Refs #34406 Added support for GDAL curved geometries.

Co-authored-by: David Smith<smithdc@gmail.com>

django/contrib/gis/gdal/geometries.py

@@ -64,6 +64,7 @@ class OGRGeometry(GDALBase):
     """Encapsulate an OGR geometry."""
 
     destructor = capi.destroy_geom
+    geos_support = True
 
     def __init__(self, geom_input, srs=None):
         """Initialize Geometry on either WKT or an OGR pointer as input."""
@@ -304,6 +305,19 @@ def set_measured(self, value):
                 f"Input to 'set_measured' must be a boolean, got '{value!r}'."
             )
 
+    @property
+    def has_curve(self):
+        """Return True if the geometry is or has curve geometry."""
+        return capi.has_curve(self.ptr, 0)
+
+    def get_linear_geometry(self):
+        """Return a linear version of this geometry."""
+        return OGRGeometry(capi.get_linear_geometry(self.ptr, 0, None))
+
+    def get_curve_geometry(self):
+        """Return a curve version of this geometry."""
+        return OGRGeometry(capi.get_curve_geometry(self.ptr, None))
+
     # #### SpatialReference-related Properties ####
 
     # The SRS property
@@ -360,9 +374,14 @@ def _geos_ptr(self):
     @property
     def geos(self):
         "Return a GEOSGeometry object from this OGRGeometry."
-        from django.contrib.gis.geos import GEOSGeometry
+        if self.geos_support:
+            from django.contrib.gis.geos import GEOSGeometry
 
-        return GEOSGeometry(self._geos_ptr(), self.srid)
+            return GEOSGeometry(self._geos_ptr(), self.srid)
+        else:
+            from django.contrib.gis.geos import GEOSException
+
+            raise GEOSException(f"GEOS does not support {self.__class__.__qualname__}.")
 
     @property
     def gml(self):
@@ -727,6 +746,18 @@ def point_count(self):
         return sum(self[i].point_count for i in range(self.geom_count))
 
 
+class CircularString(LineString):
+    geos_support = False
+
+
+class CurvePolygon(Polygon):
+    geos_support = False
+
+
+class CompoundCurve(OGRGeometry):
+    geos_support = False
+
+
 # Geometry Collection base class.
 class GeometryCollection(OGRGeometry):
     "The Geometry Collection class."
@@ -788,6 +819,14 @@ class MultiPolygon(GeometryCollection):
     pass
 
 
+class MultiSurface(GeometryCollection):
+    geos_support = False
+
+
+class MultiCurve(GeometryCollection):
+    geos_support = False
+
+
 # Class mapping dictionary (using the OGRwkbGeometryType as the key)
 GEO_CLASSES = {
     1: Point,
@@ -797,21 +836,41 @@ class MultiPolygon(GeometryCollection):
     5: MultiLineString,
     6: MultiPolygon,
     7: GeometryCollection,
+    8: CircularString,
+    9: CompoundCurve,
+    10: CurvePolygon,
+    11: MultiCurve,
+    12: MultiSurface,
     101: LinearRing,
+    1008: CircularString,  # CIRCULARSTRING Z
+    1009: CompoundCurve,  # COMPOUNDCURVE Z
+    1010: CurvePolygon,  # CURVEPOLYGON Z
+    1011: MultiCurve,  # MULTICURVE Z
+    1012: MultiSurface,  # MULTICURVE Z
     2001: Point,  # POINT M
     2002: LineString,  # LINESTRING M
     2003: Polygon,  # POLYGON M
     2004: MultiPoint,  # MULTIPOINT M
     2005: MultiLineString,  # MULTILINESTRING M
     2006: MultiPolygon,  # MULTIPOLYGON M
     2007: GeometryCollection,  # GEOMETRYCOLLECTION M
+    2008: CircularString,  # CIRCULARSTRING M
+    2009: CompoundCurve,  # COMPOUNDCURVE M
+    2010: CurvePolygon,  # CURVEPOLYGON M
+    2011: MultiCurve,  # MULTICURVE M
+    2012: MultiSurface,  # MULTICURVE M
     3001: Point,  # POINT ZM
     3002: LineString,  # LINESTRING ZM
     3003: Polygon,  # POLYGON ZM
     3004: MultiPoint,  # MULTIPOINT ZM
     3005: MultiLineString,  # MULTILINESTRING ZM
     3006: MultiPolygon,  # MULTIPOLYGON ZM
     3007: GeometryCollection,  # GEOMETRYCOLLECTION ZM
+    3008: CircularString,  # CIRCULARSTRING ZM
+    3009: CompoundCurve,  # COMPOUNDCURVE ZM
+    3010: CurvePolygon,  # CURVEPOLYGON ZM
+    3011: MultiCurve,  # MULTICURVE ZM
+    3012: MultiSurface,  # MULTISURFACE ZM
     1 + OGRGeomType.wkb25bit: Point,  # POINT Z
     2 + OGRGeomType.wkb25bit: LineString,  # LINESTRING Z
     3 + OGRGeomType.wkb25bit: Polygon,  # POLYGON Z

