Hi there, I am one of the developers of xournal. We have been trying very hard to port from gtk2 to gtk3 (specially since gnomecanvas was abandoned). I recently joined xournalpp which is a new rewrite of xournal, and it is in the same boat: trying to go from gtk2 to gtk3.
So far the functionality is there, but we have been hit by a major problem in both apps: gtk3 is much slower rendering to the canvas than gtk2. I have tried to track this problem down, and my experiments suggest that it is the call to gtk_widget_queue_draw_area We draw a segment of a line using cairo, but it does not get drawn to the screen until gtk_widget_queue_draw_area is called. Which is fine. But under gtk3 it really slows down sampling of the stylus. Imagine drawing a circle with a stylus on the screen (or a mouse). Under gtk2 circles are nice and smooth. Under gtk3 they are harsh polygons. I have removed the call to gtk_widget_queue_draw under gtk3, and then circles are smooth (of course they are only redrawn when I force a refresh by changing workspaces under linux). is there any suggestion on why is this happening, specially when it was working properly under gtk2? alternatively, is there another way to force that drawings done with cairo be drawn on the screen without using gtk_widget_queue_draw? thank you! -- --dmg --- Daniel M. German http://turingmachine.org _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
