path: root/doc/man/man3/tqpoint.3qt

'\" t
.TH TQPoint 3qt "2 February 2007" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2007 Trolltech ASA.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
TQPoint \- Defines a point in the plane
.SH SYNOPSIS
\fC#include <tqpoint.h>\fR
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBTQPoint\fR ()"
.br
.ti -1c
.BI "\fBTQPoint\fR ( int xpos, int ypos )"
.br
.ti -1c
.BI "bool \fBisNull\fR () const"
.br
.ti -1c
.BI "int \fBx\fR () const"
.br
.ti -1c
.BI "int \fBy\fR () const"
.br
.ti -1c
.BI "void \fBsetX\fR ( int x )"
.br
.ti -1c
.BI "void \fBsetY\fR ( int y )"
.br
.ti -1c
.BI "int \fBmanhattanLength\fR () const"
.br
.ti -1c
.BI "QCOORD & \fBrx\fR ()"
.br
.ti -1c
.BI "QCOORD & \fBry\fR ()"
.br
.ti -1c
.BI "TQPoint & \fBoperator+=\fR ( const TQPoint & p )"
.br
.ti -1c
.BI "TQPoint & \fBoperator-=\fR ( const TQPoint & p )"
.br
.ti -1c
.BI "TQPoint & \fBoperator*=\fR ( int c )"
.br
.ti -1c
.BI "TQPoint & \fBoperator*=\fR ( double c )"
.br
.ti -1c
.BI "TQPoint & \fBoperator/=\fR ( int c )"
.br
.ti -1c
.BI "TQPoint & \fBoperator/=\fR ( double c )"
.br
.in -1c
.SH RELATED FUNCTION DOCUMENTATION
.in +1c
.ti -1c
.BI "bool \fBoperator==\fR ( const TQPoint & p1, const TQPoint & p2 )"
.br
.ti -1c
.BI "bool \fBoperator!=\fR ( const TQPoint & p1, const TQPoint & p2 )"
.br
.ti -1c
.BI "const TQPoint \fBoperator+\fR ( const TQPoint & p1, const TQPoint & p2 )"
.br
.ti -1c
.BI "const TQPoint \fBoperator-\fR ( const TQPoint & p1, const TQPoint & p2 )"
.br
.ti -1c
.BI "const TQPoint \fBoperator*\fR ( const TQPoint & p, int c )"
.br
.ti -1c
.BI "const TQPoint \fBoperator*\fR ( int c, const TQPoint & p )"
.br
.ti -1c
.BI "const TQPoint \fBoperator*\fR ( const TQPoint & p, double c )"
.br
.ti -1c
.BI "const TQPoint \fBoperator*\fR ( double c, const TQPoint & p )"
.br
.ti -1c
.BI "const TQPoint \fBoperator-\fR ( const TQPoint & p )"
.br
.ti -1c
.BI "const TQPoint \fBoperator/\fR ( const TQPoint & p, int c )"
.br
.ti -1c
.BI "const TQPoint \fBoperator/\fR ( const TQPoint & p, double c )"
.br
.ti -1c
.BI "TQDataStream & \fBoperator<<\fR ( TQDataStream & s, const TQPoint & p )"
.br
.ti -1c
.BI "TQDataStream & \fBoperator>>\fR ( TQDataStream & s, TQPoint & p )"
.br
.in -1c
.SH DESCRIPTION
The TQPoint class defines a point in the plane.
.PP
A point is specified by an x coordinate and a y coordinate.
.PP
The coordinate type is \fCQCOORD\fR (a 32-bit integer). The minimum value of \fCQCOORD\fR is \fCQCOORD_MIN\fR (-2147483648) and the maximum value is \fCQCOORD_MAX\fR (2147483647).
.PP
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().
.PP
Given a point \fIp\fR, the following statements are all equivalent:
.PP
.nf
.br
        p.setX( p.x() + 1 );
.br
        p += TQPoint( 1, 0 );
.br
        p.rx()++;
.br
.fi
.PP
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 \fCint\fR or a \fCdouble\fR. The function manhattanLength() gives an inexpensive approximation of the length of the TQPoint interpreted as a vector.
