1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5
6 int
_cloadmemimage(Memimage * i,Rectangle r,uchar * data,int ndata)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 }
69