/****************************************************************************
**
** Implementation of TQPoint class
**
** Created : 931028
**
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**
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**********************************************************************/
#include "ntqpoint.h"
#include "ntqdatastream.h"
/*!
\class TQPoint ntqpoint.h
\brief The TQPoint class defines a point in the plane.
\ingroup images
\ingroup graphics
\mainclass
A point is specified by an x coordinate and a y coordinate.
The coordinate type is \c TQCOORD (a 32-bit integer). The minimum
value of \c TQCOORD is \c TQCOORD_MIN (-2147483648) and the maximum
value is \c TQCOORD_MAX (2147483647).
The coordinates are accessed by the functions x() and y(); they
can be set by setX() and setY() or by the reference functions rx()
and ry().
Given a point \e p, the following statements are all equivalent:
\code
p.setX( p.x() + 1 );
p += TQPoint( 1, 0 );
p.rx()++;
\endcode
A TQPoint can also be used as a vector. Addition and subtraction
of TQPoints are defined as for vectors (each component is added
separately). You can divide or multiply a TQPoint by an \c int or a
\c double. The function manhattanLength() gives an inexpensive
approximation of the length of the TQPoint interpreted as a vector.
Example:
\code
//TQPoint oldPos is defined somewhere else
MyWidget::mouseMoveEvent( TQMouseEvent *e )
{
TQPoint vector = e->pos() - oldPos;
if ( vector.manhattanLength() > 3 )
... //mouse has moved more than 3 pixels since oldPos
}
\endcode
TQPoints can be compared for equality or inequality, and they can
be written to and read from a TQStream.
\sa TQPointArray TQSize, TQRect
*/
/*****************************************************************************
TQPoint member functions
*****************************************************************************/
/*!
\fn TQPoint::TQPoint()
Constructs a point with coordinates (0, 0) (isNull() returns TRUE).
*/
/*!
\fn TQPoint::TQPoint( int xpos, int ypos )
Constructs a point with x value \a xpos and y value \a ypos.
*/
/*!
\fn bool TQPoint::isNull() const
Returns TRUE if both the x value and the y value are 0; otherwise
returns FALSE.
*/
/*!
\fn int TQPoint::x() const
Returns the x coordinate of the point.
\sa setX() y()
*/
/*!
\fn int TQPoint::y() const
Returns the y coordinate of the point.
\sa setY() x()
*/
/*!
\fn void TQPoint::setX( int x )
Sets the x coordinate of the point to \a x.
\sa x() setY()
*/
/*!
\fn void TQPoint::setY( int y )
Sets the y coordinate of the point to \a y.
\sa y() setX()
*/
/*!
\fn TQCOORD &TQPoint::rx()
Returns a reference to the x coordinate of the point.
Using a reference makes it possible to directly manipulate x.
Example:
\code
TQPoint p( 1, 2 );
p.rx()--; // p becomes (0, 2)
\endcode
\sa ry()
*/
/*!
\fn TQCOORD &TQPoint::ry()
Returns a reference to the y coordinate of the point.
Using a reference makes it possible to directly manipulate y.
Example:
\code
TQPoint p( 1, 2 );
p.ry()++; // p becomes (1, 3)
\endcode
\sa rx()
*/
/*!
\fn TQPoint &TQPoint::operator+=( const TQPoint &p )
Adds point \a p to this point and returns a reference to this
point.
Example:
\code
TQPoint p( 3, 7 );
TQPoint q( -1, 4 );
p += q; // p becomes (2,11)
\endcode
*/
/*!
\fn TQPoint &TQPoint::operator-=( const TQPoint &p )
Subtracts point \a p from this point and returns a reference to
this point.
Example:
\code
TQPoint p( 3, 7 );
TQPoint q( -1, 4 );
p -= q; // p becomes (4,3)
\endcode
*/
/*!
\fn TQPoint &TQPoint::operator*=( int c )
Multiplies this point's x and y by \a c, and returns a reference
to this point.
Example:
\code
TQPoint p( -1, 4 );
p *= 2; // p becomes (-2,8)
\endcode
*/
/*!
\overload TQPoint &TQPoint::operator*=( double c )
Multiplies this point's x and y by \a c, and returns a reference
to this point.
Example:
\code
TQPoint p( -1, 4 );
p *= 2.5; // p becomes (-3,10)
\endcode
Note that the result is truncated because points are held as
integers.
*/
/*!
