Re: gtk_widget_queue_draw_area much slower in gtk3 than gtk3

[Stefan Salewski <mail ssalewski de>]

On Mon, 2015-03-30 at 13:22 +0100, Emmanuele Bassi wrote:
>  * use the event history for the devices you're interested in
>  * disable motion event compression on the GdkWindow that you're using
> to detect events, and build up the positions you will then draw
>
> Other painting applications opted for the latter solution, so you
> should likely explore it first; see the API reference:

For my Gentoo Linux box with gtk+-3.14.9 disabling motion event
compression seems to have no effect currently.

I just took the example program gtk+-3.15.8/examples/drawing.c and added
the two inner lines

gtk_widget_show_all (window);
gdk_window = gtk_widget_get_window(GTK_WIDGET(window));
gdk_window_set_event_compression(gdk_window, FALSE);
gtk_main ();

(I think I have to put it after show all, to ensure that gtk window is
realized and gdk window exists.)

Makes no difference for me -- when I move the mouse pointer fast, I get
separated points but no continuous line. I did a similar tests earlier,
hoped that it would work now with GTK 3.14. I just tested with gimp --
with that tool free hand drawing gives continuous lines instead of
separated points. So my mouse or other input hardware, and X event
handling seems to be not the problem. There must be still some event
filtering of GTK3 involved. Later I may test using event history...