lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/GeoS2Shape.java

/*
 * 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.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Fast implementation of a polygon representing S2 geometry cell. There are no checks validating that
 * points are convex therefore users must be provide four points in CCW or the logic will fail.
 *
 * @lucene.internal
 */
class GeoS2Shape extends GeoBasePolygon {

    /** The first point */
    protected final GeoPoint point1;
    /** The second point */
    protected final GeoPoint point2;
    /** The third point */
    protected final GeoPoint point3;
    /** The fourth point */
    protected final GeoPoint point4;

    /** The first plane */
    protected final SidedPlane plane1;
    /** The second plane */
    protected final SidedPlane plane2;
    /** The third plane */
    protected final SidedPlane plane3;
    /** The fourth plane */
    protected final SidedPlane plane4;

    /** Notable points for the first plane */
    protected final GeoPoint[] plane1Points;
    /** Notable points for second plane */
    protected final GeoPoint[] plane2Points;
    /** Notable points for third plane */
    protected final GeoPoint[] plane3Points;
    /** Notable points for fourth plane */
    protected final GeoPoint[] plane4Points;

    /** Edge point for this S2 cell */
    protected final GeoPoint[] edgePoints;

    /**
     * It builds from 4 points given in CCW. It must be convex or logic will fail.
     *
     *@param planetModel is the planet model.
     *@param point1  the first point.
     *@param point2  the second point.
     *@param point3  the third point.
     *@param point4  the four point.
     */
    public GeoS2Shape(final PlanetModel planetModel, GeoPoint point1, GeoPoint point2, GeoPoint point3, GeoPoint point4) {
        super(planetModel);
        this.point1 = point1;
        this.point2 = point2;
        this.point3 = point3;
        this.point4 = point4;

        // Now build the four planes
        this.plane1 = new SidedPlane(point4, point1, point2);
        this.plane2 = new SidedPlane(point1, point2, point3);
        this.plane3 = new SidedPlane(point2, point3, point4);
        this.plane4 = new SidedPlane(point3, point4, point1);

        //collect the notable points for the planes
        this.plane1Points = new GeoPoint[]{point1, point2};
        this.plane2Points = new GeoPoint[]{point2, point3};
        this.plane3Points = new GeoPoint[]{point3, point4};
        this.plane4Points = new GeoPoint[]{point4, point1};

        this.edgePoints = new GeoPoint[]{point1};
    }

    /**
     * Constructor for deserialization.
     * @param planetModel is the planet model.
     * @param inputStream is the input stream.
     */
    public GeoS2Shape(final PlanetModel planetModel, final InputStream inputStream) throws IOException {
        this(planetModel,
                (GeoPoint) SerializableObject.readObject(inputStream),
                (GeoPoint) SerializableObject.readObject(inputStream),
                (GeoPoint) SerializableObject.readObject(inputStream),
                (GeoPoint) SerializableObject.readObject(inputStream));
    }

    @Override
    public void write(final OutputStream outputStream) throws IOException {
        SerializableObject.writeObject(outputStream, point1);
        SerializableObject.writeObject(outputStream, point2);
        SerializableObject.writeObject(outputStream, point3);
        SerializableObject.writeObject(outputStream, point4);
    }


    @Override
    public boolean isWithin(final double x, final double y, final double z) {
        return plane1.isWithin(x, y, z) &&
               plane2.isWithin(x, y, z) &&
               plane3.isWithin(x, y, z) &&
               plane4.isWithin(x, y, z);
    }


    @Override
    public GeoPoint[] getEdgePoints() {
        return edgePoints;
    }

    @Override
    public boolean intersects(final Plane p, final GeoPoint[] notablePoints, final Membership... bounds) {
        return p.intersects(planetModel, plane1, notablePoints, plane1Points, bounds, plane2, plane4) ||
               p.intersects(planetModel, plane2, notablePoints, plane2Points, bounds, plane3, plane1) ||
               p.intersects(planetModel, plane3, notablePoints, plane3Points, bounds, plane4, plane2) ||
               p.intersects(planetModel, plane4, notablePoints, plane4Points, bounds, plane1, plane3);
    }

    @Override
    public boolean intersects(GeoShape geoShape) {
        return geoShape.intersects(plane1, plane1Points, plane2, plane4) ||
               geoShape.intersects(plane2, plane2Points, plane3, plane1) ||
               geoShape.intersects(plane3, plane3Points, plane4, plane2) ||
               geoShape.intersects(plane4, plane4Points, plane1, plane3);
    }

    @Override
    public void getBounds(Bounds bounds) {
        super.getBounds(bounds);
        bounds.addPlane(planetModel, plane1, plane2, plane4)
              .addPlane(planetModel, plane2, plane3, plane1)
              .addPlane(planetModel, plane3, plane4, plane2)
              .addPlane(planetModel, plane4, plane1, plane3)
              .addPoint(point1).addPoint(point2).addPoint(point3).addPoint(point4);
    }

    @Override
    public double outsideDistance(DistanceStyle distanceStyle, double x, double y, double z) {
        final double planeDistance1 = distanceStyle.computeDistance(planetModel, plane1, x,y,z, plane2, plane4);
        final double planeDistance2 = distanceStyle.computeDistance(planetModel, plane2, x,y,z, plane3, plane1);
        final double planeDistance3 = distanceStyle.computeDistance(planetModel, plane3, x,y,z, plane4, plane2);
        final double planeDistance4 = distanceStyle.computeDistance(planetModel, plane4, x,y,z, plane1, plane3);

        final double pointDistance1 = distanceStyle.computeDistance(point1, x,y,z);
        final double pointDistance2 = distanceStyle.computeDistance(point2, x,y,z);
        final double pointDistance3 = distanceStyle.computeDistance(point3, x,y,z);
        final double pointDistance4 = distanceStyle.computeDistance(point4, x,y,z);

        return Math.min(
                Math.min(
                        Math.min(planeDistance1, planeDistance2),
                        Math.min(planeDistance3, planeDistance4)),
                Math.min(
                        Math.min(pointDistance1, pointDistance2),
                        Math.min(pointDistance3, pointDistance4)));
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof GeoS2Shape))
            return false;
        GeoS2Shape other = (GeoS2Shape) o;
        return super.equals(other) && other.point1.equals(point1)
                && other.point2.equals(point2) && other.point3.equals(point3)
                && other.point4.equals(point4);
    }

    @Override
    public int hashCode() {
        int result = super.hashCode();
        result = 31 * result  + point1.hashCode();
        result = 31 * result  + point2.hashCode();
        result = 31 * result  + point3.hashCode();
        result = 31 * result  + point4.hashCode();
        return result;
    }

    @Override
    public String toString() {
        return "GeoS2Shape: {planetmodel="+planetModel+", point1=" + point1 +", point2=" + point2 +", point3=" + point3 +", point4=" + point4+ "}";
    }

}