/**
* Computes the closest points on two line segments.
*
* @param line the segment to find the closest point to
* @return a pair of Coordinates which are the closest points on the line segments
*/
public Coordinate[] closestPoints(LineSegment line) {
// test for intersection
Coordinate intPt = intersection(line);
if (intPt != null) {
return new Coordinate[] {intPt, intPt};
}
/**
* if no intersection closest pair contains at least one endpoint. Test each endpoint in turn.
*/
Coordinate[] closestPt = new Coordinate[2];
double minDistance = Double.MAX_VALUE;
double dist;
Coordinate close00 = closestPoint(line.p0);
minDistance = close00.distance(line.p0);
closestPt[0] = close00;
closestPt[1] = line.p0;
Coordinate close01 = closestPoint(line.p1);
dist = close01.distance(line.p1);
if (dist < minDistance) {
minDistance = dist;
closestPt[0] = close01;
closestPt[1] = line.p1;
}
Coordinate close10 = line.closestPoint(p0);
dist = close10.distance(p0);
if (dist < minDistance) {
minDistance = dist;
closestPt[0] = p0;
closestPt[1] = close10;
}
Coordinate close11 = line.closestPoint(p1);
dist = close11.distance(p1);
if (dist < minDistance) {
minDistance = dist;
closestPt[0] = p1;
closestPt[1] = close11;
}
return closestPt;
}
/*
* (non-Javadoc)
*
* @see com.iver.cit.gvsig.gui.cad.snapping.ISnapper#getSnapPoint(Point2D
* point, IGeometry geom,double tolerance, Point2D lastPointEntered)
*/
public Point2D getSnapPoint(
Point2D point, IGeometry geom, double tolerance, Point2D lastPointEntered) {
Point2D resul = null;
Coordinate c = new Coordinate(point.getX(), point.getY());
if (lastPointEntered == null) {
return null;
}
Coordinate cLastPoint = new Coordinate(lastPointEntered.getX(), lastPointEntered.getY());
PathIterator theIterator =
geom.getPathIterator(null, FConverter.FLATNESS); // polyLine.getPathIterator(null,
// flatness);
double[] theData = new double[6];
double minDist = tolerance;
Coordinate from = null;
Coordinate first = null;
while (!theIterator.isDone()) {
// while not done
int theType = theIterator.currentSegment(theData);
switch (theType) {
case PathIterator.SEG_MOVETO:
from = new Coordinate(theData[0], theData[1]);
first = from;
break;
case PathIterator.SEG_LINETO:
// System.out.println("SEG_LINETO");
Coordinate to = new Coordinate(theData[0], theData[1]);
LineSegment line = new LineSegment(from, to);
Coordinate closestPoint = line.closestPoint(cLastPoint);
double dist = c.distance(closestPoint);
if (!(line.getCoordinate(0).equals2D(closestPoint)
|| line.getCoordinate(1).equals2D(closestPoint))) {
if ((dist < minDist)) {
resul = new Point2D.Double(closestPoint.x, closestPoint.y);
minDist = dist;
}
}
from = to;
break;
case PathIterator.SEG_CLOSE:
line = new LineSegment(from, first);
closestPoint = line.closestPoint(cLastPoint);
dist = c.distance(closestPoint);
if (!(line.getCoordinate(0).equals2D(closestPoint)
|| line.getCoordinate(1).equals2D(closestPoint))) {
if ((dist < minDist)) {
resul = new Point2D.Double(closestPoint.x, closestPoint.y);
minDist = dist;
}
}
from = first;
break;
} // end switch
theIterator.next();
}
return resul;
}