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[] browser renders blurry while scrolling [answered]

asked 2015-09-14 12:47:17 +0200

limarkus gravatar image

updated 2016-08-17 11:29:12 +0200

jiit gravatar image

I have observed that the browser in uses a blurry preview of the current page while scrolling. When moving around a website I often have to look at blurry content now, since I upgraded to After waiting for a second or two, the blurred preview gets sharp and is readable.

I have read that there is a new rendering mechanism because of fps performance on the tablet - is this a side effect of this? I have not experienced this issue with the browser of previous OS releases.

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The question has been closed for the following reason "the question is answered, an answer was accepted" by raketti
close date 2015-09-14 13:01:30.872556

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answered 2015-09-14 12:56:26 +0200

tworaz gravatar image

This is a gecko feature known as low precision buffer (layers.low-precision-buffer). In 1.1.9 its enabled by default as it is in newer firefox versions for android. Without it you would only see page background until the engine finishes rendering the content in its normal resolution.

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Hi, thanks for the explanation. Does this feature also apply for the following scenario?:

  • enter a URL
  • wait for the content to be displayed (no blur)
  • scroll down (see blurred content)
  • wait until content is readable
  • scroll back to content that had already been loaded and rendered without blur - and observe that that content is now blurry again
  • wait for the content to be readable again.

I was quite surprised to see that previously loaded content has to be rendered again - especially since I think this was not the case in earlier versions. At the moment I cannot test it using an older version of Sailfish, because I only have one phone =)

limarkus ( 2015-09-14 13:57:55 +0200 )edit

Well, this is not ideal, but not unexpected. Gecko v31 seems to still have some problems where it can trigger full screen repaints even when nothing animated is actually visible on the screen. If you're interested nglayout.debug.paint_flashing pref can be used to show paint invalidations. The situation does seem to be a lot better in gecko v38. We're currently in the process of upgrading to it, but it'll take some time until the migration is done. If the feature bothers you too much you can disable it by setting layers.low-precision-buffer gecko pref to false.

tworaz ( 2015-09-15 21:29:40 +0200 )edit

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Asked: 2015-09-14 12:47:17 +0200

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Last updated: Sep 14 '15