Bug 44394 – [Qt] TransparencyLayer: Always use anti-aliasing and smooth pixmap transform

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Andreas Kling]

We currently render things like -webkit-mask-box-image without anti-aliasing or bilinear transform which looks very poor.

An example can be found under User Interface / Icons on this page:
http://dev.sencha.com/deploy/touch/examples/kitchensink/

[Andreas Kling]

Created attachment 65052 [details]
Proposed patch

[Andreas Kling]

Created attachment 65054 [details]
Comparison (bottom version is with patch)

[Ariya Hidayat]

Comment on attachment 65052 [details]
Proposed patch

WebCore/platform/graphics/qt/TransparencyLayer.h:55
 +          painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
Can't we copy the hints from p? Or does p have the wrong hints?

[Andreas Kling]

(In reply to comment #3)
> (From update of attachment 65052 [details])
> WebCore/platform/graphics/qt/TransparencyLayer.h:55
>  +          painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
> Can't we copy the hints from p? Or does p have the wrong hints?

It has the wrong hints in this case. Regardless, when do we want to paint with a low quality mask?

[Ariya Hidayat]

> It has the wrong hints in this case. Regardless, when do we want to paint with a low quality mask?

We don't, but it's up to the developer. One may want to call QWebFrame::render with low-quality because she is animating, capturing thumbnail only, or doing other funky stuff for which she care more about speed as opposed to pixel perfectness.

[Ariya Hidayat]

Comment on attachment 65052 [details]
Proposed patch

r+ for this fix, as it works for now.

I guess I need to resume my render hints propagation investigation...

[Andreas Kling]

Comment on attachment 65052 [details]
Proposed patch

Clearing flags on attachment: 65052

Committed r65784: <http://trac.webkit.org/changeset/65784>

[Andreas Kling]

All reviewed patches have been landed.  Closing bug.