GEOS 3.13.1
Geometry.h
1/**********************************************************************
2 *
3 * GEOS - Geometry Engine Open Source
4 * http://geos.osgeo.org
5 *
6 * Copyright (C) 2009 2011 Sandro Santilli <strk@kbt.io>
7 * Copyright (C) 2005 2006 Refractions Research Inc.
8 * Copyright (C) 2001-2002 Vivid Solutions Inc.
9 *
10 * This is free software; you can redistribute and/or modify it under
11 * the terms of the GNU Lesser General Public Licence as published
12 * by the Free Software Foundation.
13 * See the COPYING file for more information.
14 *
15 **********************************************************************
16 *
17 * Last port: geom/Geometry.java rev. 1.112
18 *
19 **********************************************************************/
20
21#pragma once
22
23#ifndef USE_UNSTABLE_GEOS_CPP_API
24#ifndef _MSC_VER
25# warning "The GEOS C++ API is unstable, please use the C API instead"
26# warning "HINT: #include geos_c.h"
27#else
28#pragma message("The GEOS C++ API is unstable, please use the C API instead")
29#pragma message("HINT: #include geos_c.h")
30#endif
31#endif
32
33#include <geos/export.h>
34#include <geos/geom/Envelope.h>
35#include <geos/geom/Dimension.h> // for Dimension::DimensionType
36#include <geos/geom/GeometryComponentFilter.h> // for inheritance
37#include <geos/geom/CoordinateSequence.h> // to materialize CoordinateSequence
38
39#include <algorithm>
40#include <string>
41#include <iostream>
42#include <vector>
43#include <memory>
44
45#ifdef _MSC_VER
46#pragma warning(push)
47#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
48#pragma warning(disable: 4355) // warning C4355: 'this' : used in base member initializer list
49#endif
50
51// Forward declarations
52namespace geos {
53namespace geom {
54class Coordinate;
55class CoordinateFilter;
56class CoordinateSequence;
57class CoordinateSequenceFilter;
58class GeometryComponentFilter;
59class GeometryFactory;
60class GeometryFilter;
61class PrecisionModel;
62class Point;
63class IntersectionMatrix;
64}
65namespace io { // geos.io
66class Unload;
67} // namespace geos.io
68}
69
70namespace geos { // geos
71namespace geom { // geos::geom
72
74enum GeometryTypeId : int {
91 GEOS_CIRCULARSTRING,
92 GEOS_COMPOUNDCURVE,
93 GEOS_CURVEPOLYGON,
94 GEOS_MULTICURVE,
95 GEOS_MULTISURFACE,
96};
97
98enum GeometrySortIndex {
99 SORTINDEX_POINT = 0,
100 SORTINDEX_MULTIPOINT = 1,
101 SORTINDEX_LINESTRING = 2,
102 SORTINDEX_LINEARRING = 3,
103 SORTINDEX_MULTILINESTRING = 4,
104 SORTINDEX_POLYGON = 5,
105 SORTINDEX_MULTIPOLYGON = 6,
106 SORTINDEX_GEOMETRYCOLLECTION = 7,
107 SORTINDEX_CIRCULARSTRING = 8,
108 SORTINDEX_COMPOUNDCURVE = 9,
109 SORTINDEX_CURVEPOLYGON = 10,
110 SORTINDEX_MULTICURVE = 11,
111 SORTINDEX_MULTISURFACE = 12,
112};
113
197class GEOS_DLL Geometry {
198
199public:
200
201 friend class GeometryFactory;
202
204 using ConstVect = std::vector<const Geometry*>;
205
207 using NonConstVect = std::vector<Geometry*>;
208
210 using Ptr = std::unique_ptr<Geometry> ;
211
213 std::unique_ptr<Geometry> clone() const { return std::unique_ptr<Geometry>(cloneImpl()); }
214
216 virtual ~Geometry();
217
218
226 const GeometryFactory*
228 {
229 return _factory;
230 }
231
245 void
246 setUserData(void* newUserData)
247 {
248 _userData = newUserData;
249 }
250
257 void*
259 {
260 return _userData;
261 }
262
273 virtual int
274 getSRID() const
275 {
276 return SRID;
277 }
278
282 virtual void
283 setSRID(int newSRID)
284 {
285 SRID = newSRID;
286 }
287
293
295 virtual const CoordinateXY* getCoordinate() const = 0; //Abstract
296
302 virtual std::unique_ptr<CoordinateSequence> getCoordinates() const = 0; //Abstract
303
305 virtual std::size_t getNumPoints() const = 0; //Abstract
306
308 virtual bool isSimple() const;
309
311 virtual std::string getGeometryType() const = 0; //Abstract
312
314 virtual bool hasCurvedComponents() const;
