engineer-thesis-WUT/breakout/breakout.cpp

// Copyright [2023] Krzysztof Rudnicki
#ifndef HOME_KUCHY_ENGINEER_THESIS_WUT_BREAKOUT_BREAKOUT_CPP
#define HOME_KUCHY_ENGINEER_THESIS_WUT_BREAKOUT_BREAKOUT_CPP
#include <GLFW/glfw3.h>

#include <array>
#include <iostream>

#include "../dependencies/include/glad/glad.h"
#include "./game.hpp"
#include "./resourceManager.hpp"
#include "./constants.hpp"

// GLFW function declarations
void framebuffer_size_callback(GLFWwindow *window, int width, int height);
void key_callback(GLFWwindow *window, int key, int scancode, int action,
                  int mode);

// The Width of the screen
constexpr int SCREEN_WIDTH = 800;
// The height of the screen
constexpr int SCREEN_HEIGHT = 600;

Game &getBreakoutInstance() {
  static Game Breakout(SCREEN_WIDTH, SCREEN_HEIGHT);
  return Breakout;
}

void initGLFW() {
  glfwInit();
  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif
  glfwWindowHint(GLFW_RESIZABLE, 0);
}

int failedGLAD() {
  // we are forced to use reinterpret_cast since there is no standard-compliant
  // way to convert a void* (which is what glfwGetProcAddress returns) to a
  // function pointer in C++
  if (gladLoadGLLoader(reinterpret_cast<GLADloadproc>(glfwGetProcAddress)) ==
      0) {
    std::cout << "Failed to initialize GLAD" << std::endl;
    return -1;
  }
  return 0;
}

std::pair<double, double> calculate_delta_time(double deltaTime,
                                               double lastFrame) {
  // calculate delta time
  // --------------------
  double const currentFrame = glfwGetTime();
  deltaTime = currentFrame - lastFrame;
  lastFrame = currentFrame;
  glfwPollEvents();
  return std::make_pair(deltaTime, lastFrame);
}

void main_loop_render(Game Breakout) {
  // render
  glClearColor(0.0F, 0.0F, 0.0F, 1.0F);
  glClear(GL_COLOR_BUFFER_BIT);
  Breakout.Render();
}

void main_loop_inside(GLFWwindow *window, double deltaTime, double lastFrame,
                      Game Breakout) {
  const std::pair<double, double> times =
      calculate_delta_time(deltaTime, lastFrame);
  deltaTime = times.first;
  lastFrame = times.second;

  // manage user input
  Breakout.ProcessInput(deltaTime);

  // update game state
  Breakout.Update(deltaTime);

  main_loop_render(Breakout);
  glfwSwapBuffers(window);
}

void main_loop(GLFWwindow *window, const Game &Breakout) {
  // deltaTime variables
  const double deltaTime = 0.0F;
  const double lastFrame = 0.0F;
  // We do not comply with altera-unroll-loops
  // since each loop iteration is dependent on the previous one.
  while (glfwWindowShouldClose(window) == 0) {
    main_loop_inside(window, deltaTime, lastFrame, Breakout);
  }
}

int delete_resources() {
  // delete all resources as loaded using the resource manager
  ResourceManager::Clear();
  glfwTerminate();
  return 0;
}

void gl_magic(GLFWwindow *window) {
  glfwSetKeyCallback(window, key_callback);
  glViewport(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

int main(int /*argc*/, char * /*argv*/[]) {
  initGLFW();
  GLFWwindow *window = glfwCreateWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "Breakout",
                                        nullptr, nullptr);
  glfwMakeContextCurrent(window);
  if (failedGLAD() != 0) {
    return -1;
  }
  gl_magic(window);
  Game Breakout = getBreakoutInstance();
  // initialize game
  Breakout.Init();
  main_loop(window, Breakout);
  return delete_resources();
}

void exit_window(GLFWwindow *window, const int key, const int action) {
  // when a user presses the escape key, we set the
  // WindowShouldClose property to true, closing the application
  if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) {
    glfwSetWindowShouldClose(window, 1);
  }
}

void key_callback_happy(const std::pair<int, int> action_key) {
  Game Breakout = getBreakoutInstance();
  if (action_key.first == GLFW_PRESS) {
    Breakout.Keys.at(action_key.second) = true;
  } else if (action_key.first == GLFW_RELEASE) {
    Breakout.Keys.at(action_key.second) = false;
  }
}

void key_callback_sad(int key) {
  std::cerr << "key_callback_sad Error! key is out of range!" << key
            << std::endl;
}

// Assume Breakout.Keys is of type KeyArray
void key_callback(GLFWwindow *window, int key, int /*scancode*/, int action,
                  int /*mode*/) {
  // Define the array type for keys
  const int MAX_KEYS_TRACKED = constants::MAX_KEYS_TRACKED;
  using KeyArray = std::array<bool, MAX_KEYS_TRACKED>;
  exit_window(window, key, action);
  if (key >= 0 && key < MAX_KEYS_TRACKED) {
    try {
      key_callback_happy(std::pair<int, int>(action, key));
    } catch (const std::out_of_range &e) {
      key_callback_sad(key);
    }
  }
}

void framebuffer_size_callback(GLFWwindow * /*window*/, int width, int height) {
  // make sure the viewport matches the new window dimensions;
  // note that width and
  // height will be significantly larger than specified on retina displays.
  glViewport(0, 0, width, height);
}

#endif
// BREAKOUT_CPP