1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5 #include <memlayer.h>
6 
7 int
8 memlsetrefresh(Memimage *i, Refreshfn fn, void *ptr)
9 {
10 	Memlayer *l;
11 
12 	l = i->layer;
13 	if(l->refreshfn!=0 && fn!=0){	/* just change functions */
14 		l->refreshfn = fn;
15 		l->refreshptr = ptr;
16 		return 1;
17 	}
18 
19 	if(l->refreshfn == 0){	/* is using backup image; just free it */
20 		freememimage(l->save);
21 		l->save = nil;
22 		l->refreshfn = fn;
23 		l->refreshptr = ptr;
24 		return 1;
25 	}
26 
27 	l->save = allocmemimage(i->r, i->chan);
28 	if(l->save == nil)
29 		return 0;
30 	/* easiest way is just to update the entire save area */
31 	l->refreshfn(i, i->r, l->refreshptr);
32 	l->refreshfn = 0;
33 	l->refreshptr = nil;
34 	return 1;
35 }