.PP
Example:
.PP
.nf
.br
        //TQPoint oldPos is defined somewhere else
.br
        MyWidget::mouseMoveEvent( TQMouseEvent *e )
.br
        {
.br
            TQPoint vector = e->pos() - oldPos;
.br
            if ( vector.manhattanLength() > 3 )
.br
            ... //mouse has moved more than 3 pixels since oldPos
.br
        }
.br
.fi
.PP
TQPoints can be compared for equality or inequality, and they can be written to and read from a QStream.
.PP
See also TQPointArray, TQSize, TQRect, Graphics Classes, and Image Processing Classes.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "TQPoint::TQPoint ()"
Constructs a point with coordinates (0, 0) (isNull() returns TRUE).
.SH "TQPoint::TQPoint ( int xpos, int ypos )"
Constructs a point with x value \fIxpos\fR and y value \fIypos\fR.
.SH "bool TQPoint::isNull () const"
Returns TRUE if both the x value and the y value are 0; otherwise returns FALSE.
.SH "int TQPoint::manhattanLength () const"
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.
.PP
This is a useful, and quick to calculate, approximation to the true length: sqrt(pow(x(),2)+pow(y(),2)).
.SH "TQPoint & TQPoint::operator*= ( int c )"
Multiplies this point's x and y by \fIc\fR, and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p( -1, 4 );
.br
        p *= 2;            // p becomes (-2,8)
.br
.fi
.SH "TQPoint & TQPoint::operator*= ( double c )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Multiplies this point's x and y by \fIc\fR, and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p( -1, 4 );
.br
        p *= 2.5;          // p becomes (-3,10)
.br
.fi
.PP
Note that the result is truncated because points are held as integers.
.SH "TQPoint & TQPoint::operator+= ( const TQPoint & p )"
Adds point \fIp\fR to this point and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p(  3, 7 );
.br
        TQPoint q( -1, 4 );
.br
        p += q;            // p becomes (2,11)
.br
.fi
.SH "TQPoint & TQPoint::operator-= ( const TQPoint & p )"
Subtracts point \fIp\fR from this point and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p(  3, 7 );
.br
        TQPoint q( -1, 4 );
.br
        p -= q;            // p becomes (4,3)
.br
.fi
.SH "TQPoint & TQPoint::operator/= ( int c )"
Divides both x and y by \fIc\fR, and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p( -2, 8 );
.br
        p /= 2;            // p becomes (-1,4)
.br
.fi
.SH "TQPoint & TQPoint::operator/= ( double c )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Divides both x and y by \fIc\fR, and returns a reference to this point.
.PP
Example:
.PP
.nf
.br
        TQPoint p( -3, 10 );
.br
        p /= 2.5;           // p becomes (-1,4)
.br
.fi
.PP
Note that the result is truncated because points are held as integers.
.SH "QCOORD & TQPoint::rx ()"
Returns a reference to the x coordinate of the point.
.PP
Using a reference makes it possible to directly manipulate x.
.PP
Example:
.PP
.nf
.br
        TQPoint p( 1, 2 );
.br
        p.rx()--;         // p becomes (0, 2)
.br
.fi
.PP
See also ry().
.SH "QCOORD & TQPoint::ry ()"
Returns a reference to the y coordinate of the point.
.PP
Using a reference makes it possible to directly manipulate y.
.PP
Example:
.PP
.nf
.br
        TQPoint p( 1, 2 );
.br
        p.ry()++;         // p becomes (1, 3)
.br
.fi
.PP
See also rx().
.SH "void TQPoint::setX ( int x )"
Sets the x coordinate of the point to \fIx\fR.
.PP
See also x() and setY().
.PP
Example: t14/cannon.cpp.
.SH "void TQPoint::setY ( int y )"
Sets the y coordinate of the point to \fIy\fR.
