QPointF Class

QPointF p;

p.setX(p.x() + 1.0);
p += QPointF(1.0, 0.0);
p.rx()++;

Member Function Documentation

QPointF::QPointF()

Constructs a null point, i.e. with coordinates (0.0, 0.0)

See also isNull().

QPointF::QPointF(const QPoint &point)

Constructs a copy of the given point.

See also toPoint().

QPointF::QPointF(qreal xpos, qreal ypos)

Constructs a point with the given coordinates (xpos, ypos).

See also setX() and setY().

[static] qreal QPointF::dotProduct(const QPointF &p1, const QPointF &p2)

QPointF p( 3.1, 7.1);
QPointF q(-1.0, 4.1);
int lengthSquared = QPointF::dotProduct(p, q);   // lengthSquared becomes 26.01

Returns the dot product of p1 and p2.

This function was introduced in Qt 5.1.

[static] QPointF QPointF::fromCGPoint(CGPoint point)

Creates a QRectF from CGPoint point.

This function was introduced in Qt 5.8.

See also toCGPoint().

bool QPointF::isNull() const

Returns true if both the x and y coordinates are set to 0.0 (ignoring the sign); otherwise returns false.

qreal QPointF::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.

This function was introduced in Qt 4.6.

See also QPoint::manhattanLength().

qreal &QPointF::rx()

Returns a reference to the x coordinate of this point.

Using a reference makes it possible to directly manipulate x. For example:

 QPointF p(1.1, 2.5);
 p.rx()--;   // p becomes (0.1, 2.5)

See also x() and setX().

qreal &QPointF::ry()

Returns a reference to the y coordinate of this point.

Using a reference makes it possible to directly manipulate y. For example:

QPointF p(1.1, 2.5);
p.ry()++;   // p becomes (1.1, 3.5)

See also y() and setY().

void QPointF::setX(qreal x)

Sets the x coordinate of this point to the given x coordinate.

See also x() and setY().

void QPointF::setY(qreal y)

Sets the y coordinate of this point to the given y coordinate.

See also y() and setX().

CGPoint QPointF::toCGPoint() const

Creates a CGPoint from a QPointF.

This function was introduced in Qt 5.8.

See also fromCGPoint().

QPoint QPointF::toPoint() const

Rounds the coordinates of this point to the nearest integer, and returns a QPoint object with the rounded coordinates.

See also QPointF().

qreal QPointF::x() const

Returns the x coordinate of this point.

See also setX() and rx().

qreal QPointF::y() const

Returns the y coordinate of this point.

See also setY() and ry().

QPointF &QPointF::operator*=(qreal factor)

Multiplies this point's coordinates by the given factor, and returns a reference to this point. For example:

QPointF p(-1.1, 4.1);
p *= 2.5;    // p becomes (-2.75, 10.25)

See also operator/=().

QPointF &QPointF::operator+=(const QPointF &point)

Adds the given point to this point and returns a reference to this point. For example:

QPointF p( 3.1, 7.1);
QPointF q(-1.0, 4.1);
p += q;    // p becomes (2.1, 11.2)

See also operator-=().

QPointF &QPointF::operator-=(const QPointF &point)

Subtracts the given point from this point and returns a reference to this point. For example:

QPointF p( 3.1, 7.1);
QPointF q(-1.0, 4.1);
p -= q;    // p becomes (4.1, 3.0)

See also operator+=().

QPointF &QPointF::operator/=(qreal divisor)

Divides both x and y by the given divisor, and returns a reference to this point. For example:

QPointF p(-2.75, 10.25);
p /= 2.5;           // p becomes (-1.1, 4.1)

See also operator*=().