Hi webkit-dev,

I was looking into bug 48459: "Glyphs in vertical text tests are rotated 90 
degrees clockwise on Windows"
https://bugs.webkit.org/show_bug.cgi?id=48459

and found that it has two issues:

1. It does not support text-orientation[1] property as OS X does.

2. It uses @-font, which lets Windows do a magic to rotate some code points and 
apply 'vert' automatically. But that means WebKit has no control over the glyph 
orientations, and therefore orientation of some code points don't match to the 
one on OS X.

I think the correct fix for the bug is to port showGlyphsWithAdvances from 
FontMac.mm to FontCGWin.cpp.

But I then encounter an issue that WebKitLibraries does not support 
CTFontGetVerticalTranslationsForGlyphs API.

Since Windows doesn't have such API, possible options I can think of are:

1. Bring the CTFontGetVerticalTranslationsForGlyphs API to WebKitLibraries.
2. Use other libraries such as FreeType[2] to read related OpenType tables.
3. Read raw tables using GetFontData Win32 API and parse vhea/vorg/vmtx tables 
etc.

I have no idea how I can make option 1 happen.

Any suggestions?

[1] http://dev.w3.org/csswg/css3-writing-modes/#text-orientation
[2] http://freetype.sourceforge.net/license.html

Regards,
Koji
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