1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5 
6 int
7 _cloadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata)
8 {
9 	int y, bpl, c, cnt, offs;
10 	uchar mem[NMEM], *memp, *omemp, *emem, *linep, *elinep, *u, *eu;
11 
12 	if(!rectinrect(r, i->r))
13 		return -1;
14 	bpl = bytesperline(r, i->depth);
15 	u = data;
16 	eu = data+ndata;
17 	memp = mem;
18 	emem = mem+NMEM;
19 	y = r.min.y;
20 	linep = byteaddr(i, Pt(r.min.x, y));
21 	elinep = linep+bpl;
22 	for(;;){
23 		if(linep == elinep){
24 			if(++y == r.max.y)
25 				break;
26 			linep = byteaddr(i, Pt(r.min.x, y));
27 			elinep = linep+bpl;
28 		}
29 		if(u == eu){	/* buffer too small */
30 			return -1;
31 		}
32 		c = *u++;
33 		if(c >= 128){
34 			for(cnt=c-128+1; cnt!=0 ;--cnt){
35 				if(u == eu){		/* buffer too small */
36 					return -1;
37 				}
38 				if(linep == elinep){	/* phase error */
39 					return -1;
40 				}
41 				*linep++ = *u;
42 				*memp++ = *u++;
43 				if(memp == emem)
44 					memp = mem;
45 			}
46 		}
47 		else{
48 			if(u == eu)	/* short buffer */
49 				return -1;
50 			offs = *u++ + ((c&3)<<8)+1;
51 			if(memp-mem < offs)
52 				omemp = memp+(NMEM-offs);
53 			else
54 				omemp = memp-offs;
55 			for(cnt=(c>>2)+NMATCH; cnt!=0; --cnt){
56 				if(linep == elinep)	/* phase error */
57 					return -1;
58 				*linep++ = *omemp;
59 				*memp++ = *omemp++;
60 				if(omemp == emem)
61 					omemp = mem;
62 				if(memp == emem)
63 					memp = mem;
64 			}
65 		}
66 	}
67 	return u-data;
68 }