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geos::geom::CoordinateSequence Class Reference

The internal representation of a list of coordinates inside a Geometry. More...

#include <geos.h>

Inheritance diagram for geos::geom::CoordinateSequence:

geos::geom::CoordinateArraySequence List of all members.

Public Types

typedef std::auto_ptr< CoordinateSequenceAutoPtr
enum  { X, Y, Z, M }
 Standard ordinate index values.

Public Member Functions

virtual CoordinateSequenceclone () const =0
 Returns a deep copy of this collection.
virtual const CoordinategetAt (size_t i) const =0
 Returns a read-only reference to Coordinate at position i.
const Coordinateback () const
 Return last Coordinate in the sequence.
const Coordinatefront () const
 Return first Coordinate in the sequence.
const Coordinateoperator[] (size_t i) const
virtual void getAt (size_t i, Coordinate &c) const =0
 Write Coordinate at position i to given Coordinate.
virtual size_t getSize () const =0
 Returns the number of Coordinates (actual or otherwise, as this implementation may not store its data in Coordinate objects).
size_t size () const
virtual const std::vector<
Coordinate > * 
toVector () const =0
 Returns a read-only vector with the Coordinates in this collection.
void add (const std::vector< Coordinate > *vc, bool allowRepeated)
 Add an array of coordinates.
void add (const CoordinateSequence *cl, bool allowRepeated, bool direction)
 Add an array of coordinates.
virtual void add (const Coordinate &c, bool allowRepeated)
 Add a coordinate.
virtual void add (size_t i, const Coordinate &coord, bool allowRepeated)=0
 Inserts the specified coordinate at the specified position in this list.
virtual bool isEmpty () const =0
 Returns true it list contains no coordinates.
virtual void add (const Coordinate &c)=0
 Add a Coordinate to the list.
virtual void setAt (const Coordinate &c, size_t pos)=0
 Copy Coordinate c to position pos.
virtual void deleteAt (size_t pos)=0
 Delete Coordinate at position pos (list will shrink).
virtual std::string toString () const =0
 Get a string rapresentation of CoordinateSequence.
virtual void setPoints (const std::vector< Coordinate > &v)=0
 Substitute Coordinate list with a copy of the given vector.
bool hasRepeatedPoints () const
 Returns true if contains any two consecutive points.
const CoordinateminCoordinate () const
 Returns lower-left Coordinate in list.
virtual CoordinateSequenceremoveRepeatedPoints ()=0
 Remove consecutive equal Coordinates from the sequence.
virtual size_t getDimension () const =0
virtual double getOrdinate (size_t index, size_t ordinateIndex) const =0
virtual double getX (size_t index) const
virtual double getY (size_t index) const
virtual void setOrdinate (size_t index, size_t ordinateIndex, double value)=0
virtual void expandEnvelope (Envelope &env) const
virtual void apply_rw (const CoordinateFilter *filter)=0
virtual void apply_ro (CoordinateFilter *filter) const =0
template<class T>
void applyCoordinateFilter (T &f)
 Apply a fiter to each Coordinate of this sequence. The filter is expected to provide a .filter(Coordinate&) method.

Static Public Member Functions

static CoordinateSequenceremoveRepeatedPoints (const CoordinateSequence *cl)
 Returns a new CoordinateSequence being a copy of the input with any consecutive equal Coordinate removed.
static bool hasRepeatedPoints (const CoordinateSequence *cl)
 Returns true if given CoordinateSequence contains any two consecutive Coordinate.
static CoordinateSequenceatLeastNCoordinatesOrNothing (size_t n, CoordinateSequence *c)
 Returns either the given CoordinateSequence if its length is greater than the given amount, or an empty CoordinateSequence.
static const CoordinateminCoordinate (CoordinateSequence *cl)
 Returns lower-left Coordinate in given CoordinateSequence. This is actually the Coordinate with lower X (and Y if needed) ordinate.
static int indexOf (const Coordinate *coordinate, const CoordinateSequence *cl)
 Return position of a Coordinate, or -1 if not found.
static bool equals (const CoordinateSequence *cl1, const CoordinateSequence *cl2)
 Returns true if the two arrays are identical, both null, or pointwise equal.
static void scroll (CoordinateSequence *cl, const Coordinate *firstCoordinate)
 Scroll given CoordinateSequence so to start with given Coordinate.
static int increasingDirection (const CoordinateSequence &pts)
 Determines which orientation of the Coordinate array is (overall) increasing.
static void reverse (CoordinateSequence *cl)
 Reverse Coordinate order in given CoordinateSequence.