django/contrib/gis/gdal/prototypes/geom.py

@@ -85,6 +85,14 @@ def topology_func(f):
 set_3d = void_output(lgdal.OGR_G_Set3D, [c_void_p, c_int], errcheck=False)
 is_measured = bool_output(lgdal.OGR_G_IsMeasured, [c_void_p])
 set_measured = void_output(lgdal.OGR_G_SetMeasured, [c_void_p, c_int], errcheck=False)
+has_curve = bool_output(lgdal.OGR_G_HasCurveGeometry, [c_void_p, c_int])
+get_linear_geometry = geom_output(
+    lgdal.OGR_G_GetLinearGeometry, [c_void_p, c_double, POINTER(c_char_p)]
+)
+get_curve_geometry = geom_output(
+    lgdal.OGR_G_GetCurveGeometry, [c_void_p, POINTER(c_char_p)]
+)
+
 
 # Geometry modification routines.
 add_geom = void_output(lgdal.OGR_G_AddGeometry, [c_void_p, c_void_p])

docs/ref/contrib/gis/gdal.txt

@@ -611,6 +611,26 @@ coordinate transformation:
         >>> polygon.geom_count
         1
 
+    .. attribute:: has_curve
+
+    .. versionadded:: 5.1
+
+    A boolean indicating if this geometry is or has curve geometry.
+
+    .. method:: get_linear_geometry
+
+    .. versionadded:: 5.1
+
+    Returns a linear version of the geometry. If no conversion can be made the
+    original geometry is returned.
+
+    .. method:: get_curve_geometry
+
+    .. versionadded:: 5.1
+
+    Returns a curved version of the geometry. If no conversion can be made the
+    original geometry is returned.
+
     .. attribute:: point_count
 
     Returns the number of points used to describe this geometry:

docs/releases/5.1.txt

@@ -112,6 +112,12 @@ Minor features
   now support the optional ``srid`` argument (except for Oracle where it is
   ignored).
 
+* Added GDAL support for curved geometries ``CurvePolygon``, ``CompoundCurve``,
+  ``CircularString``, ``MultiSurface``, and ``MultiCurve`` via the new
+  :attr:`.OGRGeometry.has_curve` property, and the
+  :meth:`.OGRGeometry.get_linear_geometry` and
+  :meth:`.OGRGeometry.get_curve_geometry` methods.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tests/gis_tests/data/geometries.json

