#include <ogr_geometry.h>
Inheritance diagram for OGRPolygon:
Public Member Functions | |
OGRPolygon () | |
virtual void | empty () |
virtual OGRErr | transform (OGRCoordinateTransformation *poCT) |
virtual void | flattenTo2D () |
virtual double | get_Area () const |
virtual int | Centroid (OGRPoint *poPoint) const |
virtual OGRErr | importFromWkb (unsigned char *, int=-1) |
virtual OGRErr | importFromWkt (char **) |
virtual OGRBoolean | Equals (OGRGeometry *) const |
void | addRing (OGRLinearRing *) |
void | addRingDirectly (OGRLinearRing *) |
OGRLinearRing * | getExteriorRing () |
int | getNumInteriorRings () const |
OGRLinearRing * | getInteriorRing (int) |
virtual void | closeRings () |
Note that the OpenGIS simple features polygons consist of one outer ring, and zero or more inner rings. A polygon cannot represent disconnected regions (such as multiple islands in a political body). The OGRMultiPolygon must be used for this.
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Create an empty polygon. |
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Add a ring to a polygon. If the polygon has no external ring (it is empty) this will be used as the external ring, otherwise it is used as an internal ring. The passed OGRLinearRing remains the responsibility of the caller (an internal copy is made). This method has no SFCOM analog.
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Add a ring to a polygon. If the polygon has no external ring (it is empty) this will be used as the external ring, otherwise it is used as an internal ring. Ownership of the passed ring is assumed by the OGRPolygon, but otherwise this method operates the same as OGRPolygon::AddRing(). This method has no SFCOM analog.
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Compute the polygon centroid. The centroid location is applied to the passed in OGRPoint object.
Implements OGRSurface. |
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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. |
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Clear geometry information. This restores the geometry to it's 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. |
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Returns two if two geometries are equivalent. This method is the same as the C function OGR_G_Equal().
Implements OGRGeometry. |
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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. |
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Compute area of polygon. The area is computed as the area of the outer ring less the area of all internal rings.
Implements OGRSurface. |
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Fetch reference to external polygon ring. Note that the returned ring pointer is to an internal data object of the OGRPolygon. It should not be modified or deleted by the application, and the pointer is only valid till the polygon is next modified. Use the OGRGeometry::clone() method to make a separate copy within the application. Relates to the SFCOM IPolygon::get_ExteriorRing() method.
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Fetch reference to indicated internal ring. Note that the returned ring pointer is to an internal data object of the OGRPolygon. It should not be modified or deleted by the application, and the pointer is only valid till the polygon is next modified. Use the OGRGeometry::clone() method to make a separate copy within the application. Relates to the SFCOM IPolygon::get_InternalRing() method.
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Fetch the number of internal rings. Relates to the SFCOM IPolygon::get_NumInteriorRings() method.
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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().
Implements OGRGeometry. |
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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().
Implements OGRGeometry. |
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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 is the same as the C function OGR_G_Transform().
Implements OGRGeometry. |