Line data    Source code

       1             : /******************************************************************************
       2             :  *
       3             :  * Project:  GDAL
       4             :  * Purpose:  "gdal vector geom buffer"
       5             :  * Author:   Even Rouault <even dot rouault at spatialys.com>
       6             :  *
       7             :  ******************************************************************************
       8             :  * Copyright (c) 2025, Even Rouault <even dot rouault at spatialys.com>
       9             :  *
      10             :  * SPDX-License-Identifier: MIT
      11             :  ****************************************************************************/
      12             : 
      13             : #include "gdalalg_vector_geom_buffer.h"
      14             : 
      15             : #include "gdal_priv.h"
      16             : #include "ogrsf_frmts.h"
      17             : 
      18             : //! @cond Doxygen_Suppress
      19             : 
      20             : #ifndef _
      21             : #define _(x) (x)
      22             : #endif
      23             : 
      24             : /************************************************************************/
      25             : /*                  GDALVectorGeomBufferAlgorithm()                     */
      26             : /************************************************************************/
      27             : 
      28          12 : GDALVectorGeomBufferAlgorithm::GDALVectorGeomBufferAlgorithm(
      29          12 :     bool standaloneStep)
      30             :     : GDALVectorGeomAbstractAlgorithm(NAME, DESCRIPTION, HELP_URL,
      31          12 :                                       standaloneStep, m_opts)
      32             : {
      33             :     AddArg("distance", 0, _("Distance to which to extend the geometry."),
      34          24 :            &m_opts.m_distance)
      35          12 :         .SetPositional()
      36          12 :         .SetRequired();
      37          24 :     AddArg("endcap-style", 0, _("Endcap style."), &m_opts.m_endCapStyle)
      38          12 :         .SetChoices("round", "flat", "square")
      39          12 :         .SetDefault(m_opts.m_endCapStyle);
      40          24 :     AddArg("join-style", 0, _("Join style."), &m_opts.m_joinStyle)
      41          12 :         .SetChoices("round", "mitre", "bevel")
      42          12 :         .SetDefault(m_opts.m_joinStyle);
      43             :     AddArg("mitre-limit", 0,
      44             :            _("Mitre ratio limit (only affects mitered join style)."),
      45          24 :            &m_opts.m_mitreLimit)
      46          12 :         .SetDefault(m_opts.m_mitreLimit)
      47          12 :         .SetMinValueIncluded(0);
      48             :     AddArg("quadrant-segments", 0,
      49             :            _("Number of line segments used to approximate a quarter circle."),
      50          24 :            &m_opts.m_quadrantSegments)
      51          12 :         .SetDefault(m_opts.m_quadrantSegments)
      52          12 :         .SetMinValueIncluded(1);
      53             :     AddArg("side", 0,
      54             :            _("Sets whether the computed buffer should be single-sided or not."),
      55          24 :            &m_opts.m_side)
      56          12 :         .SetChoices("both", "left", "right")
      57          12 :         .SetDefault(m_opts.m_side);
      58          12 : }
      59             : 
      60             : #ifdef HAVE_GEOS
      61             : 
      62             : namespace
      63             : {
      64             : 
      65             : /************************************************************************/
      66             : /*                   GDALVectorGeomBufferAlgorithmLayer                 */
      67             : /************************************************************************/
      68             : 
      69             : class GDALVectorGeomBufferAlgorithmLayer final
      70             :     : public GDALVectorGeomOneToOneAlgorithmLayer<GDALVectorGeomBufferAlgorithm>
      71             : {
      72             :   public:
      73           7 :     GDALVectorGeomBufferAlgorithmLayer(
      74             :         OGRLayer &oSrcLayer, const GDALVectorGeomBufferAlgorithm::Options &opts)
      75           7 :         : GDALVectorGeomOneToOneAlgorithmLayer<GDALVectorGeomBufferAlgorithm>(
      76           7 :               oSrcLayer, opts)
      77             :     {
      78             :         m_aosBufferOptions.SetNameValue("ENDCAP_STYLE",
      79           7 :                                         opts.m_endCapStyle.c_str());
      80           7 :         m_aosBufferOptions.SetNameValue("JOIN_STYLE", opts.m_joinStyle.c_str());
      81             :         m_aosBufferOptions.SetNameValue("MITRE_LIMIT",
      82           7 :                                         CPLSPrintf("%.17g", opts.m_mitreLimit));
