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#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.h>
int
_loadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata)
{
int y, l, lpart, rpart, mx, m, mr;
uchar *q;
if(!rectinrect(r, i->r))
return -1;
l = bytesperline(r, i->depth);
if(ndata < l*Dy(r))
return -1;
ndata = l*Dy(r);
q = byteaddr(i, r.min);
mx = 7/i->depth;
lpart = (r.min.x & mx) * i->depth;
rpart = (r.max.x & mx) * i->depth;
m = 0xFF >> lpart;
/* may need to do bit insertion on edges */
if(l == 1){ /* all in one byte */
if(rpart)
m ^= 0xFF >> rpart;
for(y=r.min.y; y<r.max.y; y++){
*q ^= (*data^*q) & m;
q += i->width*sizeof(u32int);
data++;
}
return ndata;
}
if(lpart==0 && rpart==0){ /* easy case */
for(y=r.min.y; y<r.max.y; y++){
memmove(q, data, l);
q += i->width*sizeof(u32int);
data += l;
}
return ndata;
}
mr = 0xFF ^ (0xFF >> rpart);
if(lpart!=0 && rpart==0){
for(y=r.min.y; y<r.max.y; y++){
*q ^= (*data^*q) & m;
if(l > 1)
memmove(q+1, data+1, l-1);
q += i->width*sizeof(u32int);
data += l;
}
return ndata;
}
if(lpart==0 && rpart!=0){
for(y=r.min.y; y<r.max.y; y++){
if(l > 1)
memmove(q, data, l-1);
q[l-1] ^= (data[l-1]^q[l-1]) & mr;
q += i->width*sizeof(u32int);
data += l;
}
return ndata;
}
for(y=r.min.y; y<r.max.y; y++){
*q ^= (*data^*q) & m;
if(l > 2)
memmove(q+1, data+1, l-2);
q[l-1] ^= (data[l-1]^q[l-1]) & mr;
q += i->width*sizeof(u32int);
data += l;
}
return ndata;
}
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