QAxisAccumulator Class

class Qt3DInput ::QAxisAccumulator

QAxisAccumulator processes velocity or acceleration data from a QAxis . 更多...

头：	#include <QAxisAccumulator>
qmake:	QT += 3dinput
Since:	Qt 5.8
实例化：	AxisAccumulator
继承：	Qt3DCore::QComponent

该类在 Qt 5.8 引入。

所有成员列表，包括继承成员

公共类型

enum	SourceAxisType { Velocity, Acceleration }

特性

value : const float

公共函数

	QAxisAccumulator (Qt3DCore::QNode * parent = nullptr)
float	scale () const
Qt3DInput::QAxis *	sourceAxis () const
Qt3DInput::QAxisAccumulator::SourceAxisType	sourceAxisType () const
float	value () const
float	velocity () const

公共槽

void	setScale (float scale )
void	setSourceAxis (Qt3DInput::QAxis * sourceAxis )
void	setSourceAxisType (QAxisAccumulator::SourceAxisType sourceAxisType )

信号

void	scaleChanged (float scale )
void	sourceAxisChanged (Qt3DInput::QAxis * sourceAxis )
void	sourceAxisTypeChanged (QAxisAccumulator::SourceAxisType sourceAxisType )
void	valueChanged (float value )
void	velocityChanged (float value )

详细描述

Constructs a new QAxisAccumulator instance with parent .

A Qt3DInput::QAxis reports the current position of an axis on an input device. When the axis is returned to its neutral position the value of that axis returns to 0. Often, it is required to have the input from an axis control a variable in other ways, for example treating the value from the Qt3DInput::QAxis as a velocity (first derivative with respect to time) or as an acceleration (second derivative with respect to time). This can be done with user code or with a Qt3DLogic::QFrameAction but those approached are not ideal as they add more work to the main thread and are inherently imperative. The Qt3DInput::QAxisAccumulator class allows for this common task to be performed on the Qt 3D backend and be specified in a declarative manner.

成员类型文档编制

enum QAxisAccumulator:: SourceAxisType

常量	值
`Qt3DInput::QAxisAccumulator::Velocity`	`0`
`Qt3DInput::QAxisAccumulator::Acceleration`	`1`

特性文档编制

value : const float

Returns the accumulated (integrated) value.

访问函数：

float

value () const

通知程序信号：

void	valueChanged (float value )

成员函数文档编制

QAxisAccumulator:: QAxisAccumulator ( Qt3DCore::QNode * parent = nullptr)

Constructs a new QAxisAccumulator instance with parent parent .

`[slot]` void QAxisAccumulator:: setSourceAxis ( Qt3DInput::QAxis * sourceAxis )

Sets the source axis from which the accumulator should receive values from to sourceAxis . How these values are treated is controlled by the sourceAxisType and scale properties.

注意： setter 函数对于特性 sourceAxis .

另请参阅 sourceAxis ().

`[slot]` void QAxisAccumulator:: setSourceAxisType ( QAxisAccumulator::SourceAxisType sourceAxisType )

Sets how the accumulator treats the values originating from the sourceAxisType .

注意： setter 函数对于特性 sourceAxisType .

另请参阅 sourceAxisType ().

float QAxisAccumulator:: scale () const

The amount to scale the axis value by when accumulating. This can be thought of as the maximum velocity or acceleration the axis can control.

Returns the amount the input axis values are scaled by.

注意： Getter function for property scale.

另请参阅 setScale ().

Qt3DInput::QAxis *QAxisAccumulator:: sourceAxis () const

返回 QAxis for which the accumulator should integrate axis values.

注意： Getter function for property sourceAxis.

另请参阅 setSourceAxis ().

Qt3DInput::QAxisAccumulator::SourceAxisType QAxisAccumulator:: sourceAxisType () const

Returns how the accumulator treats the value of the sourceAxis .

注意： Getter function for property sourceAxisType.

另请参阅 setSourceAxisType ().

float QAxisAccumulator:: velocity () const

Returns the velocity. If the sourceAxisType is set to Velocity this is simply the value of the source axis multiplied by the scale. If the sourceAxisType is set to Acceleration, the velocity is integrated using the source axis' value as an acceleration.

注意： Getter function for property velocity.