QVector2D Class

The QVector2D class represents a vector or vertex in 2D space. More...

 Header: #include CMake: find_package(Qt6 COMPONENTS Gui REQUIRED) target_link_libraries(mytarget PRIVATE Qt6::Gui) qmake: QT += gui

Public Functions

 QVector2D(QVector4D vector) QVector2D(QVector3D vector) QVector2D(QPointF point) QVector2D(QPoint point) QVector2D(float xpos, float ypos) QVector2D() float distanceToLine(QVector2D point, QVector2D direction) const float distanceToPoint(QVector2D point) const bool isNull() const float length() const float lengthSquared() const void normalize() QVector2D normalized() const void setX(float x) void setY(float y) QPoint toPoint() const QPointF toPointF() const QVector3D toVector3D() const QVector4D toVector4D() const float x() const float y() const QVariant operator QVariant() const QVector2D & operator*=(float factor) QVector2D & operator*=(QVector2D vector) QVector2D & operator+=(QVector2D vector) QVector2D & operator-=(QVector2D vector) QVector2D & operator/=(float divisor) QVector2D & operator/=(QVector2D vector) float & operator[](int i) float operator[](int i) const

Static Public Members

 float dotProduct(QVector2D v1, QVector2D v2)
 bool qFuzzyCompare(QVector2D v1, QVector2D v2) bool operator!=(QVector2D v1, QVector2D v2) QVector2D operator*(float factor, QVector2D vector) QVector2D operator*(QVector2D vector, float factor) QVector2D operator*(QVector2D v1, QVector2D v2) QVector2D operator+(QVector2D v1, QVector2D v2) QVector2D operator-(QVector2D v1, QVector2D v2) QVector2D operator-(QVector2D vector) QVector2D operator/(QVector2D vector, float divisor) QVector2D operator/(QVector2D vector, QVector2D divisor) QDataStream & operator<<(QDataStream &stream, QVector2D vector) bool operator==(QVector2D v1, QVector2D v2) QDataStream & operator>>(QDataStream &stream, QVector2D &vector)

Detailed Description

Vectors are one of the main building blocks of 2D representation and drawing. They consist of two finite floating-point coordinates, traditionally called x and y.

The QVector2D class can also be used to represent vertices in 2D space. We therefore do not need to provide a separate vertex class.

Member Function Documentation

QVector2D::QVector2D(QVector4Dvector)

Constructs a vector with x and y coordinates from a 3D vector. The z and w coordinates of vector are dropped.

QVector2D::QVector2D(QVector3Dvector)

Constructs a vector with x and y coordinates from a 3D vector. The z coordinate of vector is dropped.

QVector2D::QVector2D(QPointFpoint)

Constructs a vector with x and y coordinates from a 2D point.

QVector2D::QVector2D(QPointpoint)

Constructs a vector with x and y coordinates from a 2D point.

QVector2D::QVector2D(floatxpos, floatypos)

Constructs a vector with coordinates (xpos, ypos). Both coordinates must be finite.

QVector2D::QVector2D()

Constructs a null vector, i.e. with coordinates (0, 0).

`[since 5.1] `float QVector2D::distanceToLine(QVector2Dpoint, QVector2Ddirection) const

Returns the distance that this vertex is from a line defined by point and the unit vector direction.

If direction is a null vector, then it does not define a line. In that case, the distance from point to this vertex is returned.

This function was introduced in Qt 5.1.

`[since 5.1] `float QVector2D::distanceToPoint(QVector2Dpoint) const

Returns the distance from this vertex to a point defined by the vertex point.

This function was introduced in Qt 5.1.

`[static] `float QVector2D::dotProduct(QVector2Dv1, QVector2Dv2)

Returns the dot product of v1 and v2.

bool QVector2D::isNull() const

Returns `true` if the x and y coordinates are set to 0.0, otherwise returns `false`.

float QVector2D::length() const

Returns the length of the vector from the origin.

float QVector2D::lengthSquared() const

Returns the squared length of the vector from the origin. This is equivalent to the dot product of the vector with itself.

void QVector2D::normalize()

Normalizes the currect vector in place. Nothing happens if this vector is a null vector or the length of the vector is very close to 1.

QVector2D QVector2D::normalized() const

Returns the normalized unit vector form of this vector.