@@ -137,5 +137,87 @@
   "union_geoms": [
       {"wkt": "POLYGON ((-5 0,-5 10,5 10,5 5,10 5,10 -5,0 -5,0 0,-5 0))"},
       {"wkt": "POLYGON ((2 0, 2 15, 18 15, 18 0, 2 0))"}
+  ],
+"curved_geoms": [
+    {"wkt": "CIRCULARSTRING(1 5, 6 2, 7 3)",
+     "name": "CircularString",
+     "num": 8
+    },
+    {"wkt": "COMPOUNDCURVE((5 3, 5 13), CIRCULARSTRING(5 13, 7 15, 9 13), (9 13, 9 3), CIRCULARSTRING(9 3, 7 1, 5 3))",
+     "name": "CompoundCurve",
+     "num": 9
+    },
+    {"wkt": "CURVEPOLYGON(CIRCULARSTRING(0 0, 4 0, 4 4, 0 4, 0 0),(1 1, 3 3, 3 1, 1 1))",
+     "name": "CurvePolygon",
+     "num": 10
+    },
+    {"wkt": "MULTICURVE((0 0, 5 5), CIRCULARSTRING(4 0, 4 4, 8 4))",
+     "name": "MultiCurve",
+     "num": 11
+    },
+    {"wkt": "MULTISURFACE(((0 0, 0 1, 1 1, 1 0, 0 0)), ((1 1, 1 2, 2 2, 2 1, 1 1)))",
+     "name": "MultiSurface",
+     "num": 12
+    },
+    {"wkt": "CIRCULARSTRING Z (1 5 1, 6 2 2, 7 3 3)",
+     "name": "CircularStringZ",
+     "num": 1008
+    },
+    {"wkt": "COMPOUNDCURVE Z ((5 3 0, 5 13 0), CIRCULARSTRING Z (5 13 0, 7 15 0, 9 13 0), (9 13 0 , 9 3 0), CIRCULARSTRING(9 3 0, 7 1 0, 5 3 0))",
+     "name": "CompoundCurveZ",
+     "num": 1009
+    },
+    {"wkt": "CURVEPOLYGON Z(CIRCULARSTRING Z (0 0 0, 4 0 0, 4 4 0, 0 4 0, 0 0 0),(1 1 0, 3 3 0, 3 1 0, 1 1 0))",
+     "name": "CurvePolygonZ",
+     "num": 1010
+    },
+    {"wkt": "MULTICURVE Z ((0 0 1, 5 5 2), CIRCULARSTRING Z (4 0 0, 4 4 0, 8 4 0))",
+     "name": "MultiCurveZ",
+     "num": 1011
+    },
+    {"wkt": "MULTISURFACE Z (((0 0 1, 0 1 2, 1 1 3, 1 0 4, 0 0 5)), ((1 1 0, 1 2 0, 2 2 0, 2 1 0, 1 1 0)))",
+     "name": "MultiSurfaceZ",
+     "num": 1012
+    },
+    {"wkt": "CIRCULARSTRING M (1 5 1, 6 2 2, 7 3 3)",
+     "name": "CircularStringM",
+     "num": 2008
+    },
+    {"wkt": "COMPOUNDCURVE M ((5 3 0, 5 13 0), CIRCULARSTRING M (5 13 0, 7 15 0, 9 13 0), (9 13 0 , 9 3 0), CIRCULARSTRING M (9 3 0, 7 1 0, 5 3 0))",
+     "name": "CompoundCurveM",
+     "num": 2009
+    },
+    {"wkt": "CURVEPOLYGON M (CIRCULARSTRING M (0 0 0, 4 0 0, 4 4 0, 0 4 0, 0 0 0),(1 1 0, 3 3 1, 3 1 1, 1 1 2))",
+     "name": "CurvePolygonM",
+     "num": 2010
+    },
+    {"wkt": "MULTICURVE M ((0 0 1, 5 5 2), CIRCULARSTRING M (4 0 0, 4 4 0, 8 4 0))",
+     "name": "MultiCurveM",
+     "num": 2011
+    },
+    {"wkt": "MULTISURFACE M (((0 0 1, 0 1 2, 1 1 3, 1 0 4, 0 0 5)), ((1 1 0, 1 2 0, 2 2 0, 2 1 0, 1 1 0)))",
+     "name": "MultiSurfaceM",
+     "num": 2012
+    },
+    {"wkt": "CIRCULARSTRING ZM (1 5 0 1, 6 2 0 2, 7 3 0 3)",
+     "name": "CircularStringZM",
+     "num": 3008
+    },
+    {"wkt": "COMPOUNDCURVE ZM ((5 3 0 0, 5 13 0 0), CIRCULARSTRING ZM (5 13 0 0, 7 15 0 0, 9 13 0 0), (9 13 0 0, 9 3 0 0), CIRCULARSTRING ZM (9 3 0 0, 7 1 0 0, 5 3 0 0))",
+     "name": "CompoundCurveZM",
+     "num": 3009
+    },
+    {"wkt": "CURVEPOLYGON ZM (CIRCULARSTRING ZM (0 0 0 0, 4 0 0 0, 4 4 0 0, 0 4 0 0, 0 0 0 0), (1 1 0 0, 3 3 0 0, 3 1 0 0, 1 1 0 0))",
+     "name": "CurvePolygonZM",
+     "num": 3010
+    },
+    {"wkt": "MULTICURVE ZM ((0 0 0 1, 5 5 0 2), CIRCULARSTRING ZM (4 0 0 0, 4 4 0 0, 8 4 0 0))",
+     "name": "MultiCurveZM",
+     "num": 3011
+    },
+    {"wkt": "MULTISURFACE ZM (((0 0 0 1, 0 1 0 2, 1 1 0 3, 1 0 0 4, 0 0 0 5)), ((1 1 0 0, 1 2 0 0, 2 2 0 0, 2 1 0 0, 1 1 0 0)))",
+     "name": "MultiSurfaceZM",
+     "num": 3012
+    }
   ]
 }