On Wed, Mar 02, 2016 at 06:41:21AM +0200, John Found wrote:
On Tue, 1 Mar 2016 22:54:34 +0100 Johannes Hofmann <Johannes.Hofmann at gmx.de> wrote:
with buffered_drawing=2 dillo uses the Fl_Double_Window class from FLTK, so the result should be similar to e.g. the test/fonts program from FLTK. Do you have it available and can test how that program feels when resizing on your system? In my setup I only get some light flickering at the scroll bars with buffered_drawing=2. Whereas I see heavy flickering with buffered_drawing=0. Do you see any difference between buffered_drawing=0 and buffered_drawing=2?
Yes. These are different kind of flickering. On buffered_drawing=0 I see how Dillo redraws the page content on the window surface. No artifacts, only normal redraws one after another. On buffered_drawing=1 is approximately the same but a little bit rarely.
While on buffered_drawing=2, when the user resize the window, the whole window becomes full of garbage - this is specific kind of garbage. It happens when you reuse some memory previously used to store images with different sizes and then allocate it for a new image and draw it on the screen as it is. A mess of graphical scanlines, rectangles full of color, distorted images of different kind.
Unfortunately, I can't get screenshot, because it is a dynamic effect. After stopping resizing window, the last redraw is OK.
As buffered_drawing=2 uses Fl_Double_Window from FLTK which in turn tries to use the Xorg DOUBLE-BUFFER extension, you might want to try xdpyinfo | grep DOUBLE-BUFFER to see if this extension is enabled on your system and either disable or enable it in your xorg.conf to see if that makes a difference.