/// <summary>
/// Return an edge that is the bisection between two sites
/// </summary>
/// <param name="siteA">The first site</param>
/// <param name="siteB">The second site</param>
/// <returns>The new edge</returns>
public static VoronoiDiagramEdge <T> Bisect(VoronoiDiagramSite <T> siteA, VoronoiDiagramSite <T> siteB)
{
float dx, dy;
var newEdge = new VoronoiDiagramEdge <T>
{
LeftSite = siteA,
RightSite = siteB,
LeftEndPoint = null,
RightEndPoint = null
};
dx = siteB.Coordinate.x - siteA.Coordinate.x;
dy = siteB.Coordinate.y - siteA.Coordinate.y;
newEdge.C = siteA.Coordinate.x * dx + siteA.Coordinate.y * dy + (dx * dx + dy * dy) * 0.5f;
if (Mathf.Abs(dx) > Mathf.Abs(dy))
{
newEdge.A = 1f;
newEdge.B = dy / dx;
newEdge.C /= dx;
}
else
{
newEdge.B = 1f;
newEdge.A = dx / dy;
newEdge.C /= dy;
}
siteA.Edges.Add(newEdge);
siteB.Edges.Add(newEdge);
return(newEdge);
}
/// <summary>
/// Creates a new half edge
/// </summary>
/// <param name="edge">The edge of the new half edge</param>
/// <param name="edgeType">The edge type that this half edge represents (left or right). The only half edges that should be "None" are the buckets in the priority queue.</param>
public VoronoiDiagramHalfEdge(VoronoiDiagramEdge <T> edge, VoronoiDiagramEdgeType edgeType)
{
Edge = edge;
EdgeType = edgeType;
Vertex = null;
StarY = 0f;
EdgeListLeft = null;
EdgeListRight = null;
NextInPriorityQueue = null;
}
/// <summary>
/// Runs Fortune's Algorithm to generate sites with edges for the diagram
/// </summary>
/// <param name="relaxationCycles">Number of relaxation cycles to run</param>
public void GenerateSites(int relaxationCycles)
{
if (_originalSites.Count == 0)
{
Debug.LogError("No points added to the diagram. Sites cannot be generated");
return;
}
_sites.Clear();
foreach (VoronoiDiagramSite <T> site in _originalSites)
{
_sites.Add(new VoronoiDiagramSite <T>(_sites.Count, site));
}
SortSitesAndSetValues();
// Cycles related to Lloyd's algorithm
for (int cycles = 0; cycles < relaxationCycles; cycles++)
{
// Fortune's Algorithm
int numGeneratedEdges = 0;
int numGeneratedVertices = 0;
_currentSiteIndex = 0;
var priorityQueue = new VoronoiDiagramPriorityQueue <T>(_sites.Count, _minValues, _deltaValues);
var edgeList = new VoronoiDiagramEdgeList <T>(_sites.Count, _minValues, _deltaValues);
Vector2 currentIntersectionStar = Vector2.zero;
VoronoiDiagramSite <T> currentSite;
var generatedEdges = new List <VoronoiDiagramEdge <T> >();
bool done = false;
_bottomMostSite = GetNextSite();
currentSite = GetNextSite();
while (!done)
{
if (!priorityQueue.IsEmpty())
{
currentIntersectionStar = priorityQueue.GetMinimumBucketFirstPoint();
}
VoronoiDiagramSite <T> bottomSite;
VoronoiDiagramHalfEdge <T> bisector;
VoronoiDiagramHalfEdge <T> rightBound;
VoronoiDiagramHalfEdge <T> leftBound;
VoronoiDiagramVertex <T> vertex;
VoronoiDiagramEdge <T> edge;
if (
currentSite != null &&
(
priorityQueue.IsEmpty() ||
currentSite.Coordinate.y < currentIntersectionStar.y ||
(
currentSite.Coordinate.y.IsAlmostEqualTo(currentIntersectionStar.y) &&
currentSite.Coordinate.x < currentIntersectionStar.x
)
)
)
{
// Current processed site is the smallest
leftBound = edgeList.GetLeftBoundFrom(currentSite.Coordinate);
rightBound = leftBound.EdgeListRight;
bottomSite = GetRightRegion(leftBound);
edge = VoronoiDiagramEdge <T> .Bisect(bottomSite, currentSite);
edge.Index = numGeneratedEdges;
numGeneratedEdges++;
generatedEdges.Add(edge);
bisector = new VoronoiDiagramHalfEdge <T>(edge, VoronoiDiagramEdgeType.Left);
edgeList.Insert(leftBound, bisector);
vertex = VoronoiDiagramVertex <T> .Intersect(leftBound, bisector);
if (vertex != null)
{
priorityQueue.Delete(leftBound);
leftBound.Vertex = vertex;
leftBound.StarY = vertex.Coordinate.y + currentSite.GetDistanceFrom(vertex);
priorityQueue.Insert(leftBound);
}
leftBound = bisector;
bisector = new VoronoiDiagramHalfEdge <T>(edge, VoronoiDiagramEdgeType.Right);
edgeList.Insert(leftBound, bisector);
vertex = VoronoiDiagramVertex <T> .Intersect(bisector, rightBound);
if (vertex != null)
{
bisector.Vertex = vertex;
bisector.StarY = vertex.Coordinate.y + currentSite.GetDistanceFrom(vertex);
priorityQueue.Insert(bisector);
}
currentSite = GetNextSite();
}
else if (priorityQueue.IsEmpty() == false)
{
// Current intersection is the smallest
leftBound = priorityQueue.RemoveAndReturnMinimum();
VoronoiDiagramHalfEdge <T> leftLeftBound = leftBound.EdgeListLeft;
