main.cpp

#include <allegro5/allegro.h>
#include <iostream>

class Vector {
public:
  Vector(int x, int y);
  Vector();
  Vector operator+(Vector &);

private:
  int x;
  int y;
};

class Drawable {
public:
  virtual void draw() = 0;
  virtual void update() = 0;
};

class ALSystem {
private:
  ALLEGRO_DISPLAY *display = NULL;
  ALLEGRO_EVENT_QUEUE *queue = NULL;
  ALLEGRO_COLOR clearcol;

public:
  ALSystem(int xres, int yres, ALLEGRO_COLOR col);
  ALSystem();
  ~ALSystem();
  void MainLoop();
};

class Square : public Drawable {
public:
  void draw();
  void update();

private:
  Vector pos;
  Vector size;
};

ALSystem::ALSystem(int xres, int yres, ALLEGRO_COLOR col) {
  // Make allegro functions available
  al_init();
  // Create a display for future drawing
  this->display = al_create_display(xres, yres);
  if (!this->display) {
    throw "Failed to create display";
  }
  // To detect events such as closing the window
  this->queue = al_create_event_queue();
  if (!this->queue) {
    throw "Failed to create event queue";
  }
  // To have the same color bg
  this->clearcol = col;
  al_clear_to_color(this->clearcol);
}

ALSystem::~ALSystem() {
  al_destroy_display(this->display);
  al_destroy_event_queue(this->queue);
}

void ALSystem::MainLoop() {}

int main(int argc, char **argv) {
  try {
    ALSystem sys(500, 500, al_map_rgb(0, 0, 0));
  } catch (const char *errmsg) {
    std::cerr << "ERROR WHILE INITIALIZING SYSTEM: " << errmsg << std::endl;
  }
  return 0;
}