[Qt] Implement SimpleFontData::platformBoundsForGlyph

[Allan Sandfeld Jensen]

We are missing a Qt implementation of platformBoundsForGlyph. This method is essential to working MathML and Ruby support.

With this method implementated MathML is possible to enable and use.

[Allan Sandfeld Jensen]

Created attachment 177760 [details]
Patch

[Jocelyn Turcotte]

Comment on attachment 177760 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=177760&action=review

> Source/WebCore/platform/graphics/qt/SimpleFontDataQt.cpp:72
> +    // Round to pixel bounds.
> +    return enclosingIntRect(bounds);

Other platforms don't seem to round it, why do we need to?

[Allan Sandfeld Jensen]

(In reply to comment #2)
> (From update of attachment 177760 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=177760&action=review
> 
> > Source/WebCore/platform/graphics/qt/SimpleFontDataQt.cpp:72
> > +    // Round to pixel bounds.
> > +    return enclosingIntRect(bounds);
> 
> Other platforms don't seem to round it, why do we need to?

Actually I followed Chromium here. They round whenever they don't have subpixel text rendering, and I think we currently use integer metrics only in Qt. I didn't see any artifacts when I ran it without rounding though, so I can't really say we need it.

[Allan Sandfeld Jensen]

Created attachment 179702 [details]
Patch

Do not round so that returned width matches that of platformWidthForGlyph

[Allan Sandfeld Jensen]

Committed r138703: <http://trac.webkit.org/changeset/138703>