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Apache Lucene (module: spatial3d)
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.lucene.spatial3d.geom;
import java.util.ArrayList;
import java.util.BitSet;
import java.util.List;
import java.util.HashMap;
import java.util.Map;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
/**
* GeoConvexPolygon objects are generic building blocks of more complex structures.
* The only restrictions on these objects are: (1) they must be convex; (2) they must have
* a maximum extent no larger than PI. Violating either one of these limits will
* cause the logic to fail.
*
* @lucene.internal
*/
class GeoConvexPolygon extends GeoBasePolygon {
/** The list of polygon points */
protected final List points;
/** A bitset describing, for each edge, whether it is internal or not */
protected final BitSet isInternalEdges;
/** The list of holes. If a point is in the hole, it is *not* in the polygon */
protected final List holes;
/** A list of edges */
protected SidedPlane[] edges = null;
/** The set of notable points for each edge */
protected GeoPoint[][] notableEdgePoints = null;
/** A point which is on the boundary of the polygon */
protected GeoPoint[] edgePoints = null;
/** Set to true when the polygon is complete */
protected boolean isDone = false;
/** A bounds object for each sided plane */
protected Map eitherBounds = null;
/** Map from edge to its previous non-coplanar brother */
protected Map prevBrotherMap = null;
/** Map from edge to its next non-coplanar brother */
protected Map nextBrotherMap = null;
/**
* Create a convex polygon from a list of points. The first point must be on the
* external edge.
*@param planetModel is the planet model.
*@param pointList is the list of points to create the polygon from.
*/
public GeoConvexPolygon(final PlanetModel planetModel, final List pointList) {
this(planetModel, pointList, null);
}
/**
* Create a convex polygon from a list of points. The first point must be on the
* external edge.
*@param planetModel is the planet model.
*@param pointList is the list of points to create the polygon from.
*@param holes is the list of GeoPolygon objects that describe holes in the complex polygon. Null == no holes.
*/
public GeoConvexPolygon(final PlanetModel planetModel, final List pointList, final List holes) {
super(planetModel);
this.points = pointList;
if (holes != null && holes.size() == 0) {
this.holes = null;
} else {
this.holes = holes;
}
this.isInternalEdges = new BitSet();
done(false);
}
/**
* Create a convex polygon from a list of points, keeping track of which boundaries
* are internal. This is used when creating a polygon as a building block for another shape.
*@param planetModel is the planet model.
*@param pointList is the set of points to create the polygon from.
*@param internalEdgeFlags is a bitset describing whether each edge is internal or not.
*@param returnEdgeInternal is true when the final return edge is an internal one.
*/
public GeoConvexPolygon(final PlanetModel planetModel,
final List pointList,
final BitSet internalEdgeFlags,
final boolean returnEdgeInternal) {
this(planetModel, pointList, null, internalEdgeFlags, returnEdgeInternal);
}
/**
* Create a convex polygon from a list of points, keeping track of which boundaries
* are internal. This is used when creating a polygon as a building block for another shape.
*@param planetModel is the planet model.
*@param pointList is the set of points to create the polygon from.
*@param holes is the list of GeoPolygon objects that describe holes in the complex polygon. Null == no holes.
*@param internalEdgeFlags is a bitset describing whether each edge is internal or not.
*@param returnEdgeInternal is true when the final return edge is an internal one.
*/
public GeoConvexPolygon(final PlanetModel planetModel,
final List pointList,
final List holes,
final BitSet internalEdgeFlags,
final boolean returnEdgeInternal) {
super(planetModel);
this.points = pointList;
if (holes != null && holes.size() == 0) {
this.holes = null;
} else {
this.holes = holes;
}
this.isInternalEdges = internalEdgeFlags;
done(returnEdgeInternal);
}
/**
* Create a convex polygon, with a starting latitude and longitude.
* Accepts only values in the following ranges: lat: {@code -PI/2 -> PI/2}, lon: {@code -PI -> PI}
*@param planetModel is the planet model.
*@param startLatitude is the latitude of the first point.
*@param startLongitude is the longitude of the first point.
*/
public GeoConvexPolygon(final PlanetModel planetModel,
final double startLatitude,
final double startLongitude) {
this(planetModel, startLatitude, startLongitude, null);
}
/**
* Create a convex polygon, with a starting latitude and longitude.
* Accepts only values in the following ranges: lat: {@code -PI/2 -> PI/2}, lon: {@code -PI -> PI}
*@param planetModel is the planet model.
