/// <summary>
/// Gets sequence 1, the first vertices right after the start vertex with a maximum of n.
/// </summary>
public static uint[] GetSequence1 <T>(this EdgePath <T> path, DirectedDynamicGraph.EdgeEnumerator enumerator, int n)
where T : struct
{
if (path.From == null)
{
return(Constants.EMPTY_SEQUENCE);
}
var s = new List <uint>();
s.Add(path.Vertex);
while (true)
{
if (path.IsOriginal(enumerator))
{ // current segment is original.
if (s == null)
{
s = new List <uint>();
}
if (path.From.From != null)
{ // we need more vertices and there are some more available.
s.Add(path.From.Vertex);
path = path.From;
}
else
{ // we have enough.
var result = s.ToArray();
if (n < result.Length)
{ // TODO: this can be way more efficient by creating only one array.
result = result.SubArray(result.Length - n, n);
}
result.Reverse();
return(result);
}
}
else
{ // not an original edge, just return the start sequence.
var sequence = enumerator.GetSequence1();
if (path.From.From == null)
{
if (sequence.Length > n)
{
sequence = sequence.SubArray(sequence.Length - n, n);
}
return(sequence);
}
s.Clear();
sequence.Reverse();
s.AddRange(sequence);
s.Add(path.From.Vertex);
path = path.From;
}
}
}
/// <summary>
/// Gets sequence 2, the last vertices right before the end vertex with a maximum of n.
/// </summary>
public static uint[] GetSequence2 <T>(this EdgePath <T> path, DirectedDynamicGraph.EdgeEnumerator enumerator, int n)
where T : struct
{
if (path.From == null)
{
return(Constants.EMPTY_SEQUENCE);
}
List <uint> s = null;
while (true)
{
if (path.IsOriginal(enumerator))
{ // current segment is original.
if (s == null)
{
s = new List <uint>();
}
s.Add(path.From.Vertex);
if (s.Count < n && path.From.From != null)
{ // we need more vertices and there are some more available.
path = path.From;
}
else
{ // we have enough.
var result = s.ToArray();
result.Reverse();
return(result);
}
}
else
{ // not an original edge, just return the start sequence.
if (s != null)
{
var s2 = enumerator.GetSequence2();
var result = new uint[s.Count + s2.Length];
for (var i = 0; i < s.Count; i++)
{
result[result.Length - 1 - i] = s[i];
}
for (var i = 0; i < s2.Length; i++)
{
result[i] = s2[i];
}
return(result);
}
return(enumerator.GetSequence2());
}
}
}