Cube  Diff

}

// utility functions also used by editing code

block *
blockcopy(block &s)
{
	block *b = (block *)OFAllocZeroedMemory(
	block *b = (block *)alloc(sizeof(block) + s.xs * s.ys * sizeof(sqr));
	    1, sizeof(block) + s.xs * s.ys * sizeof(sqr));
	*b = s;
	sqr *q = (sqr *)(b + 1);
	for (int x = s.x; x < s.xs + s.x; x++)
		for (int y = s.y; y < s.ys + s.y; y++)
			*q++ = *S(x, y);
	return b;
}