.PP
See also y() and setX().
.PP
Example: t14/cannon.cpp.
.SH "int TQPoint::x () const"
Returns the x coordinate of the point.
.PP
See also setX() and y().
.PP
Examples:
.)l canvas/canvas.cpp, chart/canvasview.cpp, dirview/dirview.cpp, fileiconview/tqfileiconview.cpp, helpsystem/tooltip.cpp, life/life.cpp, and t14/cannon.cpp.
.SH "int TQPoint::y () const"
Returns the y coordinate of the point.
.PP
See also setY() and x().
.PP
Examples:
.)l canvas/canvas.cpp, chart/canvasview.cpp, fileiconview/tqfileiconview.cpp, helpsystem/tooltip.cpp, life/life.cpp, t14/cannon.cpp, and themes/wood.cpp.
.SH RELATED FUNCTION DOCUMENTATION
.SH "bool operator!= ( const TQPoint & p1, const TQPoint & p2 )"
Returns TRUE if \fIp1\fR and \fIp2\fR are not equal; otherwise returns FALSE.
.SH "const TQPoint operator* ( const TQPoint & p, int c )"
Returns the TQPoint formed by multiplying both components of \fIp\fR by \fIc\fR.
.SH "const TQPoint operator* ( int c, const TQPoint & p )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the TQPoint formed by multiplying both components of \fIp\fR by \fIc\fR.
.SH "const TQPoint operator* ( const TQPoint & p, double c )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the TQPoint formed by multiplying both components of \fIp\fR by \fIc\fR.
.PP
Note that the result is truncated because points are held as integers.
.SH "const TQPoint operator* ( double c, const TQPoint & p )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the TQPoint formed by multiplying both components of \fIp\fR by \fIc\fR.
.PP
Note that the result is truncated because points are held as integers.
.SH "const TQPoint operator+ ( const TQPoint & p1, const TQPoint & p2 )"
Returns the sum of \fIp1\fR and \fIp2\fR; each component is added separately.
.SH "const TQPoint operator- ( const TQPoint & p1, const TQPoint & p2 )"
Returns \fIp2\fR subtracted from \fIp1\fR; each component is subtracted separately.
.SH "const TQPoint operator- ( const TQPoint & p )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the TQPoint formed by changing the sign of both components of \fIp\fR, equivalent to \fCTQPoint(0,0) - p\fR.
.SH "const TQPoint operator/ ( const TQPoint & p, int c )"
Returns the TQPoint formed by dividing both components of \fIp\fR by \fIc\fR.
.SH "const TQPoint operator/ ( const TQPoint & p, double c )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Returns the TQPoint formed by dividing both components of \fIp\fR by \fIc\fR.
.PP
Note that the result is truncated because points are held as integers.
.SH "TQDataStream & operator<< ( TQDataStream & s, const TQPoint & p )"
Writes point \fIp\fR to the stream \fIs\fR and returns a reference to the stream.
.PP
See also Format of the TQDataStream operators.
.SH "bool operator== ( const TQPoint & p1, const TQPoint & p2 )"
Returns TRUE if \fIp1\fR and \fIp2\fR are equal; otherwise returns FALSE.
.SH "TQDataStream & operator>> ( TQDataStream & s, TQPoint & p )"
Reads a TQPoint from the stream \fIs\fR into point \fIp\fR and returns a reference to the stream.
.PP
See also Format of the TQDataStream operators.

.SH "SEE ALSO"
.BR http://doc.trolltech.com/tqpoint.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports help us to help you. Thank you.
.P
The definitive TQt documentation is provided in HTML format; it is
located at $TQTDIR/doc/html and can be read using TQt Assistant or with
a web browser. This man page is provided as a convenience for those
users who prefer man pages, although this format is not officially
supported by Trolltech. 
.P
If you find errors in this manual page, please report them to
.BR [email protected] .
Please include the name of the manual page (tqpoint.3qt) and the Qt
version (3.3.8).