[Development] The place of QML
Uwe Rathmann
Uwe.Rathmann at tigertal.de
Fri May 18 13:01:32 CEST 2012
On 05/18/2012 09:07 AM, marius.storm-olsen at nokia.com wrote:
> Often it's hard to beat the performance of the main CPU(s for most people
> these days) filling in a polygon directly, rather than handing it off to a
> GPU.
Guess this is the reason behind the decision why in Qt 4.8 raster has
become the default graphics system on X11 - what more or less means
turning hardware acceleration off
( maybe it's worth to mention that QPainter is not synonym for software
renderer - QPainter/X11 and QPainter/OpenGL are usually hardware
accelerated ).
While I can't confirm that the CPU does things faster for the most
relevant use cases I have in the Qwt library ( + the result is terrible
for remote X11 or NX ), I can imagine that there are other use cases
where this is true. F.e. on my box it is way faster to fill a QImage
with a gradient + converting it expensively to a QPixmap, than to fill
the QPixmap with the X11 paint engine. Don't know why - but, maybe this
is an example where a scene graph could do things better ?
But before you read me wrong: I'm absolutely not against having a new
and better graphic system - all I wanted to say is to be careful with
performance statistics.
Uwe
More information about the Development
mailing list