1 files changed, 21 insertions, 1 deletions

diff --git a/FL/Fl_Overlay_Window.H b/FL/Fl_Overlay_Window.H
index ff8677ce3..8f4c96b78 100644
--- a/FL/Fl_Overlay_Window.H
+++ b/FL/Fl_Overlay_Window.H
@@ -30,6 +30,17 @@
 
 #include "Fl_Double_Window.H"
 
+/**
+  This window provides double buffering and also the ability to draw the
+  "overlay" which is another picture placed on top of the main image. The
+  overlay is designed to be a rapidly-changing but simple graphic such as
+  a mouse selection box. Fl_Overlay_Window uses the overlay
+  planes provided by your graphics hardware if they are available.
+  <P>If no hardware support is found the overlay is simulated by drawing
+  directly into the on-screen copy of the double-buffered window, and
+  &quot;erased&quot; by copying the backbuffer over it again.  This means the
+  overlay will blink if you change the image in the window.
+*/
 class FL_EXPORT Fl_Overlay_Window : public Fl_Double_Window {
   friend class _Fl_Overlay;
   virtual void draw_overlay() = 0;
@@ -42,9 +53,18 @@ public:
   ~Fl_Overlay_Window();
   int can_do_overlay();
   void redraw_overlay();
+  /**
+    Creates a new Fl_Overlay_Window widget using the given
+    position, size, and label (title) string. If the 
+    positions (x,y) are not given, then the window manager
+    will choose them.
+  */
   Fl_Overlay_Window(int W, int H, const char *l=0)
     : Fl_Double_Window(W,H,l) {overlay_ = 0; force_doublebuffering_=1; image(0); }
-  Fl_Overlay_Window(int X, int Y, int W, int H, const char *l=0)
+   /**
+    See Fl_Overlay_Window::Fl_Overlay_Window(int W, int H, const char *l=0)
+  */
+ Fl_Overlay_Window(int X, int Y, int W, int H, const char *l=0)
     : Fl_Double_Window(X,Y,W,H,l) {overlay_ = 0; force_doublebuffering_=1; image(0); }
   void show(int a, char **b) {Fl_Double_Window::show(a,b);}
 };