public static void resolveLinks(Vector subcurves, Vector chains, Vector links) {
int numlinks = links.size();
CurveLink[] linklist;
if (numlinks == 0) {
linklist = EmptyLinkList;
} else {
if ((numlinks & 1) != 0) {
throw new RuntimeException("Odd number of new curves!");
}
linklist = new CurveLink[numlinks + 2];
links.toArray(linklist);
}
int numchains = chains.size();
ChainEnd[] endlist;
if (numchains == 0) {
endlist = EmptyChainList;
} else {
if ((numchains & 1) != 0) {
throw new RuntimeException("Odd number of chains!");
}
endlist = new ChainEnd[numchains + 2];
chains.toArray(endlist);
}
int curchain = 0;
int curlink = 0;
chains.clear();
ChainEnd chain = endlist[0];
ChainEnd nextchain = endlist[1];
CurveLink link = linklist[0];
CurveLink nextlink = linklist[1];
while (chain != null || link != null) {
/*
* Strategy 1:
* Connect chains or links if they are the only things left...
*/
boolean connectchains = (link == null);
boolean connectlinks = (chain == null);
if (!connectchains && !connectlinks) {
// assert(link != null && chain != null);
/*
* Strategy 2:
* Connect chains or links if they close off an open area...
*/
connectchains = ((curchain & 1) == 0 && chain.getX() == nextchain.getX());
connectlinks = ((curlink & 1) == 0 && link.getX() == nextlink.getX());
if (!connectchains && !connectlinks) {
/*
* Strategy 3:
* Connect chains or links if their successor is
* between them and their potential connectee...
*/
double cx = chain.getX();
double lx = link.getX();
connectchains =
(nextchain != null && cx < lx && obstructs(nextchain.getX(), lx, curchain));
connectlinks = (nextlink != null && lx < cx && obstructs(nextlink.getX(), cx, curlink));
}
}
if (connectchains) {
CurveLink subcurve = chain.linkTo(nextchain);
if (subcurve != null) {
subcurves.add(subcurve);
}
curchain += 2;
chain = endlist[curchain];
nextchain = endlist[curchain + 1];
}
if (connectlinks) {
ChainEnd openend = new ChainEnd(link, null);
ChainEnd closeend = new ChainEnd(nextlink, openend);
openend.setOtherEnd(closeend);
chains.add(openend);
chains.add(closeend);
curlink += 2;
link = linklist[curlink];
nextlink = linklist[curlink + 1];
}
if (!connectchains && !connectlinks) {
// assert(link != null);
// assert(chain != null);
// assert(chain.getEtag() == link.getEtag());
chain.addLink(link);
chains.add(chain);
curchain++;
chain = nextchain;
nextchain = endlist[curchain + 1];
curlink++;
link = nextlink;
nextlink = linklist[curlink + 1];
}
}
}
private Vector pruneEdges(Vector edges) {
int numedges = edges.size();
if (numedges < 2) {
return edges;
}
Edge[] edgelist = (Edge[]) edges.toArray(new Edge[numedges]);
Arrays.sort(edgelist, YXTopComparator);
Edge e;
int left = 0;
int right = 0;
int cur = 0;
int next = 0;
double yrange[] = new double[2];
Vector subcurves = new Vector();
Vector chains = new Vector();
Vector links = new Vector();
// Active edges are between left (inclusive) and right (exclusive)
while (left < numedges) {
double y = yrange[0];
// Prune active edges that fall off the top of the active y range
for (cur = next = right - 1; cur >= left; cur--) {
e = edgelist[cur];
if (e.getCurve().getYBot() > y) {
if (next > cur) {
edgelist[next] = e;
}
next--;
}
}
left = next + 1;
// Grab a new "top of Y range" if the active edges are empty
if (left >= right) {
if (right >= numedges) {
break;
}
y = edgelist[right].getCurve().getYTop();
if (y > yrange[0]) {
finalizeSubCurves(subcurves, chains);
}
yrange[0] = y;
}
// Incorporate new active edges that enter the active y range
while (right < numedges) {
e = edgelist[right];
if (e.getCurve().getYTop() > y) {
break;
}
right++;
}
// Sort the current active edges by their X values and
// determine the maximum valid Y range where the X ordering
// is correct
yrange[1] = edgelist[left].getCurve().getYBot();
if (right < numedges) {
y = edgelist[right].getCurve().getYTop();
if (yrange[1] > y) {
yrange[1] = y;
}
}
// Note: We could start at left+1, but we need to make
// sure that edgelist[left] has its equivalence set to 0.
