QPointF Class

 QPointF p;

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

Member Function Documentation

QPointF::QPointF(qreal xpos, qreal ypos)

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

See also setX() and setY().

QPointF::QPointF(const QPoint &point)

Constructs a copy of the given point.

See also toPoint().

QPointF::QPointF()

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

See also isNull().

[static, since 5.1] 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, since 5.8] 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.

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 finite x coordinate.

See also x() and setY().

void QPointF::setY(qreal y)

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

See also y() and setX().

[since 5.8] 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().

[since 5.14] QPointF QPointF::transposed() const

Returns a point with x and y coordinates exchanged:

 QPointF{1.0, 2.0}.transposed() // {2.0, 1.0}

This function was introduced in Qt 5.14.

See also x(), y(), setX(), and setY().

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 finite 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)

The divisor must not be zero or NaN.

See also operator*=().