1096934 - bad font rendering - corrupt anti aliasing

Status: UNCONFIRMED

(Core :: Graphics: Text, defect)

Description

[towe]

Attachment: ff_331_rendering_problems.jpg

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:33.0) Gecko/20100101 Firefox/33.0
Build ID: 20141106120505

Steps to reproduce:

Texts and font-icons from fontello have no or bad anti aliasing.
I could delimit the issue. In Firefox Version 33.0 is the rendering intact!
The Problem must came in between version 33.0 and 33.1 (look at the screenshot at the word "Notes")!

Comment 1

[towe]

Attachment: ff_331_rendering_problems.png

Added the same screenshot in png-format.

Comment 2

[Masatoshi Kimura [:emk]]

Does it have an effect to disable OMTC? (by flipping "layers.offmainthreadcomposition.enabled" in about:config)

Comment 3

[Jonathan Kew [:jfkthame]]

It looks like 33.0 is giving the "symmetric cleartype" antialiasing mode, while 33.1 is giving one of the horizontal-only modes.

I also notice that the text in the address bar was cleartype-antialiased in 33.0, but is grayscale-only in 33.1. (This might or might not have the same underlying cause.)

I wonder if it's falling back to GDI rendering because hardware acceleration is blocked/unavailable for some reason? Please post the Graphics section from about:support on your system; this may help to indicate what's happening.

Comment 4

[towe]

Attachment: about_support_ff.PNG

I posted the graphic section as PNG-file from about:support!

Comment 5

[towe]

In my window7 device-manager i can see two grafic cards:
AMD Radeon HD 8790M
Intel HD Graphics 4600

Comment 6

[towe]

(In reply to Masatoshi Kimura [:emk] from comment #2)
> Does it have an effect to disable OMTC? (by flipping
> "layers.offmainthreadcomposition.enabled" in about:config)

No, this has no visual effect to the text rendering.
I could only see that twitter-bootstrap's popovers and tooltips shows a black overlay for some milliseconds.
So i better switch it back to 'true' ;-)

Comment 7

[Jeff Muizelaar [:jrmuizel]]

Can you post the graphics section of about:support from Firefox 32 and from Firefox 33?

Comment 8

[towe]

Attachment: about_support_ff_32.PNG

Here is the about:support-screenshot of ff 32

Comment 9

[pjunkel-pcmind]

Towe, because you show two video cards, you likely have the setup that switches between onboard video and the Radeon graphics chip, with the default for all programs being the onboard video. If that is the case, you should be able to right-click on the AMD Radeon icon in your system tray, and find somewhere in the Radeon properties to select the Firefox.exe program, assign it to run with the Radeon GPU at all times, and then look to see if you still have the same problem.

Comment 10

[Jeff Muizelaar [:jrmuizel]]

towe, you're gpu configuration is being blacklisted because of bug 1093863. We're working on figure out a smaller set of configurations to blacklist.

Comment 11

[towe]

(In reply to pjunkel-pcmind from comment #9)
> Towe, because you show two video cards, you likely have the setup that
> switches between onboard video and the Radeon graphics chip, with the
> default for all programs being the onboard video. If that is the case, you
> should be able to right-click on the AMD Radeon icon in your system tray,
> and find somewhere in the Radeon properties to select the Firefox.exe
> program, assign it to run with the Radeon GPU at all times, and then look to
> see if you still have the same problem.

Ok, I had spend some time to bring ff to use the AMD graphic card. But when I set all options in amd control  center to max. performance the ff uses the intel graphic chip anyway.
Then i deactivated the intel chip in the windows device-manager. Then the AMD chip also do not work properly. The AMD control center could not be opened anymore and the screen-resolution is 640 x 480.

Comment 12

[Bruce Lott]

Just noticed in the past about week (keeping up timely with all FF updates) that font rendering on parts of certain webpages (e.g. www.esa.int Rosetta blog) is poor.  I don't usually have cleartype enabled, but to test, I turned it on, which fixed the problem.  Turned it back off, because I'm not a fan of cleartype's visual effects, and the poor rendering returned.  I've only viewed that site recently, so I can't say when this behavior showed up.  Win7 Home Premium SP1 (latest updates), ATI Radeon HD 5670, driver rev 8.690.0.0 (latest Dell version).

Comment 13

[Bruce Lott]

(In reply to Bruce Lott from comment #12)
With cleartype OFF (my usual setting), IE 11 does not have the problem.

Comment 14

[Terrell Kelley]

If you prefer ClearType off, you may be better off getting your hands on the Antialiasing Tuner addon: https://addons.mozilla.org/en-US/firefox/addon/anti-aliasing-tuner/

To disable ClearType altogether, choose the Aliased font mode in both sections. See if you like the text better that way. If not, feel free to try other options.

Comment 15

[Bruce Lott]

This comment relates to this bug as well as the UI slowness (FF v33.0+) problem (bug 1089183).  Reminder, my video card is an ATI (now AMD) Radeon HD5670.

Finally got tired of the font rendering/anti-aliasing problem, and decided to just try the AMD website driver upgrade for the HD5670, or just buy a new video card if that failed.  Didn't really care anymore whether Dell had some "special sauce" in their "official" driver for my XPS 7100, which they last updated in 2009.  

I'm happy to report that downloading and installing the latest (ver 14.501.1003) AMD driver (and Catalyst utility ver 14.12) allowed me to re-enable hardware acceleration in Firefox (as well as restore the various about:config workarounds back to their defaults).  This fixed the UI slowness that appeared with FF v33.0, as well as the font rendering/anti-aliasing problem.  Everything appears to be working great now (current FF v38.0.6).  Problem solved for me!