GDAL

Concrete representation of a closed ring. More...
#include <ogr_geometry.h>
Public Types  
typedef OGRPoint  ChildType 
Type of child elements.  
Public Member Functions  
OGRLinearRing ()  
Constructor.  
OGRLinearRing (const OGRLinearRing &other)  
Copy constructor. More...  
OGRLinearRing (OGRLinearRing *)  
Constructor. More...  
OGRLinearRing &  operator= (const OGRLinearRing &other) 
Assignment operator. More...  
virtual const char *  getGeometryName () const override 
Fetch WKT name for geometry type. More...  
virtual OGRLinearRing *  clone () const override 
Make a copy of this object. More...  
virtual void  reverseWindingOrder () 
Reverse order of points.  
virtual void  closeRings () override 
Force rings to be closed. More...  
OGRBoolean  isPointInRing (const OGRPoint *pt, int bTestEnvelope=TRUE) const 
Returns whether the point is inside the ring. More...  
OGRBoolean  isPointOnRingBoundary (const OGRPoint *pt, int bTestEnvelope=TRUE) const 
Returns whether the point is on the ring boundary. More...  
virtual OGRErr  transform (OGRCoordinateTransformation *poCT) override 
Apply arbitrary coordinate transformation to geometry. More...  
OGRLineString *  toUpperClass () 
Return pointer of this in upper class.  
const OGRLineString *  toUpperClass () const 
Return pointer of this in upper class.  
virtual void  accept (IOGRGeometryVisitor *visitor) override 
Accept a visitor. More...  
virtual void  accept (IOGRConstGeometryVisitor *visitor) const override 
Accept a visitor. More...  
virtual OGRLineString *  CurveToLine (double dfMaxAngleStepSizeDegrees=0, const char *const *papszOptions=nullptr) const override 
Return a linestring from a curve geometry. More...  
virtual OGRGeometry *  getCurveGeometry (const char *const *papszOptions=nullptr) const override 
Return curve version of this geometry. More...  
virtual double  get_Area () const override 
Get the area of the (closed) curve. More...  
virtual OGRwkbGeometryType  getGeometryType () const override 
Fetch geometry type. More...  
virtual int  isClockwise () const override 
Returns TRUE if the ring has clockwise winding (or less than 2 points) More...  
Iterator  begin () 
Return begin of point iterator. More...  
ConstIterator  begin () const 
Return begin of point iterator. More...  
Iterator  end () 
Return end of point iterator.  
ConstIterator  end () const 
Return end of point iterator.  
OGRErr  importFromWkb (const GByte *, size_t=static_cast< size_t >(1), OGRwkbVariant=wkbVariantOldOgc) 
Assign geometry from well known binary data. More...  
OGRErr  importFromWkt (const char **) override 
deprecated More...  
virtual OGRErr  importFromWkt (const char **ppszInput)=0 
Assign geometry from well known text data. More...  
OGRErr  importFromWkt (char **ppszInput) 
Deprecated. More...  
virtual std::string  exportToWkt (const OGRWktOptions &opts=OGRWktOptions(), OGRErr *err=nullptr) const override 
Export a simple curve to WKT. More...  
OGRErr  exportToWkt (char **ppszDstText, OGRwkbVariant=wkbVariantOldOgc) const 
Convert a geometry into well known text format. More...  
virtual std::string  exportToWkt (const OGRWktOptions &opts=OGRWktOptions(), OGRErr *err=nullptr) const=0 
Export a WKT geometry. More...  
virtual void  empty () override 
Clear geometry information. More...  
virtual void  getEnvelope (OGREnvelope *psEnvelope) const override 
Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure. More...  
virtual void  getEnvelope (OGREnvelope3D *psEnvelope) const override 
Computes and returns the bounding envelope (3D) for this geometry in the passed psEnvelope structure. More...  
virtual OGRBoolean  IsEmpty () const override 
Returns TRUE (nonzero) if the object has no points. More...  
virtual double  get_Length () const override 
Returns the length of the curve. More...  
virtual void  StartPoint (OGRPoint *) const override 
Return the curve start point. More...  
virtual void  EndPoint (OGRPoint *) const override 
Return the curve end point. More...  
virtual void  Value (double, OGRPoint *) const override 
Fetch point at given distance along curve. More...  
virtual double  Project (const OGRPoint *) const 
Project point on linestring. More...  
virtual OGRLineString *  getSubLine (double, double, int) const 
Get the portion of linestring. More...  
virtual int  getNumPoints () const override 
Fetch vertex count. More...  
void  getPoint (int, OGRPoint *) const 
Fetch a point in line string. More...  
double  getX (int i) const 
Get X at vertex. More...  
double  getY (int i) const 
Get Y at vertex. More...  
double  getZ (int i) const 
Get Z at vertex. More...  
double  getM (int i) const 
Get measure at vertex. More...  
virtual OGRBoolean  Equals (const OGRGeometry *) const override 
Returns TRUE if two geometries are equivalent. More...  
virtual void  setCoordinateDimension (int nDimension) override 
Set the coordinate dimension. More...  
virtual void  set3D (OGRBoolean bIs3D) override 
Add or remove the Z coordinate dimension. More...  
virtual void  setMeasured (OGRBoolean bIsMeasured) override 
Add or remove the M coordinate dimension. More...  
void  setNumPoints (int nNewPointCount, int bZeroizeNewContent=TRUE) 
Set number of points in geometry. More...  
void  setPoint (int, OGRPoint *) 
Set the location of a vertex in line string. More...  
void  setPoint (int, double, double) 
Set the location of a vertex in line string. More...  
void  setPoint (int, double, double, double) 
Set the location of a vertex in line string. More...  
void  setPoint (int, double, double, double, double) 
Set the location of a vertex in line string. More...  
void  setZ (int, double) 
Set the Z of a vertex in line string. More...  
void  setM (int, double) 
Set the M of a vertex in line string. More...  
void  setPointM (int, double, double, double) 
Set the location of a vertex in line string. More...  
void  setPoints (int, const OGRRawPoint *, const double *=nullptr) 
Assign all points in a line string. More...  
void  setPoints (int, const OGRRawPoint *, const double *, const double *) 
Assign all points in a line string. More...  
void  setPoints (int, const double *padfX, const double *padfY, const double *padfZIn=nullptr) 
Assign all points in a line string. More...  
void  setPoints (int, const double *padfX, const double *padfY, const double *padfZIn, const double *padfMIn) 
Assign all points in a line string. More...  
void  setPointsM (int, const OGRRawPoint *, const double *) 
Assign all points in a line string. More...  
void  setPointsM (int, const double *padfX, const double *padfY, const double *padfMIn=nullptr) 
Assign all points in a line string. More...  
void  addPoint (const OGRPoint *) 
Add a point to a line string. More...  
void  addPoint (double, double) 
Add a point to a line string. More...  
void  addPoint (double, double, double) 
Add a point to a line string. More...  
void  addPoint (double, double, double, double) 
Add a point to a line string. More...  
void  addPointM (double, double, double) 
Add a point to a line string. More...  
bool  removePoint (int) 
Remove a point from a line string. More...  
void  getPoints (OGRRawPoint *, double *=nullptr) const 
Returns all points of line string. More...  
void  getPoints (void *pabyX, int nXStride, void *pabyY, int nYStride, void *pabyZ=nullptr, int nZStride=0, void *pabyM=nullptr, int nMStride=0) const 
Returns all points of line string. More...  
void  addSubLineString (const OGRLineString *, int nStartVertex=0, int nEndVertex=1) 
Add a segment of another linestring to this one. More...  
void  reversePoints (void) 
Reverse point order. More...  
virtual OGRPointIterator *  getPointIterator () const override 
Returns a point iterator over the curve. More...  
virtual void  flattenTo2D () override 
Convert geometry to strictly 2D. More...  
virtual void  segmentize (double dfMaxLength) override 
Modify the geometry such it has no segment longer then the given distance. More...  
virtual void  swapXY () override 
Swap x and y coordinates. More...  
virtual int  get_IsClosed () const 
Return TRUE if curve is closed. More...  
virtual int  getDimension () const override 
Get the dimension of this object. More...  
virtual OGRBoolean  IsConvex () const 
Returns if a (closed) curve forms a convex shape. More...  
OGRSimpleCurve *  toSimpleCurve () 
Downcast to OGRSimpleCurve*. More...  
const OGRSimpleCurve *  toSimpleCurve () const 
Downcast to OGRSimpleCurve*. More...  
bool  operator== (const OGRGeometry &other) const 
Returns if two geometries are equal.  
bool  operator!= (const OGRGeometry &other) const 
Returns if two geometries are different.  
virtual int  getCoordinateDimension () const 
Get the dimension of the coordinates in this object. More...  
int  CoordinateDimension () const 
Get the dimension of the coordinates in this object. More...  
virtual OGRBoolean  IsValid () const 
Test if the geometry is valid. More...  
virtual OGRGeometry *  MakeValid (CSLConstList papszOptions=nullptr) const 
Attempts to make an invalid geometry valid without losing vertices. More...  
virtual OGRGeometry *  Normalize () const 
Attempts to bring geometry into normalized/canonical form. More...  
virtual OGRBoolean  IsSimple () const 
Test if the geometry is simple. More...  
