Rendering rectangles speed issue

**jacek** · 13th March 2007, 21:04

Originally Posted by macbeth

Don't have any idea. The rects were added in less than 0.1 seconds to the scene, their rasterization took about 30secs, but I have no idea what is going on afterwards.

Could you prepare a minimal compilable example, so I can test it too?

**macbeth** · 14th March 2007, 00:56

Of course, just slightly modified portedcanvas example -- try to add rectangle using Edit menu (or Alt + R), it should draw +-100 000 rects (some of them maybe cut out) quite fast, but afterwards the cpu load remains high (according to top or KDE task manager), on my machie around 90%...

here is an archive
just try to run qmake && make/gmake on it, it should be compiled & able to run...

and let me know how it works on your machine...

And thank you for the fruitful discussion

**jacek** · 14th March 2007, 22:15

On my machine it uses around 30% when idle, but when I drag items over the rectangles CPU utilization jumps to 70%--80% (according to top). I've commented out three lines in main() and now it uses less than 1% when I don't touch the items. Finding which lines should be commented out I leave to you

**macbeth** · 15th March 2007, 02:30

Well, I don't know what to say. I was searching for a timer in all other cpp files and did not find anything, supposing that main is just usual app.exec()... but as sherlock holmes said, if you foreclose all other possibilities, it must be the last one, even if it's almost improbable.

Sorry, sometimes I don't see what's in front of me...

And thanks, once more...