QVector2D Class Reference

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

#include <qvector2d.h>

Public Functions
bool	isNull () const
	Returns true if the x and y coordinates are set to 0. More...
qreal	length () const
	Returns the length of the vector from the origin. More...
qreal	lengthSquared () const
	Returns the squared length of the vector from the origin. More...
void	normalize ()
	Normalizes the currect vector in place. More...
QVector2D	normalized () const
	Returns the normalized unit vector form of this vector. More...
	operator QVariant () const
	Returns the 2D vector as a QVariant. More...
QVector2D &	operator*= (qreal factor)
	Multiplies this vector's coordinates by the given factor, and returns a reference to this vector. More...
QVector2D &	operator*= (const QVector2D &vector)
	Multiplies the components of this vector by the corresponding components in vector. More...
QVector2D &	operator+= (const QVector2D &vector)
	Adds the given vector to this vector and returns a reference to this vector. More...
QVector2D &	operator-= (const QVector2D &vector)
	Subtracts the given vector from this vector and returns a reference to this vector. More...
QVector2D &	operator/= (qreal divisor)
	Divides this vector's coordinates by the given divisor, and returns a reference to this vector. More...
	QVector2D ()
	Constructs a null vector, i. More...
	QVector2D (qreal xpos, qreal ypos)
	Constructs a vector with coordinates (xpos, ypos). More...
	QVector2D (const QPoint &point)
	Constructs a vector with x and y coordinates from a 2D point. More...
	QVector2D (const QPointF &point)
	Constructs a vector with x and y coordinates from a 2D point. More...
	QVector2D (const QVector3D &vector)
	Constructs a vector with x and y coordinates from a 3D vector. More...
	QVector2D (const QVector4D &vector)
	Constructs a vector with x and y coordinates from a 3D vector. More...
void	setX (qreal x)
	Sets the x coordinate of this point to the given x coordinate. More...
void	setY (qreal y)
	Sets the y coordinate of this point to the given y coordinate. More...
QPoint	toPoint () const
	Returns the QPoint form of this 2D vector. More...
QPointF	toPointF () const
	Returns the QPointF form of this 2D vector. More...
QVector3D	toVector3D () const
	Returns the 3D form of this 2D vector, with the z coordinate set to zero. More...
QVector4D	toVector4D () const
	Returns the 4D form of this 2D vector, with the z and w coordinates set to zero. More...
qreal	x () const
	Returns the x coordinate of this point. More...
qreal	y () const
	Returns the y coordinate of this point. More...

Static Public Functions
static qreal	dotProduct (const QVector2D &v1, const QVector2D &v2)
	Returns the dot product of v1 and v2. More...

Private Functions
	QVector2D (float xpos, float ypos, int dummy)

Properties
float	xp
float	yp

Friends
bool	operator!= (const QVector2D &v1, const QVector2D &v2)
	Returns true if v1 is not equal to v2; otherwise returns false. More...
const QVector2D	operator* (qreal factor, const QVector2D &vector)
const QVector2D	operator* (const QVector2D &vector, qreal factor)
const QVector2D	operator* (const QVector2D &v1, const QVector2D &v2)
const QVector2D	operator+ (const QVector2D &v1, const QVector2D &v2)
	Returns a QVector2D object that is the sum of the given vectors, v1 and v2; each component is added separately. More...
const QVector2D	operator- (const QVector2D &v1, const QVector2D &v2)
	Returns a QVector2D object that is formed by subtracting v2 from v1; each component is subtracted separately. More...
const QVector2D	operator- (const QVector2D &vector)
	Returns a QVector2D object that is formed by changing the sign of the components of the given vector. More...
const QVector2D	operator/ (const QVector2D &vector, qreal divisor)
	Returns the QVector2D object formed by dividing all three components of the given vector by the given divisor. More...
bool	operator== (const QVector2D &v1, const QVector2D &v2)
	Returns true if v1 is equal to v2; otherwise returns false. More...
bool	qFuzzyCompare (const QVector2D &v1, const QVector2D &v2)
	Returns true if v1 and v2 are equal, allowing for a small fuzziness factor for floating-point comparisons; false otherwise. More...
class	QVector3D
class	QVector4D

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QVector2D &vector)
	Writes the given vector to the given stream and returns a reference to the stream. More...
QDataStream &	operator>> (QDataStream &stream, QVector2D &vector)
	Reads a 2D vector from the given stream into the given vector and returns a reference to the stream. More...

