Bug 54004 – -webkit-font-smoothing:antialiased has no effect on GDI text

• Component: Text
• Status: RESOLVED FIXED

[Adam Roben (:aroben)]

To reproduce:

1. Turn on ClearType
2. In Edit > Preferences... > Appearance, set "Font smoothing:" to "Windows Standard"
3. Go to data:text/html,<p style="-webkit-font-smoothing:antialiased">This text should not be subpixel-antialiased.</p><p>This text should be subpixel-antialiased.</p>

Both sentences look the same. If you turn on CG text (by changing "Font smoothing:" to some other setting), you can see that the first sentence is not subpixel-antialiased, while the second one is.

[Adam Roben (:aroben)]

<rdar://problem/8971429>

[Roger Fong]

When specifying -webkit-font-smoothing: antialised; the code path ends up using GDI to draw the text. 
Firstly, this causes a lot of transparency issues since GDI has no concept of an alpha channel.
Secondly, in the code path, GDI ends up drawing subpixel antialiased text, not aliased text anyways.

The CG code path also has the capability of drawing antialiased text. The reason that the GDI path was used in the first place is no longer a concern here so we can stop using the GDI code path.

I'll be getting rid of the GDI code path so that font rendering on windows only uses CG code path for font rendering, instead of sometimes using CG and sometimes using GDI.

[Roger Fong]

*** Bug 94958 has been marked as a duplicate of this bug. ***

[Roger Fong]

Created attachment 160460 [details]
patch

[WebKit Review Bot]

Comment on attachment 160460 [details]
patch

Rejecting attachment 160460 [details] from commit-queue.

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[WebKit Review Bot]

Comment on attachment 160460 [details]
patch

Clearing flags on attachment: 160460

Committed r126666: <http://trac.webkit.org/changeset/126666>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.