Program structure issue (pacman)

Hi, I've been coding a pacman game in C++ using the openGL GLUT library. Right now I've got three main files 1. Pacman.cpp 2. Ghost.cpp 3. Manager.cpp Pacman.cpp defines the class pacman which I used to instatiate pacman. Ghost.cpp is a base class I used to create ghost objects. Manager.cpp is not a class but is the driver code (contains the 'main' function). Right now, Manager.cpp has global variables declared as follows:

Pacman * pacman;
Ghost * blinky;

and my main() looks like this:

int main(int argc, char **argv) {
	glutInit(&argc, argv);            // initialize GLUT
	glutInitDisplayMode(GLUT_RGBA);   // set RGBA display mode
	glutInitWindowPosition(325, 0);
	glutInitWindowSize(600, 600);
	glutCreateWindow("Pacman");
	init();
	srand((unsigned)time(0)); //for random number generation
	pacman = new Pacman();
	blinky = new Ghost();
	glutDisplayFunc(displayScene); // set the rendering function
	glutTimerFunc(0,Timer,0);
	glutSpecialFunc(arrow_keys);
	glutIdleFunc(update);
	glutMainLoop(); // process events and wait until exit
	return 0;
}

My issue is that I don't want to use global variables but I don't see how else I can organize the files since my glutDisplayFunc callback procedure (displayScene) needs to access the global variables pacman and blinky to call their draw functions... i.e.

void displayScene()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glPushMatrix();
	Map::drawMap();
	pacman->draw();
	blinky->draw();
	glPopMatrix();
	glFlush();
}

Any ideas as to how I might be able to organize these files (or how I could use a new class) so that I can avoid using the global variables? Note that the reason I'm using global variables in "Manager" in the first place is because I need to be able to access pacman and blinky (and soon the other 3 ghosts) all in one place so I can compare their variables (positions, states, etc.). Thanks, Omelas UPDATE: I tried creating a class Game as follows: Game.h:

#ifndef GAME_H
#define GAME_H

#include "Character.h"
#include "Pacman.h"
#include "Ghost.h"

class Game
{
public:
	Game();
	void displayScene();

private:
	Pacman * pacman;
	Ghost * blinky;
	/*Ghost pinky;
	Ghost inky;
	Ghost clyde;*/
};

#endif

Game.cpp:

#include "Game.h"

using namespace std;

void Game::displayScene()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glPushMatrix();
	Map::drawMap();
	pacman->draw();
	blinky->draw();
	glPopMatrix();
	glFlush();
}

Game::Game()
	: pacman(new Pacman()), blinky(new Ghost())
{
}

then I removed displayScene from Manager.cpp since its now in Game and I modified main as follows:

int main(int argc, char **argv) {
	glutInit(&argc, argv);            // initialize GLUT
	glutInitDisplayMode(GLUT_RGBA);   // set RGBA display mode
	glutInitWindowPosition(325, 0);
	glutInitWindowSize(600, 600);
	glutCreateWindow("Pacman");
	init();
	srand((unsigned)time(0)); //for random number generation
	Game game;
	glutDisplayFunc(game.displayScene()); // set the rendering function
	glutTimerFunc(0,Timer,0);
	glutSpecialFunc(arrow_keys);
	glutIdleFunc(update);
	glutMainLoop(); // process events and wait until exit
	return 0;
}

but I get an error saying: error C2664: 'glutDisplayFunc' : cannot convert parameter 1 from 'void' to 'void (__cdecl *)(void)' 1> Expressions of type void cannot be converted to other types Any idea how to get around this? Am I on the right track? [Edited by - Omelas0469 on December 17, 2008 9:50:16 PM]