1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5
6 int
_loadmemimage(Memimage * i,Rectangle r,uchar * data,int ndata)7 _loadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata)
8 {
9 int y, l, lpart, rpart, mx, m, mr;
10 uchar *q;
11
12 if(!rectinrect(r, i->r))
13 return -1;
14 l = bytesperline(r, i->depth);
15 if(ndata < l*Dy(r))
16 return -1;
17 ndata = l*Dy(r);
18 q = byteaddr(i, r.min);
19 mx = 7/i->depth;
20 lpart = (r.min.x & mx) * i->depth;
21 rpart = (r.max.x & mx) * i->depth;
22 m = 0xFF >> lpart;
23 /* may need to do bit insertion on edges */
24 if(l == 1){ /* all in one byte */
25 if(rpart)
26 m ^= 0xFF >> rpart;
27 for(y=r.min.y; y<r.max.y; y++){
28 *q ^= (*data^*q) & m;
29 q += i->width*sizeof(ulong);
30 data++;
31 }
32 return ndata;
33 }
34 if(lpart==0 && rpart==0){ /* easy case */
35 for(y=r.min.y; y<r.max.y; y++){
36 memmove(q, data, l);
37 q += i->width*sizeof(ulong);
38 data += l;
39 }
40 return ndata;
41 }
42 mr = 0xFF ^ (0xFF >> rpart);
43 if(lpart!=0 && rpart==0){
44 for(y=r.min.y; y<r.max.y; y++){
45 *q ^= (*data^*q) & m;
46 if(l > 1)
47 memmove(q+1, data+1, l-1);
48 q += i->width*sizeof(ulong);
49 data += l;
50 }
51 return ndata;
52 }
53 if(lpart==0 && rpart!=0){
54 for(y=r.min.y; y<r.max.y; y++){
55 if(l > 1)
56 memmove(q, data, l-1);
57 q[l-1] ^= (data[l-1]^q[l-1]) & mr;
58 q += i->width*sizeof(ulong);
59 data += l;
60 }
61 return ndata;
62 }
63 for(y=r.min.y; y<r.max.y; y++){
64 *q ^= (*data^*q) & m;
65 if(l > 2)
66 memmove(q+1, data+1, l-2);
67 q[l-1] ^= (data[l-1]^q[l-1]) & mr;
68 q += i->width*sizeof(ulong);
69 data += l;
70 }
71 return ndata;
72 }
73