#ifdef PLAN9#pragma src "/sys/src/libmemlayer"#pragma lib "libmemlayer.a"#endif typedef struct Memscreen Memscreen;typedef void (*Refreshfn)(Memimage*, Rectangle, void*); struct Memscreen{	Memimage	*frontmost;	/* frontmost layer on screen */	Memimage	*rearmost;	/* rearmost layer on screen */	Memimage	*image;		/* upon which all layers are drawn */	Memimage	*fill;			/* if non-zero, picture to use when repainting */}; struct Memlayer{	Rectangle		screenr;	/* true position of layer on screen */	Point			delta;	/* add delta to go from image coords to screen */	Memscreen	*screen;	/* screen this layer belongs to */	Memimage	*front;	/* window in front of this one */	Memimage	*rear;	/* window behind this one*/	int		clear;	/* layer is fully visible */	Memimage	*save;	/* save area for obscured parts */	Refreshfn	refreshfn;		/* function to call to refresh obscured parts if save==nil */	void		*refreshptr;	/* argument to refreshfn */}; /* * These functions accept local coordinates */int			memload(Memimage*, Rectangle, uchar*, int, int);int			memunload(Memimage*, Rectangle, uchar*, int); /* * All these functions accept screen coordinates, not local ones. */void			_memlayerop(void (*fn)(Memimage*, Rectangle, Rectangle, void*, int), Memimage*, Rectangle, Rectangle, void*);Memimage*	memlalloc(Memscreen*, Rectangle, Refreshfn, void*, ulong);void			memldelete(Memimage*);void			memlfree(Memimage*);void			memltofront(Memimage*);void			memltofrontn(Memimage**, int);void			_memltofrontfill(Memimage*, int);void			memltorear(Memimage*);void			memltorearn(Memimage**, int);int			memlsetrefresh(Memimage*, Refreshfn, void*);void			memlhide(Memimage*, Rectangle);void			memlexpose(Memimage*, Rectangle);void			_memlsetclear(Memscreen*);int			memlorigin(Memimage*, Point, Point);void			memlnorefresh(Memimage*, Rectangle, void*);