Detailed Description

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

Since

4.6

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

Note: By design values in the QVector2D instance are stored as float. This means that on platforms where the qreal arguments to QVector2D functions are represented by double values, it is possible to lose precision.

See also

QVector3D, QVector4D, QQuaternion

Definition at line 60 of file qvector2d.h.

Constructors and Destructors

QVector2D() [1/7]

QVector2D::QVector2D ( )

inline

Constructs a null vector, i.

e. with coordinates (0, 0, 0).

Definition at line 131 of file qvector2d.h.

Referenced by normalized(), operator*(), operator+(), operator-(), and operator/().

: xp(0.0f), yp(0.0f) {}

QVector2D() [2/7]

QVector2D::QVector2D ( qreal  xpos, qreal  ypos  )

inline

Constructs a vector with coordinates (xpos, ypos).

Definition at line 135 of file qvector2d.h.

: xp(xpos), yp(ypos) {}

QVector2D() [3/7]

QVector2D::QVector2D ( const QPoint &  point )

inlineexplicit

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

Definition at line 137 of file qvector2d.h.

: xp(point.x()), yp(point.y()) {}

QVector2D() [4/7]

QVector2D::QVector2D ( const QPointF &  point )

inlineexplicit

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

Definition at line 139 of file qvector2d.h.

: xp(point.x()), yp(point.y()) {}

QVector2D() [5/7]

QVector2D::QVector2D ( const QVector3D &  vector )

explicit

Constructs a vector with x and y coordinates from a 3D vector.

The z coordinate of vector is dropped.

See also

toVector3D()

Definition at line 118 of file qvector2d.cpp.

{
    xp = vector.xp;
    yp = vector.yp;
}

QVector2D() [6/7]

QVector2D::QVector2D ( const QVector4D &  vector )

explicit

Constructs a vector with x and y coordinates from a 3D vector.

The z and w coordinates of vector are dropped.

See also

toVector4D()

Definition at line 134 of file qvector2d.cpp.

{
    xp = vector.xp;
    yp = vector.yp;
}

QVector2D() [7/7]

QVector2D::QVector2D ( float  xpos, float  ypos, int  dummy  )

inlineprivate

Definition at line 133 of file qvector2d.h.

: xp(xpos), yp(ypos) {}

Functions

dotProduct()

qreal QVector2D::dotProduct ( const QVector2D &  v1, const QVector2D &  v2  )

static

Returns the dot product of v1 and v2.

Definition at line 311 of file qvector2d.cpp.

{
    return v1.xp * v2.xp + v1.yp * v2.yp;
}

isNull()

bool QVector2D::isNull ( ) const

inline

Returns true if the x and y coordinates are set to 0.

0, otherwise returns false.

Definition at line 141 of file qvector2d.h.

{
    return qIsNull(xp) && qIsNull(yp);
}

length()

qreal QVector2D::length

(

)

const

Returns the length of the vector from the origin.

See also

lengthSquared(), normalized()

Definition at line 201 of file qvector2d.cpp.

{
    return qSqrt(xp * xp + yp * yp);
}

lengthSquared()

qreal 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.

See also

length(), dotProduct()

Definition at line 212 of file qvector2d.cpp.

{
    return xp * xp + yp * yp;
}

normalize()

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.

See also

length(), normalized()

Definition at line 245 of file qvector2d.cpp.

{
    // Need some extra precision if the length is very small.
    double len = double(xp) * double(xp) +
                 double(yp) * double(yp);
    if (qFuzzyIsNull(len - 1.0f) || qFuzzyIsNull(len))
        return;

    len = qSqrt(len);

    xp /= len;
    yp /= len;
}

normalized()

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.

See also

length(), normalize()

Definition at line 226 of file qvector2d.cpp.

{
    // Need some extra precision if the length is very small.
    double len = double(xp) * double(xp) +
                 double(yp) * double(yp);
    if (qFuzzyIsNull(len - 1.0f))
        return *this;
    else if (!qFuzzyIsNull(len))
        return *this / qSqrt(len);
    else
        return QVector2D();
}

operator QVariant()

QVector2D::operator QVariant

(

)

const

Returns the 2D vector as a QVariant.

Definition at line 481 of file qvector2d.cpp.

