public double GetMinEpsilon(TPoint2D shortcutEnd, bool doExtremePointQueries)
{
double[] distances;
if (doExtremePointQueries)
{
//O(4log n)
distances = new []
{
Geometry2D.Distance(shortcutStart, shortcutEnd, upper.ExtremePointFromShortcutLine(shortcutEnd)),
Geometry2D.Distance(shortcutStart, shortcutEnd, lower.ExtremePointFromShortcutLine(shortcutEnd)),
upper.ExtremeDistanceLeftOfShortcut(shortcutEnd),
lower.ExtremeDistanceLeftOfShortcut(shortcutEnd)
};
}
else
{
//O(2log n)
distances = new []
{
upper.ExtremeDistanceLeftOfShortcut(shortcutEnd),
lower.ExtremeDistanceLeftOfShortcut(shortcutEnd)
};
}
return(distances.Max());
}
public static double GetMinEpsilon(Trajectory2D trajectory, int start, int end)
{
var maxDistance = 0.0;
for (var k = start + 1; k < end; k++)
{
var point = trajectory[k];
maxDistance = Math.Max(maxDistance, Geometry2D.Distance(trajectory[start], trajectory[end], point));
}
return(maxDistance);
}
public static int GetSplit(Trajectory2D trajectory, int start, int end, out double maxDistance)
{
maxDistance = 0.0;
var split = -1;
var startPoint = trajectory[start];
var endPoint = trajectory[end];
for (var k = start + 1; k < end; k++)
{
var point = trajectory[k];
var dist = Geometry2D.Distance(startPoint, endPoint, point);
if (dist > maxDistance)
{
maxDistance = dist;
split = k;
}
}
return(split);
}
public void Intersect(TPoint2D shortcutEnd, double epsilon)
{
//angle between shortcut line and epsilon circles
var distance = Geometry2D.Distance(Origin, shortcutEnd);
//if within epsilon circle, keep wedge and continue with next
if (distance <= epsilon)
{
return;
}
//get angle of shortcut line with respect to the unit circle
var worldAngle = Geometry2D.Angle(Origin, shortcutEnd);
var wedgeAngle = Math.Asin(epsilon / distance);
//build wedge
var wedgeStart = Geometry2D.SubtractRadians(worldAngle, wedgeAngle);
var wedgeEnd = Geometry2D.SumRadians(worldAngle, wedgeAngle);
var newWedge = new Wedge(Origin, wedgeStart, wedgeEnd);
//intersect wedge
Intersect(newWedge);
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary> Creates a circle event. </summary>
/// <remarks>Circle events are created at the circumcenters of three sites - the sites for poly1/2/3.</remarks>
/// <param name="poly1"> The first polygon. </param>
/// <param name="poly2"> The second polygon. </param>
/// <param name="poly3"> The third polygon. </param>
/// <param name="yScanLine"> The y coordinate scan line. </param>
/// <returns> A new circle event. </returns>
////////////////////////////////////////////////////////////////////////////////////////////////////
internal static CircleEvent CreateCircleEvent(FortunePoly poly1, FortunePoly poly2, FortunePoly poly3,
double yScanLine)
{
// Locals
CircleEvent cevtRet = null;
// Determine a circumcenter for the sites of poly1/2/3.
if (Geometry2D.FFindCircumcenter(poly1.VoronoiPoint, poly2.VoronoiPoint, poly3.VoronoiPoint, out var ptCenter))
{
// Determine y coordinate for the side of the circle
// The event will fire when the scan line hits that y position
var radius = Geometry2D.Distance(poly1.VoronoiPoint, ptCenter);
ptCenter.Y -= radius;
// If the circumcenter is above the scan line we've already passed it by, so don't put it in the queue
if (ptCenter.Y <= yScanLine)
{
cevtRet = new CircleEvent(ptCenter, radius);
}
}
return(cevtRet);
}
private static EnhancedPoint InitializeEnhancedPoint(TPoint2D p, TPoint2D shortcutStart)
{
return(new EnhancedPoint(p, Geometry2D.Distance(p, shortcutStart)));
}
