#include <string>
#include <curses.h>
#include <unistd.h> // usleep

struct Object {
	int x1, y1; // top left
	int x2, y2; // bottom right
	double scale;

	int Left()   const { return x1; }
	int Right()  const { return x2; }
	int Top()    const { return y1; }
	int Bottom() const { return y2; }
};

bool InBounds(Object bounds, Object object);

int main(int argc, char *argv[])
{
	WINDOW * mainwin;
	// Initialize ncurses
	if ( (mainwin = initscr()) == NULL ) {
		fprintf(stderr, "Error initialising ncurses.\n");
		exit(EXIT_FAILURE);
	}

	Object screen;
	screen.x1 = 10;
	screen.x2 = 31;
	screen.y1 = 10;
	screen.y2 = 15;
	screen.scale = 1.0;

	const Object initial_screen = screen;

	Object object;
	object.x1 = 1;
	object.x2 = 5;
	object.y1 = 4;
	object.y2 = 8;
	object.scale = 1.0;

	const Object initial_object = object;

	while(true)
	{
		screen = initial_screen;
		object = initial_object;

		bool covered_last_frame = false;

		for(auto y = 0; y < 14; ++y)
		{
			for(auto x = 0; x < 40; ++x)
			{
				// DRAW
				clear();
				std::string scr(screen.Right() - screen.Left() + 1, '+');
				for(auto row = screen.Top(); row <= screen.Bottom(); ++row)
					mvaddstr(row, screen.Left(), scr.c_str());

				std::string obj(object.Right() - object.Left() + 1, '*');
				for(auto row = object.Top(); row <= object.Bottom(); ++row)
					mvaddstr(row, object.Left(), obj.c_str());

				bool covered = InBounds(screen, object);

				mvaddstr(1, 1, covered ? "Covered: YES" : "Covered: NO");

				refresh();

				if(covered != covered_last_frame)
					usleep(500000); // 1/2 sec
				else
					usleep(35000); // quick

				covered_last_frame = covered;

				++object.x1;
				++object.x2;
			}
			++object.y1;
			++object.y2;
			object.x1 -= 40;
			object.x2 -= 40;
		}
	}

	// destroy ncurses
	delwin(mainwin);
	endwin();
	refresh();

	return 0;
}

bool InBounds(Object bounds, Object object)
{
	if(object.Right() < bounds.Left()
	   || object.Left() > bounds.Right()
	   || object.Bottom() < bounds.Top()
	   || object.Top() > bounds.Bottom())
		return false;
	return true;
}