/******************************************************************************
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements translation of Shapefile shapes into OGR
 *           representation.
 * Author:   Frank Warmerdam, warmerda@home.com
 *
 ******************************************************************************
 * Copyright (c) 1999,  Les Technologies SoftMap Inc.
 * Copyright (c) 2007-2013, Even Rouault <even dot rouault at spatialys.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.
 ****************************************************************************/

#include "cpl_port.h"
#include "ogrshape.h"

#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <limits>
#include <memory>

#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_string.h"
#include "ogr_core.h"
#include "ogr_feature.h"
#include "ogr_geometry.h"
#include "ogrpgeogeometry.h"
#include "ogrshape.h"
#include "shapefil.h"

CPL_CVSID("$Id: shape2ogr.cpp b1c9c12ad373e40b955162b45d704070d4ebf7b0 2019-06-19 16:50:15 +0200 Even Rouault $")

/************************************************************************/
/*                        RingStartEnd                                  */
/*        Set first and last vertex for given ring.                     */
/************************************************************************/
static void RingStartEnd( SHPObject *psShape, int ring, int *start, int *end )
{
    if( psShape->panPartStart == nullptr )
    {
        *start = 0;
        *end = psShape->nVertices - 1;
    }
    else
    {
        *start = psShape->panPartStart[ring];

        if( ring == psShape->nParts - 1 )
            *end = psShape->nVertices - 1;
        else
            *end = psShape->panPartStart[ring+1] - 1;
    }
}

/************************************************************************/
/*                        CreateLinearRing                              */
/************************************************************************/
static OGRLinearRing * CreateLinearRing(
    SHPObject *psShape, int ring, bool bHasZ, bool bHasM )
{
    int nRingStart = 0;
    int nRingEnd = 0;
    RingStartEnd( psShape, ring, &nRingStart, &nRingEnd );

    OGRLinearRing * const poRing = new OGRLinearRing();
    if( !(nRingEnd >= nRingStart) )
        return poRing;

    const int nRingPoints = nRingEnd - nRingStart + 1;

    if( bHasZ && bHasM )
        poRing->setPoints(
            nRingPoints, psShape->padfX + nRingStart,
            psShape->padfY + nRingStart,
            psShape->padfZ + nRingStart,
            psShape->padfM ? psShape->padfM + nRingStart : nullptr );
    else if( bHasM )
        poRing->setPointsM(
            nRingPoints, psShape->padfX + nRingStart,
            psShape->padfY + nRingStart,
            psShape->padfM ? psShape->padfM + nRingStart :nullptr );
    else
        poRing->setPoints(
            nRingPoints, psShape->padfX + nRingStart,
            psShape->padfY + nRingStart );

    return poRing;
}

/************************************************************************/
/*                          SHPReadOGRObject()                          */
/*                                                                      */
/*      Read an item in a shapefile, and translate to OGR geometry      */
/*      representation.                                                 */
/************************************************************************/

OGRGeometry *SHPReadOGRObject( SHPHandle hSHP, int iShape, SHPObject *psShape )
{
#if DEBUG_VERBOSE
    CPLDebug( "Shape", "SHPReadOGRObject( iShape=%d )", iShape );
#endif

    if( psShape == nullptr )
        psShape = SHPReadObject( hSHP, iShape );

    if( psShape == nullptr )
    {
        return nullptr;
    }

    OGRGeometry *poOGR = nullptr;

/* -------------------------------------------------------------------- */
/*      Point.                                                          */
/* -------------------------------------------------------------------- */
    if( psShape->nSHPType == SHPT_POINT )
    {
        poOGR = new OGRPoint( psShape->padfX[0], psShape->padfY[0] );
    }
    else if(psShape->nSHPType == SHPT_POINTZ )
    {
        if( psShape->bMeasureIsUsed )
        {
            poOGR = new OGRPoint( psShape->padfX[0], psShape->padfY[0],
                                  psShape->padfZ[0], psShape->padfM[0] );
        }
        else
        {
            poOGR = new OGRPoint( psShape->padfX[0], psShape->padfY[0],
                                  psShape->padfZ[0] );
        }
    }
    else if( psShape->nSHPType == SHPT_POINTM )
    {
        poOGR = new OGRPoint( psShape->padfX[0], psShape->padfY[0],
                              0.0, psShape->padfM[0] );
        poOGR->set3D(FALSE);
    }
/* -------------------------------------------------------------------- */
/*      Multipoint.                                                     */
/* -------------------------------------------------------------------- */
    else if( psShape->nSHPType == SHPT_MULTIPOINT
             || psShape->nSHPType == SHPT_MULTIPOINTM
             || psShape->nSHPType == SHPT_MULTIPOINTZ )
    {
        if( psShape->nVertices == 0 )
        {
            poOGR = nullptr;
        }
        else
        {
            OGRMultiPoint *poOGRMPoint = new OGRMultiPoint();

            for( int i = 0; i < psShape->nVertices; i++ )
            {
                OGRPoint *poPoint = nullptr;

                if( psShape->nSHPType == SHPT_MULTIPOINTZ )
                {
                    if( psShape->padfM )
                    {
                        poPoint = new OGRPoint(
                            psShape->padfX[i], psShape->padfY[i],
                            psShape->padfZ[i], psShape->padfM[i] );
                    }
                    else
                    {
                        poPoint = new OGRPoint(
                            psShape->padfX[i], psShape->padfY[i],
                            psShape->padfZ[i] );
                    }
                }
                else if( psShape->nSHPType == SHPT_MULTIPOINTM &&
                         psShape->padfM )
                {
                    poPoint = new OGRPoint(psShape->padfX[i], psShape->padfY[i],
                                           0.0, psShape->padfM[i]);
                    poPoint->set3D(FALSE);
                }
                else
                {
                    poPoint =
                        new OGRPoint( psShape->padfX[i], psShape->padfY[i] );
                }

                poOGRMPoint->addGeometry( poPoint );

                delete poPoint;
            }

            poOGR = poOGRMPoint;
        }
    }

/* -------------------------------------------------------------------- */
/*      Arc (LineString)                                                */
/*                                                                      */
/*      Ignoring parts though they can apply to arcs as well.           */
/* -------------------------------------------------------------------- */
    else if( psShape->nSHPType == SHPT_ARC
             || psShape->nSHPType == SHPT_ARCM
             || psShape->nSHPType == SHPT_ARCZ )
    {
        if( psShape->nParts == 0 )
        {
            poOGR = nullptr;
        }
        else if( psShape->nParts == 1 )
        {
            OGRLineString *poOGRLine = new OGRLineString();
            poOGR = poOGRLine;

            if( psShape->nSHPType == SHPT_ARCZ )
                poOGRLine->setPoints( psShape->nVertices,
                                      psShape->padfX, psShape->padfY,
                                      psShape->padfZ, psShape->padfM );
            else if( psShape->nSHPType == SHPT_ARCM )
                poOGRLine->setPointsM( psShape->nVertices,
                                       psShape->padfX, psShape->padfY,
                                       psShape->padfM );
            else
                poOGRLine->setPoints( psShape->nVertices,
                                      psShape->padfX, psShape->padfY );
        }
        else
        {
            OGRMultiLineString *poOGRMulti = new OGRMultiLineString();
            poOGR = poOGRMulti;

            for( int iRing = 0; iRing < psShape->nParts; iRing++ )
            {
                int nRingPoints = 0;
                int nRingStart = 0;

