[gtkada] Preserving background pixmap when animating (CONTINUED...)

[Kay M]

>  > My problem is not with flicker, it is with the background pixmap 
>getting
>  > wiped over. In short can you animate the drawing area with pixmaps that 
>have
>  > transparency , AND also preseve the background of the drawing 
>area......may
>  > be by applying the background pixmap to the Transparency!...(that 
>should do
>  > it)
>
>You did report a problem with flickering in your original email :-)
>
>Anyway, the solution is trivial, and in fact completely standard when one 
>does
>animation: you need to redraw the part of the background pixmap that was 
>below
>the item, then draw the items on top of it. To do this, you need to use a
>double_buffer or things will really flicker too much, and we are back to 
>the
>double_buffer widget.
>
>
>  > Can you in Gtkada draw on to the drawing area (or some widget) with a
>  > trasparent color, so that the widget will become transparent. (useful 
>for
>  > also custom shaped window!)
>
>I don't understand this part. Transparent means that nothing is drawn, this 
>is
>not a color!
>And since windows are not handled by your application itself but by the 
>window
>manager itself, using transparent pixmaps is definitely not the way to get
>custom shapes. This is in fact part of a gdk package that is not bound in
>GtkAda (can't remember the name though), since it wasn't portable across
>systems.
>
>Emmanuel

I am on a windows system, when running the doubke buffer demo, it crashes 
immmeadiatly , what can i do ???

So you Have to redraw the background pixmap manually?...is this what
gtkpixmap does when you switch pixmaps ?
Redraw the background pixmap ?.....The transparency is in a gdkbitmap, can 
you invert this bitmap somehow so you only draw over the previously 
used/draw pixels ?.
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.