On Wed, May 18, 2011 at 9:22 PM, Tobias Hoffmann <<a href="mailto:lcairo-list@thax.hardliners.org">lcairo-list@thax.hardliners.org</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> <div class="im">Manu wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On 05/17/2011 01:35 PM, Tobias Hoffmann wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hint: Don't use the default visual for the widget: GdkColormap *rgba = gdk_screen_get_rgba_colormap (screen); // GTK3: gdk_screen_get_rgba_visual(screen), etc... if (rgba&& gdk_screen_is_composited (screen)) { gtk_widget_set_colormap(GTK_WIDGET(drawing_area), rgba); } </blockquote> Sorry, sill one issue: gdk_screen_get_rgba_colormap() is not implemented in the win32 backend. The gdk visual depth is always reported as 24. </blockquote></div> AFAIU this has to do with limitations on GDI surfaces on windows, so there's no easy workaround. Maybe someone with better win32 knowledge can tell you (and me) more. </blockquote> </div>It is possible to draw RGBA windows with cairo-win32 on Windows Vista and Windows 7. Firefox 4 does it. We don't use GTK on Windows, though. Rob -- "Now the Bereans were of more noble character than the Thessalonians, for they received the message with great eagerness and examined the Scriptures every day to see if what Paul said was true." [Acts 17:11]