Pass the coodinates to the damage region to fix the damage code

Terminal.Gui/Drivers/WindowsDriver.cs

@@ -83,7 +83,7 @@ namespace Terminal.Gui {
 				ReadConsoleOutput (OutputHandle, OriginalStdOutChars, coords, new Coord () { X = 0, Y = 0 }, ref window);
 			}
 
-			return WriteConsoleOutput (ScreenBuffer, charInfoBuffer, coords, new Coord () { X = 0, Y = 0 }, ref window);
+			return WriteConsoleOutput (ScreenBuffer, charInfoBuffer, coords, new Coord () { X = window.Left, Y = window.Top }, ref window);
 		}
 
 		public bool SetCursorPosition (Coord position)
@@ -323,7 +323,7 @@ namespace Terminal.Gui {
 			public static void Update (ref SmallRect rect, short col, short row)
 			{
 				if (rect.Left == -1) {
-					System.Diagnostics.Debugger.Log (0, "debug", $"damager From Empty {col},{row}\n");
+					//System.Diagnostics.Debugger.Log (0, "debug", $"damager From Empty {col},{row}\n");
 					rect.Left = rect.Right = col;
 					rect.Bottom = rect.Top = row;
 					return;
@@ -338,7 +338,7 @@ namespace Terminal.Gui {
 					rect.Top = row;
 				if (row > rect.Bottom)
 					rect.Bottom = row;
-				System.Diagnostics.Debugger.Log (0, "debug", $"Expanding {rect.ToString ()}\n");
+				//System.Diagnostics.Debugger.Log (0, "debug", $"Expanding {rect.ToString ()}\n");
 			}
 
 			public override string ToString ()
@@ -826,6 +826,7 @@ namespace Terminal.Gui {
 
 			UpdateCursor();
 			winConsole.WriteToConsole (OutputBuffer, bufferCoords, damageRegion);
+			System.Diagnostics.Debugger.Log(0, "debug", $"Region={damageRegion.Right - damageRegion.Left},{damageRegion.Bottom - damageRegion.Top}\n");
 			WindowsConsole.SmallRect.MakeEmpty (ref damageRegion);
 		}
 

