1646141 - 3d-transformed text renders pixelated in Firefox

Status: RESOLVED DUPLICATE of bug 1639764

(Core :: Web Painting, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. load attached testcase

ACTUAL RESULTS:
First line of text is blurry.

EXPECTED RESULTS:
Both lines of text crisp.

Chrome gives EXPECTED RESULTS; Firefox gives ACTUAL RESULTS. This seems to be independent of graphics backend, too (at least, I can reproduce it regardless of whether WebRender is enabled)

This was originally reported in https://bugzilla.mozilla.org/show_bug.cgi?id=1462659#c7 but I'm spinning it off here because I think it's unrelated.

Comment 1

[Timothy Nikkel (:tnikkel)]

Possibly the same as bug 1639764

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: testcase 2 (nearly the same as 1, but using `transform-origin: 0 0`)

Here's another testcase which also shows ACTUAL RESULTS (fuzzy first line) in Firefox vs. EXPECTED RESULTS (crisp) in Chrome.

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: testcase 3 (adding a large explicit 'width')

Interestingly, if I add a large width to these elements (as in this testcase), then Chrome renders the first line blurry, too (i.e. this testcase gives ACTUAL RESULTS in both Chrome and Firefox).

Comment 5

[Daniel Holbert [:dholbert]]

(In reply to Timothy Nikkel (:tnikkel) from comment #1)

Possibly the same as bug 1639764

I suspect not. At least: based on that other bug's title ("... with apz.allow_zooming enabled"), it sounds like that bug is specific to configurations where that pref is set to true.

In my case here (in Firefox Nightly on Desktop), that pref is set to false. (And the behavior doesn't seem to change regardless of whether it's true or false.)

Comment 6

[Timothy Nikkel (:tnikkel)]

(In reply to Daniel Holbert [:dholbert] from comment #5)

(In reply to Timothy Nikkel (:tnikkel) from comment #1)

Possibly the same as bug 1639764

I suspect not. At least: based on that other bug's title ("... with apz.allow_zooming enabled"), it sounds like that bug is specific to configurations where that pref is set to true.

Oops, that is a mistake. I copy-pasted the bug title from the original bug, apz.allow_zooming doesn't actually have anything to do with that bug (either it or the original).

Comment 7

[Daniel Holbert [:dholbert]]

OK! Maybe the same, then. I'll defer to your judgement on that (and/or what-we-discover in the future). I can't tell at this point whether they're dupes/related or not.

Comment 8

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:mattwoodrow, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 9

[Matt Woodrow (:mattwoodrow)]

These indeed are the same bug.

3D transformed content is usually drawn at it's original size, and then we apply the transform on the compositor.

We attempt to determine the scale factors of the transform to draw the content at higher resolution, but we don't have code that understands how to do this with a perspective transform - https://searchfox.org/mozilla-central/rev/c86c19bd64f8f19590a4190c282781d3a9631422/layout/painting/FrameLayerBuilder.cpp#6024