From f566917239890fbd899083b0ae80c7ad72145696 Mon Sep 17 00:00:00 2001
From: fanoI <fanoIlPrimo@gmail.com>
Date: Wed, 18 Nov 2015 23:27:33 +0100
Subject: [PATCH] Console modifications

- In MemoryBlock added Fill overloads that accept UInt16
- In TextScreen removed unused variables, magic number and finally the
Clear() method does what is expected!
---
 source/Cosmos.Core/MemoryBlock.cs | 20 ++++++++++++++++++++
 source/Cosmos.HAL/TextScreen.cs   | 26 +++++++++++++-------------
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/source/Cosmos.Core/MemoryBlock.cs b/source/Cosmos.Core/MemoryBlock.cs
index e11055813..a8e77f7c1 100644
--- a/source/Cosmos.Core/MemoryBlock.cs
+++ b/source/Cosmos.Core/MemoryBlock.cs
@@ -67,11 +67,31 @@ namespace Cosmos.Core
                 xDest++;
             }
         }
+
         public void Fill(byte aData)
         {
             Fill(0, Size, aData);
         }
 
+        public void Fill(UInt16 aData)
+        {
+            Fill(0, Size / 2, aData);
+        }
+
+        [DebugStub(Off = true)]
+        public unsafe void Fill(UInt32 aStart, UInt32 aCount, UInt16 aData)
+        {
+            //TODO: before next step can at least check bounds here and do the addition just once to 
+            //start the loop.
+            //TODO - When asm can check count against size just one time and use a native fill asm op
+            UInt16* xDest = (UInt16*)(this.Base + aStart);
+            for (UInt32 i = 0; i < aCount; i++)
+            {
+                *xDest = aData;
+                xDest++;
+            }
+        }
+
         [DebugStub(Off = true)]
         public unsafe void Fill(UInt32 aStart, UInt32 aCount, byte aData)
         {
diff --git a/source/Cosmos.HAL/TextScreen.cs b/source/Cosmos.HAL/TextScreen.cs
index b3f3de6f1..637180453 100644
--- a/source/Cosmos.HAL/TextScreen.cs
+++ b/source/Cosmos.HAL/TextScreen.cs
@@ -10,12 +10,9 @@ namespace Cosmos.HAL {
   // by memory moves
   public class TextScreen : TextScreenBase {
     protected byte Color = 0x0F; // White
-    // Empty + White
-    protected UInt16 mClearCellValue = 0x000F;
-    protected UInt32 mClearCellValue32;
+    protected UInt16 mClearCellValue;
     protected UInt32 mRow2Addr;
     protected UInt32 mScrollSize;
-    protected UInt32 mRowSize32;
 
     protected Core.IOGroup.TextScreen IO = new Cosmos.Core.IOGroup.TextScreen();
     protected readonly MemoryBlock08 mRAM;
@@ -31,10 +28,10 @@ namespace Cosmos.HAL {
         Debugger.DoSend("ERROR: This is not of type TextScreen!");
       }
       mRAM = IO.Memory.Bytes;
-      mClearCellValue32 = (UInt32)(mClearCellValue << 16 | mClearCellValue);
+      // Set the Console default colors: White foreground on Black background, the default value of mClearCellValue is set there too as it is linked with the Color
+      SetColors(ConsoleColor.White, ConsoleColor.Black);
       mRow2Addr = (UInt32)(Cols * 2);
       mScrollSize = (UInt32)(Cols * (Rows - 1) * 2);
-      mRowSize32 = (UInt32)Cols * 2 / 4;
       Debugger.DoSend("End of TextScreen..ctor");
     }
 
@@ -42,13 +39,16 @@ namespace Cosmos.HAL {
     public override UInt16 Cols { get { return 80; } }
 
     public override void Clear() {
-      IO.Memory.Fill(mClearCellValue32);
+        Debugger.DoSend("Clearing screen with value ");
+        Debugger.DoSendNumber(mClearCellValue);
+        IO.Memory.Fill(mClearCellValue);
     }
 
     public override void ScrollUp()
     {
       IO.Memory.MoveDown(0, mRow2Addr, mScrollSize);
-      IO.Memory.Fill(mScrollSize, mRowSize32, mClearCellValue32);
+      //IO.Memory.Fill(mScrollSize, mRowSize32, mClearCellValue32);
+      IO.Memory.Fill(mScrollSize, Cols, mClearCellValue);
     }
 
     public override char this[int aX, int aY]
@@ -64,11 +64,11 @@ namespace Cosmos.HAL {
       }
     }
 
-
-
-        public override void SetColors(ConsoleColor aForeground, ConsoleColor aBackground) {
-      Color = (byte)((byte)(aForeground) | ((byte)(aBackground) << 4));
-    }
+    public override void SetColors(ConsoleColor aForeground, ConsoleColor aBackground) {
+            Color = (byte)((byte)(aForeground) | ((byte)(aBackground) << 4));
+            // The Color | the NUL character this is used to Clear the Screen
+            mClearCellValue = (UInt16)(Color << 8 | 0x00);
+        }
 
     public override void SetCursorPos(int aX, int aY)
     {