OGRBoolean  Is3D () const 
OGRBoolean  IsMeasured () const 
virtual OGRBoolean  IsRing () const 
Test if the geometry is a ring. More...  
OGRwkbGeometryType  getIsoGeometryType () const 
Get the geometry type that conforms with ISO SQL/MM Part3. More...  
void  dumpReadable (FILE *, const char *=nullptr, CSLConstList papszOptions=nullptr) const 
Dump geometry in well known text format to indicated output file. More...  
std::string  dumpReadable (const char *=nullptr, CSLConstList papszOptions=nullptr) const 
Dump geometry in well known text format to indicated output file. More...  
virtual char *  exportToGML (const char *const *papszOptions=nullptr) const 
Convert a geometry into GML format. More...  
virtual char *  exportToKML () const 
Convert a geometry into KML format. More...  
virtual char *  exportToJson () const 
Convert a geometry into GeoJSON format. More...  
virtual GEOSGeom  exportToGEOS (GEOSContextHandle_t hGEOSCtxt) const 
Returns a GEOSGeom object corresponding to the geometry. More...  
virtual OGRBoolean  hasCurveGeometry (int bLookForNonLinear=FALSE) const 
Returns if this geometry is or has curve geometry. More...  
virtual OGRGeometry *  getLinearGeometry (double dfMaxAngleStepSizeDegrees=0, const char *const *papszOptions=nullptr) const 
Return, possibly approximate, noncurve version of this geometry. More...  
virtual void  assignSpatialReference (const OGRSpatialReference *poSR) 
Assign spatial reference to this object. More...  
const OGRSpatialReference *  getSpatialReference (void) const 
Returns spatial reference system for object. More...  
OGRErr  transformTo (const OGRSpatialReference *poSR) 
Transform geometry to new spatial reference system. More...  
virtual OGRBoolean  Intersects (const OGRGeometry *) const 
Do these features intersect? More...  
virtual OGRBoolean  Disjoint (const OGRGeometry *) const 
Test for disjointness. More...  
virtual OGRBoolean  Touches (const OGRGeometry *) const 
Test for touching. More...  
virtual OGRBoolean  Crosses (const OGRGeometry *) const 
Test for crossing. More...  
virtual OGRBoolean  Within (const OGRGeometry *) const 
Test for containment. More...  
virtual OGRBoolean  Contains (const OGRGeometry *) const 
Test for containment. More...  
virtual OGRBoolean  Overlaps (const OGRGeometry *) const 
Test for overlap. More...  
virtual OGRGeometry *  Boundary () const 
Compute boundary. More...  
virtual double  Distance (const OGRGeometry *) const 
Compute distance between two geometries. More...  
virtual OGRGeometry *  ConvexHull () const 
Compute convex hull. More...  
virtual OGRGeometry *  ConcaveHull (double dfRatio, bool bAllowHoles) const 
Compute "concave hull" of a geometry. More...  
virtual OGRGeometry *  Buffer (double dfDist, int nQuadSegs=30) const 
Compute buffer of geometry. More...  
virtual OGRGeometry *  Intersection (const OGRGeometry *) const 
Compute intersection. More...  
virtual OGRGeometry *  Union (const OGRGeometry *) const 
Compute union. More...  
virtual OGRGeometry *  UnionCascaded () const 
Compute union using cascading. More...  
OGRGeometry *  UnaryUnion () const 
Returns the union of all components of a single geometry. More...  
virtual OGRGeometry *  Difference (const OGRGeometry *) const 
Compute difference. More...  
virtual OGRGeometry *  SymDifference (const OGRGeometry *) const 
Compute symmetric difference. More...  
virtual OGRErr  Centroid (OGRPoint *poPoint) const 
Compute the geometry centroid. More...  
virtual OGRGeometry *  Simplify (double dTolerance) const 
Simplify the geometry. More...  
OGRGeometry *  SimplifyPreserveTopology (double dTolerance) const 
Simplify the geometry while preserving topology. More...  
virtual OGRGeometry *  DelaunayTriangulation (double dfTolerance, int bOnlyEdges) const 
Return a Delaunay triangulation of the vertices of the geometry. More...  
virtual OGRGeometry *  Polygonize () const 
Polygonizes a set of sparse edges. More...  
virtual double  Distance3D (const OGRGeometry *poOtherGeom) const 
Returns the 3D distance between two geometries. More...  
OGRPoint *  toPoint () 
Downcast to OGRPoint*. More...  
const OGRPoint *  toPoint () const 
Downcast to OGRPoint*. More...  
OGRCurve *  toCurve () 
Downcast to OGRCurve*. More...  
const OGRCurve *  toCurve () const 
Downcast to OGRCurve*. More...  
OGRLineString *  toLineString () 
Downcast to OGRLineString*. More...  
const OGRLineString *  toLineString () const 
Downcast to OGRLineString*. More...  
OGRLinearRing *  toLinearRing () 
Downcast to OGRLinearRing*. More...  
const OGRLinearRing *  toLinearRing () const 
Downcast to OGRLinearRing*. More...  
OGRCircularString *  toCircularString () 
Downcast to OGRCircularString*. More...  
const OGRCircularString *  toCircularString () const 
Downcast to OGRCircularString*. More...  
OGRCompoundCurve *  toCompoundCurve () 
Downcast to OGRCompoundCurve*. More...  
const OGRCompoundCurve *  toCompoundCurve () const 
Downcast to OGRCompoundCurve*. More...  
OGRSurface *  toSurface () 
Downcast to OGRSurface*. More...  
const OGRSurface *  toSurface () const 
Downcast to OGRSurface*. More...  
OGRPolygon *  toPolygon () 
Downcast to OGRPolygon*. More...  
const OGRPolygon *  toPolygon () const 
Downcast to OGRPolygon*. More...  
OGRTriangle *  toTriangle () 
Downcast to OGRTriangle*. More...  
const OGRTriangle *  toTriangle () const 
Downcast to OGRTriangle*. More...  
OGRCurvePolygon *  toCurvePolygon () 
Downcast to OGRCurvePolygon*. More...  
const OGRCurvePolygon *  toCurvePolygon () const 
Downcast to OGRCurvePolygon*. More...  
OGRGeometryCollection *  toGeometryCollection () 
Downcast to OGRGeometryCollection*. More...  
const OGRGeometryCollection *  toGeometryCollection () const 
Downcast to OGRGeometryCollection*. More...  
OGRMultiPoint *  toMultiPoint () 
Downcast to OGRMultiPoint*. More...  
const OGRMultiPoint *  toMultiPoint () const 
Downcast to OGRMultiPoint*. More...  
OGRMultiLineString *  toMultiLineString () 
Downcast to OGRMultiLineString*. More...  
const OGRMultiLineString *  toMultiLineString () const 
Downcast to OGRMultiLineString*. More...  
OGRMultiPolygon *  toMultiPolygon () 
Downcast to OGRMultiPolygon*. More...  
const OGRMultiPolygon *  toMultiPolygon () const 
Downcast to OGRMultiPolygon*. More...  
OGRMultiCurve *  toMultiCurve () 
Downcast to OGRMultiCurve*. More...  
const OGRMultiCurve *  toMultiCurve () const 
Downcast to OGRMultiCurve*. More...  
OGRMultiSurface *  toMultiSurface () 
Downcast to OGRMultiSurface*. More...  
const OGRMultiSurface *  toMultiSurface () const 
Downcast to OGRMultiSurface*. More...  
OGRPolyhedralSurface *  toPolyhedralSurface () 
Downcast to OGRPolyhedralSurface*. More...  
const OGRPolyhedralSurface *  toPolyhedralSurface () const 
Downcast to OGRPolyhedralSurface*. More...  
OGRTriangulatedSurface *  toTriangulatedSurface () 
Downcast to OGRTriangulatedSurface*. More...  
const OGRTriangulatedSurface *  toTriangulatedSurface () const 
Downcast to OGRTriangulatedSurface*. More...  
Static Public Member Functions  
static OGRLinearRing *  CastToLinearRing (OGRCurve *poCurve) 
Cast to linear ring. More...  
static OGRCompoundCurve *  CastToCompoundCurve (OGRCurve *puCurve) 
Cast to compound curve. More...  
static OGRLineString *  CastToLineString (OGRCurve *poCurve) 
Cast to linestring. More...  
static GEOSContextHandle_t  createGEOSContext () 
Create a new GEOS context. More...  
static void  freeGEOSContext (GEOSContextHandle_t hGEOSCtxt) 
Destroy a GEOS context. More...  
static OGRGeometryH  ToHandle (OGRGeometry *poGeom) 
Convert a OGRGeometry* to a OGRGeometryH. More...  
static OGRGeometry *  FromHandle (OGRGeometryH hGeom) 
Convert a OGRGeometryH to a OGRGeometry*. More...  
Protected Member Functions  
virtual double  get_LinearArea () const 
Compute area of ring / closed linestring. More...  
virtual int  ContainsPoint (const OGRPoint *p) const 
Returns if a point is contained in a (closed) curve. More...  
virtual int  IntersectsPoint (const OGRPoint *p) const 
Returns if a point intersects a (closed) curve. More...  
virtual double  get_AreaOfCurveSegments () const =0 
Get the area of the purely curve portions of a (closed) curve. More...  
Static Protected Member Functions  
static OGRLineString *  CastToLineString (OGRLinearRing *poLR) 
Cast to line string. More...  
static OGRLinearRing *  CastToLinearRing (OGRLineString *poLS) 
Cast to linear ring. More...  
Concrete representation of a closed ring.
This class is functionally equivalent to an OGRLineString, but has a separate identity to maintain alignment with the OpenGIS simple feature data model. It exists to serve as a component of an OGRPolygon.
The OGRLinearRing has no corresponding free standing well known binary representation, so importFromWkb() and exportToWkb() will not actually work. There is a nonstandard GDAL WKT representation though.
Because OGRLinearRing is not a "proper" free standing simple features object, it cannot be directly used on a feature via SetGeometry(), and cannot generally be used with GEOS for operations like Intersects(). Instead the polygon should be used, or the OGRLinearRing should be converted to an OGRLineString for such operations.
Note: this class exists in SFSQL 1.2, but not in ISO SQL/MM Part 3.

