polygonize_polygonizer.h

/******************************************************************************
 * Project:  GDAL
 * Purpose:  Implements The Two-Arm Chains EdgeTracing Algorithm
 * Author:   kikitte.lee
 *
 ******************************************************************************
 * Copyright (c) 2023, kikitte.lee <kikitte.lee@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/
 
#ifndef POLYGONIZE_POLYGONIZER_H_INCLUDED
#define POLYGONIZE_POLYGONIZER_H_INCLUDED
 
// Implements Junhua Teng, Fahui Wang, Yu Liu: An Efficient Algorithm for
// Raster-to-Vector Data Conversion: https://doi.org/10.1080/10824000809480639
 
#include <array>
#include <cstdint>
#include <vector>
#include <limits>
#include <map>
 
#include "cpl_error.h"
#include "ogr_api.h"
 
namespace gdal
{
namespace polygonizer
{
 
using IndexType = std::uint32_t;
using Point = std::array<IndexType, 2>;
using Arc = std::vector<Point>;
 
struct IndexedArc
{
    Arc *poArc;
    std::size_t iIndex;
};
 
struct RPolygon
{
    IndexType iBottomRightRow{0};
    IndexType iBottomRightCol{0};
    // arc object list
    std::vector<Arc *> oArcs{};
    // does arc follows the right-hand rule with
    std::vector<bool> oArcRighthandFollow{};
    // each element is the next arc index of the current arc
    std::vector<std::size_t> oArcConnections{};
 
    RPolygon() = default;
 
    RPolygon(const RPolygon &) = delete;
 
    RPolygon &operator=(const RPolygon &) = delete;
 
    ~RPolygon();
 
    IndexedArc newArc(bool bFollowRighthand);
 
    void setArcConnection(const IndexedArc &oArc, const IndexedArc &oNextArc);
 
    void updateBottomRightPos(IndexType iRow, IndexType iCol);
};
 
struct TwoArm
{
    IndexType iRow{0};
    IndexType iCol{0};
 
    RPolygon *poPolyInside{nullptr};
    RPolygon *poPolyAbove{nullptr};
    RPolygon *poPolyLeft{nullptr};
 
    IndexedArc oArcHorOuter{};
    IndexedArc oArcHorInner{};
    IndexedArc oArcVerInner{};
    IndexedArc oArcVerOuter{};
 
    bool bSolidHorizontal{false};
    bool bSolidVertical{false};
};
 
template <typename DataType> class PolygonReceiver
{
  public:
    PolygonReceiver() = default;
 
    PolygonReceiver(const PolygonReceiver<DataType> &) = delete;
 
    virtual ~PolygonReceiver() = default;
 
    PolygonReceiver<DataType> &
    operator=(const PolygonReceiver<DataType> &) = delete;
 
    virtual void receive(RPolygon *poPolygon, DataType nPolygonCellValue) = 0;
};
 
template <typename PolyIdType, typename DataType> class Polygonizer
{
  public:
    static constexpr PolyIdType THE_OUTER_POLYGON_ID =
        std::numeric_limits<PolyIdType>::max();
 
  private:
    using PolygonMap = std::map<PolyIdType, RPolygon *>;
    using PolygonMapEntry = typename PolygonMap::value_type;
 
    PolyIdType nInvalidPolyId_;
    RPolygon *poTheOuterPolygon_{nullptr};
    PolygonMap oPolygonMap_{};
 
    PolygonReceiver<DataType> *poPolygonReceiver_;
 
    RPolygon *getPolygon(PolyIdType nPolygonId);
 
    RPolygon *createPolygon(PolyIdType nPolygonId);
 
    void destroyPolygon(PolyIdType nPolygonId);
 
  public:
    explicit Polygonizer(PolyIdType nInvalidPolyId,
                         PolygonReceiver<DataType> *poPolygonReceiver);
 
    Polygonizer(const Polygonizer<PolyIdType, DataType> &) = delete;
 
    ~Polygonizer();
 
    Polygonizer<PolyIdType, DataType> &
    operator=(const Polygonizer<PolyIdType, DataType> &) = delete;
 
    RPolygon *getTheOuterPolygon() const
    {
        return poTheOuterPolygon_;
    }
 
    void processLine(const PolyIdType *panThisLineId,
                     const DataType *panLastLineVal, TwoArm *poThisLineArm,
                     TwoArm *poLastLineArm, IndexType nCurrentRow,
                     IndexType nCols);
};
 
template <typename DataType>
class OGRPolygonWriter : public PolygonReceiver<DataType>
{
    OGRLayerH hOutLayer_;
    int iPixValField_;
    double *padfGeoTransform_;
 
    CPLErr eErr_{CE_None};
 
  public:
    OGRPolygonWriter(OGRLayerH hOutLayer, int iPixValField,
                     double *padfGeoTransform);
 
    OGRPolygonWriter(const OGRPolygonWriter<DataType> &) = delete;
 
    ~OGRPolygonWriter() = default;
 
    OGRPolygonWriter<DataType> &
    operator=(const OGRPolygonWriter<DataType> &) = delete;
 
    void receive(RPolygon *poPolygon, DataType nPolygonCellValue) override;
 
    inline CPLErr getErr()
    {
        return eErr_;
    }
};
 
}  // namespace polygonizer
}  // namespace gdal
 
#endif /* POLYGONIZE_POLYGONIZER_H_INCLUDED */