315
317 virtual GeometryTypeId getGeometryTypeId() const = 0; //Abstract
318
326 virtual std::size_t
328 {
329 return 1;
330 }
331
334 virtual const Geometry*
335 getGeometryN(std::size_t /*n*/) const
336 {
337 return this;
338 }
339
349 virtual bool isValid() const;
350
352 virtual bool isEmpty() const = 0; //Abstract
353
355 virtual bool
357 {
358 return false;
359 }
360
362 virtual Dimension::DimensionType getDimension() const = 0; //Abstract
363
366 return getDimension() == d;
367 }
368
371 return d == getDimension();
372 }
373
374 bool isPuntal() const {
375 return isDimensionStrict(Dimension::P);
376 }
377
378 bool isLineal() const {
379 return isDimensionStrict(Dimension::L);
380 }
381
382 bool isPolygonal() const {
383 return isDimensionStrict(Dimension::A);
384 }
385
386 bool isMixedDimension() const;
387 bool isMixedDimension(Dimension::DimensionType* baseDim) const;
388
389 bool isCollection() const {
390 int t = getGeometryTypeId();
391 return t == GEOS_GEOMETRYCOLLECTION ||
392 t == GEOS_MULTIPOINT ||
395 }
396
397 static GeometryTypeId multiTypeId(GeometryTypeId typeId) {
398 switch (typeId) {
399 case GEOS_POINT: return GEOS_MULTIPOINT;
401 case GEOS_POLYGON: return GEOS_MULTIPOLYGON;
402 default: return typeId;
403 }
404 }
405
407 virtual uint8_t getCoordinateDimension() const = 0; //Abstract
408
409 virtual bool hasZ() const = 0;
410
411 virtual bool hasM() const = 0;
412
429 virtual std::unique_ptr<Geometry> getBoundary() const = 0; //Abstract
430
432 virtual int getBoundaryDimension() const = 0; //Abstract
433
435 virtual std::unique_ptr<Geometry> getEnvelope() const;
436
441 virtual const Envelope* getEnvelopeInternal() const = 0;
442
459 virtual bool disjoint(const Geometry* other) const;
460
465 virtual bool touches(const Geometry* other) const;
466
468 virtual bool intersects(const Geometry* g) const;
469
492 virtual bool crosses(const Geometry* g) const;
493
498 virtual bool within(const Geometry* g) const;
499
501 virtual bool contains(const Geometry* g) const;
502
508 virtual bool overlaps(const Geometry* g) const;
509
524 bool relate(const Geometry* g,
525 const std::string& intersectionPattern) const;
526
527 bool
528 relate(const Geometry& g, const std::string& intersectionPattern) const
529 {
530 return relate(&g, intersectionPattern);
531 }
532
534 std::unique_ptr<IntersectionMatrix> relate(const Geometry* g) const;
535
536 std::unique_ptr<IntersectionMatrix> relate(const Geometry& g) const;
537
543 virtual bool equals(const Geometry* g) const;
544
583 bool covers(const Geometry* g) const;
584
615 bool coveredBy(const Geometry* g) const;
616
617
619 virtual std::string toString() const;
620
621 virtual std::string toText() const;
622
627 std::unique_ptr<Geometry> buffer(double distance) const;
628
636 std::unique_ptr<Geometry> buffer(double distance, int quadrantSegments) const;
637
674 std::unique_ptr<Geometry> buffer(double distance, int quadrantSegments,
675 int endCapStyle) const;
676
680 virtual std::unique_ptr<Geometry> convexHull() const;
681
688 std::unique_ptr<Geometry> reverse() const { return std::unique_ptr<Geometry>(reverseImpl()); }
689
699 std::unique_ptr<Geometry> intersection(const Geometry* other) const;
700
710 std::unique_ptr<Geometry> Union(const Geometry* other) const;
711 // throw(IllegalArgumentException *, TopologyException *);
712
730 Ptr Union() const;
731 // throw(IllegalArgumentException *, TopologyException *);
732
743 std::unique_ptr<Geometry> difference(const Geometry* other) const;
744
754 std::unique_ptr<Geometry> symDifference(const Geometry* other) const;
755
762 virtual bool equalsExact(const Geometry* other, double tolerance = 0)
763 const = 0; // Abstract
764
769 virtual bool equalsIdentical(const Geometry* other) const = 0;
770
771 virtual void apply_rw(const CoordinateFilter* filter) = 0; //Abstract
