public Coordinate[] GetOffsetCurve(Coordinate[] inputPts, double distance)
{
_distance = distance;
// a zero width offset curve is empty
if (distance == 0.0)
{
return(null);
}
var isRightSide = distance < 0.0;
double posDistance = Math.Abs(distance);
OffsetSegmentGenerator segGen = GetSegmentGenerator(posDistance);
if (inputPts.Length <= 1)
{
ComputePointCurve(inputPts[0], segGen);
}
else
{
ComputeOffsetCurve(inputPts, isRightSide, segGen);
}
Coordinate[] curvePts = segGen.GetCoordinates();
// for right side line is traversed in reverse direction, so have to reverse generated line
if (isRightSide)
{
CoordinateArrays.Reverse(curvePts);
}
return(curvePts);
}
/// <summary>
/// This method handles the degenerate cases of single points and lines,
/// as well as rings.
/// </summary>
/// <returns>A Coordinate array representing the curve<br/>
/// or <c>null</c> if the curve is empty</returns>
public Coordinate[] GetRingCurve(Coordinate[] inputPts, Positions side, double distance)
{
_distance = distance;
if (inputPts.Length <= 2)
{
return(GetLineCurve(inputPts, distance));
}
// optimize creating ring for for zero distance
if (distance == 0.0)
{
return(CopyCoordinates(inputPts));
}
OffsetSegmentGenerator segGen = GetSegmentGenerator(distance);
ComputeRingBufferCurve(inputPts, side, segGen);
return(segGen.GetCoordinates());
}