[webkit-qt] Inconsistent acceleration of linear gradients and atlas maps

[Jonathan Morton]

On Wed, 2010-07-07 at 11:09 -0700, Ariya Hidayat wrote:
> > Meanwhile, we're trying to use Callgrind to narrow down the gradient
> > case ourselves.  Callgrind doesn't seem to like the JIT, so it's taking
> > extra time to disable it.
> 
> Oh BTW, it's a long shot, but did you try to draw the web page's main
> frame via QWebFrame::render operating on a QPainter WITHOUT
> antialiasing in its render hints?

Yes, and again it has paradoxically made things worse rather than
better.

> It's probably overkill to use Callgrind for this case, especially if
> you haven't figured out the code path via Graphics Context down to
> QPainter yet.

What Callgrind is now telling us is that Qt's raster engine is being
called for two reasons:

- To draw a tiled image.

- To draw the background of some text.  This might itself be tiled.

It's not immediately obvious how to enable QtGui to pass these on to
XRender, if it isn't already able to do that.

Someone mentioned Qt 4.7 earlier.  Would upgrading to that help at all?

-- 
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From: Jonathan Morton
      jonathan.morton at movial.com