diff -u -r1.4 -r1.5
--- HPSEcalClusterer.java	24 May 2011 19:31:04 -0000	1.4
+++ HPSEcalClusterer.java	25 May 2011 20:55:36 -0000	1.5
@@ -12,7 +12,6 @@

 import org.lcsim.geometry.Detector;
 import org.lcsim.geometry.IDDecoder;
 import org.lcsim.geometry.subdetector.HPSEcal;

-import org.lcsim.geometry.subdetector.HPSEcal.XYSide;

 import org.lcsim.geometry.util.IDEncoder;
 import org.lcsim.recon.cluster.util.BasicCluster;
 import org.lcsim.util.Driver;

@@ -24,7 +23,7 @@

  * Clustering algorithm is from pages 83 and 84 of the HPS Proposal. 
  * 
  * @author Jeremy McCormick <[log in to unmask]>

- * @version $Id: HPSEcalClusterer.java,v 1.4 2011/05/24 19:31:04 jeremy Exp $

+ * @version $Id: HPSEcalClusterer.java,v 1.5 2011/05/25 20:55:36 jeremy Exp $

  */
 public class HPSEcalClusterer extends Driver 
 {

@@ -43,6 +42,8 @@

     // Odd or even number of crystals in X.
     boolean oddX;
     

+    Map<Long,Set<Long>> neighborsMap = null;
+    

     public HPSEcalClusterer()
     {}
     

@@ -88,6 +89,8 @@

     public void detectorChanged(Detector detector)
     {
         ecal = (HPSEcal)detector.getSubdetector(ecalName);

+        
+        neighborsMap = ecal.makeNeighborsMap();

                         
         System.out.println(ecal.getName());
         System.out.println(" nx="+ecal.nx());

@@ -113,10 +116,7 @@

             dec.setID(hit.getCellID());
             hitMap.put(hit.getCellID(), hit);
         }

-        
-        // Setup an encoder from the decoder.
-        IDEncoder enc = new IDEncoder(dec.getIDDescription());
-        

+                

         // Cluster list to be added to event.
         List<Cluster> clusters = new ArrayList<Cluster>();
         

@@ -127,35 +127,15 @@

             if (hit.getRawEnergy() < seedEMin)
                 continue;
             

-            // Set decoder's ID.
-            dec.setID(hit.getCellID());
-            
-            // Get ID values.
-            int ix = dec.getValue("ix");
-            int iy = dec.getValue("iy");
-            int side = dec.getValue("side");
-            
-            // Get neighboring crystals to hit.
-            Set<XYSide> neighbors = ecal.getNeighbors(ix, iy, side);
-            
-            //System.out.println("neighbors of " + ix + ", " + iy + ", " + side);
-           
-            int[] buffer = new int[dec.getFieldCount()];                        
-            dec.getValues(buffer);
-            

+            // Get neighbor crystal IDs.
+            Set<Long> neighbors = ecal.getNeighbors(hit.getCellID());
+                        

             // Loop over neighbors.
             List<CalorimeterHit> neighborHits = new ArrayList<CalorimeterHit>();

+            

             boolean isSeed = true;

-            for (XYSide neighbor : neighbors)
-            {                             
-                buffer[dec.getFieldIndex("ix")] = neighbor.x();
-                buffer[dec.getFieldIndex("iy")] = neighbor.y();
-                buffer[dec.getFieldIndex("side")] = neighbor.side();                
-                
-                // Create ID for this crystal.
-                // FIXME This is redundant and inefficient.
-                long neighborId = enc.setValues(buffer);
-              

+            for (Long neighborId : neighbors)
+            {                               

                 // Find neighbor hit if it exists.
                 CalorimeterHit neighborHit = hitMap.get(neighborId);
                 

@@ -174,7 +154,8 @@

                         neighborHits.add(neighborHit);
                 }                                
             }

-                        

+                      
+            // Did we find a seed?

             if (isSeed)
             {
                 // Make cluster.