Glue.h

#pragma once

#include <GL/glew.h>
// prevent clang-format from re-ordering these two includes
#include <GL/gl.h>

#include <memory>

#include "Camera.h"
#include "Light.h"

class Object3D;
class Renderer;

/*
A thin wrapper around freeglut which covers initialization
of the CUDA device, creation of textures, render targets,
setting up the view port, etc.
*/
class Glue {
 public:
  /*
  Initializes freeglut, OpenGL and CUDA and sets everything up
  for rendering (textures, render targets, etc.)
  @param renderer takes ownership of the pointer
  @param model takes ownership of the pointer

  @return true if the initialization was successful,
  false otherwise (in this case the app should be aborted)

  @precond windowWidth > 0
  @precond windowHeight > 0
  @precond renderer != nullptr
  @precond model != nullptr
  */
  static bool init(int argc, char** argv, int windowWidth, int windowHeight,
                   Renderer* renderer, Object3D* model, Light light,
                   Camera camera);
  /*
  Cleans up all initialized resources.
  */
  static void cleanUp();

  static void startGlutMainLoop();

 private:
  static Glue* m_globalInstance;

  Glue(int argc, char** argv, int windowWidth, int windowHeight,
       Renderer* renderer, Object3D* model, Light light, Camera camera,

       bool& outSuccess);
  ~Glue();

  /*
  Registered as glutDisplayFunc.
  Calls display.
  If called without a preceding call to setGlobalInstance, the
  behavior is undefined!
  */
  static void displayFunc();
  /*
  Main render function. Binds buffers and calls Renderer::render
  */
  void display();

  /*
  Registered as glutMouseFunc.
  Calls Camera::handleMouseButtonPress
  */
  static void mouseFunc(int button, int state, int x, int y);
  /*
  Registered as glutMotionFunc.
  Calls Camera::handleMouseMovement
  */
  static void motionFunc(int newX, int newY);

  int m_windowWidth;
  int m_windowHeight;

  std::unique_ptr<Renderer> m_renderer;
  std::unique_ptr<Object3D> m_model;

  Light m_light;
  Camera m_camera;

  GLuint m_pbo;
  struct cudaGraphicsResource* m_cuda_pbo_resource;
  GLuint m_texture;

  double m_lastFrameTimeInMilliseconds;

  int windowResolution() const;
  // windowWidth() / windowHeight()
  double windowAspectRatio() const;
};