private void ComputeMinDistancePolygonPoint(PlanarPolygon3D polyPlane, IPoint point,
bool flip)
{
var pt = point.Coordinate;
var shell = polyPlane.Polygon.ExteriorRing;
if (polyPlane.Intersects(pt, shell))
{
// point is either inside or in a hole
int nHole = polyPlane.Polygon.NumInteriorRings;
for (int i = 0; i < nHole; i++)
{
var hole = polyPlane.Polygon.GetInteriorRingN(i);
if (polyPlane.Intersects(pt, hole))
{
ComputeMinDistanceLinePoint(hole, point, flip);
return;
}
}
// point is in interior of polygon
// distance is distance to polygon plane
double dist = Math.Abs(polyPlane.Plane.OrientedDistance(pt));
UpdateDistance(dist,
new GeometryLocation(polyPlane.Polygon, 0, pt),
new GeometryLocation(point, 0, pt),
flip
);
}
// point is outside polygon, so compute distance to shell linework
ComputeMinDistanceLinePoint(shell, point, flip);
}
private static Coordinate Intersection(PlanarPolygon3D poly, ILineString line)
{
var seq = line.CoordinateSequence;
if (seq.Count == 0)
{
return(null);
}
// start point of line
var p0 = new Coordinate();
seq.GetCoordinate(0, p0);
double d0 = poly.Plane.OrientedDistance(p0);
// for each segment in the line
var p1 = new Coordinate();
for (int i = 0; i < seq.Count - 1; i++)
{
seq.GetCoordinate(i, p0);
seq.GetCoordinate(i + 1, p1);
double d1 = poly.Plane.OrientedDistance(p1);
/**
* If the oriented distances of the segment endpoints have the same sign,
* the segment does not cross the plane, and is skipped.
*/
if (d0 * d1 > 0)
{
continue;
}
/**
* Compute segment-plane intersection point
* which is then used for a point-in-polygon test.
* The endpoint distances to the plane d0 and d1
* give the proportional distance of the intersection point
* along the segment.
*/
var intPt = SegmentPoint(p0, p1, d0, d1);
// Coordinate intPt = polyPlane.intersection(p0, p1, s0, s1);
if (poly.Intersects(intPt))
{
return(intPt);
}
// shift to next segment
d0 = d1;
}
return(null);
}
private void ComputeMinDistancePolygonPoint(PlanarPolygon3D polyPlane, IPoint point,
bool flip)
{
var pt = point.Coordinate;
var shell = polyPlane.Polygon.ExteriorRing;
if (polyPlane.Intersects(pt, shell))
{
// point is either inside or in a hole
var nHole = polyPlane.Polygon.NumInteriorRings;
for (int i = 0; i < nHole; i++)
{
var hole = polyPlane.Polygon.GetInteriorRingN(i);
if (polyPlane.Intersects(pt, hole))
{
ComputeMinDistanceLinePoint(hole, point, flip);
return;
}
}
// point is in interior of polygon
// distance is distance to polygon plane
var dist = Math.Abs(polyPlane.Plane.OrientedDistance(pt));
UpdateDistance(dist,
new GeometryLocation(polyPlane.Polygon, 0, pt),
new GeometryLocation(point, 0, pt),
flip
);
}
// point is outside polygon, so compute distance to shell linework
ComputeMinDistanceLinePoint(shell, point, flip);
}
private static Coordinate Intersection(PlanarPolygon3D poly, ILineString line)
{
var seq = line.CoordinateSequence;
if (seq.Count == 0)
return null;
// start point of line
var p0 = new Coordinate();
seq.GetCoordinate(0, p0);
var d0 = poly.Plane.OrientedDistance(p0);
// for each segment in the line
var p1 = new Coordinate();
for (var i = 0; i < seq.Count - 1; i++)
{
seq.GetCoordinate(i, p0);
seq.GetCoordinate(i + 1, p1);
var d1 = poly.Plane.OrientedDistance(p1);
/**
* If the oriented distances of the segment endpoints have the same sign,
* the segment does not cross the plane, and is skipped.
*/
if (d0 * d1 > 0)
continue;
/**
* Compute segment-plane intersection point
* which is then used for a point-in-polygon test.
* The endpoint distances to the plane d0 and d1
* give the proportional distance of the intersection point
* along the segment.
*/
var intPt = SegmentPoint(p0, p1, d0, d1);
// Coordinate intPt = polyPlane.intersection(p0, p1, s0, s1);
if (poly.Intersects(intPt))
{
return intPt;
}
// shift to next segment
d0 = d1;
}
return null;
}
