1 typedef struct Memscreen Memscreen;
2 typedef void (*Refreshfn)(Memimage*, Rectangle, void*);
3 
4 struct Memscreen
5 {
6 	Memimage	*frontmost;	/* frontmost layer on screen */
7 	Memimage	*rearmost;	/* rearmost layer on screen */
8 	Memimage	*image;		/* upon which all layers are drawn */
9 	Memimage	*fill;			/* if non-zero, picture to use when repainting */
10 };
11 
12 struct Memlayer
13 {
14 	Rectangle		screenr;	/* true position of layer on screen */
15 	Point			delta;	/* add delta to go from image coords to screen */
16 	Memscreen	*screen;	/* screen this layer belongs to */
17 	Memimage	*front;	/* window in front of this one */
18 	Memimage	*rear;	/* window behind this one*/
19 	int		clear;	/* layer is fully visible */
20 	Memimage	*save;	/* save area for obscured parts */
21 	Refreshfn	refreshfn;		/* function to call to refresh obscured parts if save==nil */
22 	void		*refreshptr;	/* argument to refreshfn */
23 };
24 
25 /*
26  * These functions accept local coordinates
27  */
28 int			memload(Memimage*, Rectangle, uchar*, int, int);
29 int			memunload(Memimage*, Rectangle, uchar*, int);
30 
31 /*
32  * All these functions accept screen coordinates, not local ones.
33  */
34 void			_memlayerop(void (*fn)(Memimage*, Rectangle, Rectangle, void*, int), Memimage*, Rectangle, Rectangle, void*);
35 Memimage*	memlalloc(Memscreen*, Rectangle, Refreshfn, void*, u32int);
36 void			memldelete(Memimage*);
37 void			memlfree(Memimage*);
38 void			memltofront(Memimage*);
39 void			memltofrontn(Memimage**, int);
40 void			_memltofrontfill(Memimage*, int);
41 void			memltorear(Memimage*);
42 void			memltorearn(Memimage**, int);
43 int			memlsetrefresh(Memimage*, Refreshfn, void*);
44 void			memlhide(Memimage*, Rectangle);
45 void			memlexpose(Memimage*, Rectangle);
46 void			_memlsetclear(Memscreen*);
47 int			memlorigin(Memimage*, Point, Point);
48 void			memlnorefresh(Memimage*, Rectangle, void*);