/* Copyright (c) 2010, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
package com.cburch.logisim.circuit;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import com.cburch.logisim.comp.Component;
import com.cburch.logisim.data.Location;
public class WireUtil {
private WireUtil() { }
static CircuitPoints computeCircuitPoints(Collection<? extends Component> components) {
CircuitPoints points = new CircuitPoints();
for (Component comp : components) {
points.add(comp);
}
return points;
}
// Merge all parallel endpoint-to-endpoint wires within the given set.
public static Collection<? extends Component> mergeExclusive(Collection<? extends Component> toMerge) {
if (toMerge.size() <= 1) {
return toMerge;
}
HashSet<Component> ret = new HashSet<Component>(toMerge);
CircuitPoints points = computeCircuitPoints(toMerge);
HashSet<Wire> wires = new HashSet<Wire>();
for (Location loc : points.getSplitLocations()) {
Collection<? extends Component> at = points.getComponents(loc);
if (at.size() == 2) {
Iterator<? extends Component> atIt = at.iterator();
Component o0 = atIt.next();
Component o1 = atIt.next();
if (o0 instanceof Wire && o1 instanceof Wire) {
Wire w0 = (Wire) o0;
Wire w1 = (Wire) o1;
if (w0.is_x_equal == w1.is_x_equal) {
wires.add(w0);
wires.add(w1);
}
}
}
}
points = null;
ret.removeAll(wires);
while (!wires.isEmpty()) {
Iterator<Wire> it = wires.iterator();
Wire w = it.next();
Location e0 = w.e0;
Location e1 = w.e1;
it.remove();
boolean found;
do {
found = false;
for (it = wires.iterator(); it.hasNext(); ) {
Wire cand = it.next();
if (cand.e0.equals(e1)) {
e1 = cand.e1;
found = true;
it.remove();
} else if (cand.e1.equals(e0)) {
e0 = cand.e0;
found = true;
it.remove();
}
}
} while (found);
ret.add(Wire.create(e0, e1));
}
return ret;
}
}