private ArcFeature ImportArc(Ntx.Line line, Operation creator, ILength tol)
{
Debug.Assert(line.IsCurve);
IEntity what = GetEntityType(line, SpatialType.Line);
// Get positions defining the arc
PointGeometry[] pts = GetPositions(line);
// Ignore zero-length lines
if (HasZeroLength(pts))
{
return(null);
}
// Add a point at the center of the circle
Ntx.Position pos = line.Center;
PointGeometry pc = new PointGeometry(pos.Easting, pos.Northing);
PointFeature center = EnsurePointExists(pc, tol, creator);
// Calculate exact positions for the arc endpoints
double radius = line.Radius;
ICircleGeometry cg = new CircleGeometry(pc, radius);
IPosition bc = CircleGeometry.GetClosestPosition(cg, pts[0]);
IPosition ec = CircleGeometry.GetClosestPosition(cg, pts[pts.Length - 1]);
// Round off to nearest micron
PointGeometry bcg = PointGeometry.Create(bc);
PointGeometry ecg = PointGeometry.Create(ec);
// Ensure point features exist at both ends of the line.
PointFeature ps = GetArcEndPoint(bcg, tol, creator);
PointFeature pe = GetArcEndPoint(ecg, tol, creator);
// Try to find a circle that's already been added by this import.
Circle c = EnsureCircleExists(center, radius, tol, creator);
// Determine which way the arc is directed
bool iscw = LineStringGeometry.IsClockwise(pts, center);
InternalIdValue id = CadastralMapModel.Current.WorkingSession.AllocateNextId();
ArcFeature arc = new ArcFeature(creator, id, what, c, ps, pe, iscw);
// The toological status of the incoming arc may override the status that the
// constructor derived from the entity type
arc.SetTopology(line.IsTopologicalArc);
#if DEBUG
// Confirm the NTX data was valid (ensure it's consistent with what we've imported)...
double readRad = c.Radius;
double calcRad = BasicGeom.Distance(c.Center, ps);
Debug.Assert(Math.Abs(readRad - calcRad) < tol.Meters);
foreach (IPointGeometry pg in pts)
{
ILength check = arc.Geometry.Distance(pg);
Debug.Assert(check.Meters < tol.Meters);
}
#endif
return(arc);
}
/// <summary>
/// Creates the geometry that can be used to detect intersections with the map.
/// </summary>
/// <returns>The geometry for the new line (null if insufficient information has been specified)</returns>
ArcGeometry CreateIntersectGeometry()
{
if (m_Circles == null)
{
return(null);
}
PointFeature start = StartPoint;
if (start == null)
{
return(null);
}
IPointGeometry end = LastMousePosition;
if (end == null)
{
return(null);
}
ITerminal endTerm = new FloatingTerminal(end);
// Find the circle that is closest to the end (only looking at the valid circles
// that are within a 1mm tolerance). Return null geometry if none of the circles
// are within reach.
Circle bestCircle = m_Circles[0];
double bestdist = bestCircle.Distance(end).Meters;
if (m_Circles.Count > 1)
{
// See if there is any better choice
for (int i = 1; i < m_Circles.Count; i++)
{
Circle c = m_Circles[i];
double dist = c.Distance(end).Meters;
if (dist < bestdist)
{
bestCircle = c;
bestdist = dist;
}
}
}
// Ignore if the best circle is too far away
double tol = CircleTolerance.Meters;
if (bestdist > tol)
{
return(null);
}
// Project the end point ON to the circle.
//IPointGeometry center = bestCircle.Center;
//Turn eturn = new Turn(center, end);
//IAngle bearing = eturn.Bearing;
//IPosition cirend = Geom.Polar(center, bearing.Radians, bestCircle.Radius.Meters);
IPosition cirend = CircleGeometry.GetClosestPosition(bestCircle, end);
// Get the clockwise angle from the start to the current end point.
IPointGeometry center = bestCircle.Center;
Turn sturn = new Turn(center, start);
double angle = sturn.GetAngleInRadians(cirend);
// Figure out which direction the curve should go, depending
// on whether the user wants the short arc or the long one.
bool iscw = (angle < MathConstants.PI ? m_IsShortArc : !m_IsShortArc);
// Create the required geometry
ITerminal ec = new FloatingTerminal(cirend);
return(new ArcGeometry(bestCircle, start, ec, iscw));
}
