The QVector2D class represents a vector or vertex in 2D space. 更多...
| 头： | #include <QVector2D> |
| Since: | Qt 4.6 |
| QVector2D () | |
| QVector2D (qreal xpos , qreal ypos ) | |
| QVector2D (const QPoint & point ) | |
| QVector2D (const QPointF & point ) | |
| QVector2D (const QVector3D & vector ) | |
| QVector2D (const QVector4D & vector ) | |
| bool | isNull () const |
| qreal | length () const |
| qreal | lengthSquared () const |
| void | normalize () |
| QVector2D | normalized () const |
| void | setX (qreal x ) |
| void | setY (qreal y ) |
| QPoint | toPoint () const |
| QPointF | toPointF () const |
| QVector3D | toVector3D () const |
| QVector4D | toVector4D () const |
| qreal | x () const |
| qreal | y () const |
| operator QVariant () const | |
| QVector2D & | operator*= (qreal factor ) |
| QVector2D & | operator*= (const QVector2D & vector ) |
| QVector2D & | operator+= (const QVector2D & vector ) |
| QVector2D & | operator-= (const QVector2D & vector ) |
| QVector2D & | operator/= (qreal divisor ) |
| qreal | dotProduct (const QVector2D & v1 , const QVector2D & v2 ) |
| bool | qFuzzyCompare (const QVector2D & v1 , const QVector2D & v2 ) |
| bool | operator!= (const QVector2D & v1 , const QVector2D & v2 ) |
| 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 ) |
| const QVector2D | operator- (const QVector2D & v1 , const QVector2D & v2 ) |
| const QVector2D | operator- (const QVector2D & vector ) |
| const QVector2D | operator/ (const QVector2D & vector , qreal divisor ) |
| QDataStream & | operator<< (QDataStream & stream , const QVector2D & vector ) |
| bool | operator== (const QVector2D & v1 , const QVector2D & v2 ) |
| QDataStream & | operator>> (QDataStream & stream , QVector2D & vector ) |
The QVector2D class represents a vector or vertex in 2D space.
The QVector2D class can also be used to represent vertices in 2D space. We therefore do not need to provide a separate vertex class.
注意：
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.
另请参阅 QVector3D , QVector4D ，和 QQuaternion .
构造 null 向量，即：采用坐标 (0, 0, 0)。
构造向量采用坐标 ( xpos , ypos ).
Constructs a vector with x and y coordinates from a 2D point .
Constructs a vector with x and y coordinates from a 2D point .
Constructs a vector with x and y coordinates from a 3D vector . The z coordinate of vector is dropped.
另请参阅 toVector3D ().
Constructs a vector with x and y coordinates from a 3D vector . The z and w coordinates of vector are dropped.
另请参阅 toVector4D ().
[static]
qreal
QVector2D::
dotProduct
(const
QVector2D
&
v1
, const
QVector2D
&
v2
)
返回点积为 v1 and v2 .
Returns true if the x and y coordinates are set to 0.0, otherwise returns false.
从原点返回向量长度。
另请参阅 lengthSquared () 和 normalized ().
Returns the squared length of the vector from the origin. This is equivalent to the dot product of the vector with itself.
另请参阅 length () 和 dotProduct ().
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.
另请参阅 length () 和 normalized ().
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.
另请参阅 length () 和 normalize ().
将此点的 X 坐标设为给定 x 坐标。
将此点的 Y 坐标设为给定 y 坐标。
返回 QPoint form of this 2D vector.
另请参阅 toPointF () 和 toVector3D ().
返回 QPointF form of this 2D vector.
另请参阅 toPoint () 和 toVector3D ().
Returns the 3D form of this 2D vector, with the z coordinate set to zero.
另请参阅 toVector4D () 和 toPoint ().
Returns the 4D form of this 2D vector, with the z and w coordinates set to zero.
另请参阅 toVector3D () 和 toPoint ().
返回此点的 X 坐标。
返回此点的 Y 坐标。
Returns the 2D vector as a QVariant .
Multiplies this vector's coordinates by the given factor , and returns a reference to this vector.
另请参阅 operator/= ().
Multiplies the components of this vector by the corresponding components in vector .
添加给定 vector to this vector and returns a reference to this vector.
另请参阅 operator-= ().
减去给定 vector from this vector and returns a reference to this vector.
另请参阅 operator+= ().
Divides this vector's coordinates by the given divisor , and returns a reference to this vector.
另请参阅 operator*= ().
返回 true 若 v1 and v2 are equal, allowing for a small fuzziness factor for floating-point comparisons; false otherwise.
返回 true 若 v1 不等于 v2 ; otherwise returns false. This operator uses an exact floating-point comparison.
返回副本为给定 vector ，乘以给定 factor .
另请参阅 QVector2D::operator*= ().
返回副本为给定 vector ，乘以给定 factor .
另请参阅 QVector2D::operator*= ().
Multiplies the components of v1 by the corresponding components in v2 .
返回 QVector2D object that is the sum of the given vectors, v1 and v2 ；分别相加各分量。
另请参阅 QVector2D::operator+= ().
返回 QVector2D 对象的形成是通过减去 v2 from v1 ；分别减去各分量。
另请参阅 QVector2D::operator-= ().
这是重载函数。
返回 QVector2D object that is formed by changing the sign of the components of the given vector .
相当于
QVector2D(0,0) - vector
.
返回 QVector2D object formed by dividing all three components of the given vector 通过给定 divisor .
另请参阅 QVector2D::operator/= ().
写入给定 vector 到给定 stream 并返回流引用。
另请参阅 序列化 Qt 数据类型 .
返回 true 若 v1 等于 v2 ; otherwise returns false. This operator uses an exact floating-point comparison.
Reads a 2D vector from the given stream 进给定 vector 并返回流引用。
另请参阅 序列化 Qt 数据类型 .