public Event(EVENT_TYPE type, double x, Point p, Arc a)
: this(type)
{
this.x = x;
this.p = p;
this.a = a;
}
public Arc(VoronoiCell cell, Point p, Arc prev, Arc next)
: this(cell, p, prev)
{
this.next = next;
}
public Arc(VoronoiCell cell, Point p, Arc prev)
: this(cell, p)
{
this.prev = prev;
}
void FinishEdges()
{
// Advance the sweep line so no parabolas can cross the bounding box.
double l = X1 + (X1 - X0) + (Y1 - Y0);
// Extend each remaining segment to the new parabola intersections.
for (Arc i = root; i.next != null; i = i.next)
{
if (i.s1 != null)
{
i.s1.Finish(Intersection(i.p, i.next.p, l * 2));
}
}
// Crop output
for (int c = 0; c < cells.Length; c++)
{
VoronoiCell cell = cells [c];
bool cropped = false;
// Crop segments if needed
for (int k = 0; k < cell.segments.Count; k++)
{
Segment s = cell.segments [k];
// is the segment completely outside?
if (!s.done || (s.start.x < X0 && s.end.x < X0) || (s.start.y < Y0 && s.end.y < Y0) || (s.start.x > X1 && s.end.x > X1) || (s.start.y > Y1 && s.end.y > Y1) ||
Point.EqualsBoth(s.start, s.end))
{
s.deleted = true;
continue;
}
// is any endpoint outside of the canvas?
bool p1inside = PointInsideRect(s.start);
if (!p1inside)
{
s.start = CropPoint(s.start, s, cell);
cropped = true;
}
bool p2inside = PointInsideRect(s.end);
if (!p2inside)
{
s.end = CropPoint(s.end, s, cell);
cropped = true;
}
}
if (cropped)
{
// join borders with 2 points
if (cell.top.Count > 1)
{
cell.segments.Add(new Segment(cell.top [0], cell.top [1], true));
}
if (cell.bottom.Count > 1)
{
cell.segments.Add(new Segment(cell.bottom [0], cell.bottom [1], true));
}
if (cell.left.Count > 1)
{
cell.segments.Add(new Segment(cell.left [0], cell.left [1], true));
}
if (cell.right.Count > 1)
{
cell.segments.Add(new Segment(cell.right [0], cell.right [1], true));
}
}
}
// 2nd step - snap to nearest corners
Point[] corners = new Point[4];
corners [0] = new Point(X0, Y0);
corners [1] = new Point(X0, Y1);
corners [2] = new Point(X1, Y0);
corners [3] = new Point(X1, Y1);
Point np;
for (int cornerIndex = 0; cornerIndex < corners.Length; cornerIndex++)
{
Point corner = corners [cornerIndex];
// Get the nearest point of the segments
VoronoiCell nearestCell = GetNearestCellFrom(corner);
// this territory is the nearest to the corner so now we can snap the nearest segment safely
if (GetNearestSegmentPointToCorner(corner, nearestCell.segments, true, out np))
{
nearestCell.segments.Add(new Segment(np, corner, true));
}
if (GetNearestSegmentPointToCorner(corner, nearestCell.segments, false, out np))
{
nearestCell.segments.Add(new Segment(np, corner, true));
}
}
}
public void AssignData(Point[] centers)
{
if (this.cells == null || this.cells.Length != centers.Length)
{
this.cells = new VoronoiCell[centers.Length];
}
for (int k = 0; k < cells.Length; k++)
{
cells [k] = new VoronoiCell(centers [k]);
}
if (eventQueue == null)
{
eventQueue = new List <Event> (cells.Length);
}
else
{
eventQueue.Clear();
}
root = null;
eventQueueTop = 0;
if (hit == null)
{
hit = new Dictionary <Point, bool> (cells.Length);
}
else
{
hit.Clear();
}
for (int k = 0; k < cells.Length; k++)
{
Point p = cells [k].center;
// Checks that p is not near than PRECISION from other point
while (hit.ContainsKey(p))
{
if (p.x > 0)
{
p.x -= Point.PRECISION * 2.0f;
}
else
{
p.x += Point.PRECISION * 2.0f;
}
}
hit.Add(p, true);
Event siteEvent = new Event(EVENT_TYPE.SiteEvent);
siteEvent.p = p;
siteEvent.x = p.x;
siteEvent.cell = cells [k];
eventQueue.Add(siteEvent);
}
eventQueue.Sort((Event e1, Event e2) => {
if (e1.x < e2.x - Point.PRECISION)
{
return(-1);
}
else if (e1.x > e2.x + Point.PRECISION)
{
return(1);
}
else if (e1.p.y < e2.p.y - Point.PRECISION)
{
return(-1);
}
else if (e1.p.y > e2.p.y + Point.PRECISION)
{
return(1);
}
else
{
return(0);
}
});
}
void HandleSiteEvent(Event ev)
{
Point p = ev.p;
if (root == null)
{
root = new Arc(ev.cell, p);
return;
}
Arc i;
// Find the current arc(s) at height p.y (if there are any).
for (i = root; i != null; i = i.next)
{
Point z, zz;
if (Intersect(p, i, out z))
{
// New parabola intersects arc i. If necessary, duplicate i.
if (i.next != null && !Intersect(p, i.next, out zz))
{
i.next.prev = new Arc(i.cell, i.p, i, i.next);
i.next = i.next.prev;
}
else
{
i.next = new Arc(i.cell, i.p, i);
}
i.next.s1 = i.s1;
// Add p between i and i->next.
i.next.prev = new Arc(ev.cell, p, i, i.next);
i.next = i.next.prev;
i = i.next; // Now i points to the new arc.
// Add new half-edges connected to i's endpoints.
i.prev.s1 = i.s0 = new Segment(z);
i.prev.cell.segments.Add(i.prev.s1);
i.cell.segments.Add(i.prev.s1);
i.next.s0 = i.s1 = new Segment(z);
i.next.cell.segments.Add(i.next.s0);
i.cell.segments.Add(i.next.s0);
// Check for new circle events around the new arc:
CheckCircleEvent(i, p.x);
CheckCircleEvent(i.prev, p.x);
CheckCircleEvent(i.next, p.x);
return;
}
}
// Special case: If p never intersects an arc, append it to the list.
for (i = root; i.next != null; i = i.next)
{
; // Find the last node.
}
i.next = new Arc(ev.cell, p, i);
// Insert segment between p and i
Point start = new Point(X0 - 1, (i.next.p.y + i.p.y) / 2);
i.next.s0 = i.s1 = new Segment(start);
i.next.cell.segments.Add(i.next.s0);
i.cell.segments.Add(i.next.s0);
}
public Event(EVENT_TYPE type, double x, Point p, Arc a) : this(type) {
this.x = x;
this.p = p;
this.a = a;
}
