From bb809c736e2c930de4dd98f74502398e6b967366 Mon Sep 17 00:00:00 2001
From: srowen <srowen@59b500cc-1b3d-0410-9834-0bbf25fbcc57>
Date: Tue, 13 Mar 2012 16:07:41 +0000
Subject: [PATCH] Issue 1210 fix toBitmap handling of stride

git-svn-id: https://zxing.googlecode.com/svn/trunk@2225 59b500cc-1b3d-0410-9834-0bbf25fbcc57
---
 csharp/common/ByteMatrix.cs | 58 +++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/csharp/common/ByteMatrix.cs b/csharp/common/ByteMatrix.cs
index c240a53c3..94d310e7f 100755
--- a/csharp/common/ByteMatrix.cs
+++ b/csharp/common/ByteMatrix.cs
@@ -137,38 +137,40 @@ namespace com.google.zxing.common
 		/// <returns>A black and white bitmap converted from this ByteMatrix.</returns>
 		public Bitmap ToBitmap()
 		{
-			 const byte BLACK = 0;
-			 const byte WHITE = 255;
-			 int width = Width;
-			 int height = Height;
+			const byte BLACK = 0;
+			const byte WHITE = 255;
+			sbyte[][] array = this.Array;
+			int width = this.Width;
+			int height = this.Height;
+			//Here create the Bitmap to the known height, width and format
+			Bitmap bmp = new Bitmap(width, height, PixelFormat.Format8bppIndexed);
+			//Create a BitmapData and Lock all pixels to be written
+			BitmapData bmpData =
+				bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),
+										 ImageLockMode.WriteOnly, bmp.PixelFormat);
 
-			 // create the bitmap and lock the bits because we need the stride
-			 // which is the width of the image and possible padding bytes
-			 var bmp = new Bitmap(width, height, PixelFormat.Format8bppIndexed);
-			 var bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.WriteOnly, bmp.PixelFormat);
-			 try
-			 {
-				var pixels = new byte[bmpData.Stride*height];
+			// If you wanted to support formats other than 8bpp, you should use Bitmap.GetPixelFormatSize(bmp.PixelFormat) to adjust the array size
+			byte[] pixels = new byte[bmpData.Stride * height];
 
-				for (int y = 0; y < height; y++)
-				{
-				   var offset = y*bmpData.Stride;
-				   for (var x = 0; x < width; x++)
-				   {
-					  pixels[offset + x] = this[x, y] ? BLACK : WHITE;
-				   }
-				}
+			int iPixelsCounter = 0;
+			for (int y = 0; y < height; y++)
+			{
+					int offset = y * width;
+					for (int x = 0; x < width; x++)
+					{
+						pixels[iPixelsCounter++] = array[y][x] == BLACK ? BLACK : WHITE;
+					}
+					iPixelsCounter += bmpData.Stride - width;
+			}
 
-				//Copy the data from the byte array into BitmapData.Scan0
-				Marshal.Copy(pixels, 0, bmpData.Scan0, pixels.Length);
-			 }
-			 finally
-			 {
-				//Unlock the pixels
-				bmp.UnlockBits(bmpData);
-			 }
+			//Copy the data from the byte array into BitmapData.Scan0
+			System.Runtime.InteropServices.Marshal.Copy(pixels, 0, bmpData.Scan0, pixels.Length);
 
-			 return bmp;
+			//Unlock the pixels
+			bmp.UnlockBits(bmpData);
+
+			//Return the bitmap
+			return bmp;
 		}
 	}
 }