      83             :         m_aosBufferOptions.SetNameValue(
      84           7 :             "QUADRANT_SEGMENTS", CPLSPrintf("%d", opts.m_quadrantSegments));
      85             :         m_aosBufferOptions.SetNameValue("SINGLE_SIDED",
      86           7 :                                         m_opts.m_side != "both" ? "YES" : "NO");
      87           7 :     }
      88             : 
      89             :   protected:
      90             :     using GDALVectorGeomOneToOneAlgorithmLayer::TranslateFeature;
      91             : 
      92             :     std::unique_ptr<OGRFeature>
      93             :     TranslateFeature(std::unique_ptr<OGRFeature> poSrcFeature) const override;
      94             : 
      95             :   private:
      96             :     CPLStringList m_aosBufferOptions{};
      97             : };
      98             : 
      99             : /************************************************************************/
     100             : /*                          TranslateFeature()                          */
     101             : /************************************************************************/
     102             : 
     103             : std::unique_ptr<OGRFeature>
     104          14 : GDALVectorGeomBufferAlgorithmLayer::TranslateFeature(
     105             :     std::unique_ptr<OGRFeature> poSrcFeature) const
     106             : {
     107          14 :     const int nGeomFieldCount = poSrcFeature->GetGeomFieldCount();
     108          28 :     for (int i = 0; i < nGeomFieldCount; ++i)
     109             :     {
     110          14 :         if (IsSelectedGeomField(i))
     111             :         {
     112          14 :             if (auto poGeom = std::unique_ptr<OGRGeometry>(
     113          28 :                     poSrcFeature->StealGeometry(i)))
     114             :             {
     115          14 :                 poGeom.reset(poGeom->BufferEx(m_opts.m_distance,
     116           7 :                                               m_aosBufferOptions.List()));
     117           7 :                 if (poGeom)
     118             :                 {
     119          14 :                     poGeom->assignSpatialReference(m_srcLayer.GetLayerDefn()
     120           7 :                                                        ->GetGeomFieldDefn(i)
     121          14 :                                                        ->GetSpatialRef());
     122           7 :                     poSrcFeature->SetGeomField(i, std::move(poGeom));
     123             :                 }
     124             :             }
     125             :         }
     126             :     }
     127             : 
     128          14 :     return poSrcFeature;
     129             : }
     130             : 
     131             : }  // namespace
     132             : 
     133             : #endif  // HAVE_GEOS
     134             : 
     135             : /************************************************************************/
     136             : /*            GDALVectorGeomBufferAlgorithm::CreateAlgLayer()           */
     137             : /************************************************************************/
     138             : 
     139             : std::unique_ptr<OGRLayerWithTranslateFeature>
     140           7 : GDALVectorGeomBufferAlgorithm::CreateAlgLayer(
     141             :     [[maybe_unused]] OGRLayer &srcLayer)
     142             : {
     143             : #ifdef HAVE_GEOS
     144           7 :     return std::make_unique<GDALVectorGeomBufferAlgorithmLayer>(srcLayer,
     145           7 :                                                                 m_opts);
     146             : #else
     147             :     CPLAssert(false);
     148             :     return nullptr;
     149             : #endif
     150             : }
     151             : 
     152             : /************************************************************************/
     153             : /*                GDALVectorGeomBufferAlgorithm::RunStep()              */
     154             : /************************************************************************/
     155             : 
     156           7 : bool GDALVectorGeomBufferAlgorithm::RunStep(GDALProgressFunc, void *)
     157             : {
     158             : #ifdef HAVE_GEOS
     159           7 :     if (m_opts.m_side == "right")
     160           1 :         m_opts.m_distance = -m_opts.m_distance;
     161             : 
     162           7 :     return GDALVectorGeomAbstractAlgorithm::RunStep(nullptr, nullptr);
     163             : #else
     164             :     ReportError(CE_Failure, CPLE_NotSupported,
     165             :                 "This algorithm is only supported for builds against GEOS");
     166             :     return false;
     167             : #endif
     168             : }
     169             : 
     170             : //! @endcond