unsharp font in thai language.




8 years ago
8 years ago


(Reporter: kawewong, Unassigned)



Windows XP

Firefox Tracking Flags

(Not tracked)





8 years ago
User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b12) Gecko/20100101 Firefox/4.0b12
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b12) Gecko/20100101 Firefox/4.0b12

unsharpen font on many website eg. facebook.com, manager.co.th that have thai language.
and sometime english too.
please take a look at this screenshot. http://img821.imageshack.us/i/ff4unsharpfont.jpg/
chrome and firefox 3.6 are very sharpen but firefox 4 is so bad.

Reproducible: Always

Steps to Reproduce:
1.browse some website that have thai language. eg.. http://www.manager.co.th/home/ or http://gallery.okvee.net/
2.browse same url in chrome and firefox 3.6 and opera and safari and ie8
3.look at it. only firefox 4 is unsharp font.
Actual Results:  
thai font unsharp
sometime english unsharp too.

Expected Results:  
it should sharpen font like firefox 3.6


8 years ago
Keywords: fonts
This seems to be DirectWrite issue.

vee, do you reproduce when you turn off direct2d (gfx.direct2d.disabled=true)?
Component: General → Graphics
Product: Firefox → Core
QA Contact: general → thebes
It's difficult to tell much from the screenshot because of JPEG compression artifacts. Please provide an image in PNG format instead.
OS: Windows 7 → Windows XP

Comment 3

8 years ago
updated png screenshot http://img28.imageshack.us/i/ff4q.png/
i think it isn't difficult to tell different from screenshot because jpg image and png image are as sams as it show up on firefox every detail.

sorry, i don't know how to turn off d2d.
put that command in address box?

Comment 4

8 years ago
this blur font really make my eyes hurt.

Comment 5

8 years ago
(In reply to comment #3) 
> sorry, i don't know how to turn off d2d.
> put that command in address box?

Go to about:config (type that in the locationbar + enter), then look for the gfx.direct2d.disabled preference. You can change that to true. I'm not sure if you need to restart in this case.

If Direct 2D is disabled, you'll use the built-in algorithm. Firefox 4 uses by default the one from the OS (Microsoft DirectWrite), because it can be accelerated by your graphics card.

Comment 6

8 years ago
disabled direct2d is better result. it's sharp font now. but why i have to do this?
is something wrong with ff4?
disable direct2d will reduce something else?
I think the main difference you're seeing is due to subpixel glyph positioning with DirectWrite/D2D. This generally gives better and more consistent spacing, and more accurately preserves the original design of the font, but it does tend to make the glyph images less "crisp" because many of them are not aligned to pixel edges on the screen, and so you don't get as many clear, sharp transitions between the "ink" of the glyphs and the empty space between them.

GDI font rendering, which we use if Direct2D is not enabled, does not support subpixel positioning and therefore the glyph positions are always rounded to screen pixels. This gives "sharper" and more consistent glyph images, at the cost of disturbing the actual glyph shapes and/or the inter-glyph spacing more.

If you compare the rendering in IE9, you will probably see a similar effect - but only on sites where IE9 runs in "native" IE9 mode, not on sites where it switches to IE8 or earlier "compatibility" modes.

Comment 8

8 years ago
i think it is not good if you use more advance technology but worse result in clear font. this is very bad for people's eyes.
i hope this can be fix before release the real one because i love firefox :)

Comment 9

8 years ago
If you disable the hardware acceleration, it works fine.

Go to option > advanced > uncheck "use hardware acceleration when available".

Maybe the hardware acceleration should be off? (at least on Windows because all the fonts are fugly atm)
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