envelope.h

在Linux下做的QuadTree的程序

/**********************************************************************
 * $Id: Envelope.h 1820 2006-09-06 16:54:23Z mloskot $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2006 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.
 *
 **********************************************************************
 *
 * Last port: geom/Envelope.java rev. 1.41 (JTS-1.7)
 *
 **********************************************************************/

#ifndef GEOS_GEOM_ENVELOPE_H
#define GEOS_GEOM_ENVELOPE_H

#include <geos/inline.h>

#include <string>
#include <vector>
#include <memory>

namespace geos {
namespace geom { // geos::geom

class Coordinate;

/**
 * \class Envelope geom.h geos.h
 *
 * \brief
 * An Envelope defines a rectangulare region of the 2D coordinate plane.
 *
 * It is often used to represent the bounding box of a Geometry,
 * e.g. the minimum and maximum x and y values of the Coordinates.
 *  
 * Note that Envelopes support infinite or half-infinite regions, by using
 * the values of <code>Double_POSITIVE_INFINITY</code> and
 * <code>Double_NEGATIVE_INFINITY</code>.
 *
 * When Envelope objects are created or initialized,
 * the supplies extent values are automatically sorted into the correct order.
 *
 */
class Envelope {

public:

	typedef std::auto_ptr<Envelope> AutoPtr;

	/** \brief
	 * Creates a null <code>Envelope</code>.
	 */
	Envelope(void);

	/** \brief
	 * Creates an <code>Envelope</code> for a region defined by
	 * maximum and minimum values.
	 *
	 * @param  x1  the first x-value
	 * @param  x2  the second x-value
	 * @param  y1  the first y-value
	 * @param  y2  the second y-value
	 */
	Envelope(double x1, double x2, double y1, double y2);

	/** \brief
	 * Creates an <code>Envelope</code> for a region defined by
	 * two Coordinates.
	 *
	 * @param  p1  the first Coordinate
	 * @param  p2  the second Coordinate
	 */
	Envelope(const Coordinate& p1, const Coordinate& p2);

	/** \brief
	 * Creates an Envelope for a region defined by a single Coordinate.
	 *
	 * @param  p  the Coordinate
	 */
	Envelope(const Coordinate& p);

	/// Copy constructor
	Envelope(const Envelope &env);

	/// Assignment operator
	Envelope& operator=(const Envelope& e);

	/** \brief
	 *  Create an <code>Envelope</code> from an Envelope 
	 *  string representation produced by Envelope.toString()
	 */
	Envelope(const std::string &str);

	~Envelope(void);

	/** \brief
	 * Test the point q to see whether it intersects the
	 * Envelope defined by p1-p2
	 *
	 * @param p1 one extremal point of the envelope
	 * @param p2 another extremal point of the envelope
	 * @param q the point to test for intersection
	 * @return <code>true</code> if q intersects the envelope p1-p2
	 */
	static bool intersects(const Coordinate& p1, const Coordinate& p2,
			const Coordinate& q);

	/** \brief
	 * Test the envelope defined by p1-p2 for intersection
	 * with the envelope defined by q1-q2
	 *
	 * @param p1 one extremal point of the envelope P
	 * @param p2 another extremal point of the envelope P
	 * @param q1 one extremal point of the envelope Q
	 * @param q2 another extremal point of the envelope Q
	 *
	 * @return <code>true</code> if Q intersects P
	 */
	static bool intersects(const Coordinate& p1, const Coordinate& p2,
			const Coordinate& q1, const Coordinate& q2);

	/** \brief
	 *  Initialize to a null <code>Envelope</code>.
	 */
	void init(void);

	/** \brief
	 * Initialize an <code>Envelope</code> for a region defined by
	 * maximum and minimum values.
	 *
	 * @param  x1  the first x-value
	 * @param  x2  the second x-value
	 * @param  y1  the first y-value
	 * @param  y2  the second y-value
	 */
	void init(double x1, double x2, double y1, double y2);

	/** \brief
	 * Initialize an <code>Envelope</code> to a region defined
	 * by two Coordinates.
	 *
	 * @param  p1  the first Coordinate
	 * @param  p2  the second Coordinate
	 */
	void init(const Coordinate& p1, const Coordinate& p2);

	/** \brief
	 * Initialize an <code>Envelope</code> to a region defined
	 * by a single Coordinate.
	 *
	 * @param  p  the Coordinate
	 */
	void init(const Coordinate& p);

	// use assignment operator instead
	//void init(Envelope env);