                OGRLineString *poLine = new OGRLineString();

                if( psShape->panPartStart == nullptr )
                {
                    nRingPoints = psShape->nVertices;
                    nRingStart = 0;
                }
                else
                {
                    if( iRing == psShape->nParts - 1 )
                        nRingPoints =
                            psShape->nVertices - psShape->panPartStart[iRing];
                    else
                        nRingPoints = psShape->panPartStart[iRing+1]
                            - psShape->panPartStart[iRing];
                    nRingStart = psShape->panPartStart[iRing];
                }

                if( psShape->nSHPType == SHPT_ARCZ )
                    poLine->setPoints(
                        nRingPoints,
                        psShape->padfX + nRingStart,
                        psShape->padfY + nRingStart,
                        psShape->padfZ + nRingStart,
                        psShape->padfM ? psShape->padfM + nRingStart : nullptr );
                else if( psShape->nSHPType == SHPT_ARCM &&
                         psShape->padfM != nullptr )
                    poLine->setPointsM( nRingPoints,
                                        psShape->padfX + nRingStart,
                                        psShape->padfY + nRingStart,
                                        psShape->padfM + nRingStart );
                else
                    poLine->setPoints( nRingPoints,
                                       psShape->padfX + nRingStart,
                                       psShape->padfY + nRingStart );

                poOGRMulti->addGeometryDirectly( poLine );
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Polygon                                                         */
/*                                                                      */
/* As for now Z coordinate is not handled correctly                     */
/* -------------------------------------------------------------------- */
    else if( psShape->nSHPType == SHPT_POLYGON
             || psShape->nSHPType == SHPT_POLYGONM
             || psShape->nSHPType == SHPT_POLYGONZ )
    {
        const bool bHasZ = psShape->nSHPType == SHPT_POLYGONZ;
        const bool bHasM = bHasZ || psShape->nSHPType == SHPT_POLYGONM;

#if DEBUG_VERBOSE
        CPLDebug( "Shape", "Shape type: polygon with nParts=%d",
                  psShape->nParts );
#endif

        if( psShape->nParts == 0 )
        {
            poOGR = nullptr;
        }
        else if( psShape->nParts == 1 )
        {
            // Surely outer ring.
            OGRPolygon *poOGRPoly = new OGRPolygon();
            poOGR = poOGRPoly;

            OGRLinearRing *poRing =
                CreateLinearRing( psShape, 0, bHasZ, bHasM );
            poOGRPoly->addRingDirectly( poRing );
        }
        else
        {
            OGRPolygon** tabPolygons = new OGRPolygon*[psShape->nParts];
            for( int iRing = 0; iRing < psShape->nParts; iRing++ )
            {
                tabPolygons[iRing] = new OGRPolygon();
                tabPolygons[iRing]->addRingDirectly(
                    CreateLinearRing( psShape, iRing, bHasZ, bHasM ));
            }

            int isValidGeometry = FALSE;
            const char* papszOptions[] = { "METHOD=ONLY_CCW", nullptr };
            OGRGeometry **tabGeom =
                reinterpret_cast<OGRGeometry**>(tabPolygons);
            poOGR = OGRGeometryFactory::organizePolygons(
                tabGeom, psShape->nParts, &isValidGeometry, papszOptions );

            if( !isValidGeometry )
            {
                CPLError(
                    CE_Warning, CPLE_AppDefined,
                    "Geometry of polygon of fid %d cannot be translated to "
                    "Simple Geometry. "
                    "All polygons will be contained in a multipolygon.",
                    iShape);
            }

            delete[] tabPolygons;
        }
    }

/* -------------------------------------------------------------------- */
/*      MultiPatch                                                      */
/* -------------------------------------------------------------------- */
    else if( psShape->nSHPType == SHPT_MULTIPATCH )
    {
        poOGR = OGRCreateFromMultiPatch( psShape->nParts,
                                         psShape->panPartStart,
                                         psShape->panPartType,
                                         psShape->nVertices,
                                         psShape->padfX,
                                         psShape->padfY,
                                         psShape->padfZ );
    }

/* -------------------------------------------------------------------- */
/*      Otherwise for now we just ignore the object.                    */
/* -------------------------------------------------------------------- */
    else
    {
        if( psShape->nSHPType != SHPT_NULL )
        {
            CPLDebug( "OGR", "Unsupported shape type in SHPReadOGRObject()" );
        }

        // Nothing returned.
    }

/* -------------------------------------------------------------------- */
/*      Cleanup shape, and set feature id.                              */
/* -------------------------------------------------------------------- */
    SHPDestroyObject( psShape );

    return poOGR;
}

/************************************************************************/
/*                         SHPWriteOGRObject()                          */
/************************************************************************/
static
OGRErr SHPWriteOGRObject( SHPHandle hSHP, int iShape,
                          const OGRGeometry *poGeom,
                          bool bRewind, OGRwkbGeometryType eLayerGeomType )

{
/* ==================================================================== */
/*      Write "shape" with no geometry or with empty geometry           */
/* ==================================================================== */
    if( poGeom == nullptr || poGeom->IsEmpty() )
    {
        SHPObject *psShape =
            SHPCreateObject( SHPT_NULL, -1, 0, nullptr, nullptr, 0,
                             nullptr, nullptr, nullptr, nullptr );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );
        if( nReturnedShapeID == -1 )
        {
            // Assuming error is reported by SHPWriteObject().
            return OGRERR_FAILURE;
        }
    }

