for(t=0;t<stroke->num_points;t++) {
update_md5(md5, (unsigned char*)&stroke->points[t].x, sizeof(stroke->points[t].x));
update_md5(md5, (unsigned char*)&stroke->points[t].y, sizeof(stroke->points[t].y));
for(t=0;t<stroke->num_points;t++) {
update_md5(md5, (unsigned char*)&stroke->points[t].x, sizeof(stroke->points[t].x));
update_md5(md5, (unsigned char*)&stroke->points[t].y, sizeof(stroke->points[t].y));