Panning vertically is very jittery

RESOLVED FIXED in Firefox 21

Status

RESOLVED FIXED
6 years ago
6 years ago

People

(Reporter: st3fan, Assigned: ajones)

Tracking

({b2g-testdriver, unagi})

unspecified
B2G C4 (2jan on)
x86
macOS
b2g-testdriver, unagi

Firefox Tracking Flags

(blocking-basecamp:-, firefox19 wontfix, firefox20 wontfix, firefox21 fixed, b2g18+ fixed)

Details

Attachments

(1 attachment, 1 obsolete attachment)

(Reporter)

Description

6 years ago
When panning vertically slowly, for example while reading an article, the text seems to rapidly jump up and down.

It does not jump up and down a lot. Probably just 1 or 2 pixels. But the effect is bad enough to make me a little seasick :-/

I'm not sure if this is a rendering or gesture issue. It does seem to depend on the zoom level.
Where do async pan and zoom bugs live? I think this is a dupe.
Component: Gaia::Browser → General
Whiteboard: DUPEME
Related bug 812517? However, already fixed in the beta build on which Stefan experienced this issue.
per comment #2
Status: NEW → RESOLVED
blocking-basecamp: ? → -
Last Resolved: 6 years ago
Resolution: --- → WORKSFORME
I can reproduce this reliably in the browser on a 2012-12-21 07:02:01 build (nightly).  I was browsing this site:  http://wp.me/p1jETZ-dH on my unagi.  Dragging my finger slowly upwards to scroll the page gives the rapid up-and-down motion of the text.
Status: RESOLVED → REOPENED
blocking-basecamp: - → ?
Resolution: WORKSFORME → ---
Assignee: nobody → roc
blocking-basecamp: ? → +
Target Milestone: --- → B2G C3 (12dec-1jan)
(In reply to Lawrence Mandel [:lmandel] from comment #2)
> Related bug 812517? However, already fixed in the beta build on which Stefan
> experienced this issue.

This isn't the "dancing text" symptom; the text snapping stays consistent.  Rather, this looks like an offset computation in APZC going wrong.
Is bug 824702 a dupe of this?

(And FWIW I can still reproduce this on a 2012-12-30 build on Unagi)
(In reply to Andrew Overholt [:overholt] from comment #6)
> Is bug 824702 a dupe of this?

While the symptoms are the same, they're not exactly the same so I don't think they're dupes.
Target Milestone: B2G C3 (12dec-1jan) → B2G C4 (2jan on)
We discussed this again at triage today and while we'd *love* to see a patch for this, we decided we can't block on it.
blocking-basecamp: + → -
tracking-b2g18: --- → +
Josh, given our out-of-band communication, would you recommend holding the release for this bug?
blocking-basecamp: - → ?
Flags: needinfo?(jcarpenter)
(In reply to Chris Jones [:cjones] [:warhammer] from comment #9)
> Josh, given our out-of-band communication, would you recommend holding the
> release for this bug?

Nope. That specifically pertained to the behaviour seen when two-finger scrolling, and is a nice-to-fix.
Flags: needinfo?(jcarpenter)
blocking-basecamp: ? → -
Created attachment 698868 [details] [diff] [review]
Fix single pixel jitter on fling
Status: REOPENED → ASSIGNED
Comment on attachment 698868 [details] [diff] [review]
Fix single pixel jitter on fling

This seems to fix the problem but I haven't investigated why this rounding change is necessary.
Attachment #698868 - Attachment description: Bug 818482 - Fix single pixel jitter on fling; r=cjones → Fix single pixel jitter on fling
Attachment #698868 - Flags: review?(roc)
Comment on attachment 698868 [details] [diff] [review]
Fix single pixel jitter on fling

Review of attachment 698868 [details] [diff] [review]:
-----------------------------------------------------------------

Add a comment that we don't know why truncation is needed here.
Attachment #698868 - Flags: review?(roc) → review+
Created attachment 701322 [details] [diff] [review]
Remove rounding of scroll compensation in AZPC
Attachment #698868 - Attachment is obsolete: true
Attachment #701322 - Flags: review?(roc)
Comment on attachment 701322 [details] [diff] [review]
Remove rounding of scroll compensation in AZPC

Review of attachment 701322 [details] [diff] [review]:
-----------------------------------------------------------------

sweet
Attachment #701322 - Flags: review?(roc) → review+
Try run for a5d85dd1a190 is complete.
Detailed breakdown of the results available here:
    https://tbpl.mozilla.org/?tree=Try&rev=a5d85dd1a190
Results (out of 28 total builds):
    success: 26
    warnings: 2
Builds (or logs if builds failed) available at:
http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/ajones@mozilla.com-a5d85dd1a190
Keywords: checkin-needed
This patch is on top of 811950 so I will rebase it if 811950 doesn't get b2g18 approval.
https://hg.mozilla.org/mozilla-central/rev/ed67c9f65a6d
Status: ASSIGNED → RESOLVED
Last Resolved: 6 years ago6 years ago
Resolution: --- → FIXED
Comment on attachment 701322 [details] [diff] [review]
Remove rounding of scroll compensation in AZPC

Very safe patch that improves browser panning.  We'd like to take this for another reason too; ping me or Josh for details.
Attachment #701322 - Flags: approval-mozilla-b2g18?
status-b2g18: --- → affected
Comment on attachment 701322 [details] [diff] [review]
Remove rounding of scroll compensation in AZPC

low risk, high user benefit - approved for landing to branch, please land before 1/25 and mark the status flag as fixed once landed.
Attachment #701322 - Flags: approval-mozilla-b2g18? → approval-mozilla-b2g18+
https://hg.mozilla.org/releases/mozilla-b2g18/rev/64bfbdb96823
status-b2g18: affected → fixed
status-firefox19: --- → wontfix
status-firefox20: --- → wontfix
status-firefox21: --- → fixed
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