691137 - Awry text rendering on canvas using hardware acceleration

Status: VERIFIED FIXED

(Core :: Graphics, defect)

Description

[Stanimir Stamenkov]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0a1) Gecko/20111001 Firefox/10.0a1

STR: Open http://mercurial.selenic.com/ and observe headings.

Actual: Characters in headings look awry.

Expected: "Smooth" characters as seen with Firefox 6 and other browsers like IE 9, Safari 5.1 and Chrome 15 beta.

Turning the hardware acceleration off seems to correct the issue.

Last good build:

http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2011/06/2011-06-25-03-07-43-mozilla-central/firefox-7.0a1.en-US.win32.zip

First bad build:

http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2011/06/2011-06-26-03-07-56-mozilla-central/firefox-7.0a1.en-US.win32.zip

Regression range:

http://hg.mozilla.org/mozilla-central/pushloghtml?startdate=2011-06-25&enddate=2011-06-27

Comment 1

[Stanimir Stamenkov]

Attachment: Awry text rendering

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0a1) Gecko/20110626 Firefox/7.0a1

Comment 2

[Stanimir Stamenkov]

Attachment: Correct text rendering

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0a1) Gecko/20110625 Firefox/7.0a1

Comment 3

[Nickolay_Ponomarev]

Likely regression from bug 651858.

Comment 4

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

Azure isn't used to render HTML content, so that regression cause looks unlikely...

Comment 5

[Jonathan Kew [:jfkthame]]

Looks like the site is using a JS library "typeface-0.15.js" that renders text using fonts defined in JS by drawing them to canvas (in this case, an Optima "clone" called "optimer_regular.typeface.js"), so the suggested regression _does_ sound plausible after all.

Comment 6

[Olli Pettay [:smaug][[e-mail]]]

This is rather bad (visual) regression.
Setting some flags...

Comment 7

[Bas Schouten (:bas.schouten)]

This almost looks as if the flattening tolerance on the path is too high or something. A reduced canvas-only testcase would help a lot in diagnosing this.

Comment 8

[John Daggett (:jtd)]

Attachment: testcase using typeface.js

Problem occurs on:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1

That's some ugly looking text...

Comment 9

[Kelsey Gilbert [:jgilbert]]

Test case also replicates for me on:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1

Comment 10

[Bas Schouten (:bas.schouten)]

I've found the root cause of this issue, fix coming up.

Comment 11

[Bas Schouten (:bas.schouten)]

Attachment: Use proper coordinates when adding a device space quadratic curve

This fixes the issue that causes this.

Quite likely this bug can be worked around by moving the 'restore()' call in renderWord to before 'beginPath()' this would also improve the performance of the library.

Comment 12

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

Comment on attachment 565912 [details] [diff] [review]
Use proper coordinates when adding a device space quadratic curve

Review of attachment 565912 [details] [diff] [review]:
-----------------------------------------------------------------

oopsie

Comment 13

[Asa Dotzler [:asa]]

Comment on attachment 565912 [details] [diff] [review]
Use proper coordinates when adding a device space quadratic curve

The release team won't be tracking this but please land the fix on Aurora and Beta.

Comment 14

[Bas Schouten (:bas.schouten)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/9975c3dd08a6

Comment 15

[Bas Schouten (:bas.schouten)]

Forgot this is only on inbound. Sorry for bugspam.

Comment 16

[Marco Bonardo [:mak]]

https://hg.mozilla.org/mozilla-central/rev/9975c3dd08a6

Comment 17

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

How hard would this be to test?

Comment 18

[Bas Schouten (:bas.schouten)]

(In reply to Ms2ger from comment #17)
> How hard would this be to test?

Very easy, but considering the rather coincidental circumstances that surround this bug I'm not sure a test case would be that useful.

We actually test all the individual facets of this bug, just not the combination.

Comment 19

[Jonathan Haas]

I thought this has to be landed on beta and aurora? (Comment 13)

Comment 20

[LegNeato]

http://hg.mozilla.org/releases/mozilla-aurora/rev/5016fa65673e
http://hg.mozilla.org/releases/mozilla-beta/rev/e38378366d23

Comment 21

[AndreiD[QA]]

I tested to see if the issue is still visible after the landing of the fix; I took as example the testcare using  typeface.js in the attachment and got the following results:
Verified Fixed on:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0 (Beta)
 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0a2) Gecko/20111019 Firefox/9.0a2 (Aurora)
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0a1) Gecko/20111020 Firefox/10.0a1 (Nightly)

Since the issue (as it was reported in the Description) is not visible anymore after the landing of the fix, on all branches, setting this bug's resolution to Verified and the whiteboard entry to qa!