private static MapEdge SelectDownhill(MapNode node)
{
double? dist = node.DistanceToCoast;
MapEdge ret = node.Edges.First();
foreach (MapEdge e in node.Edges)
{
if (e.To.DistanceToCoast < dist)
{
ret = e;
}
}
return(ret);
}
public IEnumerable <MapNode[]> GenerateRivers()
{
int c = 0;
MapNode[] eligibleRivers = map.Polygons
.SelectMany(_ => _.Nodes)
.Where(_ => _.DistanceToCoast > 0.25 && _.DistanceToCoast < 0.8)
.ToArray();
List <MapNode[]> ret = new List <MapNode[]>();
do
{
MapNode node = eligibleRivers[rand.Next(0, eligibleRivers.Length)];
Stack <MapEdge> edges = new Stack <MapEdge>();
HashSet <MapNode> visited = new HashSet <MapNode>();
edges.Push(SelectDownhill(node));
List <MapNode> nodes = new List <MapNode>();
nodes.Add(node);
while (edges.Count > 0)
{
MapEdge ed = edges.Pop();
nodes.Add(ed.To);
MapEdge edge = SelectDownhill(ed.To);
if (!edge.To.IsOcean && !visited.Contains(edge.To))
{
visited.Add(edge.To);
edges.Push(edge);
}
}
ret.Add(nodes.ToArray());
c++;
} while (c < 10);
return(ret);
}