Japanese fonts in vertical text should support synthesized italics

• Component: New Bugs
• Status: RESOLVED FIXED

[Dave Hyatt]

Japanese fonts in vertical text should support synthesized italics

[Dave Hyatt]

Created attachment 303714 [details]
Patch

[Dave Hyatt]

Not really sure if the slant direction is what we want here or not. It matches Blink, but I don't know if that's what we want here.

[Dave Hyatt]

Created attachment 303741 [details]
Patch

[Dave Hyatt]

rdar://problem/22122041

[Jon Lee]

Comment on attachment 303741 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=303741&action=review

> Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm:246
> +        static float obliqueCJKSkew = tanf(-syntheticObliqueAngle() * piFloat / 180);

isn't this just -obliqueSkew?

> Source/WebCore/platform/graphics/cocoa/FontCascadeCocoa.mm:253
>              matrix = CGAffineTransformConcat(matrix, CGAffineTransformMake(1, 0, -obliqueSkew, 1, 0, 0));

I then think this simplifies to
if (platformData.orientation() == Vertical && font.isTextOrientationFallback()
 matrix = ... obliqueSkew ...
else
 matrix = ... -obliqueSkew ...

> LayoutTests/ChangeLog:10
> +        * platform/mac/fast/text/international/synthesized-italic-vertical-expected.txt: Added.

Could a ref test have one Ahem character italicized in vertical writing mode, and the reference have the same character in horizontal writing mode and have a skew transform applied?

[Dave Hyatt]

Every ref test I've tried to make here has had small differences. The characters don't start off in the same place for vertical vs. horizontal.

[Dave Hyatt]

Created attachment 306106 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 306106 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=306106&action=review

> Source/WebCore/platform/graphics/FontCascadeFonts.cpp:305
> +        // If there is a baked-in rotated glyph, we will use it unless syntheticOblique is set. If
> +        // synthetic oblique is set, we fall back to the horizontal glyph. This allows us to guarantee that vertical fonts without isTextOrientationFallback() set
> +        // contain CJK characters only and thus we can get the oblique slant correct.

Awkward comment wrapping.

[Dave Hyatt]

Fixed in r214848.

[Ryan Haddad]

(In reply to Dave Hyatt from comment #9)
> Fixed in r214848.

The expected result files for fast/text/international/synthesized-italic-vertical-latin.html were removed with this change. Did you intend to delete the test, too?

[Ryan Haddad]

(In reply to Ryan Haddad from comment #10)
> (In reply to Dave Hyatt from comment #9)
> > Fixed in r214848.
> 
> The expected result files for
> fast/text/international/synthesized-italic-vertical-latin.html were removed
> with this change. Did you intend to delete the test, too?

This appears to have been accidental. Added the results back in http://trac.webkit.org/projects/webkit/changeset/214892