*@param startLatitude is the latitude of the first point.
*@param startLongitude is the longitude of the first point.
*@param holes is the list of GeoPolygon objects that describe holes in the complex polygon. Null == no holes.
*/
public GeoConvexPolygon(final PlanetModel planetModel,
final double startLatitude,
final double startLongitude,
final List holes) {
super(planetModel);
points = new ArrayList<>();
if (holes != null && holes.size() == 0) {
this.holes = null;
} else {
this.holes = holes;
}
isInternalEdges = new BitSet();
points.add(new GeoPoint(planetModel, startLatitude, startLongitude));
}
/**
* Add a point to the polygon.
* Accepts only values in the following ranges: lat: {@code -PI/2 -> PI/2}, lon: {@code -PI -> PI}
*
* @param latitude is the latitude of the next point.
* @param longitude is the longitude of the next point.
* @param isInternalEdge is true if the edge just added with this point should be considered "internal", and not
* intersected as part of the intersects() operation.
*/
public void addPoint(final double latitude, final double longitude, final boolean isInternalEdge) {
if (isDone)
throw new IllegalStateException("Can't call addPoint() if done() already called");
if (isInternalEdge)
isInternalEdges.set(points.size() - 1);
points.add(new GeoPoint(planetModel, latitude, longitude));
}
/**
* Finish the polygon, by connecting the last added point with the starting point.
*@param isInternalReturnEdge is true if the return edge (back to start) is an internal one.
*/
public void done(final boolean isInternalReturnEdge) {
if (isDone)
throw new IllegalStateException("Can't call done() more than once");
// If fewer than 3 points, can't do it.
if (points.size() < 3)
throw new IllegalArgumentException("Polygon needs at least three points.");
if (isInternalReturnEdge)
isInternalEdges.set(points.size() - 1);
isDone = true;
// Time to construct the planes. If the polygon is truly convex, then any adjacent point
// to a segment can provide an interior measurement.
edges = new SidedPlane[points.size()];
notableEdgePoints = new GeoPoint[points.size()][];
for (int i = 0; i < points.size(); i++) {
final GeoPoint start = points.get(i);
final GeoPoint end = points.get(legalIndex(i + 1));
// We have to find the next point that is not on the plane between start and end.
// If there is no such point, it's an error.
final Plane planeToFind = new Plane(start, end);
int endPointIndex = -1;
for (int j = 0; j < points.size(); j++) {
final int index = legalIndex(j + i + 2);
if (!planeToFind.evaluateIsZero(points.get(index))) {
endPointIndex = index;
break;
}
}
if (endPointIndex == -1) {
throw new IllegalArgumentException("Polygon points are all coplanar: "+points);
}
final GeoPoint check = points.get(endPointIndex);
final SidedPlane sp = new SidedPlane(check, start, end);
edges[i] = sp;
notableEdgePoints[i] = new GeoPoint[]{start, end};
}
// For each edge, create a bounds object.
eitherBounds = new HashMap<>(edges.length);
prevBrotherMap = new HashMap<>(edges.length);
nextBrotherMap = new HashMap<>(edges.length);
for (int edgeIndex = 0; edgeIndex < edges.length; edgeIndex++) {
final SidedPlane edge = edges[edgeIndex];
int bound1Index = legalIndex(edgeIndex+1);
while (edges[bound1Index].isNumericallyIdentical(edge)) {
if (bound1Index == edgeIndex) {
throw new IllegalArgumentException("Constructed planes are all coplanar: "+points);
}
bound1Index = legalIndex(bound1Index + 1);
}
int bound2Index = legalIndex(edgeIndex-1);
// Look for bound2
while (edges[bound2Index].isNumericallyIdentical(edge)) {
if (bound2Index == edgeIndex) {
throw new IllegalArgumentException("Constructed planes are all coplanar: "+points);
}
bound2Index = legalIndex(bound2Index - 1);
}
// Also confirm that all interior points are within the bounds
int startingIndex = bound2Index;
while (true) {
startingIndex = legalIndex(startingIndex+1);
if (startingIndex == bound1Index) {
break;
}
final GeoPoint interiorPoint = points.get(startingIndex);
if (!edges[bound1Index].isWithin(interiorPoint) || !edges[bound2Index].isWithin(interiorPoint)) {
throw new IllegalArgumentException("Convex polygon has a side that is more than 180 degrees");
}
}
eitherBounds.put(edge, new EitherBound(edges[bound1Index], edges[bound2Index]));
// When we are done with this cycle, we'll need to build the intersection bound for each edge and its brother.
