VTK mouse event -- 捕捉鼠标动作并发送信号：vtkCommand

头文件申明：

#pragma once

#include <QObject>
#include <vtkCallbackCommand.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>

class MyMouseCallback : public QObject, public vtkCommand {
  Q_OBJECT

signals:
  void leftButtonPressed(int x, int y);
  void rightButtonPressed(int x, int y);

public:
  vtkTypeMacro(MyMouseCallback, vtkCommand);
  static vtkSmartPointer<MyMouseCallback> New();
  void Execute(vtkObject *p_caller, unsigned long p_event_id, void *p_call_data) override;
};

cpp文件

#include <QDebug>

#include "vtk_mouse_events.h"

vtkSmartPointer<MyMouseCallback> MyMouseCallback::New() { return new MyMouseCallback; }

void MyMouseCallback::Execute(vtkObject *p_caller, unsigned long p_event_id, void *p_call_data) {
  if (p_event_id == vtkCommand::LeftButtonPressEvent) {
    auto *interactor = static_cast<vtkRenderWindowInteractor *>(p_caller);
    const int x = interactor->GetEventPosition()[0];
    const int y = interactor->GetEventPosition()[1];
    emit leftButtonPressed(x, y);
  } else if (p_event_id == vtkCommand::RightButtonPressEvent) {
    auto *interactor = static_cast<vtkRenderWindowInteractor *>(p_caller);
    const int x = interactor->GetEventPosition()[0];
    const int y = interactor->GetEventPosition()[1];
    emit rightButtonPressed(x, y);
  }
}

#if 0
int main(int, char *[]) {
  vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);

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

  // Create and set up a custom callback
  MyMouseCallback *myCallback = MyMouseCallback::New();

  // Connect the signal to a lambda function that handles the event
  QObject::connect(myCallback, &MyMouseCallback::leftButtonPressed, [](int x, int y) {
    qDebug() << "Left mouse button pressed at (" << x << ", " << y << ")";
    // Do something with the coordinates in the lambda function
  });

  interactor->AddObserver(vtkCommand::LeftButtonPressEvent, myCallback);

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

  return 0;
}
#endif