private void ValidateFirstWpt(int index)
{
if (index == -1)
{
if (TryParseCoord(routeInput[0]))
{
return;
}
throw new ArgumentException($"{routeInput[0]} is not a valid coordinate.");
}
if (!wptList.WaypointExists(index))
{
throw new ArgumentException("Wrong first waypoint index.");
}
var wpt = wptList[index];
if (routeInput[0] != wpt.ID)
{
throw new ArgumentException(
"The first waypoint of the route does not match the " +
"specified index in WptList.");
}
lastWpt = index;
rte.AddLastWaypoint(wpt);
}