[AvalonEdit] Adjust epsilon used for IsClose()

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ExtensionMethods.cs

@@ -14,10 +14,18 @@ namespace ICSharpCode.AvalonEdit.Utils
 	static class ExtensionMethods
 	{
 		#region Epsilon / IsClose / CoerceValue
-		public const double Epsilon = 1e-8;
+		/// <summary>
+		/// Epsilon used for <c>IsClose()</c> implementations.
+		/// We can use up quite a few digits in front of the decimal point (due to visual positions being relative to document origin),
+		/// and there's no need to be too accurate (we're dealing with pixels here),
+		/// so we will use the value 0.01.
+		/// Previosly we used 1e-8 but that was causing issues:
+		/// http://community.sharpdevelop.net/forums/t/16048.aspx
+		/// </summary>
+		public const double Epsilon = 0.01;
 		
 		/// <summary>
-		/// Returns true if the doubles are close (difference smaller than 10^-8).
+		/// Returns true if the doubles are close (difference smaller than 0.01).
 		/// </summary>
 		public static bool IsClose(this double d1, double d2)
 		{
@@ -27,7 +35,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 		}
 		
 		/// <summary>
-		/// Returns true if the doubles are close (difference smaller than 10^-8).
+		/// Returns true if the doubles are close (difference smaller than 0.01).
 		/// </summary>
 		public static bool IsClose(this Size d1, Size d2)
 		{
@@ -35,7 +43,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 		}
 		
 		/// <summary>
-		/// Returns true if the doubles are close (difference smaller than 10^-8).
+		/// Returns true if the doubles are close (difference smaller than 0.01).
 		/// </summary>
 		public static bool IsClose(this Vector d1, Vector d2)
 		{