Sluggish graphics

[Russell Shaw <rjshaw iprimus com au>]

Hi,
I'm redrawing a line (with gdk_draw_line) 10 times/sec on a pixmap,
where the line is drawn from a fixed point to the mouse position.
If i make the pixmap large (1024x768), the mouse and line updating
become *very* sluggish (500MHz PIII system, GTK2), even if i don't
have the background refreshing.

I have only these extra events for the containing drawing area:

drawing_area=gtk_drawing_area_new();

gtk_widget_set_events(drawing_area,
        GDK_EXPOSURE_MASK
      | GDK_ENTER_NOTIFY_MASK
      | GDK_BUTTON_PRESS_MASK
      | GDK_BUTTON_RELEASE_MASK
      | GDK_KEY_PRESS_MASK
      | GDK_KEY_RELEASE_MASK);

Is the pixmap stored on the client side or the server side?
Does a line-draw cause the pixmap to be transferred?
How can i draw direct to video memory?