int nexteq = 1;
for (cur = left; cur < right; cur++) {
e = edgelist[cur];
e.setEquivalence(0);
for (next = cur; next > left; next--) {
Edge prevedge = edgelist[next - 1];
int ordering = e.compareTo(prevedge, yrange);
if (yrange[1] <= yrange[0]) {
throw new RuntimeException("backstepping to " + yrange[1] + " from " + yrange[0]);
}
if (ordering >= 0) {
if (ordering == 0) {
// If the curves are equal, mark them to be
// deleted later if they cancel each other
// out so that we avoid having extraneous
// curve segments.
int eq = prevedge.getEquivalence();
if (eq == 0) {
eq = nexteq++;
prevedge.setEquivalence(eq);
}
e.setEquivalence(eq);
}
break;
}
edgelist[next] = prevedge;
}
edgelist[next] = e;
}
// Now prune the active edge list.
// For each edge in the list, determine its classification
// (entering shape, exiting shape, ignore - no change) and
// record the current Y range and its classification in the
// Edge object for use later in constructing the new outline.
newRow();
double ystart = yrange[0];
double yend = yrange[1];
for (cur = left; cur < right; cur++) {
e = edgelist[cur];
int etag;
int eq = e.getEquivalence();
if (eq != 0) {
// Find one of the segments in the "equal" range
// with the right transition state and prefer an
// edge that was either active up until ystart
// or the edge that extends the furthest downward
// (i.e. has the most potential for continuation)
int origstate = getState();
etag = (origstate == AreaOp.RSTAG_INSIDE ? AreaOp.ETAG_EXIT : AreaOp.ETAG_ENTER);
Edge activematch = null;
Edge longestmatch = e;
double furthesty = yend;
do {
// Note: classify() must be called
// on every edge we consume here.
classify(e);
if (activematch == null && e.isActiveFor(ystart, etag)) {
activematch = e;
}
y = e.getCurve().getYBot();
if (y > furthesty) {
longestmatch = e;
furthesty = y;
}
} while (++cur < right && (e = edgelist[cur]).getEquivalence() == eq);
--cur;
if (getState() == origstate) {
etag = AreaOp.ETAG_IGNORE;
} else {
e = (activematch != null ? activematch : longestmatch);
}
} else {
etag = classify(e);
}
if (etag != AreaOp.ETAG_IGNORE) {
e.record(yend, etag);
links.add(new CurveLink(e.getCurve(), ystart, yend, etag));
}
}
// assert(getState() == AreaOp.RSTAG_OUTSIDE);
if (getState() != AreaOp.RSTAG_OUTSIDE) {
System.out.println("Still inside at end of active edge list!");
System.out.println("num curves = " + (right - left));
System.out.println("num links = " + links.size());
System.out.println("y top = " + yrange[0]);
if (right < numedges) {
System.out.println("y top of next curve = " + edgelist[right].getCurve().getYTop());
} else {
System.out.println("no more curves");
}
for (cur = left; cur < right; cur++) {
e = edgelist[cur];
System.out.println(e);
int eq = e.getEquivalence();
if (eq != 0) {
System.out.println(" was equal to " + eq + "...");
}
}
}
resolveLinks(subcurves, chains, links);
links.clear();
// Finally capture the bottom of the valid Y range as the top
// of the next Y range.
yrange[0] = yend;
}
finalizeSubCurves(subcurves, chains);
Vector ret = new Vector();
Enumeration enum_ = subcurves.elements();
while (enum_.hasMoreElements()) {
CurveLink link = (CurveLink) enum_.nextElement();
ret.add(link.getMoveto());
CurveLink nextlink = link;
while ((nextlink = nextlink.getNext()) != null) {
if (!link.absorb(nextlink)) {
ret.add(link.getSubCurve());
link = nextlink;
}
}
ret.add(link.getSubCurve());
}
return ret;
}