{
    return QVariant(QVariant::Vector2D, this);
}

operator*=() [1/2]

QVector2D & QVector2D::operator*= ( qreal  factor )

inline

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

See also

operator/=()

Definition at line 166 of file qvector2d.h.

{
    xp *= factor;
    yp *= factor;
    return *this;
}

operator*=() [2/2]

QVector2D & QVector2D::operator*= ( const QVector2D &  vector )

inline

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

Definition at line 173 of file qvector2d.h.

{
    xp *= vector.xp;
    yp *= vector.yp;
    return *this;
}

operator+=()

QVector2D & QVector2D::operator+= ( const QVector2D &  vector )

inline

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

See also

operator-=()

Definition at line 152 of file qvector2d.h.

{
    xp += vector.xp;
    yp += vector.yp;
    return *this;
}

operator-=()

QVector2D & QVector2D::operator-= ( const QVector2D &  vector )

inline

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

See also

operator+=()

Definition at line 159 of file qvector2d.h.

{
    xp -= vector.xp;
    yp -= vector.yp;
    return *this;
}

operator/=()

QVector2D & QVector2D::operator/= ( qreal  divisor )

inline

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

See also

operator*=()

Definition at line 180 of file qvector2d.h.

{
    xp /= divisor;
    yp /= divisor;
    return *this;
}

setX()

void QVector2D::setX ( qreal  x )

inline

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

See also

x(), setY()

Definition at line 149 of file qvector2d.h.

Referenced by operator>>(), and QDeclarativeVector2DValueType::setX().

{ xp = aX; }

setY()

void QVector2D::setY ( qreal  y )

inline

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

See also

y(), setX()

Definition at line 150 of file qvector2d.h.

Referenced by operator>>(), and QDeclarativeVector2DValueType::setY().

{ yp = aY; }

toPoint()

QPoint QVector2D::toPoint ( ) const

inline

Returns the QPoint form of this 2D vector.

See also

toPointF(), toVector3D()

Definition at line 237 of file qvector2d.h.

{
    return QPoint(qRound(xp), qRound(yp));
}

toPointF()

QPointF QVector2D::toPointF ( ) const

inline

Returns the QPointF form of this 2D vector.

See also

toPoint(), toVector3D()

Definition at line 242 of file qvector2d.h.

{
    return QPointF(qreal(xp), qreal(yp));
}

toVector3D()

QVector3D QVector2D::toVector3D

(

)

const

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

See also

toVector4D(), toPoint()

Definition at line 435 of file qvector2d.cpp.

{
    return QVector3D(xp, yp, 0.0f, 1);
}

toVector4D()

QVector4D QVector2D::toVector4D

(

)

const

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

See also

toVector3D(), toPoint()

Definition at line 449 of file qvector2d.cpp.

{
    return QVector4D(xp, yp, 0.0f, 0.0f, 1);
}

x()

qreal QVector2D::x ( ) const

inline

Returns the x coordinate of this point.

See also

setX(), y()

Definition at line 146 of file qvector2d.h.

Referenced by operator<<(), operator>>(), and QDeclarativeVector2DValueType::setValue().

{ return qreal(xp); }

y()

qreal QVector2D::y ( ) const

inline

Returns the y coordinate of this point.

See also

setY(), x()

Definition at line 147 of file qvector2d.h.

Referenced by operator<<(), operator>>(), and QDeclarativeVector2DValueType::setValue().

{ return qreal(yp); }

Friends and Related Functions

operator!=

bool operator!= ( const QVector2D &  v1, const QVector2D &  v2  )

friend

Returns true if v1 is not equal to v2; otherwise returns false.

This operator uses an exact floating-point comparison.

Definition at line 192 of file qvector2d.h.

{
    return v1.xp != v2.xp || v1.yp != v2.yp;
}

operator* [1/3]

const QVector2D operator* ( qreal  factor, const QVector2D &  vector  )

friend

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

See also

QVector2D::operator*=()

Definition at line 207 of file qvector2d.h.

{
    return QVector2D(vector.xp * factor, vector.yp * factor, 1);
}

operator* [2/3]

const QVector2D operator* ( const QVector2D &  vector, qreal  factor  )

friend

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

See also

QVector2D::operator*=()

Definition at line 212 of file qvector2d.h.

{
    return QVector2D(vector.xp * factor, vector.yp * factor, 1);
}

operator* [3/3]

const QVector2D operator* ( const QVector2D &  v1, const QVector2D &  v2  )

friend

Multiplies the components of v1 by the corresponding components in v2.

