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The QPoint class defines a point in the plane. More...
#include <qpoint.h>
A point is specified by an x coordinate and a y coordinate.
The coordinate type is QCOORD (a 32-bit integer). The minimum value of QCOORD is QCOORD_MIN (-2147483648) and the maximum value is QCOORD_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 p, the following statements are all equivalent:
p.setX( p.x() + 1 );
p += QPoint( 1, 0 );
p.rx()++;
A QPoint can also be used as a vector. Addition and subtraction of QPoint are defined as for vectors (each component is added separately). You can divide or multiply a QPoint by an int or a double. The function manhattanLength() gives an inexpensive approximation to the length of the QPoint interpreted as a vector.
Example:
//QPoint oldPos is defined somewhere else
MyWidget::mouseMoveEvent( QMouseEvent *e )
{
QPoint vector = e->pos() - oldPos;
if ( vector.manhattanLength() > 3 )
... //mouse has moved more than 3 pixels since oldPos
}
QPoints can be compared for equality or inequality, and they can be written to and read from a QStream.
This is a useful approximation to the true length: sqrt(pow(x(),2)+pow(y(),2)).
Example:
QPoint p( -1, 4 );
p *= 2; // p becomes (-2,8)
Example:
QPoint p( -1, 4 );
p *= 2.5; // p becomes (-3,10)
Note that the result is truncated.
Example:
QPoint p( 3, 7 );
QPoint q( -1, 4 );
p += q; // p becomes (2,11)
Example:
QPoint p( 3, 7 );
QPoint q( -1, 4 );
p -= q; // p becomes (4,3)
Divides both x and y by c, and returns a reference to this point.
Example:
QPoint p( -2, 8 );
p /= 2; // p becomes (-1,4)
Divides both x and y by c, and returns a reference to this point.
Example:
QPoint p( -3, 10 );
p /= 2.5; // p becomes (-1,4)
Note that the result is truncated.
Using a reference makes it possible to directly manipulate x.
Example:
QPoint p( 1, 2 );
p.rx()--; // p becomes (0,2)
See also ry().
Using a reference makes it possible to directly manipulate y.
Example:
QPoint p( 1, 2 );
p.ry()++; // p becomes (1,3)
See also rx().
Example: t14/cannon.cpp.
Example: t14/cannon.cpp.
Examples: dirview/dirview.cpp, fileiconview/qfileiconview.cpp, life/life.cpp, t14/cannon.cpp and themes/wood.cpp.
Examples: fileiconview/qfileiconview.cpp, life/life.cpp, t14/cannon.cpp and themes/wood.cpp.
Note that the result is truncated.
Note that the result is truncated.
Returns the QPoint formed by changing the sign of both components of
p, equivalent to QPoint(0,0) - p.
Returns the QPoint formed by dividing both components of p by c.
Note that the result is truncated.
See also Format of the QDataStream operators.
See also Format of the QDataStream operators.
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