772 virtual void apply_ro(CoordinateFilter* filter) const = 0; //Abstract
773 virtual void apply_rw(GeometryFilter* filter);
774 virtual void apply_ro(GeometryFilter* filter) const;
775 virtual void apply_rw(GeometryComponentFilter* filter);
776 virtual void apply_ro(GeometryComponentFilter* filter) const;
777
786 virtual void apply_rw(CoordinateSequenceFilter& filter) = 0;
787
794 virtual void apply_ro(CoordinateSequenceFilter& filter) const = 0;
795
805 template <class T>
806 void
808 {
809 for(std::size_t i = 0, n = getNumGeometries(); i < n; ++i) {
810 f.filter(getGeometryN(i));
811 }
812 }
813
819 virtual void normalize() = 0; //Abstract
820
822 virtual int compareTo(const Geometry* geom) const;
823
825 virtual double getArea() const;
826
828 virtual double getLength() const;
829
835 virtual double distance(const Geometry* g) const;
836
837
849 virtual bool isWithinDistance(const Geometry* geom,
850 double cDistance) const;
851
861 virtual std::unique_ptr<Point> getCentroid() const;
862
864 //
867 virtual bool getCentroid(CoordinateXY& ret) const;
868
879 std::unique_ptr<Point> getInteriorPoint() const;
880
886 virtual void geometryChanged();
887
893 virtual void geometryChangedAction() = 0;
894
895protected:
897 virtual Geometry* cloneImpl() const = 0;
898
900 virtual Geometry* reverseImpl() const = 0;
901
903 template<typename T>
904 static bool hasNonEmptyElements(const std::vector<T>* geometries) {
905 return std::any_of(geometries->begin(), geometries->end(), [](const T& g) { return !g->isEmpty(); });
906 }
907
909 static bool hasNullElements(const CoordinateSequence* list);
910
912 template<typename T>
913 static bool hasNullElements(const std::vector<T>* geometries) {
914 return std::any_of(geometries->begin(), geometries->end(), [](const T& g) { return g == nullptr; });
915 }
916
917// static void reversePointOrder(CoordinateSequence* coordinates);
918// static Coordinate& minCoordinate(CoordinateSequence* coordinates);
919// static void scroll(CoordinateSequence* coordinates,Coordinate* firstCoordinate);
920// static int indexOf(Coordinate* coordinate,CoordinateSequence* coordinates);
921//
926 virtual bool isEquivalentClass(const Geometry* other) const;
927
928 static void checkNotGeometryCollection(const Geometry* g);
929
930 virtual int compareToSameClass(const Geometry* geom) const = 0; //Abstract
931
932 template<typename T>
933 static int compare(const T& a, const T& b)
934 {
935 std::size_t i = 0;
936 std::size_t j = 0;
937 while(i < a.size() && j < b.size()) {
938 const auto& aGeom = *a[i];
939 const auto& bGeom = *b[j];
940
941 int comparison = aGeom.compareTo(&bGeom);
942 if(comparison != 0) {
943 return comparison;
944 }
945
946 i++;
947 j++;
948 }
949
950 if(i < a.size()) {
951 return 1;
952 }
953
954 if(j < b.size()) {
955 return -1;
956 }
957
958 return 0;
959 }
960
961 bool equal(const CoordinateXY& a, const CoordinateXY& b,
962 double tolerance) const;
963 int SRID;
964
965 Geometry(const Geometry& geom);
966
976 Geometry(const GeometryFactory* factory);
977
978 template<typename T>
979 static std::vector<std::unique_ptr<Geometry>> toGeometryArray(std::vector<std::unique_ptr<T>> && v) {
980 static_assert(std::is_base_of<Geometry, T>::value, "");
981 std::vector<std::unique_ptr<Geometry>> gv(v.size());
982 for (std::size_t i = 0; i < v.size(); i++) {
983 gv[i] = std::move(v[i]);
984 }
985 return gv;
986 }
987
988 static std::vector<std::unique_ptr<Geometry>> toGeometryArray(std::vector<std::unique_ptr<Geometry>> && v) {
989 return std::move(v);
990 }
991
992protected:
993
994 virtual int getSortIndex() const = 0;
995
996
997private:
998
999 class GEOS_DLL GeometryChangedFilter : public GeometryComponentFilter {
1000 public:
1001 void filter_rw(Geometry* geom) override;
1002 };
1003
1004 static GeometryChangedFilter geometryChangedFilter;
1005
1010 const GeometryFactory* _factory;
