ref: c33fc43408cb22d606d2f621c34a5748cb0e2bc5
dir: /sys/src/libmemdraw/unload.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <memdraw.h> int unloadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata) { int y, l; uchar *q; if(badrect(r) || !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); for(y=r.min.y; y<r.max.y; y++){ memmove(data, q, l); q += i->width*sizeof(ulong); data += l; } return ndata; }