default 
Copy constructor.
Note: before GDAL 2.1, only the default implementation of the constructor existed, which could be unsafe to use.

explicit 
Constructor.
poSrcRing  source ring. 

inlineoverridevirtual 
Accept a visitor.
Reimplemented from OGRLineString.

inlineoverridevirtual 
Accept a visitor.
Reimplemented from OGRLineString.

inherited 
Add a point to a line string.
The vertex count of the line string is increased by one, and assigned from the passed location value.
There is no SFCOM analog to this method.
poPoint  the point to assign to the new vertex. 

inherited 
Add a point to a line string.
The vertex count of the line string is increased by one, and assigned from the passed location value.
There is no SFCOM analog to this method.
x  the X coordinate to assign to the new point. 
y  the Y coordinate to assign to the new point. 

inherited 
Add a point to a line string.
The vertex count of the line string is increased by one, and assigned from the passed location value.
There is no SFCOM analog to this method.
x  the X coordinate to assign to the new point. 
y  the Y coordinate to assign to the new point. 
z  the Z coordinate to assign to the new point (defaults to zero). 

inherited 
Add a point to a line string.
The vertex count of the line string is increased by one, and assigned from the passed location value.
There is no SFCOM analog to this method.
x  the X coordinate to assign to the new point. 
y  the Y coordinate to assign to the new point. 
z  the Z coordinate to assign to the new point (defaults to zero). 
m  the M coordinate to assign to the new point (defaults to zero). 

inherited 
Add a point to a line string.
The vertex count of the line string is increased by one, and assigned from the passed location value.
There is no SFCOM analog to this method.
x  the X coordinate to assign to the new point. 
y  the Y coordinate to assign to the new point. 
m  the M coordinate to assign to the new point. 

inherited 
Add a segment of another linestring to this one.
Adds the request range of vertices to the end of this line string in an efficient manner. If the nStartVertex is larger than the nEndVertex then the vertices will be reversed as they are copied.
poOtherLine  the other OGRLineString. 
nStartVertex  the first vertex to copy, defaults to 0 to start with the first vertex in the other linestring. 
nEndVertex  the last vertex to copy, defaults to 1 indicating the last vertex of the other line string. 

