gdal vector clip: allow to not specify any of bbox, geometry or like to adjust the extent to the one of actual features

Fixes #13519

Author: rouault

apps/gdalalg_vector_clip.cpp

@@ -181,6 +181,50 @@ class GDALVectorClipAlgorithmLayer final : public GDALVectorPipelineOutputLayer
 
 }  // namespace
 
+/************************************************************************/
+/*                  GDALVectorClipAlgorithmLayerChangeExtent            */
+/************************************************************************/
+
+namespace
+{
+class GDALVectorClipAlgorithmLayerChangeExtent final
+    : public GDALVectorPipelinePassthroughLayer
+{
+  public:
+    GDALVectorClipAlgorithmLayerChangeExtent(OGRLayer &oSrcLayer,
+                                             const OGREnvelope &sLayerEnvelope)
+        : GDALVectorPipelinePassthroughLayer(oSrcLayer),
+          m_sLayerEnvelope(sLayerEnvelope)
+    {
+    }
+
+    OGRErr IGetExtent(int /*iGeomField*/, OGREnvelope *psExtent,
+                      bool /* bForce */) override
+    {
+        if (m_sLayerEnvelope.IsInit())
+        {
+            *psExtent = m_sLayerEnvelope;
+            return OGRERR_NONE;
+        }
+        else
+        {
+            return OGRERR_FAILURE;
+        }
+    }
+
+    int TestCapability(const char *pszCap) const override
+    {
+        if (EQUAL(pszCap, OLCFastGetExtent))
+            return true;
+        return m_srcLayer.TestCapability(pszCap);
+    }
+
+  private:
+    const OGREnvelope m_sLayerEnvelope;
+};
+
+}  // namespace
+
 /************************************************************************/
 /*                 GDALVectorClipAlgorithm::RunStep()                   */
 /************************************************************************/
@@ -208,6 +252,54 @@ bool GDALVectorClipAlgorithm::RunStep(GDALPipelineStepRunContext &)
         }
     }
 
+    if (m_bbox.empty() && m_geometry.empty() &&
+        m_likeDataset.GetDatasetRef() == nullptr)
+    {
+        auto outDS =
+            std::make_unique<GDALVectorPipelineOutputDataset>(*poSrcDS);
+
+        bool ret = true;
+        for (int i = 0; ret && i < nLayerCount; ++i)
+        {
+            auto poSrcLayer = poSrcDS->GetLayer(i);
+            ret = (poSrcLayer != nullptr);
+            if (ret)
+            {
+                if (m_activeLayer.empty() ||
+                    m_activeLayer == poSrcLayer->GetDescription())
+                {
+                    OGREnvelope sLayerEnvelope, sFeatureEnvelope;
+                    for (auto &&poFeature : poSrcLayer)
+                    {
+                        const auto poGeom = poFeature->GetGeometryRef();
+                        if (poGeom && !poGeom->IsEmpty())
+                        {
+                            poGeom->getEnvelope(&sFeatureEnvelope);
+                            sLayerEnvelope.Merge(sFeatureEnvelope);
+                        }
+                    }
+                    outDS->AddLayer(
+                        *poSrcLayer,
+                        std::make_unique<
+                            GDALVectorClipAlgorithmLayerChangeExtent>(
+                            *poSrcLayer, sLayerEnvelope));
+                }
+                else
+                {
+                    outDS->AddLayer(
+                        *poSrcLayer,
+                        std::make_unique<GDALVectorPipelinePassthroughLayer>(
+                            *poSrcLayer));
+                }
+            }
+        }
+
+        if (ret)
+            m_outputDataset.Set(std::move(outDS));
+
+        return ret;
+    }
+
     auto [poClipGeom, errMsg] = GetClipGeometry();
     if (!poClipGeom)
     {

apps/gdalalg_vector_pipeline.h

@@ -232,6 +232,8 @@ class GDALVectorPipelinePassthroughLayer /* non final */
     explicit GDALVectorPipelinePassthroughLayer(OGRLayer &oSrcLayer)
         : GDALVectorPipelineOutputLayer(oSrcLayer)
     {
+        SetDescription(oSrcLayer.GetDescription());
+        SetMetadata(oSrcLayer.GetMetadata());
     }
 
     const OGRFeatureDefn *GetLayerDefn() const override;

autotest/utilities/test_gdalalg_vector_clip.py

@@ -886,15 +886,28 @@ def test_gdalalg_vector_clip_like_raster_srs():
     assert out_lyr.GetNextFeature() is None
 
 
-def test_gdalalg_vector_clip_missing_arg(tmp_vsimem):
-
-    out_filename = str(tmp_vsimem / "out.shp")
+@pytest.mark.require_driver("GPKG")
+def test_gdalalg_vector_clip_no_arg(tmp_vsimem):
 
-    clip = get_clip_alg()
-    with pytest.raises(
-        Exception, match="clip: --bbox, --geometry or --like must be specified"
-    ):
-        clip.ParseRunAndFinalize(["../ogr/data/poly.shp", out_filename])
+    src_ds = gdal.GetDriverByName("GPKG").CreateVector(tmp_vsimem / "in.gpkg")
+    src_lyr = src_ds.CreateLayer("test")
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    f.SetGeometry(ogr.CreateGeometryFromWkt("POLYGON ((0 0,0 1,1 1,1 0,0 0))"))
+    src_lyr.CreateFeature(f)
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    f.SetGeometry(ogr.CreateGeometryFromWkt("POLYGON ((10 0,10 1,11 1,11 0,10 0))"))
+    src_lyr.CreateFeature(f)
+    src_lyr.DeleteFeature(f.GetFID())
+    assert src_lyr.GetExtent() == (0, 11, 0, 1)
+    src_ds.CreateLayer("empty_layer")
+
+    with gdal.alg.vector.clip(input=src_ds, output="", output_format="MEM") as alg:
+        ds = alg.Output()
+        lyr = ds.GetLayerByName("test")
+        assert lyr.GetExtent() == (0, 1, 0, 1)
+        assert lyr.GetFeatureCount() == 1
+        lyr = ds.GetLayerByName("empty_layer")
+        assert lyr.GetExtent(can_return_null=True) is None
 
 
 def test_gdalalg_vector_clip_geometry_invalid():

doc/source/programs/gdal_vector_clip.rst

@@ -23,7 +23,9 @@ Description
 :program:`gdal vector clip` can be used to clip a vector dataset using
 georeferenced coordinates.
 
-Either :option:`--bbox`, :option:`--geometry` or :option:`--like` must be specified.
+Starting with GDAL 3.13, if none of :option:`--bbox`, :option:`--geometry` or :option:`--like`
+is specified, the extent of output layer(s) is adjusted to fit exactly the
+actual extent of input layer(s).
 
 ``clip`` can also be used as a step of :ref:`gdal_vector_pipeline`.