stash

@@ -0,0 +1,136 @@
+diff --git a/Example/demo.cs b/Example/demo.cs
+index 1413f9b..1df6170 100644
+--- a/Example/demo.cs
++++ b/Example/demo.cs
+@@ -90,7 +90,7 @@ static class Demo {
+ 			return true;
+ 		}
+ 
+-		Application.MainLoop.AddTimeout (TimeSpan.FromMilliseconds (300), timer);
++		//Application.MainLoop.AddTimeout (TimeSpan.FromMilliseconds (300), timer);
+ 
+ 
+ 		// A little convoluted, this is because I am using this to test the
+diff --git a/Terminal.Gui/Drivers/WindowsDriver.cs b/Terminal.Gui/Drivers/WindowsDriver.cs
+index 229931a..a3ab2bd 100644
+--- a/Terminal.Gui/Drivers/WindowsDriver.cs
++++ b/Terminal.Gui/Drivers/WindowsDriver.cs
+@@ -323,6 +323,10 @@ namespace Terminal.Gui {
+ 				this.X = X;
+ 				this.Y = Y;
+ 			}
++
++			public override string ToString() {
++				return $"(X={X},Y={Y}";
++			}
+ 		};
+ 
+ 		[StructLayout(LayoutKind.Explicit, CharSet=CharSet.Unicode)]
+@@ -346,6 +350,34 @@ namespace Terminal.Gui {
+ 			public short Top;
+ 			public short Right;
+ 			public short Bottom;
++
++			public static void MakeEmpty (ref SmallRect rect) {
++				rect.Left = -1;
++			}
++
++			public static void Update (ref SmallRect rect, short col, short row) {
++				if (rect.Left == -1) {
++					System.Diagnostics.Debugger.Log(0, "debug", $"damager From Empty {col},{row}\n");
++					rect.Left = rect.Right = col;
++					rect.Bottom = rect.Top = row;
++					return;
++				}
++				if (col >= rect.Left && col <= rect.Right && row >= rect.Top && row <= rect.Bottom)
++					return;
++				if (col < rect.Left)
++					rect.Left = col;
++				if (col > rect.Right)
++					rect.Right = col;
++				if (row < rect.Top)
++					rect.Top = row;
++				if (row > rect.Bottom)
++					rect.Bottom = row;
++				System.Diagnostics.Debugger.Log(0, "debug", $"Expanding {rect.ToString()}\n");
++			}
++
++			public override string ToString() {
++				return $"Left={Left},Top={Top},Right={Right},Bottom={Bottom}";
++			}
+ 		}
+ 
+ 		[DllImport ("kernel32.dll", SetLastError = true)]
+@@ -410,7 +442,7 @@ namespace Terminal.Gui {
+ 		WindowsConsole WinConsole;
+ 
+ 		WindowsConsole.CharInfo[] OutputBuffer;
+-
++		WindowsConsole.SmallRect damageRegion;
+ 		int cols, rows;
+ 
+ 		public override int Cols => cols;
+@@ -424,6 +456,7 @@ namespace Terminal.Gui {
+ 			WinConsole = new WindowsConsole();
+ 			cols = Console.WindowWidth;
+ 			rows = Console.WindowHeight - 1;
++			WindowsConsole.SmallRect.MakeEmpty(ref damageRegion);
+ 			ResizeScreen ();
+ 			UpdateOffScreen ();
+ 		}
+@@ -649,6 +682,12 @@ namespace Terminal.Gui {
+ 		{
+ 			OutputBuffer = new WindowsConsole.CharInfo[Rows * Cols];
+ 			Clip = new Rect (0, 0, Cols, Rows);
++			damageRegion = new WindowsConsole.SmallRect() {
++				Top = 0,
++				Left = 0,
++				Bottom = (short)Rows,
++				Right = (short) Cols
++			};
+ 		}
+ 
+ 		void UpdateOffScreen ()
+@@ -675,6 +714,7 @@ namespace Terminal.Gui {
+ 			if (Clip.Contains (ccol, crow)){
+ 				OutputBuffer[position].Attributes = (ushort)currentAttribute;
+ 				OutputBuffer[position].Char.UnicodeChar = (char)rune;
++				WindowsConsole.SmallRect.Update(ref damageRegion, (short)ccol, (short)crow);
+ 			}
+ 
+ 			ccol++;
+@@ -709,6 +749,8 @@ namespace Terminal.Gui {
+ 
+ 		public override void Refresh()
+ 		{
++			UpdateScreen();
++#if false
+ 			var bufferCoords = new WindowsConsole.Coord (){
+ 				X = (short)Clip.Width,
+ 				Y = (short)Clip.Height
+@@ -723,10 +765,14 @@ namespace Terminal.Gui {
+ 
+ 			UpdateCursor();
+ 			WinConsole.WriteToConsole (OutputBuffer, bufferCoords, window);
++#endif
+ 		}
+ 
+ 		public override void UpdateScreen ()
+ 		{
++			if (damageRegion.Left == -1)
++				return;
++
+ 			var bufferCoords = new WindowsConsole.Coord (){
+ 				X = (short)Clip.Width,
+ 				Y = (short)Clip.Height
+@@ -740,7 +786,9 @@ namespace Terminal.Gui {
+ 			};
+ 
+ 			UpdateCursor();
+-			WinConsole.WriteToConsole (OutputBuffer, bufferCoords, window);
++			
++			WinConsole.WriteToConsole (OutputBuffer, bufferCoords, damageRegion);
++			WindowsConsole.SmallRect.MakeEmpty(ref damageRegion);
+ 		}
+ 
+ 		public override void UpdateCursor()