virtualinherited 
Assign spatial reference to this object.
Any existing spatial reference is replaced, but under no circumstances does this result in the object being reprojected. It is just changing the interpretation of the existing geometry. Note that assigning a spatial reference increments the reference count on the OGRSpatialReference, but does not copy it.
Starting with GDAL 2.3, this will also assign the spatial reference to potential subgeometries of the geometry (OGRGeometryCollection, OGRCurvePolygon/OGRPolygon, OGRCompoundCurve, OGRPolyhedralSurface and their derived classes).
This is similar to the SFCOM IGeometry::put_SpatialReference() method.
This method is the same as the C function OGR_G_AssignSpatialReference().
poSR  new spatial reference system to apply. 
Reimplemented in OGRCompoundCurve, OGRCurvePolygon, OGRGeometryCollection, and OGRPolyhedralSurface.

inherited 
Return begin of point iterator.
Using this iterator for standard rangebased loops is safe, but due to implementation limitations, you shouldn't try to access (dereference) more than one iterator step at a time, since you will get a reference to the same OGRPoint& object.

inherited 
Return begin of point iterator.
Using this iterator for standard rangebased loops is safe, but due to implementation limitations, you shouldn't try to access (dereference) more than one iterator step at a time, since you will get a reference to the same OGRPoint& object.

virtualinherited 
Compute boundary.
A new geometry object is created and returned containing the boundary of the geometry on which the method is invoked.
This method is the same as the C function OGR_G_Boundary().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.

virtualinherited 
Compute buffer of geometry.
Builds a new geometry containing the buffer region around the geometry on which it is invoked. The buffer is a polygon containing the region within the buffer distance of the original geometry.
Some buffer sections are properly described as curves, but are converted to approximate polygons. The nQuadSegs parameter can be used to control how many segments should be used to define a 90 degree curve  a quadrant of a circle. A value of 30 is a reasonable default. Large values result in large numbers of vertices in the resulting buffer geometry while small numbers reduce the accuracy of the result.
This method is the same as the C function OGR_G_Buffer().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
dfDist  the buffer distance to be applied. Should be expressed into the same unit as the coordinates of the geometry. 
nQuadSegs  the number of segments used to approximate a 90 degree (quadrant) of curvature. 

staticinherited 
Cast to compound curve.
The passed in geometry is consumed and a new one returned (or NULL in case of failure)
poCurve  the input geometry  ownership is passed to the method. 

staticinherited 
Cast to linear ring.
The passed in geometry is consumed and a new one returned (or NULL in case of failure)
poCurve  the input geometry  ownership is passed to the method. 

staticprotectedinherited 
Cast to linear ring.
The passed in geometry is consumed and a new one returned (or NULL in case of failure)
poLS  the input geometry  ownership is passed to the method. 

staticinherited 
Cast to linestring.
The passed in geometry is consumed and a new one returned (or NULL in case of failure)
poCurve  the input geometry  ownership is passed to the method. 

staticprotected 
Cast to line string.
The passed in geometry is consumed and a new one returned .
poLR  the input geometry  ownership is passed to the method. 
Compute the geometry centroid.
The centroid location is applied to the passed in OGRPoint object. The centroid is not necessarily within the geometry.
This method relates to the SFCOM ISurface::get_Centroid() method however the current implementation based on GEOS can operate on other geometry types such as multipoint, linestring, geometrycollection such as multipolygons. OGC SF SQL 1.1 defines the operation for surfaces (polygons). SQL/MMPart 3 defines the operation for surfaces and multisurfaces (multipolygons).
This function is the same as the C function OGR_G_Centroid().
This function is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this function will always fail, issuing a CPLE_NotSupported error.

overridevirtual 
Make a copy of this object.
This method relates to the SFCOM IGeometry::clone() method.
This method is the same as the C function OGR_G_Clone().
Reimplemented from OGRLineString.

overridevirtual 
Force rings to be closed.
If this geometry, or any contained geometries has polygon rings that are not closed, they will be closed by adding the starting point at the end.
Reimplemented from OGRGeometry.

virtualinherited 
Compute "concave hull" of a geometry.
The concave hull is fully contained within the convex hull and also contains all the points of the input, but in a smaller area. The area ratio is the ratio of the area of the convex hull and the concave hull. Frequently used to convert a multipoint into a polygonal area. that contains all the points in the input Geometry.
A new geometry object is created and returned containing the concave hull of the geometry on which the method is invoked.
This method is the same as the C function OGR_G_ConcaveHull().
This method is built on the GEOS >= 3.11 library If OGR is built without the GEOS >= 3.11 librray, this method will always fail, issuing a CPLE_NotSupported error.
dfRatio  Ratio of the area of the convex hull and the concave hull. 
bAllowHoles  Whether holes are allowed. 

virtualinherited 
Test for containment.
Tests if actual geometry object contains the passed geometry.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Contains().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 
Reimplemented in OGRCurvePolygon.

protectedvirtualinherited 
Returns if a point is contained in a (closed) curve.
Final users should use OGRGeometry::Contains() instead.
p  the point to test 

virtualinherited 
Compute convex hull.
A new geometry object is created and returned containing the convex hull of the geometry on which the method is invoked.
This method is the same as the C function OGR_G_ConvexHull().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.

inherited 
Get the dimension of the coordinates in this object.
This method is the same as the C function OGR_G_CoordinateDimension().

staticinherited 
Create a new GEOS context.

virtualinherited 
Test for crossing.
Tests if this geometry and the other passed into the method are crossing.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Crosses().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 

overridevirtualinherited 
Return a linestring from a curve geometry.
The returned geometry is a new instance whose ownership belongs to the caller.
If the dfMaxAngleStepSizeDegrees is zero, then a default value will be used. This is currently 4 degrees unless the user has overridden the value with the OGR_ARC_STEPSIZE configuration variable.
This method relates to the ISO SQL/MM Part 3 ICurve::CurveToLine() method.
This function is the same as C function OGR_G_CurveToLine().
dfMaxAngleStepSizeDegrees  the largest step in degrees along the arc, zero to use the default setting. 
papszOptions  options as a nullterminated list of strings or NULL. See OGRGeometryFactory::curveToLineString() for valid options. 
Implements OGRCurve.

virtualinherited 
Return a Delaunay triangulation of the vertices of the geometry.
This function is the same as the C function OGR_G_DelaunayTriangulation().
This function is built on the GEOS library, v3.4 or above. If OGR is built without the GEOS library, this function will always fail, issuing a CPLE_NotSupported error.
dfTolerance  optional snapping tolerance to use for improved robustness 
bOnlyEdges  if TRUE, will return a MULTILINESTRING, otherwise it will return a GEOMETRYCOLLECTION containing triangular POLYGONs. 

virtualinherited 
Compute difference.
Generates a new geometry which is the region of this geometry with the region of the second geometry removed.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Difference().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the other geometry removed from "this" geometry. 

virtualinherited 
Test for disjointness.
Tests if this geometry and the other passed into the method are disjoint.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Disjoint().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 

virtualinherited 
Compute distance between two geometries.
Returns the shortest distance between the two geometries. The distance is expressed into the same unit as the coordinates of the geometries.
This method is the same as the C function OGR_G_Distance().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the other geometry to compare against. 

virtualinherited 
Returns the 3D distance between two geometries.
The distance is expressed into the same unit as the coordinates of the geometries.
This method is built on the SFCGAL library, check it for the definition of the geometry operation. If OGR is built without the SFCGAL library, this method will always return 1.0
This function is the same as the C function OGR_G_Distance3D().