\fn bool operator==( const TQPoint &p1, const TQPoint &p2 )
\relates TQPoint
Returns TRUE if \a p1 and \a p2 are equal; otherwise returns FALSE.
*/
/*!
\fn bool operator!=( const TQPoint &p1, const TQPoint &p2 )
\relates TQPoint
Returns TRUE if \a p1 and \a p2 are not equal; otherwise returns FALSE.
*/
/*!
\fn const TQPoint operator+( const TQPoint &p1, const TQPoint &p2 )
\relates TQPoint
Returns the sum of \a p1 and \a p2; each component is added separately.
*/
/*!
\fn const TQPoint operator-( const TQPoint &p1, const TQPoint &p2 )
\relates TQPoint
Returns \a p2 subtracted from \a p1; each component is subtracted
separately.
*/
/*!
\fn const TQPoint operator*( const TQPoint &p, int c )
\relates TQPoint
Returns the TQPoint formed by multiplying both components of \a p
by \a c.
*/
/*!
\overload const TQPoint operator*( int c, const TQPoint &p )
\relates TQPoint
Returns the TQPoint formed by multiplying both components of \a p
by \a c.
*/
/*!
\overload const TQPoint operator*( const TQPoint &p, double c )
\relates TQPoint
Returns the TQPoint formed by multiplying both components of \a p
by \a c.
Note that the result is truncated because points are held as
integers.
*/
/*!
\overload const TQPoint operator*( double c, const TQPoint &p )
\relates TQPoint
Returns the TQPoint formed by multiplying both components of \a p
by \a c.
Note that the result is truncated because points are held as
integers.
*/
/*!
\overload const TQPoint operator-( const TQPoint &p )
\relates TQPoint
Returns the TQPoint formed by changing the sign of both components
of \a p, equivalent to \c{TQPoint(0,0) - p}.
*/
/*!
\fn TQPoint &TQPoint::operator/=( int c )
Divides both x and y by \a c, and returns a reference to this
point.
Example:
\code
TQPoint p( -2, 8 );
p /= 2; // p becomes (-1,4)
\endcode
*/
/*!
\overload TQPoint &TQPoint::operator/=( double c )
Divides both x and y by \a c, and returns a reference to this
point.
Example:
\code
TQPoint p( -3, 10 );
p /= 2.5; // p becomes (-1,4)
\endcode
Note that the result is truncated because points are held as
integers.
*/
/*!
\fn const TQPoint operator/( const TQPoint &p, int c )
\relates TQPoint
Returns the TQPoint formed by dividing both components of \a p by
\a c.
*/
/*!
\overload const TQPoint operator/( const TQPoint &p, double c )
\relates TQPoint
Returns the TQPoint formed by dividing both components of \a p
by \a c.
Note that the result is truncated because points are held as
integers.
*/
void TQPoint::warningDivByZero()
{
#if defined(QT_CHECK_MATH)
tqWarning( "TQPoint: Division by zero error" );
#endif
}
/*****************************************************************************
TQPoint stream functions
*****************************************************************************/
#ifndef QT_NO_DATASTREAM
/*!
\relates TQPoint
Writes point \a p to the stream \a s and returns a reference to
the stream.
\sa \link datastreamformat.html Format of the TQDataStream operators \endlink
*/
TQDataStream &operator<<( TQDataStream &s, const TQPoint &p )
{
if ( s.version() == 1 )
s << (TQ_INT16)p.x() << (TQ_INT16)p.y();
else
s << (TQ_INT32)p.x() << (TQ_INT32)p.y();
return s;
}
/*!
\relates TQPoint
Reads a TQPoint from the stream \a s into point \a p and returns a
reference to the stream.
\sa \link datastreamformat.html Format of the TQDataStream operators \endlink
*/
TQDataStream &operator>>( TQDataStream &s, TQPoint &p )
{
if ( s.version() == 1 ) {
TQ_INT16 x, y;
s >> x; p.rx() = x;
s >> y; p.ry() = y;
}
else {
TQ_INT32 x, y;
s >> x; p.rx() = x;
s >> y; p.ry() = y;
}
return s;
}
#endif // QT_NO_DATASTREAM
/*!
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 because such
distances apply to travelers who can only travel on a rectangular
grid, like the streets of Manhattan.
This is a useful, and quick to calculate, approximation to the
true length: sqrt(pow(x(),2)+pow(y(),2)).
*/
int TQPoint::manhattanLength() const
{
return TQABS(x())+TQABS(y());
}