If this vector is null, then a null vector is returned. If the length of the vector is very close to 1, then the vector will be returned as-is. Otherwise the normalized form of the vector of length 1 will be returned.

void QVector2D::setX(floatx)

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

void QVector2D::setY(floaty)

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

QPoint QVector2D::toPoint() const

Returns the QPoint form of this 2D vector. Each coordinate is rounded to the nearest integer.

QPointF QVector2D::toPointF() const

Returns the QPointF form of this 2D vector.

QVector3D QVector2D::toVector3D() const

Returns the 3D form of this 2D vector, with the z coordinate set to zero.

QVector4D QVector2D::toVector4D() const

Returns the 4D form of this 2D vector, with the z and w coordinates set to zero.

float QVector2D::x() const

Returns the x coordinate of this point.

float QVector2D::y() const

Returns the y coordinate of this point.

QVariant QVector2D::operator QVariant() const

Returns the 2D vector as a QVariant.

QVector2D &QVector2D::operator*=(floatfactor)

Multiplies this vector's coordinates by the given finite factor and returns a reference to this vector.

QVector2D &QVector2D::operator*=(QVector2Dvector)

Multiplies each component of this vector by the corresponding component of vector and returns a reference to this vector.

Note: This is not a cross product of this vector with vector. (Its components add up to the dot product of this vector and vector.)

QVector2D &QVector2D::operator+=(QVector2Dvector)

Adds the given vector to this vector and returns a reference to this vector.

QVector2D &QVector2D::operator-=(QVector2Dvector)

Subtracts the given vector from this vector and returns a reference to this vector.

QVector2D &QVector2D::operator/=(floatdivisor)

Divides this vector's coordinates by the given divisor and returns a reference to this vector. The divisor must not be either zero or NaN.

`[since 5.5] `QVector2D &QVector2D::operator/=(QVector2Dvector)

Divides each component of this vector by the corresponding component of vector and returns a reference to this vector.

The vector must have no component that is either zero or NaN.

This function was introduced in Qt 5.5.

`[since 5.2] `float &QVector2D::operator[](inti)

Returns the component of the vector at index position i as a modifiable reference.

i must be a valid index position in the vector (i.e., 0 <= i < 2).

This function was introduced in Qt 5.2.

`[since 5.2] `float QVector2D::operator[](inti) const

Returns the component of the vector at index position i.

i must be a valid index position in the vector (i.e., 0 <= i < 2).

This function was introduced in Qt 5.2.

Related Non-Members

boolqFuzzyCompare(QVector2Dv1, QVector2Dv2)

Returns `true` if v1 and v2 are equal, allowing for a small fuzziness factor for floating-point comparisons; false otherwise.

booloperator!=(QVector2Dv1, QVector2Dv2)

Returns `true` if v1 is not equal to v2; otherwise returns `false`. This operator uses an exact floating-point comparison.

QVector2Doperator*(floatfactor, QVector2Dvector)

Returns a copy of the given vector, multiplied by the given finite factor.

QVector2Doperator*(QVector2Dvector, floatfactor)

Returns a copy of the given vector, multiplied by the given finite factor.

QVector2Doperator*(QVector2Dv1, QVector2Dv2)

Returns the QVector2D object formed by multiplying each component of v1 by the corresponding component of v2.

Note: This is not a cross product of v1 and v2 in any sense. (Its components add up to the dot product of v1 and v2.)

QVector2Doperator+(QVector2Dv1, QVector2Dv2)

Returns a QVector2D object that is the sum of the given vectors, v1 and v2; each component is added separately.

QVector2Doperator-(QVector2Dv1, QVector2Dv2)

Returns a QVector2D object that is formed by subtracting v2 from v1; each component is subtracted separately.

QVector2Doperator-(QVector2Dvector)

Returns a QVector2D object that is formed by changing the sign of each component of the given vector.

Equivalent to `QVector2D(0,0) - vector`.

QVector2Doperator/(QVector2Dvector, floatdivisor)

Returns the QVector2D object formed by dividing each component of the given vector by the given divisor.

The divisor must not be either zero or NaN.

`[since 5.5] `QVector2Doperator/(QVector2Dvector, QVector2Ddivisor)

Returns the QVector2D object formed by dividing each component of the given vector by the corresponding component of the given divisor.

The divisor must have no component that is either zero or NaN.

This function was introduced in Qt 5.5.

QDataStream &operator<<(QDataStream &stream, QVector2Dvector)

Writes the given vector to the given stream and returns a reference to the stream.

Returns `true` if v1 is equal to v2; otherwise returns `false`. This operator uses an exact floating-point comparison.