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

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

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 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
 Get a reference to Coordinate at 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 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 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 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.

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)

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)

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.

virtual void geos::geom::CoordinateSequence::setAt ( const Coordinate c,
size_t  pos 
) [pure virtual]

Get a reference to Coordinate at position pos.

Copy Coordinate c to position pos

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

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 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 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

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 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.

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


The documentation for this class was generated from the following file:
Generated on Fri Mar 27 04:53:17 2009 for GEOS by  doxygen 1.5.4