Vtk -鼠标位置处的世界坐标

#include <vtkSmartPointer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkActor.h>
#include <vtkPolyDataMapper.h>
#include <vtkSphereSource.h>
#include <vtkInteractorStyleTrackballCamera.h>

class CustomInteractorStyle : public vtkInteractorStyleTrackballCamera {
public:
    static CustomInteractorStyle* New();
    vtkTypeMacro(CustomInteractorStyle, vtkInteractorStyleTrackballCamera);

    virtual void OnLeftButtonDown() override {
        int* clickPos = this->GetInteractor()->GetEventPosition();
        double worldCoords[4];
        this->ComputeWorldToDisplay(clickPos[0], clickPos[1], 0, worldCoords);
        std::cout << "World coordinates at mouse click: (" 
                  << worldCoords[0] << ", " 
                  << worldCoords[1] << ", " 
                  << worldCoords[2] << ")" << std::endl;
        vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
    }
};

vtkStandardNewMacro(CustomInteractorStyle);

int main(int, char*[]) {
    vtkSmartPointer<vtkSphereSource> sphereSource = 
        vtkSmartPointer<vtkSphereSource>::New();
    sphereSource->Update();

    vtkSmartPointer<vtkPolyDataMapper> mapper = 
        vtkSmartPointer<vtkPolyDataMapper>::New();
    mapper->SetInputConnection(sphereSource->GetOutputPort());

    vtkSmartPointer<vtkActor> actor = 
        vtkSmartPointer<vtkActor>::New();
    actor->SetMapper(mapper);

    vtkSmartPointer<vtkRenderer> renderer = 
        vtkSmartPointer<vtkRenderer>::New();
    renderer->AddActor(actor);
    renderer->SetBackground(0.1, 0.2, 0.3);

    vtkSmartPointer<vtkRenderWindow> renderWindow = 
        vtkSmartPointer<vtkRenderWindow>::New();
    renderWindow->AddRenderer(renderer);

    vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = 
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
    renderWindowInteractor->SetRenderWindow(renderWindow);

    vtkSmartPointer<CustomInteractorStyle> style = 
        vtkSmartPointer<CustomInteractorStyle>::New();
    renderWindowInteractor->SetInteractorStyle(style);

    renderWindow->Render();
    renderWindowInteractor->Start();

    return EXIT_SUCCESS;
}