/****************************************************************************
** $Id: qpoint.cpp,v 2.16 1999/05/31 10:26:48 warwick Exp $
**
** Implementation of QPoint class
**
** Created : 931028
**
** Copyright (C) 1992-1999 Troll Tech AS.  All rights reserved.
**
** This file is part of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Troll Tech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** Licensees holding valid Qt Professional Edition licenses may use this
** file in accordance with the Qt Professional Edition License Agreement
** provided with the Qt Professional Edition.
**
** See http://www.troll.no/pricing.html or email sales@troll.no for
** information about the Professional Edition licensing, or see
** http://www.troll.no/qpl/ for QPL licensing information.
**
*****************************************************************************/

#include "qpoint.h"
#include "qdatastream.h"


/*!
  \class QPoint qpoint.h
  \brief The QPoint class defines a point in the plane.

  \ingroup drawing

  A point is specified by an x coordinate and a y coordinate.

  The coordinate type is QCOORD (defined in qwindowdefs.h as \c int).
  The minimum value of QCOORD is QCOORD_MIN (-2147483648) and the maximum
  value is  QCOORD_MAX (2147483647).

  We have defined many operator functions that make arithmetic on points
  simple and intuitive.

  Example:
  \code
    QPoint p(  1, 2 );
    QPoint q( -8, 5 );
    QPoint r(  9, 7 );
    QPoint x = 2*p + (q-r)*5.5 - (r+p/1.5);
  \endcode

  \sa QSize, QRect
*/


/*****************************************************************************
  QPoint member functions
 *****************************************************************************/

/*!
  \fn QPoint::QPoint()
  Constructs a point (0,0) (a \link QPoint::isNull() null point\endlink).
*/

/*!
  \fn QPoint::QPoint( int xpos, int ypos )
  Constructs a point with the x value  \e xpos and y value \e ypos.
*/

/*!
  \fn bool QPoint::isNull() const
  Returns TRUE if both the x value and the y value are 0.
*/

/*!
  \fn int QPoint::x() const
  Returns the x coordinate of the point.
  \sa y()
*/

/*!
  \fn int QPoint::y() const
  Returns the y coordinate of the point.
  \sa x()
*/

/*!
  \fn void QPoint::setX( int x )
  Sets the x coordinate of the point to \e x.
  \sa setY()
*/

/*!
  \fn void QPoint::setY( int y )
  Sets the y coordinate of the point to \e y.
  \sa setX()
*/


/*!
  \fn QCOORD &QPoint::rx()
  Returns a reference to the x coordinate of the point.

  Using a reference makes it possible to directly manipulate x.

  Example:
  \code
    QPoint p( 1, 2 );
    p.rx()--;			// p becomes (0,2)
  \endcode

  \sa ry()
*/

/*!
  \fn QCOORD &QPoint::ry()
  Returns a reference to the y coordinate of the point.

  Using a reference makes it possible to directly manipulate y.

  Example:
  \code
    QPoint p( 1, 2 );
    p.ry()++;			// p becomes (1,3)
  \endcode

  \sa rx()
*/


/*!
  \fn QPoint &QPoint::operator+=( const QPoint &p )
  Adds \e p to the point and returns a reference to this point.

  Example:
  \code
    QPoint p(  3, 7 );
    QPoint q( -1, 4 );
    p += q;			// p becomes (2,11)
  \endcode
*/

/*!
  \fn QPoint &QPoint::operator-=( const QPoint &p )
  Subtracts \e p from the point and returns a reference to this point.

  Example:
  \code
    QPoint p(  3, 7 );
    QPoint q( -1, 4 );
    p -= q;			// p becomes (4,3)
  \endcode
*/

/*!
  \fn QPoint &QPoint::operator*=( int c )
  Multiplies both x and y with \e c, and return a reference to this point.

  Example:
  \code
    QPoint p( -1, 4 );
    p *= 2;			// p becomes (-2,8)
  \endcode
*/

/*!
  \fn QPoint &QPoint::operator*=( double c )
  Multiplies both x and y with \e c, and return a reference to this point.