inherited 
Dump geometry in well known text format to indicated output file.
A few options can be defined to change the default dump :
pszPrefix  the prefix to put on each line of output. 
papszOptions  NULL terminated list of options (may be NULL) 

inherited 
Dump geometry in well known text format to indicated output file.
A few options can be defined to change the default dump :
This method is the same as the C function OGR_G_DumpReadable().
fp  the text file to write the geometry to. 
pszPrefix  the prefix to put on each line of output. 
papszOptions  NULL terminated list of options (may be NULL) 

overridevirtualinherited 
Clear geometry information.
This restores the geometry to its initial state after construction, and before assignment of actual geometry.
This method relates to the SFCOM IGeometry::Empty() method.
This method is the same as the C function OGR_G_Empty().
Implements OGRGeometry.

overridevirtualinherited 
Return the curve end point.
This method relates to the SF COM ICurve::get_EndPoint() method.
poPoint  the point to be assigned the end location. 
Implements OGRCurve.

overridevirtualinherited 
Returns TRUE if two geometries are equivalent.
This operation implements the SQL/MM ST_OrderingEquals() operation.
The comparison is done in a structural way, that is to say that the geometry types must be identical, as well as the number and ordering of subgeometries and vertices. Or equivalently, two geometries are considered equal by this method if their WKT/WKB representation is equal. Note: this must be distinguished for equality in a spatial way (which is the purpose of the ST_Equals() operation).
This method is the same as the C function OGR_G_Equals().
Implements OGRGeometry.

virtualinherited 
Returns a GEOSGeom object corresponding to the geometry.
hGEOSCtxt  GEOS context 

virtualinherited 
Convert a geometry into GML format.
The GML geometry is expressed directly in terms of GML basic data types assuming the this is available in the gml namespace. The returned string should be freed with CPLFree() when no longer required.
The supported options in OGR 1.8.0 are :
This method is the same as the C function OGR_G_ExportToGMLEx().
papszOptions  NULLterminated list of options. 

virtualinherited 
Convert a geometry into GeoJSON format.
The returned string should be freed with CPLFree() when no longer required.
This method is the same as the C function OGR_G_ExportToJson().

virtualinherited 
Convert a geometry into KML format.
The returned string should be freed with CPLFree() when no longer required.
This method is the same as the C function OGR_G_ExportToKML().

inherited 
Convert a geometry into well known text format.
This method relates to the SFCOM IWks::ExportToWKT() method.
This method is the same as the C function OGR_G_ExportToWkt().
ppszDstText  a text buffer is allocated by the program, and assigned to the passed pointer. After use, *ppszDstText should be freed with CPLFree(). 
variant  the specification that must be conformed too :


overridevirtualinherited 
Export a simple curve to WKT.
opts  Output options. 
err  Pointer to error code, if desired. 
Implements OGRGeometry.
Reimplemented in OGRCircularString, and OGRCircularString.

virtualinherited 
Export a WKT geometry.
opts  Output options. 
err  Pointer to error code, if desired. 
Implements OGRGeometry.
Reimplemented in OGRCircularString.

overridevirtualinherited 
Convert geometry to strictly 2D.
In a sense this converts all Z coordinates to 0.0.
This method is the same as the C function OGR_G_FlattenTo2D().
Implements OGRGeometry.

staticinherited 
Destroy a GEOS context.
hGEOSCtxt  GEOS context 

inlinestaticinherited 
Convert a OGRGeometryH to a OGRGeometry*.

overridevirtualinherited 
Get the area of the (closed) curve.
This method is designed to be used by OGRCurvePolygon::get_Area().
Implements OGRCurve.

protectedpure virtualinherited 
Get the area of the purely curve portions of a (closed) curve.
This method is designed to be used on a closed convex curve.
Implemented in OGRCompoundCurve.

virtualinherited 
Return TRUE if curve is closed.
Tests if a curve is closed. A curve is closed if its start point is equal to its end point.
For equality tests, the M dimension is ignored.
This method relates to the SFCOM ICurve::get_IsClosed() method.

overridevirtualinherited 
Returns the length of the curve.
This method relates to the SFCOM ICurve::get_Length() method.
Implements OGRCurve.
Reimplemented in OGRCircularString.

protectedvirtualinherited 
Compute area of ring / closed linestring.
The area is computed according to Green's Theorem:
Area is "Sum(x(i)*(y(i+1)  y(i1)))/2" for i = 0 to pointCount1, assuming the last point is a duplicate of the first.

virtualinherited 
Get the dimension of the coordinates in this object.
This method is the same as the C function OGR_G_GetCoordinateDimension().

overridevirtualinherited 
Return curve version of this geometry.
Returns a geometry that has possibly CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE in it, by deapproximating curve geometries.
If the geometry has no curve portion, the returned geometry will be a clone of it.
The ownership of the returned geometry belongs to the caller.
The reverse method is OGRGeometry::getLinearGeometry().
This function is the same as C function OGR_G_GetCurveGeometry().
papszOptions  options as a nullterminated list of strings. Unused for now. Must be set to NULL. 
Reimplemented from OGRGeometry.

overridevirtualinherited 
Get the dimension of this object.
This method corresponds to the SFCOM IGeometry::GetDimension() method. It indicates the dimension of the object, but does not indicate the dimension of the underlying space (as indicated by OGRGeometry::getCoordinateDimension()).
This method is the same as the C function OGR_G_GetDimension().
Implements OGRGeometry.

overridevirtualinherited 
Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure.
This method is the same as the C function OGR_G_GetEnvelope().
psEnvelope  the structure in which to place the results. 
Implements OGRGeometry.
Reimplemented in OGRCircularString.

overridevirtualinherited 
Computes and returns the bounding envelope (3D) for this geometry in the passed psEnvelope structure.
This method is the same as the C function OGR_G_GetEnvelope3D().
psEnvelope  the structure in which to place the results. 
Implements OGRGeometry.
Reimplemented in OGRCircularString.

overridevirtual 
Fetch WKT name for geometry type.
There is no SFCOM analog to this method.
This method is the same as the C function OGR_G_GetGeometryName().
Reimplemented from OGRLineString.

overridevirtualinherited 
Fetch geometry type.
Note that the geometry type may include the 2.5D flag. To get a 2D flattened version of the geometry type apply the wkbFlatten() macro to the return result.
This method is the same as the C function OGR_G_GetGeometryType().
Implements OGRGeometry.

inherited 
Get the geometry type that conforms with ISO SQL/MM Part3.

virtualinherited 
Return, possibly approximate, noncurve version of this geometry.
Returns a geometry that has no CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE in it, by approximating curve geometries.
The ownership of the returned geometry belongs to the caller.
The reverse method is OGRGeometry::getCurveGeometry().
This method is the same as the C function OGR_G_GetLinearGeometry().
dfMaxAngleStepSizeDegrees  the largest step in degrees along the arc, zero to use the default setting. 
papszOptions  options as a nullterminated list of strings. See OGRGeometryFactory::curveToLineString() for valid options. 
Reimplemented in OGRCircularString, OGRCompoundCurve, OGRCurvePolygon, OGRPolygon, and OGRGeometryCollection.

inherited 
Get measure at vertex.
Returns the M (measure) value at the indicated vertex. If no M value is available, 0.0 is returned.
iVertex  the vertex to return, between 0 and getNumPoints()1. 

inlineoverridevirtualinherited 
Fetch vertex count.
Returns the number of vertices in the line string.
Implements OGRCurve.

