public Segment2D getLongestEdge() {
EdgeRing edges = getEdges();
Segment2D longestEdge = null;
for (Segment2D edge : edges)
if (longestEdge == null || edge.getLength() > longestEdge.getLength()) longestEdge = edge;
return longestEdge;
}
public double getLengthTo(Point2D p) {
double res = 0;
for (Segment2D s : getEdges()) {
if (s.p0.equals(p)) break;
res += s.getLength();
}
return res;
}
public double getShortestDistance(Point2D p) {
double res = Double.POSITIVE_INFINITY;
for (Segment2D s : getEdges()) {
double d = s.getShortestDistance(p);
if (d < res) res = d;
}
return res;
}
public Polygon(EdgeRing col) {
points = new PointRing();
edges = new EdgeRing(col);
if (!edges.loop())
throw new RuntimeException(
"Can't construct " + this.getClass().getName() + " because edge list is not valid loop.");
for (Segment2D edge : edges) points.add(edge.getStart());
check();
}
public boolean isRectangular(double tolerance) {
EdgeRing edges = getEdges();
for (Segment2D edge : edges) {
double angle =
AngleUtil.getSmallestDifference(edge.getAngle(), edges.getPrevious(edge).getAngle());
if (angle < AngleUtil.RIGHT - tolerance) return false;
if (angle > AngleUtil.RIGHT + tolerance && angle < AngleUtil.FLAT - tolerance) return false;
}
return true;
}
public boolean hasInside(Point2D p) {
if (!isLoop()) return false;
int turn = Angle.NONE;
for (Segment2D s : this) {
int localTurn = Angle.getTurn(s.getStart(), s.getEnd(), p);
if (localTurn == Angle.NONE) return true;
if (turn == Angle.NONE) turn = localTurn;
else if (turn != localTurn) return false;
}
return true;
}
public boolean hasIntersectingDiagonal(Segment2D diagonal) {
for (Segment2D edge : getEdges()) {
if (edge.hasCommonEnd(diagonal)) continue;
if (edge.intersectAtSinglePoint(diagonal)) {
return true;
// Point2D intersection = edge.getUniqueIntersection(diagonal);
// if(diagonal.hasPoint(intersection))
// continue;
// else
// return true;
}
}
return false;
}
public OrientedBoundingBox getMinimumBoundingBox() {
if (obb == null) {
double minArea = Double.POSITIVE_INFINITY;
for (Segment2D s : getEdges()) {
OrientedBoundingBox b = new OrientedBoundingBox(points, s.getAngle());
if (b.getArea() < minArea) {
minArea = b.getArea();
obb = b;
}
}
if (obb == null) throw new RuntimeException("Unexpected Error.");
}
return obb;
}
/*
* Code from Computational Geometry Library
*/
public boolean hasInternalDiagonal(Segment2D diagonal) {
Point2D sum = diagonal.getEnd();
Point2D base = diagonal.getStart();
Point2D previous = points.getPrevious(base);
Point2D next = points.getNext(base);
int turn = AngleUtil.getTurn(previous, base, next);
if (turn == AngleUtil.CLOCKWISE) {
// At this point, we know that the angle at the base of the diagonal is reflex
return AngleUtil.getTurn(sum, base, previous) == AngleUtil.CLOCKWISE
|| AngleUtil.getTurn(sum, base, next) == AngleUtil.COUNTERCLOCKWISE;
} else if (turn == AngleUtil.COUNTERCLOCKWISE) {
// At this point, we know that the angle at the base of the diagonal is convex
return AngleUtil.getTurn(sum, base, previous) == AngleUtil.CLOCKWISE
&& AngleUtil.getTurn(sum, base, next) == AngleUtil.COUNTERCLOCKWISE;
} else return true;
}
/*
* Split the polygon in two, by the given line. Returns a list of polygons. The first is the one who contains the
* given point.
*/
public ArrayList<Polygon> getSplits(Point2D pointOnLeftSide, Line2D splitLine) {
PointRing left = new PointRing();
PointRing right = new PointRing();
PointRing actual = left;
// we check if the given point is valid for this polygon
if (!points.contains(pointOnLeftSide))
throw new RuntimeException("The specified point can't be found in this polygon.");
Point2D p = pointOnLeftSide;
Point2D start = null;
// TODO, gerer les splits sur un point unique
for (int i = 0; i < size(); i++) {
actual.add(p);
Point2D next = points.getNext(p);
Segment2D edge = new Segment2D(p, next);
if (edge.isCollinear(splitLine))
throw new RuntimeException(
"Trying to split a polygon with a line collinear to one of its edges : " + splitLine);
if (edge.intersect(splitLine)) {
// An intersection point is found
Point2D intersection = edge.getAnyIntersection(splitLine);
// We check if the intersection point is the end of the edge.
// In this case, we continue to the next edge which will have intersection on its start
// point.
if (!intersection.equals(edge.getEnd())) {
// We check if the intersection is on the edge start.
// In this case, we don't add the point to the actual polygon
if (!intersection.equals(edge.getStart())) actual.add(intersection);
// then we switch actual polygon
if (actual == left) {
// we save the point just before the intersection. after the split, we will shift the
// left
// polygon to this point.
start = p;
actual = right;
} else actual = left;
// after switching, we add the intersection to the new actual polygon.
actual.add(intersection);
}
}
p = next;
}
// debug : check if we get only one intersection
if (actual == right)
throw new RuntimeException(
"The polygon have been splitted on an impair number of points, which is not allowed.");
left.shiftTo(start);
ArrayList<Polygon> res = new ArrayList<Polygon>();
res.add(new Polygon(left));
res.add(new Polygon(right));
return res;
}
// TODO verifier le check
private boolean isSimple() {
ArrayList<Segment2D> edges = getEdges();
for (Segment2D e1 : edges) {
for (Segment2D e2 : edges) {
if (e1 == e2) continue;
if (e1.hasCommonEnd(e2)) continue;
if (e1.intersectAtSinglePoint(e2)) {
Point2D intersection = e1.getUniqueIntersection(e2);
if (e1.hasPoint(intersection) || e2.hasPoint(intersection))
continue; // TODO à voir si on autorise le cas des edges qui se touchent mais ne se
// croisent pas
// (gestion des trous)
else return false;
}
}
}
return true;
}
public Polyline2D getTransformed(Transform2D transform) {
Polyline2D res = new Polyline2D();
for (Segment2D s : this) res.add(s.getTransformed(transform));
return res;
}
public boolean contains(Point2D p) {
for (Segment2D s : this) if (s.contains(p)) return true;
return false;
}
public boolean hasInside(Point2D p) {
for (Segment2D s : getEdges())
if (AngleUtil.getTurn(s.getStart(), s.getEnd(), p) != AngleUtil.COUNTERCLOCKWISE)
return false;
return true;
}
/*
* returns the cumulated lengthes of all edges.
*/
public double getLength() {
double res = 0;
for (Segment2D s : getEdges()) res += s.getLength();
return res;
}