-js changelog: <changelog>Fix potential performance regression on image source updates</changelog>

[mourner]

👍 The only reservation I have is that it doesn't have a unit test, so it might regress in a future refactoring. Although I'm not sure whether this can be tested cleanly. Feel free to merge if not.

[yuvadm]

Is there any easy way to pull the PR build from CI to help test it? Alternatively, is there an estimate on when this fix lands in a release?

[mourner]

@yuvadm Here's a build I made from this branch — hopefully enough to test this out: mapbox-gl-texture-fix.zip

[karimnaaji]

@yuvadm let us know once you give it a try in your context.

[yuvadm]

@karimnaaji Yep, this fix definitely seems to do the trick! When can we expect it to be merged and released?

[karimnaaji]

Thanks for trying it out @yuvadm. This change will be carried out to the next release (v2.11.0) that we're aiming at deploying sometime this month.

[yuvadm]

@karimnaaji @mourner is there any estimate on the v2.11 release date?

[karimnaaji]

hey @yuvadm , sorry for the delay. We're aiming at deploying a beta this week or early next week. We still have another pending fix we're going after before we can deploy the new release.