inherited 
Fetch a point in line string.
This method relates to the SFCOM ILineString::get_Point() method.
i  the vertex to fetch, from 0 to getNumPoints()1. 
poPoint  a point to initialize with the fetched point. 

overridevirtualinherited 
Returns a point iterator over the curve.
The curve must not be modified while an iterator exists on it.
The iterator must be destroyed with OGRPointIterator::destroy().
Implements OGRCurve.

inherited 
Returns all points of line string.
This method copies all points into user list. This list must be at least sizeof(OGRRawPoint) * OGRGeometry::getNumPoints() byte in size. It also copies all Z coordinates.
There is no SFCOM analog to this method.
paoPointsOut  a buffer into which the points is written. 
padfZOut  the Z values that go with the points (optional, may be NULL). 

inherited 
Returns all points of line string.
This method copies all points into user arrays. The user provides the stride between 2 consecutive elements of the array.
On some CPU architectures, care must be taken so that the arrays are properly aligned.
There is no SFCOM analog to this method.
pabyX  a buffer of at least (nXStride * nPointCount) bytes, may be NULL. 
nXStride  the number of bytes between 2 elements of pabyX. 
pabyY  a buffer of at least (nYStride * nPointCount) bytes, may be NULL. 
nYStride  the number of bytes between 2 elements of pabyY. 
pabyZ  a buffer of at last size (nZStride * nPointCount) bytes, may be NULL. 
nZStride  the number of bytes between 2 elements of pabyZ. 
pabyM  a buffer of at last size (nMStride * nPointCount) bytes, may be NULL. 
nMStride  the number of bytes between 2 elements of pabyM. 

inlineinherited 
Returns spatial reference system for object.
This method relates to the SFCOM IGeometry::get_SpatialReference() method.
This method is the same as the C function OGR_G_GetSpatialReference().

virtualinherited 
Get the portion of linestring.
The portion of the linestring extracted to new one. The input distances (maybe present as ratio of length of linestring) set begin and end of extracted portion.
dfDistanceFrom  The distance from the origin of linestring, where the subline should begins 
dfDistanceTo  The distance from the origin of linestring, where the subline should ends 
bAsRatio  The flag indicating that distances are the ratio of the linestring length. 

inlineinherited 
Get X at vertex.
Returns the X value at the indicated vertex. If iVertex is out of range a crash may occur, no internal range checking is performed.
iVertex  the vertex to return, between 0 and getNumPoints()1. 

inlineinherited 
Get Y at vertex.
Returns the Y value at the indicated vertex. If iVertex is out of range a crash may occur, no internal range checking is performed.
iVertex  the vertex to return, between 0 and getNumPoints()1. 

inherited 
Get Z at vertex.
Returns the Z (elevation) value at the indicated vertex. If no Z value is available, 0.0 is returned. If iVertex is out of range a crash may occur, no internal range checking is performed.
iVertex  the vertex to return, between 0 and getNumPoints()1. 

virtualinherited 
Returns if this geometry is or has curve geometry.
Returns if a geometry is, contains or may contain a CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE or MULTISURFACE.
If bLookForNonLinear is set to TRUE, it will be actually looked if the geometry or its subgeometries are or contain a nonlinear geometry in them. In which case, if the method returns TRUE, it means that getLinearGeometry() would return an approximate version of the geometry. Otherwise, getLinearGeometry() would do a conversion, but with just converting container type, like COMPOUNDCURVE > LINESTRING, MULTICURVE > MULTILINESTRING or MULTISURFACE > MULTIPOLYGON, resulting in a "lossless" conversion.
This method is the same as the C function OGR_G_HasCurveGeometry().
bLookForNonLinear  set it to TRUE to check if the geometry is or contains a CIRCULARSTRING. 
Reimplemented in OGRCircularString, OGRCompoundCurve, OGRCurvePolygon, OGRPolygon, OGRGeometryCollection, OGRMultiSurface, OGRMultiPolygon, OGRPolyhedralSurface, OGRMultiPoint, OGRMultiCurve, and OGRMultiLineString.

inherited 
Assign geometry from well known binary data.
The object must have already been instantiated as the correct derived type of geometry object to match the binaries type. This method is used by the OGRGeometryFactory class, but not normally called by application code.
This method relates to the SFCOM IWks::ImportFromWKB() method.
This method is the same as the C function OGR_G_ImportFromWkb().
pabyData  the binary input data. 
nSize  the size of pabyData in bytes, or 1 if not known. 
eWkbVariant  if wkbVariantPostGIS1, special interpretation is done for curve geometries code 

inlineinherited 
Deprecated.

overridevirtualinherited 

virtualinherited 
Assign geometry from well known text data.
The object must have already been instantiated as the correct derived type of geometry object to match the text type. This method is used by the OGRGeometryFactory class, but not normally called by application code.
This method relates to the SFCOM IWks::ImportFromWKT() method.
This method is the same as the C function OGR_G_ImportFromWkt().
ppszInput  pointer to a pointer to the source text. The pointer is updated to pointer after the consumed text. 
Implements OGRGeometry.
Reimplemented in OGRCircularString.

virtualinherited 
Compute intersection.
Generates a new geometry which is the region of intersection of the two geometries operated on. The Intersects() method can be used to test if two geometries intersect.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Intersection().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the other geometry intersected with "this" geometry. 

virtualinherited 
Do these features intersect?
Determines whether two geometries intersect. If GEOS is enabled, then this is done in rigorous fashion otherwise TRUE is returned if the envelopes (bounding boxes) of the two geometries overlap.
The poOtherGeom argument may be safely NULL, but in this case the method will always return TRUE. That is, a NULL geometry is treated as being everywhere.
This method is the same as the C function OGR_G_Intersects().
poOtherGeom  the other geometry to test against. 
Reimplemented in OGRPoint, and OGRCurvePolygon.

protectedvirtualinherited 
Returns if a point intersects a (closed) curve.
Final users should use OGRGeometry::Intersects() instead.
p  the point to test 

inlineinherited 
Returns whether the geometry has a Z component.

overridevirtualinherited 
Returns TRUE if the ring has clockwise winding (or less than 2 points)
Assumes that the line is closed.
Reimplemented from OGRCurve.

virtualinherited 
Returns if a (closed) curve forms a convex shape.

overridevirtualinherited 
Returns TRUE (nonzero) if the object has no points.
Normally this returns FALSE except between when an object is instantiated and points have been assigned.
This method relates to the SFCOM IGeometry::IsEmpty() method.
Implements OGRGeometry.

inlineinherited 
Returns whether the geometry has a M component.
OGRBoolean OGRLinearRing::isPointInRing  (  const OGRPoint *  poPoint, 
int  bTestEnvelope = TRUE 

)  const 
Returns whether the point is inside the ring.
poPoint  point 
bTestEnvelope  set to TRUE if the presence of the point inside the ring envelope must be checked first. 
OGRBoolean OGRLinearRing::isPointOnRingBoundary  (  const OGRPoint *  poPoint, 
int  bTestEnvelope = TRUE 

)  const 
Returns whether the point is on the ring boundary.
poPoint  point 
bTestEnvelope  set to TRUE if the presence of the point inside the ring envelope must be checked first. 

virtualinherited 
Test if the geometry is a ring.
This method is the same as the C function OGR_G_IsRing().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always return FALSE.