rightBound = leftBound.EdgeListRight;
VoronoiDiagramHalfEdge <T> rightRightBound = rightBound.EdgeListRight;
bottomSite = GetLeftRegion(leftBound);
VoronoiDiagramSite <T> topSite = GetRightRegion(rightBound);
// These three sites define a Delaunay triangle
// Bottom, Top, EdgeList.GetRightRegion(rightBound);
// Debug.Log(string.Format("Delaunay triagnle: ({0}, {1}), ({2}, {3}), ({4}, {5})"),
// bottomSite.Coordinate.x, bottomSite.Coordinate.y,
// topSite.Coordinate.x, topSite.Coordinate.y,
// edgeList.GetRightRegion(leftBound).Coordinate.x,
// edgeList.GetRightRegion(leftBound).Coordinate.y);
var v = leftBound.Vertex;
v.Index = numGeneratedVertices;
numGeneratedVertices++;
leftBound.Edge.SetEndpoint(v, leftBound.EdgeType);
rightBound.Edge.SetEndpoint(v, rightBound.EdgeType);
edgeList.Delete(leftBound);
priorityQueue.Delete(rightBound);
edgeList.Delete(rightBound);
var edgeType = VoronoiDiagramEdgeType.Left;
if (bottomSite.Coordinate.y > topSite.Coordinate.y)
{
var tempSite = bottomSite;
bottomSite = topSite;
topSite = tempSite;
edgeType = VoronoiDiagramEdgeType.Right;
}
edge = VoronoiDiagramEdge <T> .Bisect(bottomSite, topSite);
edge.Index = numGeneratedEdges;
numGeneratedEdges++;
generatedEdges.Add(edge);
bisector = new VoronoiDiagramHalfEdge <T>(edge, edgeType);
edgeList.Insert(leftLeftBound, bisector);
edge.SetEndpoint(v,
edgeType == VoronoiDiagramEdgeType.Left
? VoronoiDiagramEdgeType.Right
: VoronoiDiagramEdgeType.Left);
vertex = VoronoiDiagramVertex <T> .Intersect(leftLeftBound, bisector);
if (vertex != null)
{
priorityQueue.Delete(leftLeftBound);
leftLeftBound.Vertex = vertex;
leftLeftBound.StarY = vertex.Coordinate.y + bottomSite.GetDistanceFrom(vertex);
priorityQueue.Insert(leftLeftBound);
}
vertex = VoronoiDiagramVertex <T> .Intersect(bisector, rightRightBound);
if (vertex != null)
{
bisector.Vertex = vertex;
bisector.StarY = vertex.Coordinate.y + bottomSite.GetDistanceFrom(vertex);
priorityQueue.Insert(bisector);
}
}
else
{
done = true;
}
}
GeneratedSites.Clear();
// Bound the edges of the diagram
foreach (VoronoiDiagramEdge <T> currentGeneratedEdge in generatedEdges)
{
currentGeneratedEdge.GenerateClippedEndPoints(Bounds);
}
foreach (VoronoiDiagramSite <T> site in _sites)
{
try
{
site.GenerateCentroid(Bounds);
}
catch (Exception)
{
Debug.Log("Coordinate");
Debug.Log(site.Coordinate);
Debug.Log("End points:");
foreach (var edge in site.Edges)
{
Debug.Log(edge.LeftClippedEndPoint + " , " + edge.RightClippedEndPoint);
}
throw;
}
}
foreach (VoronoiDiagramSite <T> site in _sites)
{
var generatedSite = new VoronoiDiagramGeneratedSite <T>(site.Index, site.Coordinate, site.Centroid, new T(), site.IsCorner, site.IsEdge);
generatedSite.Vertices.AddRange(site.Vertices);
generatedSite.SiteData = site.SiteData;
foreach (VoronoiDiagramEdge <T> siteEdge in site.Edges)
{
// Only add edges that are visible
// Don't need to check the Right because they will both be float.MinValue
if (siteEdge.LeftClippedEndPoint == new Vector2(float.MinValue, float.MinValue))
{
continue;
}
generatedSite.Edges.Add(new VoronoiDiagramGeneratedEdge(siteEdge.Index,
siteEdge.LeftClippedEndPoint, siteEdge.RightClippedEndPoint));
if (siteEdge.LeftSite != null && !generatedSite.NeighborSites.Contains(siteEdge.LeftSite.Index))
{
generatedSite.NeighborSites.Add(siteEdge.LeftSite.Index);
}
if (siteEdge.RightSite != null && !generatedSite.NeighborSites.Contains(siteEdge.RightSite.Index))
{
generatedSite.NeighborSites.Add(siteEdge.RightSite.Index);
}
}
GeneratedSites.Add(generatedSite.Index, generatedSite);
// Finished with the edges, remove the references so they can be removed at the end of the method
site.Edges.Clear();
}
// Clean up
_bottomMostSite = null;
_sites.Clear();
// Lloyd's Algorithm
foreach (KeyValuePair <int, VoronoiDiagramGeneratedSite <T> > generatedSite in GeneratedSites)
{
var centroidPoint =
new Vector2(
Mathf.Clamp(generatedSite.Value.Centroid.x, 0, Bounds.width),
Mathf.Clamp(generatedSite.Value.Centroid.y, 0, Bounds.height));
var newSite = new VoronoiDiagramSite <T>(new Vector2(centroidPoint.x, centroidPoint.y), generatedSite.Value.SiteData);
if (!_sites.Any(item => item.Coordinate.x.IsAlmostEqualTo(newSite.Coordinate.x) && item.Coordinate.y.IsAlmostEqualTo(newSite.Coordinate.y)))
{
_sites.Add(new VoronoiDiagramSite <T>(_sites.Count, newSite));
}
}
SortSitesAndSetValues();
}
}