1011
1012 void* _userData;
1013};
1014
1019GEOS_DLL std::ostream& operator<< (std::ostream& os, const Geometry& geom);
1020
1021struct GEOS_DLL GeometryGreaterThen {
1022 bool operator()(const Geometry* first, const Geometry* second);
1023};
1024
1025
1027GEOS_DLL std::string geosversion();
1028
1034GEOS_DLL std::string jtsport();
1035
1036// We use this instead of std::pair<unique_ptr<Geometry>> because C++11
1037// forbids that construct:
1038// http://lwg.github.com/issues/lwg-closed.html#2068
1039struct GeomPtrPair {
1040 typedef std::unique_ptr<Geometry> GeomPtr;
1041 GeomPtr first;
1042 GeomPtr second;
1043};
1044
1045} // namespace geos::geom
1046} // namespace geos
1047
1048#ifdef _MSC_VER
1049#pragma warning(pop)
1050#endif
1051
Geometry classes support the concept of applying a coordinate filter to every coordinate in the Geome...
Definition CoordinateFilter.h:43
Interface for classes which provide operations that can be applied to the coordinates in a Coordinate...
Definition CoordinateSequenceFilter.h:55
The internal representation of a list of coordinates inside a Geometry.
Definition CoordinateSequence.h:56
DimensionType
Definition Dimension.h:29
An Envelope defines a rectangulare region of the 2D coordinate plane.
Definition Envelope.h:59
Definition GeometryComponentFilter.h:41
Supplies a set of utility methods for building Geometry objects from CoordinateSequence or other Geom...
Definition GeometryFactory.h:70
Geometry classes support the concept of applying a Geometry filter to the Geometry.
Definition GeometryFilter.h:45
Basic implementation of Geometry, constructed and destructed by GeometryFactory.
Definition Geometry.h:197
virtual std::unique_ptr< Geometry > getBoundary() const =0
Returns the boundary, or an empty geometry of appropriate dimension if this Geometry is empty.
virtual int getBoundaryDimension() const =0
Returns the dimension of this Geometrys inherent boundary.
virtual bool equalsIdentical(const Geometry *other) const =0
Returns true if the two geometries are of the same type and their vertices corresponding by index are...
std::vector< Geometry * > NonConstVect
A vector of non-const Geometry pointers.
Definition Geometry.h:207
void applyComponentFilter(T &f) const
Apply a filter to each component of this geometry. The filter is expected to provide a ....
Definition Geometry.h:807
virtual const CoordinateXY * getCoordinate() const =0
Returns a vertex of this Geometry, or NULL if this is the empty geometry.
virtual int compareTo(const Geometry *geom) const
Comparator for sorting geometry.
std::unique_ptr< Geometry > symDifference(const Geometry *other) const
Returns a set combining the points in this Geometry not in other, and the points in other not in this...
std::unique_ptr< Geometry > reverse() const
Computes a new geometry which has all component coordinate sequences in reverse order (opposite orien...
Definition Geometry.h:688
virtual ~Geometry()
Destroy Geometry and all components.
virtual bool equals(const Geometry *g) const
Returns true if the DE-9IM intersection matrix for the two Geometrys is T*F**FFF*.
virtual void apply_rw(CoordinateSequenceFilter &filter)=0
const PrecisionModel * getPrecisionModel() const
Get the PrecisionModel used to create this Geometry.
std::unique_ptr< IntersectionMatrix > relate(const Geometry *g) const
Returns the DE-9IM intersection matrix for the two Geometrys.
virtual void geometryChangedAction()=0
Notifies this Geometry that its Coordinates have been changed by an external party.
virtual bool equalsExact(const Geometry *other, double tolerance=0) const =0
Returns true iff the two Geometrys are of the same type and their vertices corresponding by index are...
virtual bool isDimensionStrict(Dimension::DimensionType d) const
Checks whether this Geometry consists only of components having dimension d.
