private Coordinate[] Snap(Coordinate[] coords)
{
var snapCoords = new CoordinateList();
for (int i = 0; i < coords.Length; i++)
{
var pt = snapIndex.Snap(coords[i]);
snapCoords.Add(pt, false);
}
return(snapCoords.ToCoordinateArray());
}
/// <summary>
/// This method is called by clients
/// of the <see cref="ISegmentIntersector"/> class to process
/// intersections for two segments of the <see cref="ISegmentString"/>s being intersected.
/// Note that some clients (such as <c>MonotoneChain</c>s) may optimize away
/// this call for segment pairs which they have determined do not intersect
/// (e.g. by an disjoint envelope test).
/// </summary>
public void ProcessIntersections(
ISegmentString seg0, int segIndex0,
ISegmentString seg1, int segIndex1
)
{
// don't bother intersecting a segment with itself
if (seg0 == seg1 && segIndex0 == segIndex1)
{
return;
}
var p00 = seg0.Coordinates[segIndex0];
var p01 = seg0.Coordinates[segIndex0 + 1];
var p10 = seg1.Coordinates[segIndex1];
var p11 = seg1.Coordinates[segIndex1 + 1];
/*
* Don't node intersections which are just
* due to the shared vertex of adjacent segments.
*/
if (!IsAdjacent(seg0, segIndex0, seg1, segIndex1))
{
_li.ComputeIntersection(p00, p01, p10, p11);
//if (_li.HasIntersection && _li.IsProper) System.Diagnostics.Debug.WriteLine(_li);
/*
* Process single point intersections only.
* Two-point (colinear) ones will be handled by the near-vertex code
*/
if (_li.HasIntersection && _li.IntersectionNum == 1)
{
var intPt = _li.GetIntersection(0);
var snapPt = _snapPointIndex.Snap(intPt);
((NodedSegmentString)seg0).AddIntersection(snapPt, segIndex0);
((NodedSegmentString)seg1).AddIntersection(snapPt, segIndex1);
}
}
/*
* The segments must also be snapped to the other segment endpoints.
*/
ProcessNearVertex(seg0, segIndex0, p00, seg1, segIndex1, p10, p11);
ProcessNearVertex(seg0, segIndex0, p01, seg1, segIndex1, p10, p11);
ProcessNearVertex(seg1, segIndex1, p10, seg0, segIndex0, p00, p01);
ProcessNearVertex(seg1, segIndex1, p11, seg0, segIndex0, p00, p01);
}
