lucene/spatial3d/src/java/org/apache/lucene/spatial3d/geom/GeoBaseAreaShape.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;

/**
 * Base extended areaShape object.
 *
 * @lucene.internal
 */
abstract class GeoBaseAreaShape extends GeoBaseMembershipShape implements GeoAreaShape {

  /**
   * Constructor.
   *
   * @param planetModel is the planet model to use.
   */
  public GeoBaseAreaShape(final PlanetModel planetModel) {
    super(planetModel);
  }

  /** All edgepoints inside shape */
  protected static final int ALL_INSIDE = 0;
  /** Some edgepoints inside shape */
  protected static final int SOME_INSIDE = 1;
  /** No edgepoints inside shape */
  protected static final int NONE_INSIDE = 2;

  /**
   * Determine the relationship between the GeoAreShape and the shape's edgepoints.
   *
   * @param geoShape is the shape.
   * @return the relationship.
   */
  protected int isShapeInsideGeoAreaShape(final GeoShape geoShape) {
    boolean foundOutside = false;
    boolean foundInside = false;
    for (GeoPoint p : geoShape.getEdgePoints()) {
      if (isWithin(p)) {
        foundInside = true;
      } else {
        foundOutside = true;
      }
      if (foundInside && foundOutside) {
        return SOME_INSIDE;
      }
    }
    if (!foundInside && !foundOutside) return NONE_INSIDE;
    if (foundInside && !foundOutside) return ALL_INSIDE;
    if (foundOutside && !foundInside) return NONE_INSIDE;
    return SOME_INSIDE;
  }

  /**
   * Determine the relationship between the GeoAreaShape's edgepoints and the provided shape.
   *
   * @param geoshape is the shape.
   * @return the relationship.
   */
  protected int isGeoAreaShapeInsideShape(final GeoShape geoshape) {
    boolean foundOutside = false;
    boolean foundInside = false;
    for (GeoPoint p : getEdgePoints()) {
      if (geoshape.isWithin(p)) {
        foundInside = true;
      } else {
        foundOutside = true;
      }
      if (foundInside && foundOutside) {
        return SOME_INSIDE;
      }
    }
    if (!foundInside && !foundOutside) {
      return NONE_INSIDE;
    }
    if (foundInside && !foundOutside) {
      return ALL_INSIDE;
    }
    if (foundOutside && !foundInside) {
      return NONE_INSIDE;
    }
    return SOME_INSIDE;
  }

  @Override
  public int getRelationship(GeoShape geoShape) {
    if (!geoShape.getPlanetModel().equals(planetModel)) {
      throw new IllegalArgumentException("Cannot relate shapes with different planet models.");
    }
    final int insideGeoAreaShape = isShapeInsideGeoAreaShape(geoShape);
    if (insideGeoAreaShape == SOME_INSIDE) {
      return GeoArea.OVERLAPS;
    }

    final int insideShape = isGeoAreaShapeInsideShape(geoShape);
    if (insideShape == SOME_INSIDE) {
      return GeoArea.OVERLAPS;
    }

    if (insideGeoAreaShape == ALL_INSIDE && insideShape == ALL_INSIDE) {
      return GeoArea.OVERLAPS;
    }

    if (intersects(geoShape)) {
      return GeoArea.OVERLAPS;
    }

    if (insideGeoAreaShape == ALL_INSIDE) {
      return GeoArea.WITHIN;
    }

    if (insideShape == ALL_INSIDE) {
      return GeoArea.CONTAINS;
    }

    return GeoArea.DISJOINT;
  }
}