  Example:
  \code
    QPoint p( -1, 4 );
    p *= 2.5;			// p becomes (-3,10)
  \endcode

  Note that the result is truncated.
*/


/*!
  \fn bool operator==( const QPoint &p1, const QPoint &p2 )
  \relates QPoint
  Returns TRUE if \e p1 and \e p2 are equal, or FALSE if they are different.
*/

/*!
  \fn bool operator!=( const QPoint &p1, const QPoint &p2 )
  \relates QPoint
  Returns TRUE if \e p1 and \e p2 are different, or FALSE if they are equal.
*/

/*!
  \fn QPoint operator+( const QPoint &p1, const QPoint &p2 )
  \relates QPoint
  Returns the sum of \e p1 and \e p2; each component is added separately.
*/

/*!
  \fn QPoint operator-( const QPoint &p1, const QPoint &p2 )
  \relates QPoint
  Returns \e p2 subtracted from \e p1; each component is
  subtracted separately.
*/

/*!
  \fn QPoint operator*( const QPoint &p, int c )
  \relates QPoint
  Multiplies both of \e p's components by \e c and returns the result.
*/

/*!
  \fn QPoint operator*( int c, const QPoint &p )
  \relates QPoint
  Multiplies both of \e p's components by \e c and returns the result.
*/

/*!
  \fn QPoint operator*( const QPoint &p, double c )
  \relates QPoint
  Multiplies both of \e p's components by \e c and returns the
  result.
*/

/*!
  \fn QPoint operator*( double c, const QPoint &p )
  \relates QPoint
  Multiplies both of \e p's components by \e c and returns the
  result.
*/

/*!
  \fn QPoint operator-( const QPoint &p )
  \relates QPoint
  Returns \e p where x and y have opposite signs.
*/

/*!
  \fn QPoint &QPoint::operator/=( int c )

  Divides both x and y by \e c, and return a reference to this point.

  Example:
  \code
    QPoint p( -2, 8 );
    p /= 2;			// p becomes (-1,4)
  \endcode
*/

/*!
  \fn QPoint &QPoint::operator/=( double c )

  Divides both x and y by \e c, and return a reference to this point.

  Example:
  \code
    QPoint p( -3, 10 );
    p /= 2.5;			// p becomes (-1,4)
  \endcode

  Note that the result is truncated.
*/

/*!
  \fn QPoint operator/( const QPoint &p, int c )
  \relates QPoint
  Divides both of \e p's components by \e c and returns the result.
*/

/*!
  \fn QPoint operator/( const QPoint &p, double c )
  \relates QPoint

  Divides both of \e p's components by \e c and returns the result.

  Note that the result is truncated.
*/


void QPoint::warningDivByZero()
{
#if defined(CHECK_MATH)
    qWarning( "QPoint: Division by zero error" );
#endif
}


/*****************************************************************************
  QPoint stream functions
 *****************************************************************************/

/*!
  \relates QPoint
  Writes a QPoint to the stream and returns a reference to the stream.

  Serialization format: [x (Q_INT32), y (Q_INT32)].
*/

QDataStream &operator<<( QDataStream &s, const QPoint &p )
{
    if ( s.version() == 1 )
	s << (Q_INT16)p.x() << (Q_INT16)p.y();
    else
	s << (Q_INT32)p.x() << (Q_INT32)p.y();
    return s;
}

/*!
  \relates QPoint
  Reads a QPoint from the stream and returns a reference to the stream.
*/

QDataStream &operator>>( QDataStream &s, QPoint &p )
{
    if ( s.version() == 1 ) {
	Q_INT16 x, y;
	s >> x;  p.rx() = x;
	s >> y;  p.ry() = y;
    }
    else {
	Q_INT32 x, y;
	s >> x;  p.rx() = x;
	s >> y;  p.ry() = y;
    }
    return s;
}

/*!
  Returns the sum of the absolute values of x() and y(), traditionally
  known as the "Manhattan length" of the vector from the origin to the
  point. The tradition arises since such distances apply
  to travelers who can only travel on a rectangular grid, like the streets
  of Manhattan.

  This is a useful approximation to the true length,
  sqrt(pow(x(),2)+pow(y(),2)).
*/
int QPoint::manhattanLength() const
{
    return QABS(x())+QABS(y());
}