[Kde-games-devel] Fwd: Re: SVG Rendering speed

[Mauricio Piacentini]

Luciano Montanaro wrote:
> I'm not sure the parser is too bad; I tried to use a QPicture as the paint 
> device and to time drawing that or using SVGrender, and the results were 
> comparable. So it's actually drawing complex SVG that is not very quick. 
> There should be room for improvement, but I don't think it's a serious issue 
> for now.
> 
> Maybe we could try to keep the main widget hidden until graphics has been 
> loaded? 

I am not sure this helps, because IIRC from my earlier debugging what is 
slow in some systems is the transfer of pixmaps to the X server (*), 
specially scaled pixmaps, and specially when a conversion is necessary. 
So it ultimately does not matter if the original source was SVG, 
Picture, or even cached QPixmap. Some drivers will be slow when 
transferring and scaling large pixmaps to the X Server, and this seems 
to be consistent with the problems you guys are seeing, as it is fairly 
independent of using QGV, KGameCanvas, or even QPainter directly (KShisen).

(*) of course, complex SVGs take more time to parse and render, but the 
performance hit is usually one-time in the case of games, as we cache 
most of the rendered bits, and only re-render (and re-transfer to the 
X-Server) on resize.

Regards,
Mauricio Piacentini