836325 - seam between images when using a scale transform

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Alessandro Tagliapietra]

At work we're developing a zoomable image viewer, so we use a lot the transform functions.

On firefox I've seen that when the parent of two or more images has a scale3D different then 0 there is a space between the images contained inside it.

The issue seems to be on just one image every two, seems like a sub pixel shifting that makes one image overlap the other and the other has space between the next one.

I'll attach a test html and two images to test this.

Comment 1

[Alessandro Tagliapietra]

Attachment: Test html file

Comment 2

[Alessandro Tagliapietra]

Attachment: Test image one

Comment 3

[Alessandro Tagliapietra]

Attachment: Test image two

Comment 5

[Cork]

Attachment: Fixed testcase

Comment 6

[Cork]

Attachment: testcase with images in the correct order

Sorry for the mixup

Comment 7

[Alessandro Tagliapietra]

Someone can work on this?

Comment 8

[Timothy Nikkel (:tnikkel)]

Layout does pixel snap these images, but we end up drawing them with antialiased edges (which can be easily seen by drawing just one image), so somewhere along the line that doesn't quite happen. And I haven't had time to dig into this further to determine exactly what is going on.

Comment 9

[Timothy Nikkel (:tnikkel)]

Attachment: simplified testcase

This testcase is a bit simpler.

Comment 10

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Probably because our cairo-quartz backend doesn't support EXTEND_CLAMP properly?

Comment 11

[Timothy Nikkel (:tnikkel)]

It happens on Linux and Windows too.

Comment 12

[Timothy Nikkel (:tnikkel)]

I'm probably not going to get to this soon. Clearing needinfo so the big red dot goes away and stops bugging me.

Comment 13

[Timothy Nikkel (:tnikkel)]

Looks like this was fixed by bug 948848.

Comment 14

[Ioana (away)]

Alessandro, could you please verify that this issue is fixed for you in Firefox 29?

Comment 15

[Alessandro Tagliapietra]

Attachment: Non working example with 30.0a1 (2014-03-10)

Non working screenshot with version 30.0a1 (2014-03-10)

Comment 16

[Alessandro Tagliapietra]

I've uploaded the screenshot I get with version 30.0a1 (2014-03-10), where can I download version 29 to test? Since the beta channel has the 28 at the moment.

Comment 17

[Timothy Nikkel (:tnikkel)]

I can confirm that this is not fixed on nightly anymore, so I'm guessing it must have been re-regressed. It is however still fixed for me on Aurora.

We should find out what regressed this since comment 13.

Comment 18

[Cork]

Hmm, works fine on linux. Might the new regression be mac specific?

Comment 19

[Timothy Nikkel (:tnikkel)]

(In reply to Cork from comment #18)
> Hmm, works fine on linux. Might the new regression be mac specific?

It could be.

Comment 20

[Timothy Nikkel (:tnikkel)]

New regression range
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=4cb766685b73&tochange=529b86b92b1d

Comment 21

[Timothy Nikkel (:tnikkel)]

Most likely
http://hg.mozilla.org/mozilla-central/rev/3637434788e5 (bug 976877)

Comment 22

[Gregory Pappas [:gregp]]

Unable to reproduce in recent versions.