	/** \brief
	 * Makes this <code>Envelope</code> a "null" envelope,
	 * that is, the envelope of the empty geometry.
	 */
	void setToNull(void);

	/** \brief
	 * Returns <code>true</code> if this <code>Envelope</code>
	 * is a "null" envelope.
	 *
	 * @return <code>true</code> if this <code>Envelope</code>
	 *         is uninitialized or is the envelope of the
	 *         empty geometry.
	 */
	bool isNull(void) const;

	/** \brief
	 * Returns the difference between the maximum and minimum x values.
	 *
	 * @return  max x - min x, or 0 if this is a null Envelope
	 */
	double getWidth(void) const;

	/** \brief
	 * Returns the difference between the maximum and minimum y values.
	 *
	 * @return max y - min y, or 0 if this is a null Envelope
	 */
	double getHeight(void) const;

	/**
	 *  Returns the Envelope maximum y-value. min y > max y
	 *  indicates that this is a null Envelope.
	 */
	double getMaxY() const;

	/**
	 *  Returns the Envelope maximum x-value. min x > max x
	 *  indicates that this is a null Envelope.
	 */
	double getMaxX() const;

	/**
	 *  Returns the Envelope minimum y-value. min y > max y
	 *  indicates that this is a null Envelope.
	 */
	double getMinY() const;

	/**
	 *  Returns the Envelope minimum x-value. min x > max x
	 *  indicates that this is a null Envelope.
	 */
	double getMinX() const;

	/**
	 * Computes the coordinate of the centre of this envelope
	 * (as long as it is non-null)
	 *
	 * @param centre The coordinate to write results into
	 * @return NULL is the center could not be found
	 * (null envelope).
	 */
	bool centre(Coordinate& centre) const;

	/**
	 * Computes the intersection of two {@link Envelopes}
	 *
	 * @param env the envelope to intersect with
	 * @param result the envelope representing the intersection of
	 *               the envelopes (this will be the null envelope
	 *               if either argument is null, or they do not intersect)
	 * @return false if not intersection is found
	 */
	bool intersection(const Envelope& env, Envelope& result);

	/** \brief
	 * Translates this envelope by given amounts in the X and Y direction.
	 *
	 * @param transX the amount to translate along the X axis
	 * @param transY the amount to translate along the Y axis
	 */
	void translate(double transX, double transY);

	/** \brief
	 * Expands this envelope by a given distance in all directions.
	 * Both positive and negative distances are supported.
	 *
	 * @param deltaX the distance to expand the envelope along 
	 *               the X axis
	 * @param deltaY the distance to expand the envelope along
	 *               the Y axis
	 */
	void expandBy(double deltaX, double deltaY);

	/** \brief
	 * Expands this envelope by a given distance in all directions.
	 * Both positive and negative distances are supported.
	 *
	 * @param distance the distance to expand the envelope
	 * @return this envelope
	 */
	void expandBy(double distance) { expandBy(distance, distance); }


	/** \brief
	 * Enlarges the boundary of the Envelope so that it contains
	 *  p. Does nothing if p is already on or within the boundaries.
	 *
	 * @param  p  the Coordinate to include
	 */
	void expandToInclude(const Coordinate& p);

	/** \brief
	 * Enlarges the boundary of the Envelope so that it contains
	 * (x,y). Does nothing if (x,y) is already on or within the boundaries.
	 *
	 * @param  x  the value to lower the minimum x
	 *            to or to raise the maximum x to
	 * @param  y  the value to lower the minimum y
	 *            to or to raise the maximum y to
	 */
	void expandToInclude(double x, double y);

	/** \brief
	 * Enlarges the boundary of the Envelope so that it contains
	 * <code>other</code>. Does nothing if other is wholly on or
	 * within the boundaries.
	 *
	 * @param  other  the <code>Envelope</code> to merge with
	 */
	void expandToInclude(const Envelope* other);

	/** \brief
	 * Returns <code>true</code> if the given point lies in
	 * or on the envelope.
	 *
	 * @param  p  the point which this <code>Envelope</code> is
	 *      being checked for containing
	 * @return    <code>true</code> if the point lies in the interior or
	 *      on the boundary of this <code>Envelope</code>.
	 */
	bool contains(const Coordinate& p) const;

