OverlayUtil.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2020 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 * 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.
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/geom/Point.h>
#include <geos/geom/Polygon.h>
#include <geos/geom/LineString.h>
#include <geos/geom/Geometry.h>
 
#include <geos/export.h>
 
#include <vector>
#include <memory>
 
// Forward declarations
namespace geos {
namespace geom {
class Coordinate;
class CoordinateSequence;
class Envelope;
class GeometryFactory;
class PrecisionModel;
}
namespace operation {
namespace overlayng {
class InputGeometry;
class OverlayGraph;
}
}
}
 
namespace geos {      // geos.
namespace operation { // geos.operation
namespace overlayng { // geos.operation.overlayng

class GEOS_DLL OverlayUtil {
    using Geometry = geos::geom::Geometry;
    using Coordinate = geos::geom::Coordinate;
    using CoordinateSequence = geos::geom::CoordinateSequence;
    using Envelope = geos::geom::Envelope;
    using Point = geos::geom::Point;
    using LineString = geos::geom::LineString;
    using Polygon = geos::geom::Polygon;
    using GeometryFactory = geos::geom::GeometryFactory;
    using PrecisionModel = geos::geom::PrecisionModel;
 
private:
 
    static constexpr double SAFE_ENV_BUFFER_FACTOR = 0.1;
    static constexpr int SAFE_ENV_GRID_FACTOR = 3;
    static constexpr double AREA_HEURISTIC_TOLERANCE = 0.1;

    static bool resultEnvelope(int opCode, const InputGeometry* inputGeom, const PrecisionModel* pm, Envelope& rsltEnvelope);
    static double safeExpandDistance(const Envelope* env, const PrecisionModel* pm);
    static bool safeEnv(const Envelope* env, const PrecisionModel* pm, Envelope& rsltEnvelope);
 
    static bool isEmpty(const Geometry* geom);

    static bool isDisjoint(const Envelope* envA, const Envelope* envB, const PrecisionModel* pm);
 
    static bool isLess(double v1, double v2, double tol) {
        return v1 <= v2 * (1 + tol);
    };
 
    static bool isGreater(double v1, double v2, double tol) {
        return v1 >= v2 * (1 - tol);
    }
 
 
public:
 
    static bool isFloating(const PrecisionModel* pm);

    static bool clippingEnvelope(int opCode, const InputGeometry* inputGeom, const PrecisionModel* pm, Envelope& rsltEnvelope);

    static bool isEmptyResult(int opCode, const Geometry* a, const Geometry* b, const PrecisionModel* pm);

    static bool isEnvDisjoint(const Geometry* a, const Geometry* b, const PrecisionModel* pm);

    static std::unique_ptr<Geometry> createEmptyResult(int dim, size_t coordDim, const GeometryFactory* geomFact);

    static int resultDimension(int opCode, int dim0, int dim1);

    static uint8_t resultCoordinateDimension(uint8_t coordDim0, uint8_t coordDim1);

    static std::unique_ptr<Geometry> createResultGeometry(
        std::vector<std::unique_ptr<Polygon>>& resultPolyList,
        std::vector<std::unique_ptr<LineString>>& resultLineList,
        std::vector<std::unique_ptr<Point>>& resultPointList,
        const GeometryFactory* geometryFactory);
 
    static std::unique_ptr<Geometry> toLines(OverlayGraph* graph, bool isOutputEdges, const GeometryFactory* geomFact);

    static bool isResultAreaConsistent(
        const Geometry* geom0, const Geometry* geom1,
        int opCode, const Geometry* result);

    static bool round(const Point* pt, const PrecisionModel* pm, Coordinate& rsltCoord);
 
    template<typename T>
    static void moveGeometry(std::vector<std::unique_ptr<T>>& inGeoms, std::vector<std::unique_ptr<Geometry>>& outGeoms)
    {
        static_assert(std::is_base_of<Geometry, T>::value, "");
        for (auto& geom: inGeoms) {
            Geometry* outGeom = static_cast<Geometry*>(geom.release());
            outGeoms.emplace_back(outGeom);
        }
        return;
    }
 
 
};
 
 
} // namespace geos.operation.overlayng
} // namespace geos.operation
} // namespace geos