I'm wondering if the cario is the right solution. Because there are window transparency based on image transparency. I played a looped movie indefinitely in the X root window. And I need to paint a picture on it, like logo. I still need to mask the image window background, right? Jerry On Wed, 2011-05-11 at 18:22 +1000, Maarten Bosmans wrote: > 2011/5/11 Jerry Wang <jerry.wang@xxxxxxxxxx>: > > Hi guys, > > > > I wrote some code with GTK lib to show the image consequently and here > > is my situation. > > > > use pixbuf to get data from files: > > -pixbuf=gdk_pixbuf_new_from_file(filename, NULL); > > > > use pixmap to get the mask (for transparent consideration): > > -mask=gdk_pixmap_new(NULL, width, height, 1); > > -gdk_pixbuf_render_threshold_alpha(pixbuf, mask, 0, 0, > > 0, 0, width, height, 1) > > > > then combine the mask with shown window: > > gdk_window_shape_combine_mask(window->window, mask, 0, 0); > > > > and crate the image from pixbuf: > > -image=gtk_image_new_from_pixbuf(pixbuf); > > > > then add to window: > > gtk_container_add((GtkContainer*)window, image); > > > > > > before every image loading, remove the old one > > gtk_container_remove((GtkContainer*)window, image); > > > > My images are around 2M high definition PNG files. And my running > > machine is a ATOM N270 1.6G. Every image will take about 0.3s to load. > > > > My problem is, there are one totally transparent image in my image > > files. After showing the total transparent image, before pop out the > > next image, it will show the previous image (before the transparent > > image) for a very short of time, just like flushing the buffer. > > I'm not sure it is the cause of the problem, but using adding a new > widget to the hierarchy for every image seems like a wrong approach. A > better way would be to use Cairo to draw the pixbufs directly in the > draw event of a widget, for example a GtkDrawingArea. > > This would require some rewriting of the code, but you gain a lot of > flexibility, like e.g. the possibility for crossfading. Make sure you > don't actually load the pixbuf in the draw(expose) event, but only do > the gdk_cairo_set_source_pixbuf(), cairo_paint() there. > > > I was considering the root cause is double buffering. But if I disable > > the double buffering feature, the slide show will not be smooth, it > > looks flick. > > > > Also I try to disable the X's double buffer extension, but still see > > previous image. > > > > Need advice. > > > > Thanks, > > Jerry > > Maarten _______________________________________________ gtk-list mailing list gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
