public static Rectangle?TryUnion(this Rectangle r1, params Rectangle[] rs)
{
var tmp = rs.ToList();
Rectangle result = r1;
while (tmp.Count > 0)
{
bool foundAdjacent = false;
for (int i = 0; i < tmp.Count; ++i)
{
var r2 = tmp[i];
if (result.AdjacentTo(r2))
{
result = Rectangle.Union(result, r2);
tmp.RemoveAt(i);
foundAdjacent = true;
break;
}
}
if (!foundAdjacent)
{
return(null);
}
}
return(result);
}