Definition at line 217 of file qvector2d.h.

{
    return QVector2D(v1.xp * v2.xp, v1.yp * v2.yp, 1);
}

operator+

const QVector2D operator+ ( const QVector2D &  v1, const QVector2D &  v2  )

friend

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

See also

QVector2D::operator+=()

Definition at line 197 of file qvector2d.h.

{
    return QVector2D(v1.xp + v2.xp, v1.yp + v2.yp, 1);
}

operator- [1/2]

const QVector2D operator- ( const QVector2D &  v1, const QVector2D &  v2  )

friend

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

See also

QVector2D::operator-=()

Definition at line 202 of file qvector2d.h.

{
    return QVector2D(v1.xp - v2.xp, v1.yp - v2.yp, 1);
}

operator- [2/2]

const QVector2D operator- ( const QVector2D &  vector )

friend

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

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Equivalent to {QVector2D(0,0) - vector}.

Definition at line 222 of file qvector2d.h.

{
    return QVector2D(-vector.xp, -vector.yp, 1);
}

operator/

const QVector2D operator/ ( const QVector2D &  vector, qreal  divisor  )

friend

Returns the QVector2D object formed by dividing all three components of the given vector by the given divisor.

See also

QVector2D::operator/=()

Definition at line 227 of file qvector2d.h.

{
    return QVector2D(vector.xp / divisor, vector.yp / divisor, 1);
}

operator<<()

QDataStream & operator<< ( QDataStream &  stream, const QVector2D &  vector  )

related

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

See also

{Serializing Qt Data Types}

Definition at line 511 of file qvector2d.cpp.

Referenced by toPointF().

{
    stream << double(vector.x()) << double(vector.y());
    return stream;
}

operator==

bool operator== ( const QVector2D &  v1, const QVector2D &  v2  )

friend

Returns true if v1 is equal to v2; otherwise returns false.

This operator uses an exact floating-point comparison.

Definition at line 187 of file qvector2d.h.

{
    return v1.xp == v2.xp && v1.yp == v2.yp;
}

operator>>()

QDataStream & operator>> ( QDataStream &  stream, QVector2D &  vector  )

related

Reads a 2D vector from the given stream into the given vector and returns a reference to the stream.

See also

{Serializing Qt Data Types}

Definition at line 530 of file qvector2d.cpp.

Referenced by toPointF().

{
    double x, y;
    stream >> x;
    stream >> y;
    vector.setX(qreal(x));
    vector.setY(qreal(y));
    return stream;
}

qFuzzyCompare

bool qFuzzyCompare ( const QVector2D &  v1, const QVector2D &  v2  )

friend

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

Definition at line 232 of file qvector2d.h.

Referenced by qFuzzyCompare().

{
    return qFuzzyCompare(v1.xp, v2.xp) && qFuzzyCompare(v1.yp, v2.yp);
}

QVector3D

friend class QVector3D

friend

Definition at line 125 of file qvector2d.h.

Referenced by toVector3D().

QVector4D

friend class QVector4D

friend

Definition at line 126 of file qvector2d.h.

Referenced by toVector4D().

Properties

xp

float QVector2D::xp

private

Definition at line 121 of file qvector2d.h.

Referenced by dotProduct(), isNull(), length(), lengthSquared(), normalize(), normalized(), operator!=(), operator*(), operator*=(), operator+(), operator+=(), operator-(), operator-=(), operator/(), operator/=(), operator==(), qFuzzyCompare(), QVector2D(), QVector3D::QVector3D(), QVector4D::QVector4D(), setX(), toPoint(), toPointF(), toVector3D(), toVector4D(), and x().

yp

float QVector2D::yp

private

Definition at line 121 of file qvector2d.h.

Referenced by dotProduct(), isNull(), length(), lengthSquared(), normalize(), normalized(), operator!=(), operator*(), operator*=(), operator+(), operator+=(), operator-(), operator-=(), operator/(), operator/=(), operator==(), qFuzzyCompare(), QVector2D(), QVector3D::QVector3D(), QVector4D::QVector4D(), setY(), toPoint(), toPointF(), toVector3D(), toVector4D(), and y().

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The documentation for this class was generated from the following files:

• /src/gui/math3d/qvector2d.h
• /src/gui/math3d/qvector2d.cpp