函数介绍
VTKPointPickerInteractorStyle是一个自定义的交互样式类,它是VTK库中vtkInteractorStyleTrackballCamera类的子类。VTK(Visualization Toolkit)是一个开源的,跨平台的库,用于处理、渲染和视觉化科学数据。它包括一系列的类和方法用于3D计算机图形、图像处理和可视化。
vtkInteractorStyleTrackballCamera是VTK中的一个交互样式类,它定义了用户与3D场景交互的方式,例如:旋转、缩放、平移等。VTKPointPickerInteractorStyle类继承了vtkInteractorStyleTrackballCamera类,并重写了一些方法,以自定义用户的交互行为。
cpp
class VTKPointPickerInteractorStyle : public vtkInteractorStyleTrackballCamera
{
public:
static VTKPointPickerInteractorStyle* New();
vtkTypeMacro(VTKPointPickerInteractorStyle, vtkInteractorStyleTrackballCamera);
void setObjectIndex(int index) { m_index = index; }
int getObjectIndex() const { return m_index; }
VTKPointPickerInteractorStyle()
{
LastPickedActor = NULL;
LastPickedProperty = vtkProperty::New();
}
virtual ~VTKPointPickerInteractorStyle()
{
LastPickedProperty->Delete();
}
virtual void OnLeftButtonUp() override
{
// Forward events
vtkInteractorStyleTrackballCamera::OnLeftButtonUp();
}
virtual void OnLeftButtonDown() override
{
int* clickPos = this->GetInteractor()->GetEventPosition();
this->Interactor->GetPicker()->Pick(clickPos[0], clickPos[1], 0, // always zero.
this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer());
double picked[3];
this->Interactor->GetPicker()->GetPickPosition(picked);
// std::cout << "Picked value: " << picked[0] << " " << picked[1] << " " << picked[2] << std::endl;
// Forward events
vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
}
// virtual void OnMouseMove() override
// {
// }
private:
vtkActor *LastPickedActor;
vtkProperty *LastPickedProperty;
int m_index;
};
被重写的方法还能保留之前的功能吗?重写一个方法会完全覆盖父类中的该方法的实现。但是,可以在子类的方法中显式调用父类的方法来保留父类的功能。
例如,在VTKPointPickerInteractorStyle类的OnLeftButtonDown方法中,在方法的最后,调用了vtkInteractorStyleTrackballCamera::OnLeftButtonDown()。这样,就可以在执行完VTKPointPickerInteractorStyle类的OnLeftButtonDown方法的自定义操作后,再执行vtkInteractorStyleTrackballCamera类的OnLeftButtonDown方法。这样做可以保证在执行完子类的自定义操作后,还能执行父类的操作。
设置回调
下面是用于设置回调,同时为了在鼠标点击窗口时确认当前窗口索引,将每个窗口的索引或objectName存储在类的某个成员变量中,并添加一个方法来检索它。
cpp
class VTKPointPickerInteractorStyle : public vtkInteractorStyleTrackballCamera
{
...
public:
void setObjectIndex(int index) { m_index = index; }
int getObjectIndex() const { return m_index; }
...
private:
int m_index;
};
然后在创建VTKPointPickerInteractorStyle对象时设置索引i。
cpp
for(int i=0;i<8;i++){
vtkSmartPointer<VTKPointPickerInteractorStyle> style =
vtkSmartPointer<VTKPointPickerInteractorStyle>::New();
style->setObjectIndex(i);
render[i]->GetInteractor()->SetInteractorStyle(style);
}
将交互样式设置为 nullptr,也就是清除交互样式,回到默认的交互方法。
cpp
render[i]->GetInteractor()->SetInteractorStyle(nullptr);