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. > > Â Â Â Âuse pixbuf to get data from files: > Â Â Â Â-pixbuf=gdk_pixbuf_new_from_file(filename, NULL); > > Â Â Â Âuse pixmap to get the mask (for transparent consideration): > Â Â Â Â-mask=gdk_pixmap_new(NULL, width, height, 1); > Â Â Â Â-gdk_pixbuf_render_threshold_alpha(pixbuf, mask, 0, 0, > Â Â Â Â0, 0, width, height, 1) > > Â Â Â Âthen combine the mask with shown window: > Â Â Â Âgdk_window_shape_combine_mask(window->window, mask, 0, 0); > > Â Â Â Âand crate the image from pixbuf: > Â Â Â Â-image=gtk_image_new_from_pixbuf(pixbuf); > > Â Â Â Âthen add to window: > Â Â Â Âgtk_container_add((GtkContainer*)window, image); > > > Â Â Â Âbefore every image loading, remove the old one > Â Â Â Âgtk_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