/* ==================================================================== */
/*      Write point geometry.                                           */
/* ==================================================================== */
    else if( hSHP->nShapeType == SHPT_POINT
             || hSHP->nShapeType == SHPT_POINTM
             || hSHP->nShapeType == SHPT_POINTZ )
    {
        if( wkbFlatten(poGeom->getGeometryType()) != wkbPoint )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Attempt to write non-point (%s) geometry to"
                      " point shapefile.",
                      poGeom->getGeometryName() );

            return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
        }

        const OGRPoint *poPoint = poGeom->toPoint();
        const double dfX = poPoint->getX();
        const double dfY = poPoint->getY();
        const double dfZ = poPoint->getZ();
        double dfM = 0.0;
        double *pdfM = nullptr;
        if( wkbHasM(eLayerGeomType) &&
            (hSHP->nShapeType == SHPT_POINTM ||
             hSHP->nShapeType == SHPT_POINTZ) )
        {
            if( poGeom->IsMeasured() )
                dfM = poPoint->getM();
            else
                dfM = -std::numeric_limits<double>::max();
            pdfM = &dfM;
        }

        SHPObject *psShape =
            SHPCreateObject( hSHP->nShapeType, -1, 0, nullptr, nullptr, 1,
                             &dfX, &dfY, &dfZ, pdfM );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );
        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }
/* ==================================================================== */
/*      MultiPoint.                                                     */
/* ==================================================================== */
    else if( hSHP->nShapeType == SHPT_MULTIPOINT
             || hSHP->nShapeType == SHPT_MULTIPOINTM
             || hSHP->nShapeType == SHPT_MULTIPOINTZ )
    {
        if( wkbFlatten(poGeom->getGeometryType()) != wkbMultiPoint )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Attempt to write non-multipoint (%s) geometry to "
                      "multipoint shapefile.",
                      poGeom->getGeometryName() );

            return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
        }

        const OGRMultiPoint   *poMP = poGeom->toMultiPoint();
        double *padfX = static_cast<double *>(
            CPLMalloc(sizeof(double) * poMP->getNumGeometries()));
        double *padfY = static_cast<double *>(
            CPLMalloc(sizeof(double) * poMP->getNumGeometries()));
        // TODO(schwehr): Why a calloc for padfZ?
        double *padfZ = static_cast<double *>(
            CPLCalloc(sizeof(double), poMP->getNumGeometries()));
        double *padfM = nullptr;
        if( wkbHasM(eLayerGeomType) &&
            (hSHP->nShapeType == SHPT_MULTIPOINTM ||
             hSHP->nShapeType == SHPT_MULTIPOINTZ) )
            padfM = static_cast<double *>(
                CPLCalloc(sizeof(double), poMP->getNumGeometries()));

        int iDstPoints = 0;
        for( int iPoint = 0; iPoint < poMP->getNumGeometries(); iPoint++ )
        {
            const OGRPoint *poPoint = poMP->getGeometryRef(iPoint)->toPoint();
            // Ignore POINT EMPTY.
            if( !poPoint->IsEmpty() )
            {
                padfX[iDstPoints] = poPoint->getX();
                padfY[iDstPoints] = poPoint->getY();
                padfZ[iDstPoints] = poPoint->getZ();
                if( padfM )
                {
                    if( poGeom->IsMeasured() )
                        padfM[iDstPoints] = poPoint->getM();
                    else
                        padfM[iDstPoints] = -std::numeric_limits<double>::max();
                }
                iDstPoints++;
            }
            else
            {
                CPLDebug(
                    "OGR",
                    "Ignored POINT EMPTY inside MULTIPOINT in shapefile "
                    "writer." );
            }
        }

        SHPObject *psShape =
            SHPCreateObject( hSHP->nShapeType, -1, 0, nullptr, nullptr,
                             iDstPoints,
                             padfX, padfY, padfZ, padfM );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );

        CPLFree( padfX );
        CPLFree( padfY );
        CPLFree( padfZ );
        CPLFree( padfM );
        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }

/* ==================================================================== */
/*      Arcs from simple line strings.                                  */
/* ==================================================================== */
    else if( (hSHP->nShapeType == SHPT_ARC
              || hSHP->nShapeType == SHPT_ARCM
              || hSHP->nShapeType == SHPT_ARCZ)
             && wkbFlatten(poGeom->getGeometryType()) == wkbLineString )
    {
        const OGRLineString *poArc = poGeom->toLineString();
        double *padfX = static_cast<double *>(
            CPLMalloc(sizeof(double) * poArc->getNumPoints()));
        double *padfY = static_cast<double *>(
            CPLMalloc(sizeof(double)*poArc->getNumPoints()));
        double *padfZ = static_cast<double *>(
            CPLCalloc(sizeof(double), poArc->getNumPoints()));
        double *padfM = nullptr;
        if( wkbHasM(eLayerGeomType) &&
            (hSHP->nShapeType == SHPT_ARCM ||
             hSHP->nShapeType == SHPT_ARCZ) )
            padfM = static_cast<double *>(
                CPLCalloc(sizeof(double),poArc->getNumPoints()));

        for( int iPoint = 0; iPoint < poArc->getNumPoints(); iPoint++ )
        {
            padfX[iPoint] = poArc->getX( iPoint );
            padfY[iPoint] = poArc->getY( iPoint );
            padfZ[iPoint] = poArc->getZ( iPoint );
            if( padfM )
            {
                if( poGeom->IsMeasured() )
                    padfM[iPoint] = poArc->getM( iPoint );
                else
                    padfM[iPoint] = -std::numeric_limits<double>::max();
            }
        }

        SHPObject *psShape =
            SHPCreateObject( hSHP->nShapeType, -1, 0, nullptr, nullptr,
                             poArc->getNumPoints(),
                             padfX, padfY, padfZ, padfM );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );

        CPLFree( padfX );
        CPLFree( padfY );
        CPLFree( padfZ );
        CPLFree( padfM );
        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }
/* ==================================================================== */
/*      Arcs - Try to treat as MultiLineString.                         */
/* ==================================================================== */
    else if( hSHP->nShapeType == SHPT_ARC
             || hSHP->nShapeType == SHPT_ARCM
             || hSHP->nShapeType == SHPT_ARCZ )
    {
        OGRGeometry *poForcedGeom =
            OGRGeometryFactory::forceToMultiLineString( poGeom->clone() );

        if( wkbFlatten(poForcedGeom->getGeometryType()) != wkbMultiLineString )
        {
            delete poForcedGeom;
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Attempt to write non-linestring (%s) geometry to "
                      "ARC type shapefile.",
                      poGeom->getGeometryName() );

            return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
        }
        const OGRMultiLineString *poML = poForcedGeom->toMultiLineString();

        int *panRingStart = static_cast<int *>(
            CPLMalloc(sizeof(int) * poML->getNumGeometries()) );

        double *padfX = nullptr;
        double *padfY = nullptr;
        double *padfZ = nullptr;
        double *padfM = nullptr;
        int nPointCount = 0;
        int nParts = 0;
        const bool bSupportMeasures =
            wkbHasM(eLayerGeomType) && (hSHP->nShapeType == SHPT_ARCM ||
                                            hSHP->nShapeType == SHPT_ARCZ);

        for( int iGeom = 0; iGeom < poML->getNumGeometries(); iGeom++ )
        {
            const OGRLineString *poArc = poML->getGeometryRef(iGeom)->toLineString();
            const int nNewPoints = poArc->getNumPoints();

