Re: Pb w/ gc, pixmap and darea

[Taura Milana <learfox furry ao net>]

On 2001.12.12 17:07 Lewin A.R.W. Edwards wrote:
> > Now you might want to use the GDK RGB buffers if you plan to
> > do intensive live drawing.
>
> Eeee, but they are so darn slow. I have an app that opens a screen-size 
> window with a single drawing area in it. On a 300MHz GX1 (roughly a
> 266MHz 
> Pentium-MMX) at 1024x768x16, using the XF86_SVGA server, it is _visibly_ 
> wiping the image from top to bottom and left to right.

Here's a good example of speed with GDK RGB buffers,
http://wolfpack.twu.net/utilities.html

Take a look at iv (Image Viewer) it uses the Gdk RGB buffer system
to allow real time zoom and translation of 2D images.

   Now with respect to your specific issue, if you feel that it would
be faster on client side only operations and you don't plan to do anything
fancy then you do not need Gdk RGB buffers.

However unfortunatly, a lot of users prefer to use Gdk RGB buffers
(I don't know why though). But I just wanted to warn you on that
as Gdk RGB buffers apparently are a strong trend. *G*



> I also note that I have to go into a forced GTK idle loop after calling 
> gdk_draw_rgb_image in order for a draw operation to finish. If I don't, 
> about the bottom sixth of the screen doesn't get rendered. It seems that 
> gdk_draw_rgb_image sends the image in roughly 128x128-sized blocks; I can
>
> see them being drawn.
>
> I'm using gdk 1.something, I haven't gone to 2.x yet. I'm close to 
> wondering if there is a way for me to get to the window memory directly 
> (XShm?).

Well Gdk RGB buffers does use SHM as I recall, but if you plan to use
a GdkPixmap only, and do everything on server side (no GdkImages
or anything) then you don't need the Gdk RGB buffers.


--
Sincerely,                  ,"-_                         \|/
-Capt. Taura M.             ,   O=__                    --X--
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                  http://furry.ao.net/~learfox/