[gtk+/client-side-windows: 163/284] New flicker flicker fixing approach

[Alexander Larsson <alexl src gnome org>]

commit d267452bb73b9f93f483b1afa2f645b35eb4a77d
Author: Alexander Larsson <alex localhost localdomain>
Date:   Thu Jan 22 20:54:11 2009 +0100

    New flicker flicker fixing approach
    
    There was a performance problem with the old flicker fixing
    approach. For moved windows we copied the window data to the double
    buffer pixmap and then back to the window with the rest of the
    expose data. In some cases the copy from window data to pixmap was
    very slow because the pixmap was allocated in system memory and
    the window in video memory.
    
    The new approach is to delay all window moves and then replay them
    after the expose has drawn to the double buffer pixmap but before
    drawing it to the window. Furthermore, we remove all exposed areas
    from the destination of the delayed moves so we won't copy something
    just to then immediately draw over it.
    
    This makes scrolling in firefox fast, and it makes tests/flicker not
    show any (detectable) flicker.
---
 gdk/gdkwindow.c |   78 ++++++++++++++++++++++--------------------------------
 1 files changed, 32 insertions(+), 46 deletions(-)

diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 5639f2c..4b10550 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -1961,9 +1961,6 @@ gdk_window_begin_implicit_paint (GdkWindow *window, GdkRectangle *rect)
 {
   GdkWindowObject *private = (GdkWindowObject *)window;
   GdkWindowPaint *paint;
-  GdkRectangle r, clipbox;
-  GList *l;
-  GdkWindowRegionMove *move;
 
   g_assert (gdk_window_has_impl (private));
 
@@ -1974,46 +1971,15 @@ gdk_window_begin_implicit_paint (GdkWindow *window, GdkRectangle *rect)
       private->implicit_paint != NULL)
     return FALSE; /* Don't stack implicit paints */
 
-  r = *rect;
-  for (l = private->outstanding_moves; l != NULL; l = l->next)
-    {
-      move = l->data;
-
-      if (!gdk_region_empty (move->region))
-	{
-	  gdk_region_get_clipbox (move->region, &clipbox);
-	  gdk_rectangle_union (&r, &clipbox, &r);
-	}
-    }
-  
   paint = g_new (GdkWindowPaint, 1);
   paint->region = gdk_region_new (); /* Empty */
-  paint->x_offset = r.x;
-  paint->y_offset = r.y;
+  paint->x_offset = rect->x;
+  paint->y_offset = rect->y;
   paint->uses_implicit = FALSE;
   paint->surface = NULL;
   paint->pixmap =
     gdk_pixmap_new (window,
-		    MAX (r.width, 1), MAX (r.height, 1), -1);
-  
-  _gdk_pixmap_set_as_backing (paint->pixmap,
-			      window, r.x, r.y);
-
-  for (l = private->outstanding_moves; l != NULL; l = l->next)
-    {
-      move = l->data;
-
-      gdk_region_union (paint->region, move->region);
-      g_object_ref (paint->pixmap);
-      do_move_region_bits_on_impl (private,
-				   paint->pixmap,
-				   paint->x_offset, paint->y_offset,
-				   move->region, /* In impl window coords */
-				   move->dx, move->dy);
-      gdk_region_destroy (move->region);
-      g_slice_free (GdkWindowRegionMove, move);
-    }
-  private->outstanding_moves = NULL;
+		    MAX (rect->width, 1), MAX (rect->height, 1), -1);
 
   private->implicit_paint = paint;
   
@@ -2075,7 +2041,9 @@ gdk_window_end_implicit_paint (GdkWindow *window)
   paint = private->implicit_paint;
 
   private->implicit_paint = NULL;
-  
+
+  gdk_window_flush_outstanding_moves (window);
+
   if (!gdk_region_empty (paint->region))
     {
       /* Some regions are valid, push these to window now */
@@ -2173,6 +2141,8 @@ gdk_window_begin_paint_region (GdkWindow       *window,
   GdkWindowPaint *paint, *implicit_paint;
   GdkWindowObject *impl_window;
   GSList *list;
+  GList *l;
+  GdkWindowRegionMove *move;
 
   g_return_if_fail (GDK_IS_WINDOW (window));
 
@@ -2189,15 +2159,34 @@ gdk_window_begin_paint_region (GdkWindow       *window,
       return;
     }
 
-  gdk_region_get_clipbox (region, &clip_box);
-
   impl_window = gdk_window_get_impl_window (private);
   implicit_paint = impl_window->implicit_paint;
 
   paint = g_new (GdkWindowPaint, 1);
   paint->region = gdk_region_copy (region);
   paint->region_tag = new_region_tag ();
-      
+
+  gdk_region_intersect (paint->region, private->clip_region_with_children);
+  gdk_region_get_clipbox (paint->region, &clip_box);
+
+  /* Convert to impl coords */
+  gdk_region_offset (paint->region, private->abs_x, private->abs_y);
+
+  /* Mark the region as valid on the implicit paint */
+  
+  if (implicit_paint)
+    gdk_region_union (implicit_paint->region, paint->region);
+
+  /* No need to do any moves that will end up over the exposed area */
+  for (l = impl_window->outstanding_moves; l != NULL; l = l->next)
+    {
+      move = l->data;
+      gdk_region_subtract (move->region, paint->region);
+    }
+  
+  /* Convert back to normal coords */
+  gdk_region_offset (paint->region, -private->abs_x, -private->abs_y);
+  
   if (implicit_paint)
     {
       int width, height;
@@ -2206,7 +2195,6 @@ gdk_window_begin_paint_region (GdkWindow       *window,
       paint->pixmap = g_object_ref (implicit_paint->pixmap);
       paint->x_offset = -private->abs_x + implicit_paint->x_offset;
       paint->y_offset = -private->abs_y + implicit_paint->y_offset;
-      gdk_region_intersect (paint->region, private->clip_region_with_children);
       
       /* It would be nice if we had some cairo support here so we
 	 could set the clip rect on the cairo surface */
@@ -2215,10 +2203,6 @@ gdk_window_begin_paint_region (GdkWindow       *window,
       
       paint->surface = _gdk_drawable_create_cairo_surface (paint->pixmap, width, height);
 
-      /* Mark the region as valid on the implicit paint */
-      gdk_region_offset (paint->region, private->abs_x, private->abs_y); 
-      gdk_region_union (implicit_paint->region, paint->region);
-      gdk_region_offset (paint->region, -private->abs_x, -private->abs_y); 
     }
   else
     {
@@ -2362,6 +2346,8 @@ gdk_window_end_paint (GdkWindow *window)
 
   if (!paint->uses_implicit)
     {
+      gdk_window_flush_outstanding_moves (window);
+      
       full_clip = gdk_region_copy (private->clip_region_with_children);
       gdk_region_intersect (full_clip, paint->region);
       _gdk_gc_set_clip_region_internal (tmp_gc, full_clip, TRUE); /* Takes ownership of full_clip */