830926 - AZPC TrackTouch x/y displacement should not be rounded to int

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Oleg Romashin (:romaxa)]

Found recently one problem that if page zoom value very high like 8.0
AZPC does scrolling very badly on slow motion.
in high zoom and slow motion we getting displacement values < 1 and that get's truncated to 0, result no scrolling
https://mxr.mozilla.org/mozilla-central/source/gfx/layers/ipc/AsyncPanZoomController.cpp#758

We should change these values to float

Comment 1

[Oleg Romashin (:romaxa)]

Attachment: Rounding problem fix for TrackTouch

Comment 2

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

!xDisplacement && !yDisplacement may need to be < EPSILON or < 1 device pixel. Needs some testing to make sure this is correct.

Comment 3

[Oleg Romashin (:romaxa)]

Attachment: Rounding problem fix for TrackTouch, use epsilon check

this works ok for me.

Comment 4

[Doug Sherk (:drs) (inactive)]

Comment on attachment 703154 [details] [diff] [review]
Rounding problem fix for TrackTouch, use epsilon check

Review of attachment 703154 [details] [diff] [review]:
-----------------------------------------------------------------

Nice, good catch. Just one indentation issue.

::: gfx/layers/ipc/AsyncPanZoomController.cpp
@@ +760,1 @@
>                                                            timeDelta);

Spacing is out of alignment now, just move the second line back one tab.

Comment 5

[Oleg Romashin (:romaxa)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ce70deca6e8e

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/ce70deca6e8e