public static ElementImage Merge4Tiles(ElementImage[] tiles)
{
if (tiles.Length == 0) return null;
Image im = new Bitmap(tiles[0].Image.Width << 1, tiles[0].Image.Height << 1);
Graphics g = Graphics.FromImage(im);
double bott = tiles.Min(t => t.Box.MinLat);
double left = tiles.Min(t => t.Box.MinLon);
double h = tiles.Max(t => t.Box.MaxLat) - bott;
double w = tiles.Max(t => t.Box.MaxLon) - left;
for (int i = 0; i < tiles.Length; i++)
{
Point pt = new Point();
int x = Convert.ToInt32((tiles[i].Box.MinLon - left) / w * im.Width);
int y = Convert.ToInt32((tiles[i].Box.MinLat - bott) / h * im.Width);
pt.X = x;
pt.Y = im.Height >> 1 - y;
g.DrawImageUnscaled(tiles[i].Image, pt);
}
ElementImage tile = new ElementImage(bott + h, bott, left, left + w, im);
return tile;
}