// For now, keep track of the relationships.
nextBrotherMap.put(edge, edges[bound1Index]);
prevBrotherMap.put(edge, edges[bound2Index]);
}
// Pick an edge point arbitrarily from the outer polygon. Glom this together with all edge points from
// inner polygons.
int edgePointCount = 1;
if (holes != null) {
for (final GeoPolygon hole : holes) {
edgePointCount += hole.getEdgePoints().length;
}
}
edgePoints = new GeoPoint[edgePointCount];
edgePointCount = 0;
edgePoints[edgePointCount++] = points.get(0);
if (holes != null) {
for (final GeoPolygon hole : holes) {
final GeoPoint[] holeEdgePoints = hole.getEdgePoints();
for (final GeoPoint p : holeEdgePoints) {
edgePoints[edgePointCount++] = p;
}
}
}
if (isWithinHoles(points.get(0))) {
throw new IllegalArgumentException("Polygon edge intersects a polygon hole; not allowed");
}
}
/** Check if a point is within the provided holes.
*@param point point to check.
*@return true if the point is within any of the holes.
*/
protected boolean isWithinHoles(final GeoPoint point) {
if (holes != null) {
for (final GeoPolygon hole : holes) {
if (!hole.isWithin(point)) {
return true;
}
}
}
return false;
}
/** Compute a legal point index from a possibly illegal one, that may have wrapped.
*@param index is the index.
*@return the normalized index.
*/
protected int legalIndex(int index) {
while (index >= points.size()) {
index -= points.size();
}
while (index < 0) {
index += points.size();
}
return index;
}
/**
* Constructor for deserialization.
* @param planetModel is the planet model.
* @param inputStream is the input stream.
*/
public GeoConvexPolygon(final PlanetModel planetModel, final InputStream inputStream) throws IOException {
super(planetModel);
this.points = java.util.Arrays.asList(SerializableObject.readPointArray(planetModel, inputStream));
final List holes = java.util.Arrays.asList(SerializableObject.readPolygonArray(planetModel, inputStream));
if (holes != null && holes.size() == 0) {
this.holes = null;
} else {
this.holes = holes;
}
this.isInternalEdges = SerializableObject.readBitSet(inputStream);
done(this.isInternalEdges.get(points.size()-1));
}
@Override
public void write(final OutputStream outputStream) throws IOException {
SerializableObject.writePointArray(outputStream, points);
SerializableObject.writePolygonArray(outputStream, holes);
SerializableObject.writeBitSet(outputStream, isInternalEdges);
}
@Override
public boolean isWithin(final double x, final double y, final double z) {
if (!localIsWithin(x, y, z)) {
return false;
}
if (holes != null) {
for (final GeoPolygon polygon : holes) {
if (!polygon.isWithin(x, y, z)) {
return false;
}
}
}
return true;
}
protected boolean localIsWithin(final Vector v) {
return localIsWithin(v.x, v.y, v.z);
}
protected boolean localIsWithin(final double x, final double y, final double z) {
for (final SidedPlane edge : edges) {
if (!edge.isWithin(x, y, z))
return false;
}
return true;
}
@Override
public GeoPoint[] getEdgePoints() {
return edgePoints;
}
@Override
public boolean intersects(final Plane p, final GeoPoint[] notablePoints, final Membership... bounds) {
//System.err.println("Checking for polygon intersection with plane "+p+"...");
for (int edgeIndex = 0; edgeIndex < edges.length; edgeIndex++) {
final SidedPlane edge = edges[edgeIndex];
final GeoPoint[] points = this.notableEdgePoints[edgeIndex];
if (!isInternalEdges.get(edgeIndex)) {
//System.err.println("Checking convex edge "+edge+" for intersection against plane "+p);
if (edge.intersects(planetModel, p, notablePoints, points, bounds, eitherBounds.get(edge))) {
//System.err.println(" intersects!");
return true;
}
}
}
if (holes != null) {
// Each hole needs to be looked at for intersection too, since a shape can be entirely within the hole
for (final GeoPolygon hole : holes) {
if (hole.intersects(p, notablePoints, bounds)) {
return true;
}
}
}
//System.err.println(" no intersection");
return false;
}
@Override
public boolean intersects(GeoShape shape) {
for (int edgeIndex = 0; edgeIndex < edges.length; edgeIndex++) {
final SidedPlane edge = edges[edgeIndex];
final GeoPoint[] points = this.notableEdgePoints[edgeIndex];
if (!isInternalEdges.get(edgeIndex)) {
if (shape.intersects(edge, points, eitherBounds.get(edge))) {
return true;
}
}
}
if (holes != null) {
for (final GeoPolygon hole : holes) {
if (hole.intersects(shape)) {
return true;
}
}
}
return false;
}
/** A membership implementation representing polygon edges that must apply.
