Closed Bug 660448 Opened 10 years ago Closed 10 years ago

Subpixel antialiasing too strong/incorrect everywhere

Categories

(Core :: Graphics, defect)

x86
Linux
defect
Not set
normal

Tracking

()

VERIFIED FIXED
mozilla7

People

(Reporter: echogene.alpha, Assigned: joe)

References

Details

Attachments

(4 files, 1 obsolete file)

User-Agent:       Mozilla/5.0 (X11; Linux i686; rv:7.0a1) Gecko/20110526 Firefox/7.0a1
Build Identifier: Mozilla/5.0 (X11; Linux i686; rv:7.0a1) Gecko/20110526 Firefox/7.0a1

Subpixel antialiasing has become too strong/wrong in the latest builds of Nightly.  That is, where it is red and blue, it is too red and too blue.  This happens on both web pages and the entire user interface (menu bar and below).

Reproducible: Always

Steps to Reproduce:
1. Open Firefox
2. Look at text

Actual Results:  
Text looks weird.  Upon zooming in, it's easy to see that subpixel antialiasing is wrong.

Expected Results:  
Text should look like it did in previous builds.
A comparison of subpixel antialiasing in Nightly and Firefox 4.
That's a pretty glaring difference. Jeff, might this possibly be related to the recent cairo update (bug 562746)?
Status: UNCONFIRMED → NEW
Ever confirmed: true
Component: General → Graphics
Product: Firefox → Core
QA Contact: general → thebes
The cairo update alone is definitely responsible for a change in text rendering on my Linux machine.
Blocks: 562746
Since cairo 1.9.10, this change is in effect http://cgit.freedesktop.org/cairo/commit/?id=7a023a62f7517ad0d54f4d59c99909fadcc05e82

I think it maybe related, https://bugs.freedesktop.org/show_bug.cgi?id=34886#c3
(disclaimer: I am not an expert in cairo, freetype, fontconfig or mozilla; so don't take what I say to heart... :)).
Status: NEW → RESOLVED
Closed: 10 years ago
Resolution: --- → DUPLICATE
Duplicate of bug: 456448
OK, I'm going to undupe this for a short-term patch. The long-term fix is bug 456448, but we're blocked on releng for that.
Status: RESOLVED → REOPENED
Resolution: DUPLICATE → ---
OK, let's just dlsym() FT_Library_SetLcdFilter for now. This is not a long-term fix, because on computers that don't have this symbol we'll be a rainbowy mess. (We have to stop supporting distributions with old freetypes.) But until all the infrastructural work to upgrade Freetype and stop supporting old versions of it is done, this'll do.
Assignee: nobody → joe
Status: REOPENED → NEW
Attachment #538345 - Flags: review?(karlt)
Attachment #538345 - Flags: review?(bjacob)
Forgot to qrefresh.
Attachment #538345 - Attachment is obsolete: true
Attachment #538345 - Flags: review?(karlt)
Attachment #538345 - Flags: review?(bjacob)
Attachment #538346 - Flags: review?(karlt)
Attachment #538346 - Flags: review?(bjacob)
Attachment #538346 - Flags: review?(bjacob) → review+
Comment on attachment 538346 [details] [diff] [review]
dlsym FT_Library_SetLcdFilter for now

I probably would have replaced initialized_setLcdFilter with

  static setLcdFilterFunc setLcdFilter =
      (setLcdFilterFunc) dlsym (RTLD_DEFAULT, "FT_Library_SetLcdFilter");

in the code block scope but I haven't checked the C standard to make sure that is called on first pass, and what you have does the right thing.
Attachment #538346 - Flags: review?(karlt) → review+
That's how I started out, but it seems you can't initialize statics with a non-constant.
Oh, interesting, thanks.
Mozilla/5.0 (X11; Linux i686; rv:7.0a1) Gecko/20110610 Firefox/7.0a1

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This comment works as a testcase for me. These are all quite distinctly coloured on my screen. It's almost likeable.
Attached image Pretty!
Note that I have my monospace font size set to 16 in Firefox as the default is too small for me. Zooming in and out changes the colours :-)
http://hg.mozilla.org/mozilla-central/rev/76d7b28ca1ba
Status: NEW → RESOLVED
Closed: 10 years ago10 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla7
Whiteboard: [inbound]
Duplicate of this bug: 663698
Attached image Fixed
Confirming that this is fixed for me (compare with attachment 538565 [details]).
Status: RESOLVED → VERIFIED
Depends on: 666732
Blocks: 404637
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