            // Ignore LINESTRING EMPTY.
            if( nNewPoints == 0 )
            {
                CPLDebug(
                    "OGR",
                    "Ignore LINESTRING EMPTY inside MULTILINESTRING in "
                    "shapefile writer." );
                continue;
            }

            panRingStart[nParts++] = nPointCount;

            padfX = static_cast<double *>(
                CPLRealloc( padfX, sizeof(double)*(nNewPoints+nPointCount) ));
            padfY = static_cast<double *>(
                CPLRealloc( padfY, sizeof(double)*(nNewPoints+nPointCount) ));
            padfZ = static_cast<double *>(
                CPLRealloc( padfZ, sizeof(double)*(nNewPoints+nPointCount) ));
            if( bSupportMeasures )
            {
                padfM = static_cast<double *>(
                    CPLRealloc(padfM, sizeof(double)*(nNewPoints+nPointCount)));
            }

            for( int iPoint = 0; iPoint < nNewPoints; iPoint++ )
            {
                padfX[nPointCount] = poArc->getX( iPoint );
                padfY[nPointCount] = poArc->getY( iPoint );
                padfZ[nPointCount] = poArc->getZ( iPoint );
                if( bSupportMeasures )
                    padfM[nPointCount] = poGeom->IsMeasured() ?
                        poArc->getM( iPoint ) :
                        -std::numeric_limits<double>::max();
                nPointCount++;
            }
        }

        CPLAssert(nParts != 0);

        SHPObject *psShape =
            SHPCreateObject( hSHP->nShapeType, iShape,
                             nParts,
                             panRingStart, nullptr,
                             nPointCount, padfX, padfY, padfZ, padfM );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );

        CPLFree( panRingStart );
        CPLFree( padfX );
        CPLFree( padfY );
        CPLFree( padfZ );
        CPLFree( padfM );

        delete poML;
        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }

/* ==================================================================== */
/*      Polygons/MultiPolygons                                          */
/* ==================================================================== */
    else if( hSHP->nShapeType == SHPT_POLYGON
             || hSHP->nShapeType == SHPT_POLYGONM
             || hSHP->nShapeType == SHPT_POLYGONZ )
    {
        const OGRLinearRing **papoRings = nullptr;
        int nRings = 0;
        const OGRwkbGeometryType eType = wkbFlatten(poGeom->getGeometryType());
        std::unique_ptr<OGRGeometry> poGeomToDelete;

        if( eType == wkbPolygon || eType == wkbTriangle )
        {
            const OGRPolygon* poPoly = poGeom->toPolygon();

            if( poPoly->getExteriorRing() == nullptr ||
                poPoly->getExteriorRing()->IsEmpty() )
            {
                CPLDebug( "OGR",
                          "Ignore POLYGON EMPTY in shapefile writer." );
            }
            else
            {
                const int nSrcRings = poPoly->getNumInteriorRings()+1;
                papoRings = static_cast<const OGRLinearRing **>(
                    CPLMalloc(sizeof(const OGRLinearRing *)*nSrcRings));
                for( int iRing = 0; iRing < nSrcRings; iRing++ )
                {
                    if( iRing == 0 )
                        papoRings[nRings] = poPoly->getExteriorRing();
                    else
                        papoRings[nRings] = poPoly->getInteriorRing( iRing-1 );

                    // Ignore LINEARRING EMPTY.
                    if( papoRings[nRings]->getNumPoints() != 0 )
                        nRings++;
                    else
                        CPLDebug(
                            "OGR",
                            "Ignore LINEARRING EMPTY inside POLYGON in "
                            "shapefile writer." );
                }
            }
        }
        else if( eType == wkbMultiPolygon ||
                 eType == wkbGeometryCollection ||
                 eType == wkbPolyhedralSurface ||
                 eType == wkbTIN)
        {
            const OGRGeometryCollection *poGC;
            // for PolyhedralSurface and TIN
            if (eType == wkbPolyhedralSurface || eType == wkbTIN)
            {
                poGeomToDelete = std::unique_ptr<OGRGeometry>(
                    OGRGeometryFactory::forceTo(poGeom->clone(),
                                                             wkbMultiPolygon,
                                                             nullptr));
                poGC = poGeomToDelete->toGeometryCollection();
            }

            else
                poGC = poGeom->toGeometryCollection();

            for( int iGeom=0; poGC != nullptr &&
                              iGeom < poGC->getNumGeometries(); iGeom++ )
            {
                const OGRGeometry* poSubGeom = poGC->getGeometryRef( iGeom );

                if( wkbFlatten(poSubGeom->getGeometryType()) != wkbPolygon )
                {
                    CPLFree( papoRings );
                    CPLError( CE_Failure, CPLE_AppDefined,
                              "Attempt to write non-polygon (%s) geometry to "
                              "POLYGON type shapefile.",
                              poSubGeom->getGeometryName());

                    return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
                }
                const OGRPolygon* poPoly = poSubGeom->toPolygon();

                // Ignore POLYGON EMPTY.
                if( poPoly->getExteriorRing() == nullptr ||
                    poPoly->getExteriorRing()->IsEmpty() )
                {
                    CPLDebug(
                        "OGR",
                        "Ignore POLYGON EMPTY inside MULTIPOLYGON in "
                        "shapefile writer." );
                    continue;
                }

                papoRings = static_cast<const OGRLinearRing **>(
                    CPLRealloc(papoRings,
                               sizeof(const OGRLinearRing *) *
                               (nRings+poPoly->getNumInteriorRings() + 1)) );
                for( int iRing = 0;
                     iRing < poPoly->getNumInteriorRings()+1;
                     iRing++ )
                {
                    if( iRing == 0 )
                        papoRings[nRings] = poPoly->getExteriorRing();
                    else
                        papoRings[nRings] =
                            poPoly->getInteriorRing( iRing - 1 );

