Line data    Source code

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