Re: Problem of programmation

Hi!

In general, access to the FrameBuffer device is exclusive under Linux.

Thus one process can open /dev/fbX, and use the framebuffer, but another program cannot really do so at the same time.
This is almost a necessity, since the processes could otherwise set different bit-depths or resolutions, or otherwise interfere with the settings of the other process!
There's also the memory to consider! Access to the framebuffer memory would have to be synchronized between the different processes.

There are solutions for your problem:

For example, X11 is one such solution. It will access the GFX Hardware (either through framebuffer or directly) and provides an API allowing the programmer to handle multiple windows.

DirectFB (www.directfb.org) is another interesting solution allowing multiple applications to share a linux framebuffer.

Richard Unger
 

> -----Ursprüngliche Nachricht-----
> Von: [email protected] 
> [mailto:[email protected]] Im 
> Auftrag von Bui Sy Phong
> Gesendet: Dienstag, 22. August 2006 12:02
> An: [email protected]
> Betreff: Re: [Linux-fbdev-users] Problem of programmation
> 
> Yes, understood. But let me explain my project to you :
> 
> My project consits to write a program witch will work like a 
> Linux graphic application but it must be cross-platform 
> (Linux, Zaurus and Linux based mobile phone). 
> It's a Linux graphic application so it must work when Window 
> Manager turned on :( It's cross-platform, so it must based on 
> Framebuffer.
> 
> And this is a big problem to me.
> 
> Can i have your suggestion about it ? 
> 
> Thanks so much,
> 
> Bui Sy Phong
> 
> 
> 
> 
> 
> 2006/8/22, Geert Uytterhoeven <[email protected]>:
> 
> 	On Tue, 22 Aug 2006, Bui Sy Phong wrote:
> 	> I've tried to turn off Windows Manager (X11 or 
> something else like that on
> 	> Zarus Sharp SL-C3200 - because my projet is based on) 
> by booting in text
> 	> mode.
> 	> I try to execute my program in this mode and my 
> window is one more time
> 	> broken by the console, exactly, by the text on console.
> 	>
> 	> So, i think that i'm wrong somewhere in my program or 
> my solution is bad. 
> 	
> 	There's an ioctl to switch the console to KD_GRAPHICS 
> mode. If you do that, no
> 	more text will be printed by the console driver.
> 	
> 	> I'm waiting always for your helpful.
> 	> Thanks so much.
> 	>
> 	> Bui Sy Phong
> 	>
> 	> 2006/8/22, Geert Uytterhoeven <[email protected]>:
> 	> >
> 	> > On Tue, 22 Aug 2006, Bui Sy Phong wrote:
> 	> > > I'm a newbie on Framebuffer programmation and 
> newbie also on this 
> 	> > mailing
> 	> > > list.
> 	> > >
> 	> > > Actually, i'm writing a little program witch will 
> display a full-screen
> 	> > > windows in bleu.
> 	> > > But when i execute this program, my windows is 
> always hiden by the 
> 	> > console
> 	> > > or X11's windows. I dont understant how X11 
> communicates with
> 	> > Framebuffer so
> 	> > > i cannot do the same thing to display my windows 
> in first plane.
> 	> > 
> 	> > You should not touch the frame buffer device while 
> X is active.
> 	
> 	Gr{oetje,eeting}s,
> 	
> 	                                                Geert
> 	
> 	--
> 	Geert Uytterhoeven -- There's lots of Linux beyond ia32 
> -- [email protected]
> 	
> 	In personal conversations with technical people, I call 
> myself a hacker. But
> 	when I'm talking to journalists I just say "programmer" 
> or something like that. 
> 	                                                        
>     -- Linus Torvalds
> 	
> 	
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> 	_______________________________________________
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> 
> 

-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642