                    // Ignore LINEARRING EMPTY.
                    if( papoRings[nRings]->getNumPoints() != 0 )
                        nRings++;
                    else
                        CPLDebug(
                            "OGR",
                            "Ignore LINEARRING EMPTY inside POLYGON in "
                            "shapefile writer." );
                }
            }
        }
        else
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Attempt to write non-polygon (%s) geometry to "
                      "POLYGON type shapefile.",
                      poGeom->getGeometryName() );

            return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
        }

/* -------------------------------------------------------------------- */
/*      If we only had emptypolygons or unacceptable geometries         */
/*      write NULL geometry object.                                     */
/* -------------------------------------------------------------------- */
        if( nRings == 0 )
        {
            SHPObject *psShape =
                SHPCreateObject( SHPT_NULL, -1, 0, nullptr, nullptr,
                                 0, nullptr, nullptr, nullptr, nullptr );
            const int nReturnedShapeID =
                SHPWriteObject( hSHP, iShape, psShape );
            SHPDestroyObject( psShape );

            if( nReturnedShapeID == -1 )
                return OGRERR_FAILURE;

            return OGRERR_NONE;
        }

        // Count vertices.
        int nVertex = 0;
        for( int iRing = 0; iRing < nRings; iRing++ )
            nVertex += papoRings[iRing]->getNumPoints();

        int *panRingStart =
            static_cast<int *>( CPLMalloc(sizeof(int) * nRings) );
        double *padfX =
            static_cast<double *>( CPLMalloc(sizeof(double) * nVertex) );
        double *padfY =
            static_cast<double *>( CPLMalloc(sizeof(double) * nVertex) );
        double *padfZ =
            static_cast<double *>( CPLMalloc(sizeof(double) * nVertex) );

        double *padfM = nullptr;
        if( wkbHasM(eLayerGeomType) &&
            (hSHP->nShapeType == SHPT_POLYGONM ||
             hSHP->nShapeType == SHPT_POLYGONZ) )
            padfM = static_cast<double *>(
                CPLMalloc(sizeof(double) * nVertex));

        // Collect vertices.
        nVertex = 0;
        for( int iRing = 0; iRing < nRings; iRing++ )
        {
            const OGRLinearRing *poRing = papoRings[iRing];
            panRingStart[iRing] = nVertex;

            for( int iPoint = 0; iPoint < poRing->getNumPoints(); iPoint++ )
            {
                padfX[nVertex] = poRing->getX( iPoint );
                padfY[nVertex] = poRing->getY( iPoint );
                padfZ[nVertex] = poRing->getZ( iPoint );
                if( padfM )
                {
                    padfM[nVertex] = poGeom->IsMeasured() ?
                        poRing->getM( iPoint ) :
                        -std::numeric_limits<double>::max();
                }
                nVertex++;
            }
        }

        SHPObject* psShape =
            SHPCreateObject( hSHP->nShapeType, iShape, nRings, panRingStart,
                             nullptr, nVertex, padfX, padfY, padfZ, padfM );
        if( bRewind )
            SHPRewindObject( hSHP, psShape );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );

        CPLFree( papoRings );
        CPLFree( panRingStart );
        CPLFree( padfX );
        CPLFree( padfY );
        CPLFree( padfZ );
        CPLFree( padfM );

        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }

/* ==================================================================== */
/*      Multipatch                                                      */
/* ==================================================================== */
    else if( hSHP->nShapeType == SHPT_MULTIPATCH )
    {
        int nParts = 0;
        int* panPartStart = nullptr;
        int* panPartType = nullptr;
        int nPoints = 0;
        OGRRawPoint* poPoints = nullptr;
        double* padfZ = nullptr;
        OGRErr eErr = OGRCreateMultiPatch( poGeom,
                                           FALSE, // no SHPP_TRIANGLES
                                           nParts,
                                           panPartStart,
                                           panPartType,
                                           nPoints,
                                           poPoints,
                                           padfZ );
        if( eErr != OGRERR_NONE )
            return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;

        double *padfX =
            static_cast<double *>( CPLMalloc(sizeof(double) * nPoints) );
        double *padfY =
            static_cast<double *>( CPLMalloc(sizeof(double) * nPoints) );
        for( int i = 0; i < nPoints; ++i )
        {
            padfX[i] = poPoints[i].x;
            padfY[i] = poPoints[i].y;
        }
        CPLFree(poPoints);

        SHPObject* psShape =
            SHPCreateObject( hSHP->nShapeType, iShape, nParts, panPartStart,
                             panPartType, nPoints, padfX, padfY, padfZ, nullptr );
        if( bRewind )
            SHPRewindObject( hSHP, psShape );
        const int nReturnedShapeID = SHPWriteObject( hSHP, iShape, psShape );
        SHPDestroyObject( psShape );

        CPLFree(panPartStart);
        CPLFree(panPartType);
        CPLFree(padfX);
        CPLFree(padfY);
        CPLFree(padfZ);

        if( nReturnedShapeID == -1 )
            return OGRERR_FAILURE;
    }

    else
    {
        return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
    }

    return OGRERR_NONE;
}

/************************************************************************/
/*                       SHPReadOGRFeatureDefn()                        */
/************************************************************************/

OGRFeatureDefn *SHPReadOGRFeatureDefn( const char * pszName,
                                       SHPHandle hSHP, DBFHandle hDBF,
                                       const char* pszSHPEncoding,
                                       int bAdjustType )

{
    int nAdjustableFields = 0;
    const int nFieldCount = hDBF ? DBFGetFieldCount(hDBF) : 0;

    OGRFeatureDefn * const poDefn = new OGRFeatureDefn( pszName );
    poDefn->Reference();

    for( int iField = 0; iField < nFieldCount; iField++ )
    {
        // On reading we support up to 11 characters
        char szFieldName[XBASE_FLDNAME_LEN_READ+1] = {};
        int nWidth = 0;
        int nPrecision = 0;
        DBFFieldType eDBFType =
            DBFGetFieldInfo( hDBF, iField, szFieldName, &nWidth, &nPrecision );

