/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
 * Copyright (C) 2006 Refractions Research Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************
 *
 * Last port: operation/predicate/SegmentIntersectionTester.java r378 (JTS-1.12)
 *
 **********************************************************************/

#include <geos/operation/predicate/SegmentIntersectionTester.h>
#include <geos/geom/LineString.h>
#include <geos/geom/CoordinateSequence.h>
#include <geos/algorithm/LineIntersector.h>

using namespace geos::geom;

namespace geos {
namespace operation {
namespace predicate {

bool
SegmentIntersectionTester::hasIntersectionWithLineStrings(
	const LineString &line,
	const LineString::ConstVect& lines)
{
  hasIntersectionVar = false;
	for (size_t i=0, n=lines.size(); i<n; ++i )
	{
		const LineString *testLine = lines[i];
		hasIntersection(line, *testLine);
		if (hasIntersectionVar) break;
	}
	return hasIntersectionVar;
}

bool
SegmentIntersectionTester::hasIntersection(
	const LineString &line, const LineString &testLine)
{
  typedef std::size_t size_type;

	const CoordinateSequence &seq0 = *(line.getCoordinatesRO());
  size_type seq0size = seq0.getSize();

  const CoordinateSequence &seq1 = *(testLine.getCoordinatesRO());
  size_type seq1size = seq1.getSize();

  for (size_type i = 1; i<seq0size && !hasIntersectionVar; ++i)
	{
    seq0.getAt(i - 1, pt00);
    seq0.getAt(i, pt01);

    for (size_type j = 1; j < seq1size && !hasIntersectionVar; ++j)
		{
      seq1.getAt(j-1, pt10);
      seq1.getAt(j, pt11); 
		
			li.computeIntersection(pt00, pt01, pt10, pt11);
			if (li.hasIntersection()) hasIntersectionVar = true;
		}
	}

	return hasIntersectionVar;
}

bool
SegmentIntersectionTester::hasIntersectionWithEnvelopeFilter(
	const LineString &line, const LineString &testLine)
{
  typedef std::size_t size_type;

	const CoordinateSequence &seq0 = *(line.getCoordinatesRO());
  size_type seq0size = seq0.getSize();

  const CoordinateSequence &seq1 = *(testLine.getCoordinatesRO());
  size_type seq1size = seq1.getSize();

  const Envelope* lineEnv = line.getEnvelopeInternal();

  typedef std::size_t size_type;

  for (size_type i = 1; i<seq1size && !hasIntersectionVar; ++i)
	{
    seq1.getAt(i-1, pt10);
    seq1.getAt(i, pt11); 

    // skip test if segment does not intersect query envelope
    if (! lineEnv->intersects(Envelope(pt10, pt11))) continue;

    for (size_type j = 1; j < seq0size && !hasIntersectionVar; ++j)
		{
      seq0.getAt(j - 1, pt00);
      seq0.getAt(j, pt01);
		
			li.computeIntersection(pt00, pt01, pt10, pt11);
			if (li.hasIntersection()) hasIntersectionVar = true;
		}
	}

	return hasIntersectionVar;
}

} // namespace predicate
} // namespace operation
} // namespace geos