Index: fCraft/Commands/BuildingCommands.cs
===================================================================
--- fCraft/Commands/BuildingCommands.cs   (revision 1634)
+++ fCraft/Commands/BuildingCommands.cs   (working copy)
@@ -66,9 +66,11 @@
             CdEllipsoidHollow.Help += GeneralDrawingHelp;
 
             CommandManager.RegisterCommand( CdLine );
+         CommandManager.RegisterCommand( CdSnap );
             CommandManager.RegisterCommand( CdTriangle );
             CommandManager.RegisterCommand( CdTriangleWireframe );
             CdLine.Help += GeneralDrawingHelp;
+         CdSnap.Help += GeneralDrawingHelp;
             CdTriangle.Help += GeneralDrawingHelp;
             CdTriangleWireframe.Help += GeneralDrawingHelp;
 
@@ -225,9 +227,26 @@
         static void LineHandler( Player player, CommandReader cmd ) {
             DrawOperationBegin( player, cmd, new LineDrawOperation( player ) );
         }
+      
+      
+      
+      static readonly CommandDescriptor CdSnap = new CommandDescriptor {
+         Name = "Snap",
+         Aliases = new[] { "SnapLine", "sn", "sl" },
+         Category = CommandCategory.Building,
+         Permissions = new[] { Permission.Draw },
+         RepeatableSelection = true,
+         Help = "Draws a line along the axis or at 45degrees thereof." +
+            "Second mark automatically snaps into position.",
+         Handler = SnapHandler
+      };
+      
+      static void SnapHandler( Player player, CommandReader cmd ) {
+         DrawOperationBegin( player, cmd, new SnapDrawOperation( player ) );
+      }
+      
 
 
-
         static readonly CommandDescriptor CdTriangleWireframe = new CommandDescriptor {
             Name = "TriangleW",
             Aliases = new[] { "tw" },

Index: fCraft/Drawing/DrawOps/SnapDrawOperation.cs
===================================================================
--- fCraft/Drawing/DrawOps/SnapDrawOperation.cs   (revision 0)
+++ fCraft/Drawing/DrawOps/SnapDrawOperation.cs   (revision 0)
@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+
+namespace fCraft.Drawing
+{
+   public sealed class SnapDrawOperation : DrawOperation
+   {
+        public override string Name {
+            get { return "Snap"; }
+        }
+
+       public override int ExpectedMarks {
+           get { return 2; }
+      }
+
+        public SnapDrawOperation( Player player )
+            : base( player ) {
+        }
+
+
+        public override bool Prepare( Vector3I[] marks ) {
+            if( !base.Prepare( marks ) ) return false;
+         
+         Vector3I diff = new Vector3I(marks[1]-marks[0]);
+         foreach(Axis a in Enum.GetValues(typeof(Axis)))
+            marks[1][a]=(Math.Abs(diff[a])>Math.Abs(diff[diff.LongestAxis])>>1)?
+               marks[0][a]+Math.Abs(diff[diff.LongestAxis])*Math.Sign(diff[a]):
+               marks[0][a];
+         
+            BlocksTotalEstimate = Math.Max( Bounds.Width, Math.Max( Bounds.Height, Bounds.Length ) );
+
+            coordEnumerator = LineEnumerator( marks[0], marks[1] ).GetEnumerator();
+            return true;
+        }
+
+
+        IEnumerator<Vector3I> coordEnumerator;
+        public override int DrawBatch( int maxBlocksToDraw ) {
+            int blocksDone = 0;
+            while( coordEnumerator.MoveNext() ) {
+                Coords = coordEnumerator.Current;
+                if( DrawOneBlock() ) {
+                    blocksDone++;
+                    if( blocksDone >= maxBlocksToDraw ) return blocksDone;
+                }
+                if( TimeToEndBatch ) return blocksDone;
+            }
+            IsDone = true;
+            return blocksDone;
+        }
+   }
+}
+

         CommandManager.RegisterCommand( CdSnap );
         CdSnap.Help += GeneralDrawingHelp;

      static readonly CommandDescriptor CdSnap = new CommandDescriptor {
         Name = "Snap",
         Aliases = new[] { "SnapLine", "sn", "sl" },
         Category = CommandCategory.Building,
         Permissions = new[] { Permission.Draw },
         RepeatableSelection = true,
         Help = "Draws a line along the axis or at 45degrees thereof." +
            "Second mark automatically snaps into position.",
         Handler = SnapHandler
      };
      
      static void SnapHandler( Player player, CommandReader cmd ) {
         DrawOperationBegin( player, cmd, new SnapDrawOperation( player ) );
      }

using System;
using System.Collections.Generic;

namespace fCraft.Drawing
{
   public sealed class SnapDrawOperation : DrawOperation
   {
        public override string Name {
            get { return "Snap"; }
        }

       public override int ExpectedMarks {
            get { return 2; }
        }

        public SnapDrawOperation( Player player )
            : base( player ) {
        }


        public override bool Prepare( Vector3I[] marks ) {
            if( !base.Prepare( marks ) ) return false;
         
         Vector3I diff = new Vector3I(marks[1]-marks[0]);
         foreach(Axis a in Enum.GetValues(typeof(Axis)))
            marks[1][a]=(Math.Abs(diff[a])>Math.Abs(diff[diff.LongestAxis])>>1)?
               marks[0][a]+Math.Abs(diff[diff.LongestAxis])*Math.Sign(diff[a]):
               marks[0][a];
         
            BlocksTotalEstimate = Math.Max( Bounds.Width, Math.Max( Bounds.Height, Bounds.Length ) );

            coordEnumerator = LineEnumerator( marks[0], marks[1] ).GetEnumerator();
            return true;
        }


        IEnumerator<Vector3I> coordEnumerator;
        public override int DrawBatch( int maxBlocksToDraw ) {
            int blocksDone = 0;
            while( coordEnumerator.MoveNext() ) {
                Coords = coordEnumerator.Current;
                if( DrawOneBlock() ) {
                    blocksDone++;
                    if( blocksDone >= maxBlocksToDraw ) return blocksDone;
                }
                if( TimeToEndBatch ) return blocksDone;
            }
            IsDone = true;
            return blocksDone;
        }
   }
}