#define TRUE   1
#define FALSE  0
#define ABS(x) (x < 0 ? -(x) : (x))
#define MIN(x,y) (x < y ? x : y)
#define MAX(x,y) (x > y ? x : y)

void HandleDisplay(void);
void CreateMenus(void);
void CreateEnvironment(void);
void HandleReshape(int,int);
void HandleKeyboard(unsigned char key,int x, int y);
void HandleSpecialKeyboard(int key,int x, int y);
void HandleMouse(int,int,int,int);
void HandleMainMenu(int);
void HandleVisibility(int vis);
void HandleIdle(void);
void GiveUsage(char *);
int ReadImage(char *,int);