package org.lcsim.geometry.util;
   
   /**
    * Does the opposite of IDDecoder
    * @author tonyj
    */
   public class IDEncoder
   {
      private IDDescriptor desc;
     private long id;
     /** Creates a new instance of IIDecoder */
     public IDEncoder(IDDescriptor desc)
     {
        this.desc = desc;
     }
     public long setValue(String name, int value)
     {
        return setValue(desc.indexOf(name),value);  
     }
     public long setValue(int index, int value)
     {
        int start = desc.fieldStart(index);
        int length = desc.fieldLength(index);
        long mask = ((1L<<length) - 1) << start;
        id &= ~mask;
        id |= (((long) value)<<start) & mask;
        
        return id;
     }
     public long setValues(int[] values)
     {
        if (values.length != desc.fieldCount()) throw new IllegalArgumentException("Invalid array length");
        long result = 0;
        for (int i=0; i<values.length; i++)
        {
           int start = desc.fieldStart(i);
           int length = desc.fieldLength(i);
           long mask = ((1L<<length) - 1);
           result |= (mask & values[i]) << start;
        }
        return id = result;      
     }
     public long getID()
     {
        return id;
     }
  }