From 755f354ebe0a2f9c3ee287c53013279fd864ebbe Mon Sep 17 00:00:00 2001
From: Albrecht Schlosser <albrechts.fltk@online.de>
Date: Wed, 9 Jun 2010 08:36:25 +0000
Subject: [PATCH] Fixed X11/XDBE double buffering (STR #2152, #2197). Both bugs
 could only be seen if configure was run with --enable-xdbe (default in FLTK
 1.3, optional in FLTK 1.1).

src/Fl_Double_Window.cxx/Fl_Double_Window::resize():

	STR #2152: deallocate back buffer when window is enlarged in any
	dimension to force allocation of a new back buffer. This appears
	to be necessary for some window managers (e.g. Cygwin).

src/Fl_Overlay_Window.cxx/Fl_Overlay_Window::flush() and
src/Fl_Double_Window.cxx/Fl_Double_Window::flush():

	STR #2197: make sure that the entire overlay window will be drawn
	after a window redraw, because Fl_Double_Window::flush(1) erases
	the overlay as documented.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@7636 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
---
 CHANGES                   |  1 +
 src/Fl_Double_Window.cxx  | 12 ++++++++++--
 src/Fl_Overlay_Window.cxx |  2 +-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index 1d6fd3977..dc7878b18 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,6 @@
 CHANGES IN FLTK 1.3.0
 
+	- Fixed X11/XDBE double buffering (STR #2152, #2197)
 	- Added new label and image alignments (STR #2269)
 	- Added documentation for event delivery (STR #1983)
 	- Fixed menu and tooltip window animation bug under X11 (compiz)
diff --git a/src/Fl_Double_Window.cxx b/src/Fl_Double_Window.cxx
index bd2155329..88ccfd962 100644
--- a/src/Fl_Double_Window.cxx
+++ b/src/Fl_Double_Window.cxx
@@ -296,7 +296,7 @@ void Fl_Double_Window::flush(int eraseoverlay) {
   }
 #if USE_XDBE
   if (use_xdbe) {
-    if (myi->backbuffer_bad) {
+    if (myi->backbuffer_bad || eraseoverlay) {
       // Make sure we do a complete redraw...
       if (myi->region) {XDestroyRegion(myi->region); myi->region = 0;}
       clear_damage(FL_DAMAGE_ALL);
@@ -360,7 +360,15 @@ void Fl_Double_Window::resize(int X,int Y,int W,int H) {
   int oh = h();
   Fl_Window::resize(X,Y,W,H);
 #if USE_XDBE
-  if (use_xdbe) return;
+  if (use_xdbe) {
+    Fl_X* myi = Fl_X::i(this);
+    if (myi && myi->other_xid && (ow < w() || oh < h())) {
+      // STR #2152: Deallocate the back buffer to force creation of a new one.
+      XdbeDeallocateBackBufferName(fl_display,myi->other_xid);
+      myi->other_xid = 0;
+    }
+    return;
+  }
 #endif
   Fl_X* myi = Fl_X::i(this);
   if (myi && myi->other_xid && (ow != w() || oh != h())) {
diff --git a/src/Fl_Overlay_Window.cxx b/src/Fl_Overlay_Window.cxx
index 8acb4af35..581c7057d 100644
--- a/src/Fl_Overlay_Window.cxx
+++ b/src/Fl_Overlay_Window.cxx
@@ -61,7 +61,7 @@ void Fl_Overlay_Window::flush() {
     return;
   }
 #endif
-  int erase_overlay = (damage()&FL_DAMAGE_OVERLAY);
+  int erase_overlay = (damage()&FL_DAMAGE_OVERLAY) | (overlay_ == this);
   clear_damage((uchar)(damage()&~FL_DAMAGE_OVERLAY));
   Fl_Double_Window::flush(erase_overlay);
   if (overlay_ == this) draw_overlay();