        OGRFieldDefn oField("", OFTInteger);
        if( strlen(pszSHPEncoding) > 0 )
        {
            char * const pszUTF8Field =
                CPLRecode( szFieldName, pszSHPEncoding, CPL_ENC_UTF8);
            oField.SetName( pszUTF8Field );
            CPLFree( pszUTF8Field );
        }
        else
        {
            oField.SetName( szFieldName );
        }

        oField.SetWidth( nWidth );
        oField.SetPrecision( nPrecision );

        if( eDBFType == FTDate )
        {
            // Shapefile date has following 8-chars long format:
            //
            //     20060101.
            //
            // Split as YYYY/MM/DD, so 2 additional characters are required.
            oField.SetWidth( nWidth + 2 );
            oField.SetType( OFTDate );
        }
        else if( eDBFType == FTDouble )
        {
            nAdjustableFields += (nPrecision == 0);
            if( nPrecision == 0 && nWidth < 19 )
                oField.SetType( OFTInteger64 );
            else
                oField.SetType( OFTReal );
        }
        else if( eDBFType == FTInteger )
            oField.SetType( OFTInteger );
        else
            oField.SetType( OFTString );

        poDefn->AddFieldDefn( &oField );
    }

    // Do an optional past if requested and needed to demote Integer64->Integer
    // or Real->Integer64/Integer.
    if( nAdjustableFields && bAdjustType )
    {
        int *panAdjustableField = static_cast<int *>(
            CPLCalloc(sizeof(int), nFieldCount));
        for( int iField = 0; iField < nFieldCount; iField++ )
        {
            OGRFieldType eType = poDefn->GetFieldDefn(iField)->GetType();
            if( poDefn->GetFieldDefn(iField)->GetPrecision() == 0 &&
               (eType == OFTInteger64 || eType == OFTReal) )
            {
                panAdjustableField[iField] = TRUE;
                poDefn->GetFieldDefn(iField)->SetType(OFTInteger);
            }
        }

        const int nRowCount = DBFGetRecordCount(hDBF);
        for( int iRow = 0; iRow < nRowCount && nAdjustableFields; iRow++ )
        {
           for( int iField = 0; iField < nFieldCount; iField++ )
           {
               if( panAdjustableField[iField] )
               {
                   const char* pszValue =
                       DBFReadStringAttribute( hDBF, iRow, iField );
                   const int nValueLength = static_cast<int>(strlen(pszValue));
                   if( nValueLength >= 10 )
                   {
                       int bOverflow = FALSE;
                       const GIntBig nVal =
                           CPLAtoGIntBigEx(pszValue, FALSE, &bOverflow);
                       if( bOverflow )
                       {
                           poDefn->GetFieldDefn(iField)->SetType(OFTReal);
                           panAdjustableField[iField] = FALSE;
                           nAdjustableFields--;
                       }
                       else if( !CPL_INT64_FITS_ON_INT32(nVal) )
                       {
                           poDefn->GetFieldDefn(iField)->SetType(OFTInteger64);
                           if( poDefn->GetFieldDefn(iField)->GetWidth() <= 18 )
                           {
                               panAdjustableField[iField] = FALSE;
                               nAdjustableFields--;
                           }
                       }
                   }
               }
           }
        }

        CPLFree(panAdjustableField);
    }

    if( hSHP == nullptr )
    {
        poDefn->SetGeomType( wkbNone );
    }
    else
    {
        switch( hSHP->nShapeType )
        {
          case SHPT_POINT:
            poDefn->SetGeomType( wkbPoint );
            break;

          case SHPT_POINTZ:
            poDefn->SetGeomType( wkbPointZM );
            break;

          case SHPT_POINTM:
            poDefn->SetGeomType( wkbPointM );
            break;

          case SHPT_ARC:
            poDefn->SetGeomType( wkbLineString );
            break;

          case SHPT_ARCZ:
            poDefn->SetGeomType( wkbLineStringZM );
            break;

          case SHPT_ARCM:
            poDefn->SetGeomType( wkbLineStringM );
            break;

          case SHPT_MULTIPOINT:
            poDefn->SetGeomType( wkbMultiPoint );
            break;

          case SHPT_MULTIPOINTZ:
            poDefn->SetGeomType( wkbMultiPointZM );
            break;

          case SHPT_MULTIPOINTM:
            poDefn->SetGeomType( wkbMultiPointM );
            break;

          case SHPT_POLYGON:
            poDefn->SetGeomType( wkbPolygon );
            break;

          case SHPT_POLYGONZ:
            poDefn->SetGeomType( wkbPolygonZM );
            break;

          case SHPT_POLYGONM:
            poDefn->SetGeomType( wkbPolygonM );
            break;

          case SHPT_MULTIPATCH:
            poDefn->SetGeomType( wkbUnknown ); // not ideal
            break;
        }
    }

    return poDefn;
}

/************************************************************************/
/*                         SHPReadOGRFeature()                          */
/************************************************************************/

OGRFeature *SHPReadOGRFeature( SHPHandle hSHP, DBFHandle hDBF,
                               OGRFeatureDefn * poDefn, int iShape,
                               SHPObject *psShape, const char *pszSHPEncoding )

{
    if( iShape < 0
        || (hSHP != nullptr && iShape >= hSHP->nRecords)
        || (hDBF != nullptr && iShape >= hDBF->nRecords) )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Attempt to read shape with feature id (%d) out of available"
                  " range.", iShape );
        return nullptr;
    }

    if( hDBF && DBFIsRecordDeleted( hDBF, iShape ) )
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "Attempt to read shape with feature id (%d), "
                  "but it is marked deleted.",
                  iShape );
        if( psShape != nullptr )
            SHPDestroyObject(psShape);
        return nullptr;
    }

    OGRFeature  *poFeature = new OGRFeature( poDefn );

/* -------------------------------------------------------------------- */
/*      Fetch geometry from Shapefile to OGRFeature.                    */
/* -------------------------------------------------------------------- */
    if( hSHP != nullptr )
    {
        if( !poDefn->IsGeometryIgnored() )
        {
            OGRGeometry* poGeometry =
                SHPReadOGRObject( hSHP, iShape, psShape );

            // Two possibilities are expected here (both are tested by
            // GDAL Autotests):
            //   1. Read valid geometry and assign it directly.
            //   2. Read and assign null geometry if it can not be read
            //      correctly from a shapefile.
            //
            // It is NOT required here to test poGeometry == NULL.

            if( poGeometry )
            {
                // Set/unset flags.
                const OGRwkbGeometryType eMyGeomType =
                    poFeature->GetDefnRef()->GetGeomFieldDefn(0)->GetType();

                if( eMyGeomType != wkbUnknown )
                {
                    OGRwkbGeometryType eGeomInType =
                        poGeometry->getGeometryType();
                    if( wkbHasZ(eMyGeomType) && !wkbHasZ(eGeomInType) )
                    {
                        poGeometry->set3D(TRUE);
                    }
                    else if( !wkbHasZ(eMyGeomType) && wkbHasZ(eGeomInType) )
                    {
                        poGeometry->set3D(FALSE);
                    }
                    if( wkbHasM(eMyGeomType) && !wkbHasM(eGeomInType) )
                    {
                        poGeometry->setMeasured(TRUE);
                    }
                    else if( !wkbHasM(eMyGeomType) && wkbHasM(eGeomInType) )
                    {
                        poGeometry->setMeasured(FALSE);
                    }
                }
            }

            poFeature->SetGeometryDirectly( poGeometry );
        }
        else if( psShape != nullptr )
        {
            SHPDestroyObject( psShape );
        }
    }

