public IndexedEdge Select(EdgeShape candidate)
{
object value;
if (Hash.TryGetValue(EdgeLookup.ComputeHash(candidate), out value))
{
CurrentList = value as List<IndexedEdge>;
if (CurrentList == null)
{
var entry = value as IndexedEdge;
if (EdgeLookup.MatchingEdges(entry.Shape, candidate))
return entry;
else
return null;
}
else
{
for (CurrentOffset = 0; CurrentOffset < CurrentList.Count; ++CurrentOffset)
if (EdgeLookup.MatchingEdges(CurrentList[CurrentOffset].Shape, candidate))
{
CurrentCandidate = candidate;
return CurrentList[CurrentOffset++];
}
return null;
}
}
else
return null;
}
public bool MatchingEdges(EdgeShape probe, EdgeShape candidate)
{
int lengthDelta = probe.Length - candidate.Length;
if (lengthDelta >= -MaxDistanceError && lengthDelta <= MaxDistanceError)
{
byte complementaryAngleError = Angle.Complementary(MaxAngleError);
byte referenceDelta = Angle.Difference(probe.ReferenceAngle, candidate.ReferenceAngle);
if (referenceDelta <= MaxAngleError || referenceDelta >= complementaryAngleError)
{
byte neighborDelta = Angle.Difference(probe.NeighborAngle, candidate.NeighborAngle);
if (neighborDelta <= MaxAngleError || neighborDelta >= complementaryAngleError)
return true;
}
}
return false;
}
public IEnumerable<int> HashCoverage(EdgeShape edge)
{
int minLengthBin = (edge.Length - MaxDistanceError) / MaxDistanceError;
int maxLengthBin = (edge.Length + MaxDistanceError) / MaxDistanceError;
int angleBins = Calc.DivRoundUp(256, MaxAngleError);
int minReferenceBin = Angle.Difference(edge.ReferenceAngle, MaxAngleError) / MaxAngleError;
int maxReferenceBin = Angle.Add(edge.ReferenceAngle, MaxAngleError) / MaxAngleError;
int endReferenceBin = (maxReferenceBin + 1) % angleBins;
int minNeighborBin = Angle.Difference(edge.NeighborAngle, MaxAngleError) / MaxAngleError;
int maxNeighborBin = Angle.Add(edge.NeighborAngle, MaxAngleError) / MaxAngleError;
int endNeighborBin = (maxNeighborBin + 1) % angleBins;
for (int lengthBin = minLengthBin; lengthBin <= maxLengthBin; ++lengthBin)
for (int referenceBin = minReferenceBin; referenceBin != endReferenceBin; referenceBin = (referenceBin + 1) % angleBins)
for (int neighborBin = minNeighborBin; neighborBin != endNeighborBin; neighborBin = (neighborBin + 1) % angleBins)
yield return (referenceBin << 24) + (neighborBin << 16) + lengthBin;
}
public int ComputeHash(EdgeShape edge)
{
return (edge.ReferenceAngle / MaxAngleError << 24) + (edge.NeighborAngle / MaxAngleError << 16) + edge.Length / MaxDistanceError;
}
public int ComputeHash(EdgeShape edge)
{
return((edge.ReferenceAngle / MaxAngleError << 24) + (edge.NeighborAngle / MaxAngleError << 16) + edge.Length / MaxDistanceError);
}
