Re: Displaying live video -- how to notify main loop from another thread?

[Marek Peca]

Dear GNUsteppers,

On Fri, 9 Jul 2010, David Chisnall wrote:
> (..)
>
> -setNeedsDisplay: also ought to work.  I think this is a bug in GNUstep 
> - this ought to wake up the main thread if it is sleeping and trigger a 
> redraw.  If it doesn't, you can poke the main thread with 
> -performSelectorInMainThread:

I checked SVN and it seemed to me it should really work. Replaced my old 
bad Debian version with current stable compiled from sources and voila, it 
works, as I expected.

So, sorry for my previous message. But anyway, now I know, how to 
connect multiple non-GNUstep threads to NSApplication loop.

> On 9 Jul 2010, at 12:44, Marek Peca wrote:
>
> > (..)
> >
> > And the second question is, whether I have chosen the right method of 
> > image display: I am calling NSBitmapImageRep->draw from within 
> > ImgView->drawRect:, where ImgView is descendant of NSView. Camera is 
> > grabbing at few fps, 640x480x8bit, calling [imgView setNeedsDisplay: 
> > YES]; if the event queue is being refreshed by continuous mouse motion, 
> > I can easily get CPU load 60% on my 3GHz Pentium. (Similar program 
> > under Gtk takes 2% CPU.) So I am asking, whether, and what am I doing 
> > wrong.

Now, xlib backend, version 1.18.0 & XFree86 4.3.0 (yes, you have heard it 
right, I will test it on a recent machine soon), it is better: CPU load 
around 7% on 3GHz Pentium, split evenly between my app and X.

Great, many thanks for your previous answers.


Best regards,
Marek