point.cpp

一个很好的vc底层代码

/**********************************************************************
 * $Id: Point.cpp,v 1.31.2.1 2005/05/23 16:02:33 strk Exp $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 * Copyright (C) 2005 Refractions Research Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************/

#include <geos/geom.h>
#include <geos/util.h>

namespace geos {


/**
* Creates a Point using the given CoordinateSequence (must have 1 element)
*
* @param  newCoords
*	contains the single coordinate on which to base this
*	<code>Point</code> or <code>null</code> to create
*	the empty geometry.
*
*	If not null the created Point will take ownership of newCoords.
*/  
Point::Point(CoordinateSequence *newCoords, const GeometryFactory *factory): Geometry(factory) {
	if (newCoords==NULL) {
		coordinates=factory->getCoordinateSequenceFactory()->create(NULL);
		return;
	}        
	if (newCoords->getSize() != 1)
	{
		throw new IllegalArgumentException("Point coordinate list must contain a single element");
	}
	coordinates=newCoords;
}

Point::Point(const Point &p): Geometry(p.getFactory()) {
	coordinates=p.coordinates->clone();
}

Geometry* Point::clone() const {
	return new Point(*this);
}

CoordinateSequence* Point::getCoordinates() const {
	return coordinates->clone();
}

int Point::getNumPoints() const {
	return isEmpty() ? 0 : 1;
}

bool Point::isEmpty() const {
	//return (*getCoordinate())==Coordinate::getNull();
	return coordinates->isEmpty();
}

bool Point::isSimple() const {return true;}
//bool Point::isValid() const {return true;}
int Point::getDimension() const {return 0;}
int Point::getBoundaryDimension() const {return Dimension::False;}

double Point::getX() const {
	if (isEmpty()) {
		throw new UnsupportedOperationException("getX called on empty Point\n");
	}
	return getCoordinate()->x;
}

double Point::getY() const {
	if (isEmpty()) {
		throw new UnsupportedOperationException("getY called on empty Point\n");
	}
	return getCoordinate()->y;
}

const Coordinate* Point::getCoordinate() const {
	return coordinates->getSize()!=0 ? &(coordinates->getAt(0)) : NULL;
}

string Point::getGeometryType() const {
	return "Point";
}

Geometry* Point::getBoundary() const {
	return getFactory()->createGeometryCollection(NULL);
}

Envelope* Point::computeEnvelopeInternal() const {
	if (isEmpty())
	{
		return new Envelope();
	}
	return new Envelope(getCoordinate()->x, getCoordinate()->x, getCoordinate()->y, getCoordinate()->y);
}

void Point::apply_ro(CoordinateFilter *filter) const
{
	if (isEmpty()) {
		return;
	}
	filter->filter_ro(getCoordinate());
}

void Point::apply_rw(CoordinateFilter *filter)
{
	if (isEmpty()) {
		return;
	}
	Coordinate newcoord = coordinates->getAt(0);
	filter->filter_rw(&newcoord);
	coordinates->setAt(newcoord, 0);
}

void Point::apply_rw(GeometryFilter *filter) {
	filter->filter_rw(this);
}

void Point::apply_ro(GeometryFilter *filter) const {
	filter->filter_ro(this);
}

void Point::apply_rw(GeometryComponentFilter *filter) {
	filter->filter_rw(this);
}

void Point::apply_ro(GeometryComponentFilter *filter) const {
	filter->filter_ro(this);
}

bool Point::equalsExact(const Geometry *other, double tolerance) const
{
	if (!isEquivalentClass(other)) {
		return false;
	}
	if (isEmpty() && other->isEmpty()) {
		return true;
	}
    return equal(*((Point*) other)->getCoordinate(), *getCoordinate(), tolerance);
}

int Point::compareToSameClass(const Geometry *point) const {
	return getCoordinate()->compareTo(*(((Point*)point)->getCoordinate()));
}

Point::~Point(){
	delete coordinates;
}
GeometryTypeId
Point::getGeometryTypeId() const {
	return GEOS_POINT;
}

} // namespace geos

/**********************************************************************
 * $Log: Point.cpp,v $
 * Revision 1.31.2.1  2005/05/23 16:02:33  strk
 * Backported segfault fix in isEmpty
 *
 * Revision 1.31  2004/11/23 16:22:49  strk
 * Added ElevationMatrix class and components to do post-processing draping of overlayed geometries.
 *
 * Revision 1.30  2004/09/13 12:39:14  strk
 * Made Point and MultiPoint subject to Validity tests.
 *
 * Revision 1.29  2004/07/08 19:34:49  strk
 * Mirrored JTS interface of CoordinateSequence, factory and
 * default implementations.
 * Added DefaultCoordinateSequenceFactory::instance() function.
 *
 **********************************************************************/