/* -------------------------------------------------------------------- */
/*      Fetch feature attributes to OGRFeature fields.                  */
/* -------------------------------------------------------------------- */

    for( int iField = 0;
         hDBF != nullptr && iField < poDefn->GetFieldCount();
         iField++ )
    {
        const OGRFieldDefn * const poFieldDefn = poDefn->GetFieldDefn(iField);
        if( poFieldDefn->IsIgnored() )
            continue;

        switch( poFieldDefn->GetType() )
        {
          case OFTString:
          {
              const char * const pszFieldVal =
                  DBFReadStringAttribute( hDBF, iShape, iField );
              if( pszFieldVal != nullptr && pszFieldVal[0] != '\0' )
              {
                if( pszSHPEncoding[0] != '\0' )
                {
                    char * const pszUTF8Field =
                        CPLRecode( pszFieldVal, pszSHPEncoding, CPL_ENC_UTF8);
                    poFeature->SetField( iField, pszUTF8Field );
                    CPLFree( pszUTF8Field );
                }
                else
                    poFeature->SetField( iField, pszFieldVal );
              }
              else
              {
                  poFeature->SetFieldNull(iField);
              }
              break;
          }
          case OFTInteger:
          case OFTInteger64:
          case OFTReal:
          {
              if( DBFIsAttributeNULL( hDBF, iShape, iField ) )
              {
                  poFeature->SetFieldNull(iField);
              }
              else
              {
                  poFeature->SetField(
                      iField,
                      DBFReadStringAttribute( hDBF, iShape, iField ) );
              }
              break;
          }
          case OFTDate:
          {
              if( DBFIsAttributeNULL( hDBF, iShape, iField ) )
              {
                  poFeature->SetFieldNull(iField);
                  continue;
              }

              const char* const pszDateValue =
                  DBFReadStringAttribute(hDBF,iShape,iField);

              // Some DBF files have fields filled with spaces
              // (trimmed by DBFReadStringAttribute) to indicate null
              // values for dates (#4265).
              if( pszDateValue[0] == '\0' )
                  continue;

              OGRField sFld;
              memset( &sFld, 0, sizeof(sFld) );

              if( strlen(pszDateValue) >= 10 &&
                  pszDateValue[2] == '/' && pszDateValue[5] == '/' )
              {
                  sFld.Date.Month = static_cast<GByte>(atoi(pszDateValue + 0));
                  sFld.Date.Day   = static_cast<GByte>(atoi(pszDateValue + 3));
                  sFld.Date.Year  = static_cast<GInt16>(atoi(pszDateValue + 6));
              }
              else
              {
                  const int nFullDate = atoi(pszDateValue);
                  sFld.Date.Year = static_cast<GInt16>(nFullDate / 10000);
                  sFld.Date.Month = static_cast<GByte>((nFullDate / 100) % 100);
                  sFld.Date.Day = static_cast<GByte>(nFullDate % 100);
              }

              poFeature->SetField( iField, &sFld );
          }
          break;

          default:
            CPLAssert( false );
        }
    }

    if( poFeature != nullptr )
        poFeature->SetFID( iShape );

    return poFeature;
}

/************************************************************************/
/*                             GrowField()                              */
/************************************************************************/

static OGRErr GrowField( DBFHandle hDBF, int iField, OGRFieldDefn* poFieldDefn,
                         int nNewSize )
{
    char szFieldName[20] = {};
    int nOriWidth = 0;
    int nPrecision = 0;
    DBFGetFieldInfo( hDBF, iField, szFieldName, &nOriWidth, &nPrecision );

    CPLDebug("SHAPE", "Extending field %d (%s) from %d to %d characters",
             iField, poFieldDefn->GetNameRef(), nOriWidth, nNewSize);

    const char chNativeType = DBFGetNativeFieldType( hDBF, iField );
    if( !DBFAlterFieldDefn( hDBF, iField, szFieldName,
                            chNativeType, nNewSize, nPrecision ) )
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Extending field %d (%s) from %d to %d characters failed",
                 iField, poFieldDefn->GetNameRef(), nOriWidth, nNewSize);
        return OGRERR_FAILURE;
    }

    poFieldDefn->SetWidth(nNewSize);
    return OGRERR_NONE;
}

/************************************************************************/
/*                         SHPWriteOGRFeature()                         */
/*                                                                      */
/*      Write to an existing feature in a shapefile, or create a new    */
/*      feature.                                                        */
/************************************************************************/

OGRErr SHPWriteOGRFeature( SHPHandle hSHP, DBFHandle hDBF,
                           OGRFeatureDefn * poDefn,
                           OGRFeature * poFeature,
                           const char *pszSHPEncoding,
                           bool* pbTruncationWarningEmitted,
                           bool bRewind )

{
/* -------------------------------------------------------------------- */
/*      Write the geometry.                                             */
/* -------------------------------------------------------------------- */
    if( hSHP != nullptr )
    {
        const OGRErr eErr =
            SHPWriteOGRObject( hSHP, static_cast<int>(poFeature->GetFID()),
                               poFeature->GetGeometryRef(),
                               bRewind,
                               poDefn->GetGeomType() );
        if( eErr != OGRERR_NONE )
            return eErr;
    }

/* -------------------------------------------------------------------- */
/*      If there is no DBF, the job is done now.                        */
/* -------------------------------------------------------------------- */
    if( hDBF == nullptr )
    {
/* -------------------------------------------------------------------- */
/*      If this is a new feature, establish its feature id.             */
/* -------------------------------------------------------------------- */
        if( hSHP != nullptr && poFeature->GetFID() == OGRNullFID )
            poFeature->SetFID( hSHP->nRecords - 1 );

        return OGRERR_NONE;
    }

/* -------------------------------------------------------------------- */
/*      If this is a new feature, establish its feature id.             */
/* -------------------------------------------------------------------- */
    if( poFeature->GetFID() == OGRNullFID )
        poFeature->SetFID( DBFGetRecordCount( hDBF ) );

