呈现在vtkCommand中创建的执行元(回调)

#include <vtkSmartPointer.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkCommand.h>

// 定义一个回调类
class MyCallback : public vtkCommand {
public:
    static MyCallback* New() { return new MyCallback; }
    virtual void Execute(vtkObject* caller, unsigned long eventId, void* callData) override {
        if (eventId == vtkCommand::StartEvent) {
            std::cout << "渲染开始!" << std::endl;
        } else if (eventId == vtkCommand::EndEvent) {
            std::cout << "渲染结束!" << std::endl;
        }
    }
};

int main() {
    // 创建渲染器和渲染窗口
    vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
    vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
    renderWindow->AddRenderer(renderer);

    // 创建交互器
    vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
    interactor->SetRenderWindow(renderWindow);

    // 创建回调对象并注册到交互器
    vtkSmartPointer<MyCallback> callback = MyCallback::New();
    interactor->AddObserver(vtkCommand::StartEvent, callback);
    interactor->AddObserver(vtkCommand::EndEvent, callback);

    // 启动交互循环
    renderWindow->Render();
    interactor->Start();

    return 0;
}