Protected Member Functions

 CoordinateSequence (const CoordinateSequence &)

Friends

std::ostream & operator<< (std::ostream &os, const CoordinateSequence &cs)
bool operator== (const CoordinateSequence &seq1, const CoordinateSequence &seq2)
bool operator!= (const CoordinateSequence &seq1, const CoordinateSequence &seq2)

Detailed Description

The internal representation of a list of coordinates inside a Geometry.

There are some cases in which you might want Geometries to store their points using something other than the GEOS Coordinate class. For example, you may want to experiment with another implementation, such as an array of Xs and an array of Ys. or you might want to use your own coordinate class, one that supports extra attributes like M-values.

You can do this by implementing the CoordinateSequence and CoordinateSequenceFactory interfaces. You would then create a GeometryFactory parameterized by your CoordinateSequenceFactory, and use this GeometryFactory to create new Geometries. All of these new Geometries will use your CoordinateSequence implementation.


Member Function Documentation

virtual void geos::geom::CoordinateSequence::add size_t  i,
const Coordinate coord,
bool  allowRepeated
[pure virtual]
 

Inserts the specified coordinate at the specified position in this list.

Parameters:
i the position at which to insert
coord the coordinate to insert
allowRepeated if set to false, repeated coordinates are collapsed
NOTE: this is a CoordinateList interface in JTS

Implemented in geos::geom::CoordinateArraySequence.

virtual void geos::geom::CoordinateSequence::add const Coordinate c,
bool  allowRepeated
[virtual]
 

Add a coordinate.

Parameters:
c The coordinate to add
allowRepeated if set to false, repeated coordinates are collapsed
Returns:
true (as by general collection contract)

Reimplemented in geos::geom::CoordinateArraySequence.

void geos::geom::CoordinateSequence::add const CoordinateSequence cl,
bool  allowRepeated,
bool  direction
 

Add an array of coordinates.

Parameters:
cl The coordinates
allowRepeated if set to false, repeated coordinates are collapsed
direction if false, the array is added in reverse order
Returns:
true (as by general collection contract)

void geos::geom::CoordinateSequence::add const std::vector< Coordinate > *  vc,
bool  allowRepeated
 

Add an array of coordinates.

Parameters:
vc The coordinates
allowRepeated if set to false, repeated coordinates are collapsed
Returns:
true (as by general collection contract)

template<class T>
void geos::geom::CoordinateSequence::applyCoordinateFilter T &  f  )  [inline]
 

Apply a fiter to each Coordinate of this sequence. The filter is expected to provide a .filter(Coordinate&) method.

TODO: accept a Functor instead, will be more flexible. actually, define iterators on Geometry

virtual void geos::geom::CoordinateSequence::expandEnvelope Envelope env  )  const [virtual]
 

Expands the given Envelope to include the coordinates in the sequence. Allows implementing classes to optimize access to coordinate values.

Parameters:
env the envelope to expand

Reimplemented in geos::geom::CoordinateArraySequence.

virtual const Coordinate& geos::geom::CoordinateSequence::getAt size_t  i  )  const [pure virtual]
 

Returns a read-only reference to Coordinate at position i.

Whether or not the Coordinate returned is the actual underlying Coordinate or merely a copy depends on the implementation.

Implemented in geos::geom::CoordinateArraySequence.

virtual size_t geos::geom::CoordinateSequence::getDimension  )  const [pure virtual]
 

Returns the dimension (number of ordinates in each coordinate) for this sequence.

