
/*
 * Copyright (c) 2016 Vivid Solutions.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.precision;

import org.locationtech.jts.geom.Geometry;

/**
  * Provides versions of Geometry spatial functions which use
  * enhanced precision techniques to reduce the likelihood of robustness problems.
 *
 * @version 1.7
 */
public class EnhancedPrecisionOp
{
  /**
   * Computes the set-theoretic intersection of two {@link Geometry}s, using enhanced precision.
   * @param geom0 the first Geometry
   * @param geom1 the second Geometry
   * @return the Geometry representing the set-theoretic intersection of the input Geometries.
   */
  public static Geometry intersection(Geometry geom0, Geometry geom1)
  {
    RuntimeException originalEx;
    try {
      Geometry result = geom0.intersection(geom1);
      return result;
    }
    catch (RuntimeException ex)
    {
      originalEx = ex;
    }
    /*
     * If we are here, the original op encountered a precision problem
     * (or some other problem).  Retry the operation with
     * enhanced precision to see if it succeeds
     */
    try {
      CommonBitsOp cbo = new CommonBitsOp(true);
      Geometry resultEP = cbo.intersection(geom0, geom1);
      // check that result is a valid geometry after the reshift to original precision
      if (! resultEP.isValid())
        throw originalEx;
      return resultEP;
    }
    catch (RuntimeException ex2)
    {
      throw originalEx;
    }
  }
  /**
   * Computes the set-theoretic union of two {@link Geometry}s, using enhanced precision.
   * @param geom0 the first Geometry
   * @param geom1 the second Geometry
   * @return the Geometry representing the set-theoretic union of the input Geometries.
   */
  public static Geometry union(Geometry geom0, Geometry geom1)
  {
    RuntimeException originalEx;
    try {
      Geometry result = geom0.union(geom1);
      return result;
    }
    catch (RuntimeException ex)
    {
      originalEx = ex;
    }
    /*
     * If we are here, the original op encountered a precision problem
     * (or some other problem).  Retry the operation with
     * enhanced precision to see if it succeeds
     */
    try {
      CommonBitsOp cbo = new CommonBitsOp(true);
      Geometry resultEP = cbo.union(geom0, geom1);
      // check that result is a valid geometry after the reshift to original precision
      if (! resultEP.isValid())
        throw originalEx;
      return resultEP;
    }
    catch (RuntimeException ex2)
    {
      throw originalEx;
    }
  }
  /**
   * Computes the set-theoretic difference of two {@link Geometry}s, using enhanced precision.
   * @param geom0 the first Geometry
   * @param geom1 the second Geometry
   * @return the Geometry representing the set-theoretic difference of the input Geometries.
   */
  public static Geometry difference(Geometry geom0, Geometry geom1)
  {
    RuntimeException originalEx;
    try {
      Geometry result = geom0.difference(geom1);
      return result;
    }
    catch (RuntimeException ex)
    {
      originalEx = ex;
    }
    /*
     * If we are here, the original op encountered a precision problem
     * (or some other problem).  Retry the operation with
     * enhanced precision to see if it succeeds
     */
    try {
      CommonBitsOp cbo = new CommonBitsOp(true);
      Geometry resultEP = cbo.difference(geom0, geom1);
      // check that result is a valid geometry after the reshift to original precision
      if (! resultEP.isValid())
        throw originalEx;
      return resultEP;
    }
    catch (RuntimeException ex2)
    {
      throw originalEx;
    }
  }
  /**
   * Computes the set-theoretic symmetric difference of two {@link Geometry}s, using enhanced precision.
   * @param geom0 the first Geometry
   * @param geom1 the second Geometry
   * @return the Geometry representing the set-theoretic symmetric difference of the input Geometries.
   */
  public static Geometry symDifference(Geometry geom0, Geometry geom1)
  {
    RuntimeException originalEx;
    try {
      Geometry result = geom0.symDifference(geom1);
      return result;
    }
    catch (RuntimeException ex)
    {
      originalEx = ex;
    }
    /*
     * If we are here, the original op encountered a precision problem
     * (or some other problem).  Retry the operation with
     * enhanced precision to see if it succeeds
     */
    try {
      CommonBitsOp cbo = new CommonBitsOp(true);
      Geometry resultEP = cbo.symDifference(geom0, geom1);
      // check that result is a valid geometry after the reshift to original precision
      if (! resultEP.isValid())
        throw originalEx;
      return resultEP;
    }
    catch (RuntimeException ex2)
    {
      throw originalEx;
    }
  }
  /**
   * Computes the buffer of a {@link Geometry}, using enhanced precision.
   * This method should no longer be necessary, since the buffer algorithm
   * now is highly robust.
   *
   * @param geom the first Geometry
   * @param distance the buffer distance
   * @return the Geometry representing the buffer of the input Geometry.
   */
  public static Geometry buffer(Geometry geom, double distance)
  {
    RuntimeException originalEx;
    try {
      Geometry result = geom.buffer(distance);
      return result;
    }
    catch (RuntimeException ex)
    {
      originalEx = ex;
    }
    /*
     * If we are here, the original op encountered a precision problem
     * (or some other problem).  Retry the operation with
     * enhanced precision to see if it succeeds
     */
    try {
      CommonBitsOp cbo = new CommonBitsOp(true);
      Geometry resultEP = cbo.buffer(geom, distance);
      // check that result is a valid geometry after the reshift to original precision
      if (! resultEP.isValid())
        throw originalEx;
      return resultEP;
    }
    catch (RuntimeException ex2)
    {
      throw originalEx;
    }
  }

}
