328650 - No subpixel rendering on Intel

Status: RESOLVED WORKSFORME

(Core Graveyard :: GFX: Mac, defect)

Description

[Kaya Bekiroglu]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.1) Gecko/20060225 Firefox/1.5.0.1
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.1) Gecko/20060225 Firefox/1.5.0.1

OS X has several antialiasing settings: Standard, Light, Medium, and Strong.  While "Standard" antialiasing does not make use of subpixel (Cleartype-like) rendering, the others do.  My Intel Mac is set to "Strong" but neither Firefox nor Thunderbird will render fonts to subpixel granularity.  This is easy to verify by zooming in with a Universal Access shortcut.

I imagine that either these apps are ignoring the system wide setting or else do not use OS X native font renderer. I hope it's the former; I think the world of OS X font rendering.


Reproducible: Always

Steps to Reproduce:
1. Set System Preferences -> Appearance -> Font smoothing style to Light, Medium, or Strong
2. Enable Zoom via System Preferences -> Universal Access -> Zoom
3. Restart Firefox
4. Restart Safari
5. Navigate Safari and Firefox to the same web page.
6. Zoom in on rendered text (Command-Option-=)
Actual Results:  
At high zoom, both Safari and Firefox text will contain color fringing, indicating subpixel rendering.

Expected Results:  
Safari text contains color fringing but Firefox does not.

Comment 1

[Kaya Bekiroglu]

Whoops; wrong component!

Comment 2

[Kaya Bekiroglu]

Note that in the original description, "Actual Results" and "Expected Results"
are backwards. D'oh!

Comment 3

[Kaya Bekiroglu]

Apparently disrespecting a user's font setting is common in the OS X world:

http://www.michelf.com/weblog/2006/subpixel-antialiasing-achilles-heel/

However, released 1.5.0.1 Firefox bits running on my PowerMac subpixel render
without any issues.  The same stock 1.5.0.1 release running under Rosetta on
Intel does not.  Perhaps the new Intel iMac accelerates more composting operations in hardware, killing subpixel rendering as described above.  

Comment 4

[Smokey Ardisson (offline for a while; not following bugs - do not email)]

*** Bug 331288 has been marked as a duplicate of this bug. ***

Comment 5

[Neil Lee [:neilio]]

To help clarify the difference between the PPC and Intel versions for anyone who doesn't fully get this bug, I've attached a screenshot to bug 311288 which you can also see here:

http://homepage.mac.com/thenonsuch/firefox/images/fontsmoothing.png

If you use the built-in zoom function on Mac OS X to zoom in, you will see that while both are antialiased, the PPC version also utilizes colours in its smoothing, where the Intel version does not.

Comment 6

[Simon Fraser [no longer active]]

Is this true for other QuickDraw based apps on Intel?

Comment 7

[Neil Lee [:neilio]]

It's possible - what other Apple applications do you know that use Quickdraw?

Comment 8

[Andrew n marshall]

This is definitely a bug.  I've screen cap'ed a comparison here:
 http://www.anm.la.ca.us/blog/mozilla/macbook-pro-font-rendering-with-firefox/

In particular, the same build runs fine on PPC but not on Intel (via Rosetta) nor a native Intel build.

Comment 9

[Smokey Ardisson (offline for a while; not following bugs - do not email)]

*** Bug 334242 has been marked as a duplicate of this bug. ***

Comment 10

[Neil Lee [:neilio]]

I'm actually seeing this on the Bon Echo build I'm running on my laptop (20060417), too.

Comment 11

[Neil Lee [:neilio]]

(In reply to comment #10)
> I'm actually seeing this on the Bon Echo build I'm running on my laptop
> (20060417), too.
> 

Sorry, my *PPC* laptop.

Comment 12

[Andrew n marshall]

I disagree.  I previously compared my 800Mhz DVI PowerBook to my 2.16Mhz MacBook Pro.  Here is a repeat of that link.

http://www.anm.la.ca.us/blog/mozilla/macbook-pro-font-rendering-with-firefox/

Also, I just installed 1.5.0.2 on my PowerBook and still see the "colorful fringes" indicative of sub pixel rendering.  My revisit of the issue on 1.5.0.2 on my MacBook still lacks this:

http://www.anm.la.ca.us/blog/mozilla/macbook-pro-font-rendering-with-firefox-revisited/

Comment 13

[Neil Lee [:neilio]]

Well, there's some kind of issue, especially with sites that use non-white backgrounds and white text. I'll attach a screenshot of what I see when I visit Daring Fireball:

http://www.daringfireball.net/

This is with Bon Echo 20060417.

Comment 14

[Neil Lee [:neilio]]

Attachment: Screenshot of weird inconsistent font smoothing

Comment 15

[Andrew n marshall]

Your screenshot has the tell tale color fringe of subpixel rendering.  Especially look at the italic 'hoped' at the end of the first paragraph.

Since subpixel rendering relies on knowing the background color (the right fringe of balck-on-white should be bluish, but white-on-black should reddish), you may have found some other rendering (but it doesn't look bad to me).

Comment 16

[Neil Lee [:neilio]]

Andrew - the top two paragraphs exhibit subpixel rendering, but not the bottom two, and this changes depending on what is current visible in the view port.

I'm attaching another screenshot from the NYTimes.com site that distinctly shows no subpixel rendering, from the same Bon Echo build and the same Powerbook.

Comment 17

[Neil Lee [:neilio]]

Attachment: Another screenshot of missing subpixel rendering on PPC

Comment 18

[Andrew n marshall]

Okay.  I see that now.  That's weird.

My PowerBook (ATI Mobility Radeon 7500, Chipset ATY,RageM7) has subpixel rendering on Firefox 1.5.0.2 running under OS X 10.4.6 on the nytimes.com site, including the same headline/byline/article text fonts you showed.

My MacBook Pro (ATI Radeon X1600, Chipset ATY,RadeonX1600) does not.

Comment 19

[Maciek]

Hi, we have a solution now.

It appears that the 10.4.7 update to OS X has forced the issue and turns on proper subpixel rendering of text everywhere even for applications (like Firefox) that stubbornly used an old method before.

Update your Intel Mac to OS X 10.4.7 and this bug will become a non-issue.

Comment 20

[Andrew n marshall]

(In reply to comment #19)
> Update your Intel Mac to OS X 10.4.7 and this bug will become a non-issue.


Confirmed.

Comment 21

[Mark Mentovai]

(In reply to comment #19)

You make it sound like we were doing something wrong.  We weren't.  We always worked fine on ppc, and now we work fine on x86.

Comment 22

[Kaya Bekiroglu]

Perhaps comment #19 refers to the fact that Safari's subpixel rendering has
always worked correctly, indicating a difference of approach.