Definition Geometry.h:370
virtual void normalize()=0
virtual void apply_ro(CoordinateSequenceFilter &filter) const =0
virtual bool intersects(const Geometry *g) const
Returns true if disjoint returns false.
virtual bool crosses(const Geometry *g) const
virtual GeometryTypeId getGeometryTypeId() const =0
Return an integer representation of this Geometry type.
virtual std::unique_ptr< Geometry > convexHull() const
Returns the smallest convex Polygon that contains all the points in the Geometry.
virtual bool hasDimension(Dimension::DimensionType d) const
Checks whether any component of this geometry has dimension d.
Definition Geometry.h:365
virtual std::string getGeometryType() const =0
Return a string representation of this Geometry type.
virtual uint8_t getCoordinateDimension() const =0
Returns the coordinate dimension of this Geometry (2=XY, 3=XYZ or XYM, 4=XYZM).
virtual bool isWithinDistance(const Geometry *geom, double cDistance) const
Tests whether the distance from this Geometry to another is less than or equal to a specified value.
virtual double getLength() const
Returns the length of this Geometry.
virtual double distance(const Geometry *g) const
std::unique_ptr< Point > getInteriorPoint() const
Computes an interior point of this Geometry.
std::unique_ptr< Geometry > intersection(const Geometry *other) const
Returns a Geometry representing the points shared by this Geometry and other.
virtual bool getCentroid(CoordinateXY &ret) const
Computes the centroid of this Geometry as a Coordinate.
std::unique_ptr< Geometry > Ptr
An unique_ptr of Geometry.
Definition Geometry.h:210
virtual const Geometry * getGeometryN(std::size_t) const
Returns a pointer to the nth Geometry in this collection (or self if this is not a collection)
Definition Geometry.h:335
virtual bool hasCurvedComponents() const
Returns whether the Geometry contains curved components.
virtual bool within(const Geometry *g) const
Returns true if the DE-9IM intersection matrix for the two Geometrys is T*F**F***.
virtual std::size_t getNumPoints() const =0
Returns the count of this Geometrys vertices.
static bool hasNullElements(const CoordinateSequence *list)
Returns true if the CoordinateSequence contains any null elements.
virtual Geometry * reverseImpl() const =0
Make a geometry with coordinates in reverse order.
void setUserData(void *newUserData)
A simple scheme for applications to add their own custom data to a Geometry. An example use might be ...
Definition Geometry.h:246
virtual bool isEmpty() const =0
Returns whether or not the set of points in this Geometry is empty.
bool relate(const Geometry *g, const std::string &intersectionPattern) const
Returns true if the elements in the DE-9IM intersection matrix for the two Geometrys match the elemen...
Geometry(const GeometryFactory *factory)
Construct a geometry with the given GeometryFactory.
std::vector< const Geometry * > ConstVect
A vector of const Geometry pointers.
Definition Geometry.h:204
const GeometryFactory * getFactory() const
Gets the factory which contains the context in which this geometry was created.
Definition Geometry.h:227
virtual int getSRID() const
Returns the ID of the Spatial Reference System used by the Geometry.
Definition Geometry.h:274
virtual bool touches(const Geometry *other) const
Returns true if the DE-9IM intersection matrix for the two Geometrys is FT*******,...
virtual std::unique_ptr< Geometry > getEnvelope() const
Returns this Geometrys bounding box.
virtual std::string toString() const
Returns the Well-known Text representation of this Geometry.
std::unique_ptr< Geometry > buffer(double distance, int quadrantSegments) const
Returns a buffer region around this Geometry having the given width and with a specified number of se...
virtual bool isValid() const
Tests the validity of this Geometry.
virtual Geometry * cloneImpl() const =0
Make a deep-copy of this Geometry.
virtual bool isSimple() const
Returns false if the Geometry not simple.
static bool hasNonEmptyElements(const std::vector< T > *geometries)
Returns true if the array contains any non-empty Geometrys.
