/**
* Computes the distance between this and another <code>Envelope</code>. The distance between
* overlapping Envelopes is 0. Otherwise, the distance is the Euclidean distance between the
* closest points.
*/
@Override
public double distance(final Envelope env) {
if (intersects(env)) {
return 0;
}
double dx = 0.0;
if (getMaxX() < env.getMinX()) {
dx = env.getMinX() - getMaxX();
} else if (getMinX() > env.getMaxX()) {
dx = getMinX() - env.getMaxX();
}
double dy = 0.0;
if (getMaxY() < env.getMinY()) {
dy = env.getMinY() - getMaxY();
} else if (getMinY() > env.getMaxY()) {
dy = getMinY() - env.getMaxY();
}
double dz = 0.0;
double otherMinZ = getMinZOf(env);
double otherMaxZ = getMaxZOf(env);
if (maxz < otherMinZ) {
dz = otherMinZ - maxz;
} else if (minz > otherMaxZ) {
dz = minz - otherMaxZ;
}
// if either is zero, the envelopes overlap either vertically or
// horizontally
if (dx == 0.0 && dz == 0.0) {
return dy;
}
if (dy == 0.0 && dz == 0.0) {
return dx;
}
if (dx == 0.0 && dy == 0.0) {
return dz;
}
return Math.sqrt(dx * dx + dy * dy + dz * dz);
}
/**
* Creates a {@link Geometry} with the same extent as the given envelope. The Geometry returned is
* guaranteed to be valid. To provide this behaviour, the following cases occur:
*
* <p>If the <code>Envelope</code> is:
*
* <ul>
* <li>null : returns an empty {@link Point}
* <li>a point : returns a non-empty {@link Point}
* <li>a line : returns a two-point {@link LineString}
* <li>a rectangle : returns a {@link Polygon}> whose points are (minx, miny), (minx, maxy),
* (maxx, maxy), (maxx, miny), (minx, miny).
* </ul>
*
* @param envelope the <code>Envelope</code> to convert
* @return an empty <code>Point</code> (for null <code>Envelope</code>s), a <code>Point</code>
* (when min x = max x and min y = max y) or a <code>Polygon</code> (in all other cases)
*/
public Geometry toGeometry(Envelope envelope) {
// null envelope - return empty point geometry
if (envelope.isNull()) {
return createPoint((CoordinateSequence) null);
}
// point?
if (envelope.getMinX() == envelope.getMaxX() && envelope.getMinY() == envelope.getMaxY()) {
return createPoint(new Coordinate(envelope.getMinX(), envelope.getMinY()));
}
// vertical or horizontal line?
if (envelope.getMinX() == envelope.getMaxX() || envelope.getMinY() == envelope.getMaxY()) {
return createLineString(
new Coordinate[] {
new Coordinate(envelope.getMinX(), envelope.getMinY()),
new Coordinate(envelope.getMaxX(), envelope.getMaxY())
});
}
// create a CW ring for the polygon
return createPolygon(
createLinearRing(
new Coordinate[] {
new Coordinate(envelope.getMinX(), envelope.getMinY()),
new Coordinate(envelope.getMinX(), envelope.getMaxY()),
new Coordinate(envelope.getMaxX(), envelope.getMaxY()),
new Coordinate(envelope.getMaxX(), envelope.getMinY()),
new Coordinate(envelope.getMinX(), envelope.getMinY())
}),
null);
}
/**
* Computes the intersection of two {@link Envelope}s.
*
* @param env the envelope to intersect with
* @return a new Envelope representing the intersection of the envelopes (this will be the null
* envelope if either argument is null, or they do not intersect
*/
@Override
public Envelope3D intersection(final Envelope env) {
if (isNull() || env.isNull() || !intersects(env)) {
return new Envelope3D();
}
Envelope xyInt = super.intersection(env);
double otherMinZ = getMinZOf(env);
double intMinZ = minz > otherMinZ ? minz : otherMinZ;
double otherMaxZ = getMaxZOf(env);
double intMaxZ = maxz < otherMaxZ ? maxz : otherMaxZ;
return new Envelope3D(
xyInt.getMinX(), xyInt.getMaxX(), xyInt.getMinY(), xyInt.getMaxY(), intMinZ, intMaxZ);
}
/**
* Computes the list of envelopes (from 2 to 4, possibily 0 if env covers this) resulting from the
* extrusion of env from this. Only in 2D for the moment. Does not return null envelopes.
*/
public List<Envelope> extrusion(final Envelope env) {
List<Envelope> list = new ArrayList();
double x1 = getMinX();
double x2 = getMaxX();
double y1 = getMinY();
double y2 = getMaxY();
double xx1 = env.getMinX();
double xx2 = env.getMaxX();
double yy1 = env.getMinY();
double yy2 = env.getMaxY();
if (x2 >= x1 && yy1 >= y1) {
list.add(new Envelope(x1, x2, y1, yy1));
}
if (xx1 >= x1 && y2 >= yy1) {
list.add(new Envelope(x1, xx1, yy1, y2));
}
if (x2 >= xx1 && y2 >= yy2) {
list.add(new Envelope(xx1, x2, yy2, y2));
}
if (x2 >= xx2 && yy2 >= yy1) {
list.add(new Envelope(xx2, x2, yy1, yy2));
}
return list;
}
