Image Magnify(const Image& img, int nx, int ny)
{
	if(nx == 1 && ny == 1)
		return img;
	if(nx == 0 || ny == 0)
		return Image();
	Size sz = img.GetSize();
	bool xdown = nx < 0;
	nx = abs(nx);
	int ncx = xdown ? sz.cx / nx : sz.cx * nx;
	ImageBuffer b(ncx, sz.cy * ny);
	const RGBA *s = ~img;
	const RGBA *e = s + img.GetLength();
	RGBA *t = ~b;
	while(s < e) {
		RGBA *q = t;
		const RGBA *le = s + sz.cx;
		while(s < le) {
			Fill(q, *s, nx);
			q += nx;
			s++;
		}
		for(int n = ny - 1; n--;) {
			memcpy(q, t, ncx * sizeof(RGBA));
			q += ncx;
		}
		t = q;
	}
	return b;
}