Index: vtkStripper.cxx
===================================================================
RCS file: /cvsroot/VTK/VTK/Graphics/vtkStripper.cxx,v
retrieving revision 1.65
diff -u -3 -p -r1.65 vtkStripper.cxx
--- vtkStripper.cxx	14 Nov 2003 20:43:32 -0000	1.65
+++ vtkStripper.cxx	16 May 2004 20:43:14 -0000
@@ -342,9 +342,126 @@ void vtkStripper::Execute()
   // output poly-lines
   if ( newLines )
     {
-    newLines->Squeeze();
-    output->SetLines(newLines);
+    // In some cases it may be possible to optimise the output
+    // poly-lines a bit.  The algorithm thus-far sometimes outputs
+    // polylines that could be joined together but are not.  We now
+    // go through joining any lines that we can.
+    //
+
+    // compressedLines will be our output line set, possibly
+    // with some lines joined together.
+    vtkCellArray* compressedLines = vtkCellArray::New();
+
+    bool* used = new bool[newLines->GetNumberOfCells()];
+    for (i = 0; i < newLines->GetNumberOfCells(); i++)
+      used[i] = 0;
+
+    bool done = false;
+    while (!done)
+      {
+      int out_n = 0;
+      vtkIdType* out_p = new vtkIdType[newLines->GetNumberOfConnectivityEntries()];
+
+      newLines->InitTraversal();
+      int id = -1;
+      vtkIdType n;
+      vtkIdType* p;
+
+      // Find a line from the original set that has not yet been used
+      do
+	{
+	if (newLines->GetNextCell(n, p) == 0)
+	  done = true;
+	id++;
+        } while (!done && (used[id] == 1));
+
+      if (done == false)
+	{
+	// Write it into our output line
+	memcpy(out_p + out_n, p, n * sizeof(vtkIdType));
+	out_n += n;
+	used[id] = 1;
+
+	// Now add any unused lines that adjoin this current line
+	bool done_this = false;
+	while (!done_this)
+	  {
+
+	  // Here's the start and end of our current line
+	  vtkIdType ca = out_p[0];
+	  vtkIdType cb = out_p[out_n - 1];
+
+	  vtkIdType ta;
+	  vtkIdType tb;
+	  bool found = false;
+
+	  // Look for any lines which adjoin this one
+	  while (!done_this && !found)
+	    {
+
+	    if (newLines->GetNextCell(n, p) == 0)
+	      done_this = true;
+	    id++;
+
+	    if (!done_this && (used[id] == 0))
+	      {
+	      ta = p[0];
+	      tb = p[n - 1];
+	      if ((ca == ta) || (ca == tb) || (cb == ta) || (cb == tb))
+		found = true;
+	      }
+	    }
+
+	  if (found)
+	    {
+	    // Here's a line which adjoins this one somehow; add it in
+	    vtkIdType* add_to;
+
+	    if (ca == ta || ca == tb)
+	      {
+	      // This line will go in before our current one; move
+	      // the current one forwards to make room
+	      memmove(out_p + n, out_p, out_n * sizeof(vtkIdType));
+	      add_to = out_p;
+	      }
+	    else
+	      {
+	      // This line will go in after our current one
+	      add_to = out_p + out_n;
+	      }
+
+	    // Add the new line to our current one, either forwards
+	    // or backwards as appropriate
+	    if (ca == ta || cb == tb)
+	      {
+	      for (vtkIdType x = 0; x < n; x++)
+		add_to[x] = p[n - x - 1];
+	      }
+	    else
+	      {
+	      memcpy(add_to, p, n * sizeof(vtkIdType));
+	      }
+
+	    out_n += n;
+	    used[id] = 1;
+
+	    }
+	  else
+	    done_this = true;
+	}
+
+	// We've finished this new line, so add it to the list
+	compressedLines->InsertNextCell(out_n, out_p);
+        }
+
+      delete out_p;
+      }
+
     newLines->Delete();
+    compressedLines->Squeeze();
+    output->SetLines(compressedLines);
+    compressedLines->Delete();
+    delete used;
     vtkDebugMacro (<<"Reduced " << numCells << " cells to " << numLines 
                    << " poly-lines \n\t(Average " << (float)numCells/numLines 
                    << " lines per poly-line, longest poly-line = "