QVector4D Class

成员函数

QVector4D::QVector4D()

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

QVector4D::QVector4D(float xpos, float ypos, float zpos, float wpos)

Constructs a vector with coordinates (xpos, ypos, zpos, wpos).

QVector4D::QVector4D(const QPoint &point)

Constructs a vector with x and y coordinates from a 2D point, and z and w coordinates of 0.

QVector4D::QVector4D(const QPointF &point)

Constructs a vector with x and y coordinates from a 2D point, and z and w coordinates of 0.

QVector4D::QVector4D(const QVector2D &vector)

Constructs a 4D vector from the specified 2D vector. The z and w coordinates are set to zero.

参见 toVector2D().

QVector4D::QVector4D(const QVector2D &vector, float zpos, float wpos)

Constructs a 4D vector from the specified 2D vector. The z and w coordinates are set to zpos and wpos respectively.

参见 toVector2D().

QVector4D::QVector4D(const QVector3D &vector)

Constructs a 4D vector from the specified 3D vector. The w coordinate is set to zero.

参见 toVector3D().

QVector4D::QVector4D(const QVector3D &vector, float wpos)

Constructs a 4D vector from the specified 3D vector. The w coordinate is set to wpos.

参见 toVector3D().

[static] float QVector4D::dotProduct(const QVector4D &v1, const QVector4D &v2)

Returns the dot product of v1 and v2.

bool QVector4D::isNull() const

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

float QVector4D::length() const

Returns the length of the vector from the origin.

参见 lengthSquared() and normalized().

float QVector4D::lengthSquared() const

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

参见 length() and dotProduct().

void QVector4D::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.

参见 length() and normalized().

QVector4D QVector4D::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.

参见 length() and normalize().

void QVector4D::setW(float w)

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

参见 w(), setX(), setY(), and setZ().

void QVector4D::setX(float x)

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

参见 x(), setY(), setZ(), and setW().

void QVector4D::setY(float y)

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

参见 y(), setX(), setZ(), and setW().

void QVector4D::setZ(float z)

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

参见 z(), setX(), setY(), and setW().

QPoint QVector4D::toPoint() const

Returns the QPoint form of this 4D vector. The z and w coordinates are dropped.

参见 toPointF() and toVector2D().

QPointF QVector4D::toPointF() const

Returns the QPointF form of this 4D vector. The z and w coordinates are dropped.

参见 toPoint() and toVector2D().

QVector2D QVector4D::toVector2D() const

Returns the 2D vector form of this 4D vector, dropping the z and w coordinates.

参见 toVector2DAffine(), toVector3D(), and toPoint().

QVector2D QVector4D::toVector2DAffine() const

Returns the 2D vector form of this 4D vector, dividing the x and y coordinates by the w coordinate and dropping the z coordinate. Returns a null vector if w is zero.

参见 toVector2D(), toVector3DAffine(), and toPoint().

QVector3D QVector4D::toVector3D() const

Returns the 3D vector form of this 4D vector, dropping the w coordinate.

参见 toVector3DAffine(), toVector2D(), and toPoint().

QVector3D QVector4D::toVector3DAffine() const

Returns the 3D vector form of this 4D vector, dividing the x, y, and z coordinates by the w coordinate. Returns a null vector if w is zero.

参见 toVector3D(), toVector2DAffine(), and toPoint().

float QVector4D::w() const

Returns the w coordinate of this point.

参见 setW(), x(), y(), and z().

float QVector4D::x() const

Returns the x coordinate of this point.

参见 setX(), y(), z(), and w().

float QVector4D::y() const

Returns the y coordinate of this point.

参见 setY(), x(), z(), and w().

float QVector4D::z() const

Returns the z coordinate of this point.

参见 setZ(), x(), y(), and w().

QVector4D::operator QVariant() const

Returns the 4D vector as a QVariant.

QVector4D &QVector4D::operator*=(float factor)

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

参见 operator/=().

QVector4D &QVector4D::operator*=(const QVector4D &vector)

Multiplies the components of this vector by the corresponding components in vector.

QVector4D &QVector4D::operator+=(const QVector4D &vector)

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

参见 operator-=().

QVector4D &QVector4D::operator-=(const QVector4D &vector)

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

参见 operator+=().

QVector4D &QVector4D::operator/=(float divisor)

Divides this vector's coordinates by the given divisor, and returns a reference to this vector.

参见 operator*=().

QVector4D &QVector4D::operator/=(const QVector4D &vector)

Divides the components of this vector by the corresponding components in vector.

This function was introduced in Qt 5.5.

参见 operator*=().

float &QVector4D::operator[](int i)

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 < 4).

This function was introduced in Qt 5.2.

float QVector4D::operator[](int i) 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 < 4).

This function was introduced in Qt 5.2.