Definition Geometry.h:904
Ptr Union() const
Computes the union of all the elements of this geometry. Heterogeneous GeometryCollections are fully ...
void * getUserData() const
Gets the user data object for this geometry, if any.
Definition Geometry.h:258
std::unique_ptr< Geometry > difference(const Geometry *other) const
Returns a Geometry representing the points making up this Geometry that do not make up other.
virtual bool disjoint(const Geometry *other) const
virtual bool contains(const Geometry *g) const
Returns true if other.within(this) returns true.
virtual bool isEquivalentClass(const Geometry *other) const
Returns whether the two Geometrys are equal, from the point of view of the equalsExact method.
std::unique_ptr< Geometry > buffer(double distance) const
virtual std::unique_ptr< Point > getCentroid() const
Computes the centroid of this Geometry.
bool coveredBy(const Geometry *g) const
Tests whether this geometry is covered by the specified geometry.
virtual std::unique_ptr< CoordinateSequence > getCoordinates() const =0
Returns this Geometry vertices. Caller takes ownership of the returned object.
std::unique_ptr< Geometry > Union(const Geometry *other) const
Returns a Geometry representing all the points in this Geometry and other.
virtual std::size_t getNumGeometries() const
Returns the number of geometries in this collection, or 1 if this is not a collection.
Definition Geometry.h:327
std::unique_ptr< Geometry > clone() const
Make a deep-copy of this Geometry.
Definition Geometry.h:213
virtual double getArea() const
Returns the area of this Geometry.
virtual bool isRectangle() const
Polygon overrides to check for actual rectangle.
Definition Geometry.h:356
virtual bool overlaps(const Geometry *g) const
Returns true if the DE-9IM intersection matrix for the two Geometrys is T*T***T** (for two points or ...
bool covers(const Geometry *g) const
Returns true if this geometry covers the specified geometry.
virtual Dimension::DimensionType getDimension() const =0
Returns the dimension of this Geometry (0=point, 1=line, 2=surface)
virtual void geometryChanged()
Notifies this Geometry that its Coordinates have been changed by an external party (using a Coordinat...
std::unique_ptr< Geometry > buffer(double distance, int quadrantSegments, int endCapStyle) const
Computes a buffer area around this geometry having the given width and with a specified accuracy of a...
virtual const Envelope * getEnvelopeInternal() const =0
Returns the minimum and maximum x and y values in this Geometry, or a null Envelope if this Geometry ...
static bool hasNullElements(const std::vector< T > *geometries)
Returns true if the vector contains any null elements.
Definition Geometry.h:913
virtual void setSRID(int newSRID)
Sets the ID of the Spatial Reference System used by the Geometry.
Definition Geometry.h:283
Specifies the precision model of the Coordinate in a Geometry.
Definition PrecisionModel.h:88
@ GEOS_MULTILINESTRING
Definition geos_c.h:210
@ GEOS_GEOMETRYCOLLECTION
Definition geos_c.h:214
@ GEOS_POINT
Definition geos_c.h:200
@ GEOS_MULTIPOLYGON
Definition geos_c.h:212
@ GEOS_POLYGON
Definition geos_c.h:206
@ GEOS_MULTIPOINT
Definition geos_c.h:208
@ GEOS_LINESTRING
Definition geos_c.h:202
std::string jtsport()
Return the version of JTS this GEOS release has been ported from.
std::string geosversion()
Return current GEOS version.
GeometryTypeId
Geometry types.
Definition Geometry.h:74
@ GEOS_MULTILINESTRING
a collection of linestrings
Definition Geometry.h:86
@ GEOS_LINEARRING
a linear ring (linestring with 1st point == last point)
Definition Geometry.h:80
@ GEOS_GEOMETRYCOLLECTION
a collection of heterogeneus geometries
Definition Geometry.h:90
@ GEOS_POINT
a point
Definition Geometry.h:76
@ GEOS_LINESTRING
a linestring
Definition Geometry.h:78
@ GEOS_POLYGON
a polygon
Definition Geometry.h:82
@ GEOS_MULTIPOLYGON
a collection of polygons
Definition Geometry.h:88
@ GEOS_MULTIPOINT
a collection of points
Definition Geometry.h:84
Basic namespace for all GEOS functionalities.
Definition geos.h:39