/* -------------------------------------------------------------------- */
/*      If this is the first feature to be written, verify that we      */
/*      have at least one attribute in the DBF file.  If not, create    */
/*      a dummy FID attribute to satisfy the requirement that there     */
/*      be at least one attribute.                                      */
/* -------------------------------------------------------------------- */
    if( DBFGetRecordCount( hDBF ) == 0 && DBFGetFieldCount( hDBF ) == 0 )
    {
        CPLDebug(
            "OGR",
            "Created dummy FID field for shapefile since schema is empty.");
        DBFAddField( hDBF, "FID", FTInteger, 11, 0 );
    }

/* -------------------------------------------------------------------- */
/*      Write out dummy field value if it exists.                       */
/* -------------------------------------------------------------------- */
    if( DBFGetFieldCount( hDBF ) == 1 && poDefn->GetFieldCount() == 0 )
    {
        DBFWriteIntegerAttribute(
            hDBF, static_cast<int>(poFeature->GetFID()), 0,
            static_cast<int>(poFeature->GetFID()) );
    }

/* -------------------------------------------------------------------- */
/*      Write all the fields.                                           */
/* -------------------------------------------------------------------- */
    for( int iField = 0; iField < poDefn->GetFieldCount(); iField++ )
    {
        if( !poFeature->IsFieldSetAndNotNull( iField ) )
        {
            DBFWriteNULLAttribute(
                hDBF, static_cast<int>(poFeature->GetFID()), iField );
            continue;
        }

        OGRFieldDefn * const poFieldDefn = poDefn->GetFieldDefn(iField);

        switch( poFieldDefn->GetType() )
        {
          case OFTString:
          {
              const char *pszStr = poFeature->GetFieldAsString(iField);
              char *pszEncoded = nullptr;
              if( strlen(pszSHPEncoding) > 0 )
              {
                  pszEncoded =
                      CPLRecode( pszStr, CPL_ENC_UTF8, pszSHPEncoding );
                  pszStr = pszEncoded;
              }

              int nStrLen = static_cast<int>(strlen(pszStr));
              if( nStrLen > OGR_DBF_MAX_FIELD_WIDTH )
              {
                  if( !(*pbTruncationWarningEmitted) )
                  {
                      *pbTruncationWarningEmitted = true;
                      CPLError(
                          CE_Warning, CPLE_AppDefined,
                          "Value '%s' of field %s has been truncated to %d "
                          "characters.  This warning will not be emitted any "
                          "more for that layer.",
                          poFeature->GetFieldAsString(iField),
                          poFieldDefn->GetNameRef(),
                          OGR_DBF_MAX_FIELD_WIDTH);
                  }

                  nStrLen = OGR_DBF_MAX_FIELD_WIDTH;

                  if( pszEncoded != nullptr &&  // For Coverity.
                      EQUAL(pszSHPEncoding, CPL_ENC_UTF8))
                  {
                      // TODO(schwehr): Provide a comment about what this does.
                      const char *p = pszStr + nStrLen;
                      int byteCount = nStrLen;
                      while( byteCount > 0 )
                      {
                          if( (*p & 0xc0) != 0x80 )
                          {
                              nStrLen = byteCount;
                              break;
                          }

                          byteCount--;
                          p--;
                      }

                      pszEncoded[nStrLen] = 0;
                  }
              }

              if( nStrLen > poFieldDefn->GetWidth() )
              {
                  if( GrowField(hDBF, iField, poFieldDefn, nStrLen) !=
                          OGRERR_NONE )
                  {
                      CPLFree( pszEncoded );
                      return OGRERR_FAILURE;
                  }
              }

              DBFWriteStringAttribute(
                  hDBF, static_cast<int>(poFeature->GetFID()), iField, pszStr );

              CPLFree( pszEncoded );
              break;
          }
          case OFTInteger:
          case OFTInteger64:
          {
              char szFormat[20] = {};
              char szValue[32] = {};
              int nFieldWidth = poFieldDefn->GetWidth();
              snprintf(szFormat, sizeof(szFormat),
                       "%%%d" CPL_FRMT_GB_WITHOUT_PREFIX "d",
                       std::min(nFieldWidth, static_cast<int>(sizeof(szValue)) - 1));
              snprintf(szValue, sizeof(szValue), szFormat,
                       poFeature->GetFieldAsInteger64(iField));

              const int nStrLen = static_cast<int>(strlen(szValue));
              if( nStrLen > nFieldWidth )
              {
                  if( GrowField(hDBF, iField, poFieldDefn, nStrLen) !=
                          OGRERR_NONE )
                  {
                      return OGRERR_FAILURE;
                  }
              }

              DBFWriteAttributeDirectly(
                  hDBF, static_cast<int>(poFeature->GetFID()),
                  iField, szValue );

              break;
          }

          case OFTReal:
          {
              const double dfVal = poFeature->GetFieldAsDouble(iField);
              // IEEE754 doubles can store exact values of all integers
              // below 2^53.
              if( poFieldDefn->GetPrecision() == 0 &&
                  fabs(dfVal) > (static_cast<GIntBig>(1) << 53) )
              {
                  static int nCounter = 0;
                  if( nCounter <= 10 )
                  {
                      CPLError(
                          CE_Warning, CPLE_AppDefined,
                          "Value %.18g of field %s with 0 decimal of feature "
                          CPL_FRMT_GIB " is bigger than 2^53. "
                          "Precision loss likely occurred or going to happen.%s",
                          dfVal, poFieldDefn->GetNameRef(),
                          poFeature->GetFID(),
                          (nCounter == 10) ? " This warning will not be "
                          "emitted anymore." : "");
                      nCounter++;
                  }
              }
              int ret = DBFWriteDoubleAttribute(
                  hDBF, static_cast<int>(poFeature->GetFID()), iField, dfVal );
              if( !ret )
              {
                  CPLError(
                      CE_Warning, CPLE_AppDefined,
                      "Value %.18g of field %s of feature " CPL_FRMT_GIB " not "
                      "successfully written. Possibly due to too larger number "
                      "with respect to field width",
                      dfVal, poFieldDefn->GetNameRef(), poFeature->GetFID());
              }
              break;
          }
          case OFTDate:
          {
              const OGRField * const psField =
                  poFeature->GetRawFieldRef(iField);

              if( psField->Date.Year < 0 || psField->Date.Year > 9999 )
              {
                  CPLError(
                      CE_Warning, CPLE_NotSupported,
                      "Year < 0 or > 9999 is not a valid date for shapefile");
              }
              else
              {
                  DBFWriteIntegerAttribute(
                      hDBF, static_cast<int>(poFeature->GetFID()), iField,
                      psField->Date.Year*10000 + psField->Date.Month*100 +
                      psField->Date.Day);
              }
          }
          break;

          default:
          {
              // Ignore fields of other types.
              break;
          }
        }
    }

    return OGRERR_NONE;
}