virtualinherited 
Test if the geometry is simple.
This method is the same as the C function OGR_G_IsSimple().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always return FALSE.

virtualinherited 
Test if the geometry is valid.
This method is the same as the C function OGR_G_IsValid().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always return FALSE.
Reimplemented in OGRCircularString.

virtualinherited 
Attempts to make an invalid geometry valid without losing vertices.
Alreadyvalid geometries are cloned without further intervention.
Running OGRGeometryFactory::removeLowerDimensionSubGeoms() as a postprocessing step is often desired.
This method is the same as the C function OGR_G_MakeValid().
This function is built on the GEOS >= 3.8 library, check it for the definition of the geometry operation. If OGR is built without the GEOS >= 3.8 library, this function will return a clone of the input geometry if it is valid, or NULL if it is invalid
papszOptions  NULL terminated list of options, or NULL. The following options are available:


virtualinherited 
Attempts to bring geometry into normalized/canonical form.
This method is the same as the C function OGR_G_Normalize().
This function is built on the GEOS library; check it for the definition of the geometry operation. If OGR is built without the GEOS library, this function will always fail, issuing a CPLE_NotSupported error.
OGRLinearRing & OGRLinearRing::operator=  (  const OGRLinearRing &  other  ) 
Assignment operator.
Note: before GDAL 2.1, only the default implementation of the operator existed, which could be unsafe to use.

virtualinherited 
Test for overlap.
Tests if this geometry and the other passed into the method overlap, that is their intersection has a nonzero area.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Overlaps().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 

virtualinherited 
Polygonizes a set of sparse edges.
A new geometry object is created and returned containing a collection of reassembled Polygons: NULL will be returned if the input collection doesn't corresponds to a MultiLinestring, or when reassembling Edges into Polygons is impossible due to topological inconsistencies.
This method is the same as the C function OGR_G_Polygonize().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.

virtualinherited 
Project point on linestring.
The input point projected on linestring. This is the shortest distance from point to the linestring. The distance from begin of linestring to the point projection returned.
This method is built on the GEOS library (GEOS >= 3.2.0), check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always return 1, issuing a CPLE_NotSupported error.

inherited 
Remove a point from a line string.
There is no SFCOM analog to this method.
nIndex  Point index 

inherited 
Reverse point order.
This method updates the points in this line string in place reversing the point ordering (first for last, etc).

overridevirtualinherited 
Modify the geometry such it has no segment longer then the given distance.
This method modifies the geometry to add intermediate vertices if necessary so that the maximum length between 2 consecutive vertices is lower than dfMaxLength.
Interpolated points will have Z and M values (if needed) set to 0. Distance computation is performed in 2d only
This function is the same as the C function OGR_G_Segmentize()
dfMaxLength  the maximum distance between 2 points after segmentization 
Reimplemented from OGRGeometry.
Reimplemented in OGRCircularString.

overridevirtualinherited 
Add or remove the Z coordinate dimension.
This method adds or removes the explicit Z coordinate dimension. Removing the Z coordinate dimension of a geometry will remove any existing Z values. Adding the Z dimension to a geometry collection, a compound curve, a polygon, etc. will affect the children geometries.
bIs3D  Should the geometry have a Z dimension, either TRUE or FALSE. 
Reimplemented from OGRGeometry.

overridevirtualinherited 
Set the coordinate dimension.
This method sets the explicit coordinate dimension. Setting the coordinate dimension of a geometry to 2 should zero out any existing Z values. Setting the dimension of a geometry collection, a compound curve, a polygon, etc. will affect the children geometries. This will also remove the M dimension if present before this call.
nNewDimension  New coordinate dimension value, either 2 or 3. 
Reimplemented from OGRGeometry.

inherited 
Set the M of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
mIn  input M coordinate to assign. 

overridevirtualinherited 
Add or remove the M coordinate dimension.
This method adds or removes the explicit M coordinate dimension. Removing the M coordinate dimension of a geometry will remove any existing M values. Adding the M dimension to a geometry collection, a compound curve, a polygon, etc. will affect the children geometries.
bIsMeasured  Should the geometry have a M dimension, either TRUE or FALSE. 
Reimplemented from OGRGeometry.

inherited 
Set number of points in geometry.
This method primary exists to preset the number of points in a linestring geometry before setPoint() is used to assign them to avoid reallocating the array larger with each call to addPoint().
This method has no SFCOM analog.
nNewPointCount  the new number of points for geometry. 
bZeroizeNewContent  whether to set to zero the new elements of arrays that are extended. 

inherited 
Set the location of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
xIn  input X coordinate to assign. 
yIn  input Y coordinate to assign. 

inherited 
Set the location of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
xIn  input X coordinate to assign. 
yIn  input Y coordinate to assign. 
zIn  input Z coordinate to assign (defaults to zero). 

inherited 
Set the location of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
xIn  input X coordinate to assign. 
yIn  input Y coordinate to assign. 
zIn  input Z coordinate to assign (defaults to zero). 
mIn  input M coordinate to assign (defaults to zero). 

inherited 
Set the location of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
poPoint  the value to assign to the vertex. 

inherited 
Set the location of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
xIn  input X coordinate to assign. 
yIn  input Y coordinate to assign. 
mIn  input M coordinate to assign (defaults to zero). 

inherited 
Assign all points in a line string.
This method clear any existing points assigned to this line string, and assigns a whole new set.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in padfX and padfY. 
padfX  list of X coordinates of points being assigned. 
padfY  list of Y coordinates of points being assigned. 
padfZIn  list of Z coordinates of points being assigned. 
padfMIn  list of M coordinates of points being assigned. 

inherited 
Assign all points in a line string.
This method clear any existing points assigned to this line string, and assigns a whole new set.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in padfX and padfY. 
padfX  list of X coordinates of points being assigned. 
padfY  list of Y coordinates of points being assigned. 
padfZIn  list of Z coordinates of points being assigned (defaults to NULL for 2D objects). 

inherited 
Assign all points in a line string.
This method clears any existing points assigned to this line string, and assigns a whole new set. It is the most efficient way of assigning the value of a line string.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in paoPointsIn 
paoPointsIn  list of points being assigned. 
padfZIn  the Z values that go with the points. 
padfMIn  the M values that go with the points. 

inherited 
Assign all points in a line string.
This method clears any existing points assigned to this line string, and assigns a whole new set. It is the most efficient way of assigning the value of a line string.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in paoPointsIn 
paoPointsIn  list of points being assigned. 
padfZIn  the Z values that go with the points (optional, may be NULL). 

inherited 
Assign all points in a line string.
This method clear any existing points assigned to this line string, and assigns a whole new set.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in padfX and padfY. 
padfX  list of X coordinates of points being assigned. 
padfY  list of Y coordinates of points being assigned. 
padfMIn  list of M coordinates of points being assigned. 

inherited 
Assign all points in a line string.
This method clears any existing points assigned to this line string, and assigns a whole new set. It is the most efficient way of assigning the value of a line string.
There is no SFCOM analog to this method.
nPointsIn  number of points being passed in paoPointsIn 
paoPointsIn  list of points being assigned. 
padfMIn  the M values that go with the points. 

inherited 
Set the Z of a vertex in line string.
If iPoint is larger than the number of necessary the number of existing points in the line string, the point count will be increased to accommodate the request.
There is no SFCOM analog to this method.
iPoint  the index of the vertex to assign (zero based). 
zIn  input Z coordinate to assign. 

