public static List <Line3D> GetIntersection(this Polygon3D polygon, Plane3D plane)
{
var points = new List <WM.Point3D>(2);
var count = polygon.Count;
for (var i = 1; i < count; ++i)
{
var l0 = polygon[i - 1];
var l = polygon[i] - l0;
var d = WM.Vector3D.DotProduct(l, plane.NormalVector);
if (!d.IsZero(1e-12))
{
d = GetIntersecionDistance(l0, l, plane);
if (d.IsGreaterOrEqual(0) && d.IsLesserOrEqual(1)) // d >= 0 && d <= 1
{
var intersection = d * l + l0;
points.Add(intersection);
}
}
}
RemoveDuplicates(points);
count = points.Count;
// System.Diagnostics.Debug.Assert(!(count > 2 && count % 2 != 0));
var lines = new List <Line3D>(count / 2);
for (var i = 1; i < count; i += 2)
{
var line = new Line3D(points[i - 1], points[i]);
lines.Add(line);
}
return(lines);
}
public static void Move(this Polygon3D p, WM.Vector3D dir)
{
for (var i = p.Count - 1; i >= 0; --i)
{
p[i] += dir;
}
}
public static Polygon3D Convert(IPolyLine3D polyline)
{
var points = new List <IPoint3D>(polyline.Count);
GeomOperation.ConvertPolylineToPointList(polyline, points, false, 5);
var polygon = new Polygon3D(points.Select(p => p.ToMediaPoint()));
return(polygon);
}
public static List <Line3D> GetIntersection(this Polygon3D p1, Polygon3D p2)
{
var p1Plane = p1.GetPlane();
var p2Plane = p2.GetPlane();
////if (WM.Vector3D.CrossProduct(p1Plane.NormalVector, p2Plane.NormalVector).LengthSquared.IsZero())
////{
//// // polygons are parallel, use clipper
//// var axisX = (p1[1] - p1[0]).ToIndoVector3D().Normalize;
//// var axisZ = p1Plane.NormalVector.ToIndoVector3D();
//// var axisY = (axisX * axisZ).Normalize;
//// var lcs = new Matrix44(p1[0], axisX, axisY, axisZ);
//// var p12D = new Polygon2D(p1.Select(p =>
//// {
//// var pt = lcs.TransformToLCS(p);
//// return new Point(pt.X, pt.Y);
//// }));
//// var p22D = new Polygon2D(p2.Select(p =>
//// {
//// var pt = lcs.TransformToLCS(p);
//// return new Point(pt.X, pt.Y);
//// }));
//// var clipper = new ClipperController();
//// clipper.Add(p12D, ClipperLib.PolyType.ptSubject);
//// clipper.Add(p22D, ClipperLib.PolyType.ptClip);
//// var inters2 = clipper.IntersectionPolygons();
//// var xxx = new List<Line3D>();
//// foreach (var i in inters2)
//// {
//// }
//// throw new NotImplementedException();
////}
var p1Inters = GetIntersection(p1, p2Plane);
var p2Inters = GetIntersection(p2, p1Plane);
List <Line3D> inters = GetIntersection(p1Inters, p2Inters);
if (inters.Count > 0)
{
var item0 = inters[0];
if (item0.P1.IsEqual(item0.P2, 1e-6)) // line points are the same
{
return(new List <Line3D>());
}
}
return(inters);
}
