Files
gzz-mirror/Java/transform/ReverseDim.java
2026-09-14 20:19:29 -04:00

97 lines
2.9 KiB
Java

/*
ReverseDim.java
*
* You may use and distribute under the terms of either the GNU Lesser
* General Public License, either version 2 of the license or,
* at your choice, any later version. Alternatively, you may use and
* distribute under the terms of the XPL.
*
* See the LICENSE.lgpl and LICENSE.xpl files for the specific terms of
* the licenses.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the README
* file for more details.
*
*/
/*
* Written by Tuukka Hastrup
*/
package org.gzigzag.transform;
import java.util.*;
import org.gzigzag.*;
/** ZZspace dimension changer - reverse positive and negative directions.
*/
public class ReverseDim {
String rcsid = "$Id: ReverseDim.java,v 1.6 2000/10/18 14:35:32 tjl Exp $";
public static final boolean dbg = false;
void p(String s) { if (dbg) System.out.println(s); }
String dim;
ZZSpace space;
/** Constructs direction changer for a dimension in a space
* @param d The dimension
* @param s The space to convert
*/
public ReverseDim(String d, ZZSpace s) {
dim = d;
space = s;
}
/** Performs the actual transformation. All connections along the dimension
* are disconnected and new ones connected in reverse direction.
*/
public void transform() {
Enumeration e=space.cells();
ZZCell c;
Hashtable donecells = new Hashtable(); // Cells on the reversed ranks
while(e.hasMoreElements()) { // Do ranks
c = (ZZCell)e.nextElement();
if(c.s(dim, -1)==null) {
if (c.s(dim, 1)!=null) {
if(!donecells.containsKey(c)) {
swapRank(c, donecells);
p("Swapped rank beginning from cell #"+c.getID());
}
else
p("Rank beginning from cell #"+c.getID()+" already done");
}
else
p("Cell #"+c.getID()+" not placed on "+dim);
donecells.put(c, c); // This cell is not in loop
} // Negwards connected cells will be done later
}
e = space.cells();
while(e.hasMoreElements()) { // Do loops
c = (ZZCell)e.nextElement();
if(!donecells.containsKey(c)) { // If it wasn't rank, then it's loop
c.disconnect(dim, -1); // Cut into a rank
c.connect(dim, 1, swapRank(c, donecells)); // Flip and join
}
}
}
// Swap the cells in a rank. Return the new headcell.
protected ZZCell swapRank(ZZCell head, Hashtable done)
{
ZZCell newrank = head; // The latest cell in the new rank
ZZCell curr = head.s(dim, 1); // The head of the old one
head.disconnect(dim, 1);
ZZCell next;
while (curr != null) {
next = curr.s(dim, 1);
if(next!=null) {
curr.disconnect(dim, 1);
}
curr.connect(dim, 1, newrank);
done.put(curr, curr);
newrank = curr;
curr = next;
};
return newrank;
}
}