virtualinherited 
Simplify the geometry.
This function is the same as the C function OGR_G_Simplify().
This function is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this function will always fail, issuing a CPLE_NotSupported error.
dTolerance  the distance tolerance for the simplification. 

inherited 
Simplify the geometry while preserving topology.
This function is the same as the C function OGR_G_SimplifyPreserveTopology().
This function is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this function will always fail, issuing a CPLE_NotSupported error.
dTolerance  the distance tolerance for the simplification. 

overridevirtualinherited 
Return the curve start point.
This method relates to the SF COM ICurve::get_StartPoint() method.
poPoint  the point to be assigned the start location. 
Implements OGRCurve.

overridevirtualinherited 

virtualinherited 
Compute symmetric difference.
Generates a new geometry which is the symmetric difference of this geometry and the second geometry passed into the method.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_SymDifference().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the other geometry. 

inlineinherited 
Downcast to OGRCircularString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCircularString.

inlineinherited 
Downcast to OGRCircularString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCircularString.

inlineinherited 
Downcast to OGRCompoundCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCompoundCurve.

inlineinherited 
Downcast to OGRCompoundCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCompoundCurve.

inlineinherited 
Downcast to OGRCurve*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbCurve).

inlineinherited 
Downcast to OGRCurve*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbCurve).

inlineinherited 
Downcast to OGRCurvePolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCurvePolygon or wkbPolygon or wkbTriangle.

inlineinherited 
Downcast to OGRCurvePolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbCurvePolygon or wkbPolygon or wkbTriangle.

inlineinherited 
Downcast to OGRGeometryCollection*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbGeometryCollection).

inlineinherited 
Downcast to OGRGeometryCollection*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbGeometryCollection).

inlinestaticinherited 
Convert a OGRGeometry* to a OGRGeometryH.

inlineinherited 
Downcast to OGRLinearRing*.
Implies prior checking that EQUAL(getGeometryName(), "LINEARRING").

inlineinherited 
Downcast to OGRLinearRing*.
Implies prior checking that EQUAL(getGeometryName(), "LINEARRING").

inlineinherited 
Downcast to OGRLineString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbLineString.

inlineinherited 
Downcast to OGRLineString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbLineString.

inlineinherited 
Downcast to OGRMultiCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiCurve and derived types.

inlineinherited 
Downcast to OGRMultiCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiCurve and derived types.

inlineinherited 
Downcast to OGRMultiLineString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiLineString.

inlineinherited 
Downcast to OGRMultiLineString*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiLineString.

inlineinherited 
Downcast to OGRMultiPoint*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiPoint.

inlineinherited 
Downcast to OGRMultiPoint*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiPoint.

inlineinherited 
Downcast to OGRMultiPolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiPolygon.

inlineinherited 
Downcast to OGRMultiPolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiPolygon.

inlineinherited 
Downcast to OGRMultiSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiSurface and derived types.

inlineinherited 
Downcast to OGRMultiSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbMultiSurface and derived types.

inlineinherited 
Downcast to OGRPoint*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPoint.

inlineinherited 
Downcast to OGRPoint*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPoint.

inlineinherited 
Downcast to OGRPolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPolygon or wkbTriangle.

inlineinherited 
Downcast to OGRPolygon*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPolygon or wkbTriangle.

inlineinherited 
Downcast to OGRPolyhedralSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPolyhedralSurface or wkbTIN.

inlineinherited 
Downcast to OGRPolyhedralSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbPolyhedralSurface or wkbTIN.

inlineinherited 
Downcast to OGRSimpleCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbLineString or wkbCircularString.

inlineinherited 
Downcast to OGRSimpleCurve*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbLineString or wkbCircularString.

inlineinherited 
Downcast to OGRSurface*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbSurface).

inlineinherited 
Downcast to OGRSurface*.
Implies prior checking that OGR_GT_IsSubClass(getGeometryType(), wkbSurface).

inlineinherited 
Downcast to OGRTriangle*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbTriangle.

inlineinherited 
Downcast to OGRTriangle*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbTriangle.

inlineinherited 
Downcast to OGRTriangulatedSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbTIN.

inlineinherited 
Downcast to OGRTriangulatedSurface*.
Implies prior checking that wkbFlatten(getGeometryType()) == wkbTIN.

virtualinherited 
Test for touching.
Tests if this geometry and the other passed into the method are touching.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Touches().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 

overridevirtual 
Apply arbitrary coordinate transformation to geometry.
This method will transform the coordinates of a geometry from their current spatial reference system to a new target spatial reference system. Normally this means reprojecting the vectors, but it could include datum shifts, and changes of units.
Note that this method does not require that the geometry already have a spatial reference system. It will be assumed that they can be treated as having the source spatial reference system of the OGRCoordinateTransformation object, and the actual SRS of the geometry will be ignored. On successful completion the output OGRSpatialReference of the OGRCoordinateTransformation will be assigned to the geometry.
This method only does reprojection on a pointbypoint basis. It does not include advanced logic to deal with discontinuities at poles or antimeridian. For that, use the OGRGeometryFactory::transformWithOptions() method.
This method is the same as the C function OGR_G_Transform().
poCT  the transformation to apply. 
Reimplemented from OGRSimpleCurve.

inherited 
Transform geometry to new spatial reference system.
This method will transform the coordinates of a geometry from their current spatial reference system to a new target spatial reference system. Normally this means reprojecting the vectors, but it could include datum shifts, and changes of units.
This method will only work if the geometry already has an assigned spatial reference system, and if it is transformable to the target coordinate system.
Because this method requires internal creation and initialization of an OGRCoordinateTransformation object it is significantly more expensive to use this method to transform many geometries than it is to create the OGRCoordinateTransformation in advance, and call transform() with that transformation. This method exists primarily for convenience when only transforming a single geometry.
This method is the same as the C function OGR_G_TransformTo().
poSR  spatial reference system to transform to. 

inherited 
Returns the union of all components of a single geometry.
Usually used to convert a collection into the smallest set of polygons that cover the same area.
See https://postgis.net/docs/ST_UnaryUnion.html for more details.
This method is the same as the C function OGR_G_UnaryUnion().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.

virtualinherited 
Compute union.
Generates a new geometry which is the region of union of the two geometries operated on.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Union().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the other geometry unioned with "this" geometry. 

virtualinherited 
Compute union using cascading.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
The input geometry must be a MultiPolygon.
This method is the same as the C function OGR_G_UnionCascaded().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.

overridevirtualinherited 
Fetch point at given distance along curve.
This method relates to the SF COM ICurve::get_Value() method.
This function is the same as the C function OGR_G_Value().
dfDistance  distance along the curve at which to sample position. This distance should be between zero and get_Length() for this curve. 
poPoint  the point to be assigned the curve position. 
Implements OGRCurve.
Reimplemented in OGRCircularString.

virtualinherited 
Test for containment.
Tests if actual geometry object is within the passed geometry.
Geometry validity is not checked. In case you are unsure of the validity of the input geometries, call IsValid() before, otherwise the result might be wrong.
This method is the same as the C function OGR_G_Within().
This method is built on the GEOS library, check it for the definition of the geometry operation. If OGR is built without the GEOS library, this method will always fail, issuing a CPLE_NotSupported error.
poOtherGeom  the geometry to compare to this geometry. 
Reimplemented in OGRPoint.