Re: Drawing a GdkDrawable to a frame window from gdk_foreign_new ()

[Sam Spilsbury <smspillaz gmail com>]

On Tue, Feb 16, 2010 at 10:15 AM, Sam Spilsbury <smspillaz gmail com> wrote:
> Hmm, my mail client must have cut this message into two mails (bizzare bug).
>
> In case it is actually the list doing this, here is the text of the
> mail in full: http://pastebin.ca/1797937
>
> Otherwise it is pasted below:
>
> Hey everyone,
>
> I'm helping to write a reparenting window manager and we are drawing
> some of our decorations using GDK.
>
> A X Window "frame" is provided to the application that draws the frame
> window and from this we create a GdkWindow * with
> gdk_window_foreign_new (). The colormap is set to the default colormap
> for the screen.
>
> The frame window provided to the application is the parent of a client
> window for our window manager and it's parent is a "wrapper" window
> between which the window manager handles. We draw directly into this
> "frame" window.
>
> From here, the decorations are drawn on to a GdkPixmap (made into a
> GdkDrawable) of the same depth as the frame window. Once that is done,
> that pixmap is copied on to the frame window using
> gdk_window_set_back_pixmap.
>
> Unfortunately, I must be missing something since it doesn't appear to
> render correctly. I dumped the pixmap and the corresponding frame
> window drawables using gdk_pixbuf_get_from_drawable and saving it
> using gdk_pixbuf_save. Linked at the bottom are corresponding images
> of the intended drawing on the frame window (the pixmap) and the
> drawable dump of the frame window. As you might see, the frame window
> is drawn in a corrupt fashion. I also tried calling gdk_window_clear
> () and dumping the drawable from that, but I get a similar result.
>
> I have also linked a pastebin to the code. Unfortunately, it's heavily
> linked to the development version of compiz, so you may need to
> compile that should you need to test it. The drawing happens in void
> draw_window_decoration (). The decoration size is calculated in
> calc_window_decoration_size (). We take the frame window and create a
> GdkWindow from it in add_frame_window ().

Ack, just realized I accidentally sent to gtk-devel and not
gtk-app-devel - apologies, I have cc'd the app-devel list

Sorry for bothering you!

Regards,

Sam

> Any pointers of what I might be doing wrong here would be great!
>
> Kind Regards,
>
> Sam
>
> [Intended window background] http://imgur.com/88W7x
> [Actual drawable dump of the window background] http://imgur.com/K44ed
> [Pastebin of the code, to where you should replace
> /gtk/window-decorator/gtk-window-decorator.c in the compiz/core
> section should you choose to test it] http://pastebin.ca/1797929
>
> On Tue, Feb 16, 2010 at 10:11 AM, Sam Spilsbury <smspillaz gmail com> wrote:
> > Hey everyone,
> >
> > I'm helping to write a reparenting window manager and we are drawing
> > some of our decorations using GDK.
> >
> > A X Window "frame" is provided to the application that draws the frame
> > window and from this we create a GdkWindow * with
> > gdk_window_foreign_new (). The colormap is set to the default colormap
> > for the screen.
> >
> > The frame window provided to the application is the parent of a client
> > window for our window manager and it's parent is a "wrapper" window
> > between which the window manager handles. We draw directly into this
> > "frame" window.
> >
> > From here, the decorations are drawn on to a GdkPixmap (made into a
> > GdkDrawable) of the same depth as the frame window. Once that is done,
> > that pixmap is copied on to the frame window using
> > gdk_window_set_back_pixmap.
> >
> > Unfortunately, I must be missing something since it doesn't appear to
> > render correctly. I dumped the pixmap and the corresponding frame
> > window drawables using gdk_pixbuf_get_from_drawable and saving it
> > using gdk_pixbuf_save. Linked at the bottom are corresponding images
> > of the intended drawing on the frame window (the pixmap) and the
> > drawable dump of the frame window. As you might see, the frame window
> > is drawn in a corrupt fashion. I also tried calling gdk_window_clear
> > () and dumping the drawable from that, but I get a similar result.
> >
> > I have also linked a pastebin to the code. Unfortunately, it's heavily
> > linked to the development version of compiz, so you may need to
> > compile that should you need to test it. The drawing happens in void
> > draw_window_decoration (). The decoration size is calculated in
> > calc_window_decoration_size (). We take the frame window and create a
> > GdkWindow from it in add_frame_window ().
> >
> > Any pointers of what I might be doing wrong here would be great!
> >
> > Kind Regards,
> >
> > Sam
> >
> > [Intended window background] http://imgur.com/88W7x
> > [Actual drawable dump of the window background] http://imgur.com/K44ed
> > [Pastebin of the code, to where you should replace
> > /gtk/window-decorator/gtk-window-decorator.c in the compiz/core
> > section should you choose to test it] http://pastebin.ca/1797929
> >
> > --
> > Sam Spilsbury
>
>
>
> --
> Sam Spilsbury



-- 
Sam Spilsbury