Returns:
the dimension of the sequence.

Implemented in geos::geom::CoordinateArraySequence.

virtual double geos::geom::CoordinateSequence::getOrdinate size_t  index,
size_t  ordinateIndex
const [pure virtual]
 

Returns the ordinate of a coordinate in this sequence. Ordinate indices 0 and 1 are assumed to be X and Y. Ordinates indices greater than 1 have user-defined semantics (for instance, they may contain other dimensions or measure values).

Parameters:
index the coordinate index in the sequence
ordinateIndex the ordinate index in the coordinate (in range [0, dimension-1])

Implemented in geos::geom::CoordinateArraySequence.

virtual double geos::geom::CoordinateSequence::getX size_t  index  )  const [inline, virtual]
 

Returns ordinate X (0) of the specified coordinate.

Parameters:
index 
Returns:
the value of the X ordinate in the index'th coordinate

virtual double geos::geom::CoordinateSequence::getY size_t  index  )  const [inline, virtual]
 

Returns ordinate Y (1) of the specified coordinate.

Parameters:
index 
Returns:
the value of the Y ordinate in the index'th coordinate

static int geos::geom::CoordinateSequence::increasingDirection const CoordinateSequence pts  )  [static]
 

Determines which orientation of the Coordinate array is (overall) increasing.

In other words, determines which end of the array is "smaller" (using the standard ordering on Coordinate). Returns an integer indicating the increasing direction. If the sequence is a palindrome, it is defined to be oriented in a positive direction.

Parameters:
pts the array of Coordinates to test
Returns:
1 if the array is smaller at the start or is a palindrome, -1 if smaller at the end
NOTE: this method is found in CoordinateArrays class for JTS

static int geos::geom::CoordinateSequence::indexOf const Coordinate coordinate,
const CoordinateSequence cl
[static]
 

Return position of a Coordinate, or -1 if not found.

FIXME: return size_t, using numeric_limits<size_t>::max as 'not found' value.

virtual CoordinateSequence& geos::geom::CoordinateSequence::removeRepeatedPoints  )  [pure virtual]
 

Remove consecutive equal Coordinates from the sequence.

Equality test is 2D based. Returns a reference to self.

Implemented in geos::geom::CoordinateArraySequence.

static CoordinateSequence* geos::geom::CoordinateSequence::removeRepeatedPoints const CoordinateSequence cl  )  [static]
 

Returns a new CoordinateSequence being a copy of the input with any consecutive equal Coordinate removed.

Equality test is 2D based

Ownership of returned object goes to the caller.

virtual void geos::geom::CoordinateSequence::setOrdinate size_t  index,
size_t  ordinateIndex,
double  value
[pure virtual]
 

Sets the value for a given ordinate of a coordinate in this sequence.

Parameters:
index the coordinate index in the sequence
ordinateIndex the ordinate index in the coordinate (in range [0, dimension-1])
value the new ordinate value

Implemented in geos::geom::CoordinateArraySequence.

virtual const std::vector<Coordinate>* geos::geom::CoordinateSequence::toVector  )  const [pure virtual]
 

Returns a read-only vector with the Coordinates in this collection.

Whether or not the Coordinates returned are the actual underlying Coordinates or merely copies depends on the implementation. Note that if this implementation does not store its data as an array of Coordinates, this method will incur a performance penalty because the array needs to be built from scratch.

This method is a port of the toCoordinateArray() method of JTS. It is not much used as memory management requires us to know wheter we should or not delete the returned object in a consistent way. Our options are: use shared_ptr<Coordinate> or always keep ownerhips of an eventual newly created vector. We opted for the second, so the returned object is a const, to also ensure that returning an internal pointer doesn't make the object mutable.

Implemented in geos::geom::CoordinateArraySequence.


The documentation for this class was generated from the following file:
Generated on Thu Jun 11 06:17:02 2009 for GEOS by  doxygen 1.4.4