text: #pragma once
  #include "Scene.h"
  #include <memory>
  #include <vector>
  #include "App.h"
  #include "GL/Shader.h"
  #include "Shape.h"
  #include <glm/glm.hpp>
  #include "Camera.h"
  
  class SceneBackground : public Scene
  {
  public:
      SceneBackground();
      ~SceneBackground();
  
      virtual void Init() override;
      virtual void Render() override;
  private:
      std::shared_ptr<GL::ShaderProgram> mBgShaderProgram;
  
      float viewport_height;
      float viewport_width;
      float focal_length;
  
      Vector3f origin;
      Vector3f horizontal;
      Vector3f vertical ;
      Vector3f lower_left_corner ;
  };