DisjointOperation.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2022 ISciences LLC
 *
 * 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/export.h>
#include <geos/operation/cluster/AbstractClusterFinder.h>
#include <geos/operation/cluster/GeometryFlattener.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/GeometryFactory.h>
 
namespace geos {
namespace operation {
namespace cluster {
 
class GEOS_DLL DisjointOperation {
public:
    DisjointOperation(AbstractClusterFinder& finder) : m_finder(finder), m_split_inputs(false) {}
 
    void setSplitInputs(bool b) {
        m_split_inputs = b;
    }
 
    template<typename Function>
    std::unique_ptr<geom::Geometry> processDisjointSubsets(const geom::Geometry& g, Function&& f) {
        if (g.getNumGeometries() == 1) {
            return f(g);
        }
 
        auto flattened = m_split_inputs ? operation::cluster::GeometryFlattener::flatten(g.clone()) : g.clone();
        auto clustered = m_finder.clusterToVector(std::move(flattened));
 
        for (auto& subset : clustered) {
            subset = f(*subset);
        }
 
        auto coll = g.getFactory()->createGeometryCollection(std::move(clustered));
 
        return operation::cluster::GeometryFlattener::flatten(std::move(coll));
    }
 
private:
    AbstractClusterFinder& m_finder;
    bool m_split_inputs;
};
 
 
}
}
}