	/** \brief
	 * Returns <code>true</code> if the given point lies in
	 * or on the envelope.
	 *
	 * @param  x  the x-coordinate of the point which this
	 *            <code>Envelope</code> is
	 *            being checked for containing
	 *
	 * @param  y  the y-coordinate of the point which this
	 *            <code>Envelope</code> is being checked for containing
	 *
	 * @return    <code>true</code> if <code>(x, y)</code> lies in
	 *            the interior or on the boundary of this
	 *            <code>Envelope</code>.
	 */
	bool contains(double x, double y) const;

	/** \brief
	 * Returns <code>true</code> if the <code>Envelope other</code>
	 * lies wholely inside this <code>Envelope</code> (inclusive of
	 * the boundary).
	 *
	 * @param  other  the <code>Envelope</code> which this
	 *                    <code>Envelope</code> is being checked
	 *                    for containing
	 *
	 * @return        <code>true</code> if <code>other</code>
	 *                is contained in this <code>Envelope</code>
	 */
	bool contains(const Envelope* other) const;

	bool contains(const Envelope& other) const { return contains(&other); }

	/**
	 * Check if the point p
	 * intersects (lies inside) the region of this Envelope.
	 *
	 * @param  p  	the Coordinate to be tested
	 * @return true if the point intersects this Envelope
	 */
	bool intersects(const Coordinate& p) const;

	/**
	 *  Check if the point (x, y)
	 *  intersects (lies inside) the region of this Envelope.
	 *
	 * @param  x  the x-ordinate of the point
	 * @param  y  the y-ordinate of the point
	 * @return <code>true</code> if the point intersects this Envelope
	 */
	bool intersects(double x, double y) const;

	/**
	 * Check if the region defined by other Envelope
	 * intersects (intersects) the region of this Envelope.
	 *
	 * @param other the Envelope which this Envelope is
	 *              being checked for intersection
	 *
	 * @return      true if the Envelopes intersects
	 */
	bool intersects(const Envelope* other) const;

	bool intersects(const Envelope& other) const;

	/** \brief
	 * Returns <code>true</code> if the <code>Envelope other</code>
	 * spatially equals this <code>Envelope</code>.
	 *
	 * @param  other the <code>Envelope</code> which this
	 *               <code>Envelope</code> is being checked for equality
	 *
	 * @return <code>true</code> if this and <code>other</code>
	 *         Envelope objs are spatially equal
	 */
	bool equals(const Envelope* other) const;

	/** \brief
	 * Returns a <code>string</code> of the form
	 * <I>Env[minx:maxx,miny:maxy]</I> .
	 *
	 * @return a <code>string</code> of the form
	 *         <I>Env[minx:maxx,miny:maxy]</I>
	 */
	std::string toString(void) const;

	/** \brief
	 * Computes the distance between this and another
	 * <code>Envelope</code>.
	 *
	 * The distance between overlapping Envelopes is 0.  Otherwise, the
	 * distance is the Euclidean distance between the closest points.
	 */
	double distance(const Envelope* env) const;

	int hashCode() const;

private:

	/** \brief
	 * Splits a string into parts based on the supplied delimiters.
	 *
	 * This is a generic function that really belongs in a utility
	 * file somewhere 
	 */
	std::vector<std::string> split(const std::string &str,
			const std::string &delimiters = " ");

	static double distance(double x0,double y0,double x1,double y1);

	/// the minimum x-coordinate
	double minx;

	/// the maximum x-coordinate
	double maxx;

	/// the minimum y-coordinate
	double miny;

	/// the maximum y-coordinate
	double maxy;
};

/// Checks if two Envelopes are equal (2D only check)
bool operator==(const Envelope& a, const Envelope& b);

} // namespace geos::geom
} // namespace geos

#ifdef GEOS_INLINE
# include "geos/geom/Envelope.inl"
#endif

#endif // ndef GEOS_GEOM_ENVELOPE_H

/**********************************************************************
 * $Log$
 * Revision 1.4  2006/04/10 18:15:09  strk
 * Changed Geometry::envelope member to be of type auto_ptr<Envelope>.
 * Changed computeEnvelopeInternal() signater to return auto_ptr<Envelope>
 *
 * Revision 1.3  2006/04/05 14:04:25  strk
 * Fixed copy ctor to support "Null" Envelope copies.
 * Drop init(Envelope&) method.
 * Port info and various cleanups.
 *
 * Revision 1.2  2006/03/24 09:52:41  strk
 * USE_INLINE => GEOS_INLINE
 *
 * Revision 1.1  2006/03/09 16:46:49  strk
 * geos::geom namespace definition, first pass at headers split
 *
 **********************************************************************/