public static int FindClosestPointTo(Stroke stroke, Point p, int start, int finish)
{
StrokeGeometry sg = new StrokeGeometry(stroke);
return sg.FindClosestPointTo(p,start,finish);
}
public static void AnalyzeClosedness(Stroke stroke, double tolerance,
out bool closed, out Point[] vertices) // out double tAB, out double tPQ)
{
closed = false;
vertices = null;
// Formulate closure gap-tolerance, based on stroke length (but clipped to <= 500isu).
double len = StrokeGeometry.IntegrateLength(stroke);
double segtol = Math.Max(50, Math.Min(tolerance, len / 20.0));
double gaptol = Math.Max(150, Math.Min(tolerance, len / 7.0));
dbg.WriteLine(String.Format("length: {0}", len));
dbg.WriteLine(String.Format("segtol: {0}", segtol));
dbg.WriteLine(String.Format("gaptol: {0}", gaptol));
// Break the stroke down into indices.
int[] indices;
vertices = SegmentizeStroke(stroke, segtol, out indices);
int nv = vertices.Length;
// Do the head/tail segments intersect? Are they close?
if (nv >= 4)
{
Point headA = (Point)vertices[0];
Point headB = (Point)vertices[1];
Point tailP = (Point)vertices[nv - 2];
Point tailQ = (Point)vertices[nv - 1];
double tAB, tPQ;
SegmentCollision.HitTest(headA, headB, tailP, tailQ, out tAB, out tPQ);
Point virtualIntersectH = Geometry.Interpolate(headA, headB, tAB);
Point virtualIntersectT = Geometry.Interpolate(tailP, tailQ, tPQ);
Point virtualIntersect = Geometry.Interpolate(virtualIntersectH, virtualIntersectT, 0.5);
double dh2i = Geometry.DistanceBetween(headA, virtualIntersect);
double dt2i = Geometry.DistanceBetween(tailQ, virtualIntersect);
#if DEBUG
dbg.WriteLine(String.Format("numV: {0}", nv));
dbg.WriteLine(String.Format("tAB: {0}", tAB));
dbg.WriteLine(String.Format("tPQ: {0}", tPQ));
dbg.WriteLine(String.Format("isct: {0}", virtualIntersect));
dbg.WriteLine(String.Format("dh2i: {0}", dh2i));
dbg.WriteLine(String.Format("dt2i: {0}", dt2i));
#endif
if (dh2i < gaptol && dt2i < gaptol)
{
closed = true;
// Adjust the head point to the actual intersection.
vertices[0] = virtualIntersect;
dbg.WriteLine("Closed! Why? dh/t2i < gaptol");
}
else if ((-0.3 < tAB && tAB < 0.3) && (0.7 < tPQ && tPQ < 1.3))
{
closed = true;
// Adjust the head point to the actual intersection.
vertices[0] = virtualIntersect;
dbg.WriteLine("Closed! Why? |t*| < 0.3");
}
else
{
// Last chance: measure nearest distance from head to tail segment.
int closeI = StrokeGeometry.FindClosestPointTo(
stroke, headA, indices[nv - 2], indices[nv - 1]);
Point close = stroke.GetPoint(closeI);
double d = Geometry.DistanceBetween(headA, close);
if (d < gaptol)
{
closed = true; // Keep the head point; discard the tail point below.
dbg.WriteLine("Closed! Why? Last chance head/tail distance < gaptol");
}
}
// Remove the last point as redundant if it's closed.
if (closed)
{
Point[] verticesX = new Point[nv - 1];
Array.Copy(vertices, verticesX, nv - 1);
vertices = verticesX;
}
}
}
public static int FindClosestPointTo(Stroke stroke, Point p, int start, int finish)
{
StrokeGeometry sg = new StrokeGeometry(stroke);
return(sg.FindClosestPointTo(p, start, finish));
}