*/
protected static class EitherBound implements Membership {
protected final SidedPlane sideBound1;
protected final SidedPlane sideBound2;
/** Constructor.
* @param sideBound1 is the first side bound.
* @param sideBound2 is the second side bound.
*/
public EitherBound(final SidedPlane sideBound1, final SidedPlane sideBound2) {
this.sideBound1 = sideBound1;
this.sideBound2 = sideBound2;
}
@Override
public boolean isWithin(final Vector v) {
return sideBound1.isWithin(v) && sideBound2.isWithin(v);
}
@Override
public boolean isWithin(final double x, final double y, final double z) {
return sideBound1.isWithin(x,y,z) && sideBound2.isWithin(x,y,z);
}
@Override
public String toString() {
return "(" + sideBound1 + "," + sideBound2 + ")";
}
}
@Override
public void getBounds(Bounds bounds) {
// Because of holes, we don't want to use superclass method
if (localIsWithin(planetModel.NORTH_POLE)) {
bounds.noTopLatitudeBound().noLongitudeBound()
.addPoint(planetModel.NORTH_POLE);
}
if (localIsWithin(planetModel.SOUTH_POLE)) {
bounds.noBottomLatitudeBound().noLongitudeBound()
.addPoint(planetModel.SOUTH_POLE);
}
if (localIsWithin(planetModel.MIN_X_POLE)) {
bounds.addPoint(planetModel.MIN_X_POLE);
}
if (localIsWithin(planetModel.MAX_X_POLE)) {
bounds.addPoint(planetModel.MAX_X_POLE);
}
if (localIsWithin(planetModel.MIN_Y_POLE)) {
bounds.addPoint(planetModel.MIN_Y_POLE);
}
if (localIsWithin(planetModel.MAX_Y_POLE)) {
bounds.addPoint(planetModel.MAX_Y_POLE);
}
// Add all the points and the intersections
for (final GeoPoint point : points) {
bounds.addPoint(point);
}
// Add planes with membership.
for (final SidedPlane edge : edges) {
bounds.addPlane(planetModel, edge, eitherBounds.get(edge));
final SidedPlane nextEdge = nextBrotherMap.get(edge);
bounds.addIntersection(planetModel, edge, nextEdge, prevBrotherMap.get(edge), nextBrotherMap.get(nextEdge));
}
}
@Override
protected double outsideDistance(final DistanceStyle distanceStyle, final double x, final double y, final double z) {
double minimumDistance = Double.POSITIVE_INFINITY;
for (final GeoPoint edgePoint : points) {
final double newDist = distanceStyle.computeDistance(edgePoint, x,y,z);
if (newDist < minimumDistance) {
minimumDistance = newDist;
}
}
for (final SidedPlane edgePlane : edges) {
final double newDist = distanceStyle.computeDistance(planetModel, edgePlane, x, y, z, eitherBounds.get(edgePlane));
if (newDist < minimumDistance) {
minimumDistance = newDist;
}
}
if (holes != null) {
for (final GeoPolygon hole : holes) {
double holeDistance = hole.computeOutsideDistance(distanceStyle, x, y, z);
if (holeDistance != 0.0 && holeDistance < minimumDistance) {
minimumDistance = holeDistance;
}
}
}
return minimumDistance;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof GeoConvexPolygon))
return false;
final GeoConvexPolygon other = (GeoConvexPolygon) o;
if (!super.equals(other))
return false;
if (!other.isInternalEdges.equals(isInternalEdges))
return false;
if (other.holes != null || holes != null) {
if (other.holes == null || holes == null) {
return false;
}
if (!other.holes.equals(holes)) {
return false;
}
}
return (other.points.equals(points));
}
@Override
public int hashCode() {
int result = super.hashCode();
result = 31 * result + points.hashCode();
if (holes != null) {
result = 31 * result + holes.hashCode();
}
return result;
}
@Override
public String toString() {
return "GeoConvexPolygon: {planetmodel=" + planetModel + ", points=" + points + ", internalEdges="+isInternalEdges+((holes== null)?"":", holes=" + holes) + "}";
}
}