1enum {
  2	/* levels */
  3	Empty		= 0,
  4	Background,
  5	Wall, 
  6	Cargo,
  7	Goal,
  8	GoalCargo,
  9	Glenda,
 10
 11	/* movements */
 12	Up,
 13	Down,
 14	Left,
 15	Right,
 16};
 17
 18enum {
 19	/* glenda faces the horizontal direction she's moving in */
 20	GLeft	= 0,
 21	GRight 	= 1,
 22};
 23
 24enum {
 25	MazeX = 20,
 26	MazeY = 18,
 27	BoardX = 49,
 28	BoardY = 49,
 29	SizeX = MazeX*BoardX+10,	
 30	SizeY = MazeY*BoardY+10,
 31
 32	Maxlevels = 200,
 33};
 34
 35typedef struct Step {
 36	uint dir;		/* direction */
 37	uint count;	/* number of single-step moves */
 38} Step;
 39
 40typedef struct Route {
 41	uint nstep;	/* number of valid Step */
 42	Step *step;
 43	Point dest;	/* result of step */
 44} Route;
 45
 46typedef struct Walk {
 47	uint nroute;	/* number of valid Route* */
 48	Route **route;
 49	uint beyond;	/* number of allocated Route* */
 50} Walk;
 51
 52typedef struct Visited {
 53	uint 	board[MazeX][MazeY];
 54} Visited;
 55
 56typedef struct Animation {
 57	Route* route;
 58	Step *step;
 59	int count;
 60} Animation;
 61
 62typedef struct {
 63	Point 	glenda;
 64	Point 	max;		/* that's how much the board spans */
 65	uint 	index;
 66	uint	done;
 67	uint 	board[MazeX][MazeY];
 68} Level;
 69
 70extern Level level;		/* the current level */
 71extern Level levels[Maxlevels];	/* all levels from this file */
 72extern int numlevels;		/* how many levels do we have */
 73
 74extern Image *img;		/* buffer */
 75extern Image *text;		/* for text messages */
 76extern Image *win;
 77
 78extern Image *goal;
 79extern Image *cargo;
 80extern Image *goalcargo;
 81extern Image *wall;
 82extern Image *empty;
 83extern Image *gleft;
 84extern Image *gright;
 85extern Image *glenda;
 86extern Image *bg;
 87
 88/* graphics.c */
 89void drawscreen(void);
 90void drawlevel(void);
 91void drawwin(void);
 92void drawglenda(void);
 93void drawboard(Point);
 94void resize(Point);
 95Point boardsize(Point);
 96
 97/* level.c */
 98int loadlevels(char *);
 99
100/* move.c */
101void move(int);
102
103/* route.c */
104int validpush(Point, Step*, Point*);
105int isvalid(Point, Route*, int (*)(Point, Step*, Point*));
106void freeroute(Route*);
107Route* extend(Route*, int, int, Point);
108Route* findroute(Point, Point);
109
110/* animation.c */
111void initanimation(Animation*);
112void setupanimation(Animation*, Route*);
113int onestep(Animation*);
114void stopanimation(Animation*);
115
116
117/* sokoban.c */
118char *genlevels(int);
119Image *eallocimage(Rectangle, int, uint);
120