Re: XForms: flickering images

Stephen Huyssoon (huyssoons@advancia.com)
Wed, 14 Apr 1999 15:42:55 -0500

# To subscribers of the xforms list from Stephen Huyssoon <huyssoons@advancia.com> :

Andrew McCready wrote:
>
> # To subscribers of the xforms list from Andrew McCready <mccready@andrew.cmu.edu> :
>
> On Wed, 14 Apr 1999, Steve Lamont wrote:
>
> > > So I'm displaying several pixmaps as an animation, but depending when the
> > > refresh hits, the pixmap flickers a little. Is there anyway to wait for
> > > the gun to hit the bottom of the screen before calling set pixmap?
> >
> > It's probably not a refresh issue but simply the speed at which the Pixmaps
> > are drawn. How are you swapping Pixmaps?
>
> FL_OBJECT *img;
> Pixmap p;
>
> /* create and fill Pixmap with image to be shown */
>
> fl_free_pixmap_pixmap(img);
> fl_set_pixmap_pixmap(img, p, 0);
>
>
> The images are 320x240. Is there a limit on the number pixels that can be
> drawn between refreshes with set_pixmap (due to xserver overhead, etc)?
> Regardless, unless the X server (or Xforms or anything else between my
> code and the screen) waits for the gun to start heading back to the top of
> the screen, I don't see how it'd be possible to refresh anything without
> seeing flicker at least some of the time. Or do I really have no clue?
>
> Thanks, Andrew

Hey dude. You are, like, way WAY above the level where you can be
worrying about screen refresh/draw synchronicity. You might look
for a lower level library for drawing if you want more speed.

Otherwise, you have what the X server provides. In your case, you
have XCopyArea.

Or, does XForms use something other than XCopyArea for what you
are doing? Anybody know?

Cheers.

-- 
  (Stephen Huyssoon)
>=============================>
  (huyssoons@advancia.com)							  www.advancia.com
  
To Infinity and Beyond! -- Me and Buzz Lightyear

The Truth cannot be proven nor disproven, it simply Is.

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