public Polygon CreatePolygonFromCurve(double from, double to, double padding)
{
var curve = new Curve();
foreach (var point in this.Points)
{
curve.Points.Add(new Point(point));
}
curve = curve.RemoveOverlappingPoints2D();
var len = curve.Length;
curve = CurveStrategies.CutCurve(curve, from * len, to * len);
curve = curve.RemoveOverlappingPoints2D();
var curveLeft = curve.LateralOffsetCurve(Enums.LateralPosition.Left, padding).RemoveOverlappingPoints2D();
var curveRight = curve.LateralOffsetCurve(Enums.LateralPosition.Right, padding).RemoveOverlappingPoints2D();
var poly = new Polygon();
foreach (var point in curveLeft.Points)
{
poly.Points.Add(point);
}
foreach (var point in curveRight.Points.Reverse())
{
poly.Points.Add(point);
}
poly.Points.Add(curveLeft.Points.First());
return poly;
}
private Curve LateralOffsetCurve(
Enums.LateralPosition? lateralPosition, double offset)
{
Curve curve;
if (this.UpdateOffset(lateralPosition, ref offset, out curve))
{
return curve;
}
var shiftedPoints = new Curve();
var cnt = this.Points.Count();
for (var i = 0; i < cnt - 1; i++)
{
var shiftedPointsTmp = CurveStrategies.CreateParallelLine(this.Points[i], this.Points[i + 1], offset);
shiftedPoints.Points.Add(shiftedPointsTmp.Points[0]);
shiftedPoints.Points.Add(shiftedPointsTmp.Points[1]);
}
shiftedPoints = shiftedPoints.RemoveOverlappingPoints2D();
var cntShifted = shiftedPoints.Points.Count();
for (var i = 0; i < cntShifted - 3; i += 2)
{
var innerIntersection = CurveStrategies.IntersectionOfCurves(
shiftedPoints.Points[i],
shiftedPoints.Points[i + 1],
shiftedPoints.Points[i + 2],
shiftedPoints.Points[i + 3]);
if (innerIntersection != null && innerIntersection.GetType() == typeof(Point))
{
// inner intersection
shiftedPoints.Points[i + 1].X = ((Point)innerIntersection).X;
shiftedPoints.Points[i + 1].Y = ((Point)innerIntersection).Y;
shiftedPoints.Points[i + 2].X = ((Point)innerIntersection).X;
shiftedPoints.Points[i + 2].Y = ((Point)innerIntersection).Y;
}
else
{
// outer intersection
var outerIntersection = (Point)CurveStrategies.IntersectionOfCurvesInf(
shiftedPoints.Points[i],
shiftedPoints.Points[i + 1],
shiftedPoints.Points[i + 2],
shiftedPoints.Points[i + 3]);
var angle = MathHelper.RadToDeg(MathHelper.AngleBetweenLines(
shiftedPoints.Points[i + 1],
outerIntersection,
shiftedPoints.Points[i + 2]));
if (angle >= 45f && outerIntersection != null && outerIntersection.GetType() == typeof(Point))
{
shiftedPoints.Points[i + 1].X = ((Point)outerIntersection).X;
shiftedPoints.Points[i + 1].Y = ((Point)outerIntersection).Y;
shiftedPoints.Points[i + 2].X = ((Point)outerIntersection).X;
shiftedPoints.Points[i + 2].Y = ((Point)outerIntersection).Y;
}
}
}
return shiftedPoints;
}