private Point[] GetPositions(Point start, Point end, double[] lengths, Vector startTangent, Vector endTangent)
{
var lengthSum = lengths.Sum();
var dist = (end - start).Magnitude;
BezierSpline spline = null;
double relEps = 0.001;
var startDir = startTangent.GetNormalized();
var endDir = endTangent.GetNormalized();
Point[] resPoints = null;
int lengthSampleCount = (int)(lengthSum / lengths.Min());
#if DEBUG
#region Time
double startTime = Reporting.Seconds;
double prevTime = startTime;
double curTime;
Action<string, bool> printTime = (message, fromStart) =>
{
curTime = Reporting.Seconds;
var lastTime = fromStart ? startTime : prevTime;
Reporting.LogMessage("{0} = {1} [ms] at {2} [fps]", message, Math.Round((curTime - lastTime) * 1000, 2), Math.Round(1.0 / (curTime - lastTime), 2));
if (!fromStart)
prevTime = curTime;
};
#endregion Time
#endif
Func<double, double> func = (p) =>
{
spline = new BezierSpline(start, start + startDir * p, end + endDir * p, end);
#if DEBUG
DebugGeo.Add(spline);
#endif
return spline.GetLength(lengthSampleCount * 2) - lengthSum;
};
double param = 0;
double eps = lengthSum * relEps; ;
double minParam = (lengthSum - dist) / 2;
double maxParam = Math.Sqrt(lengthSum * lengthSum - dist * dist);
var success = MathUtils.SolveByBisection(func, minParam, maxParam, out param, eps);
if (!success)
{
success = MathUtils.SolveByBisection(func, minParam / 2, maxParam * 2, out param, eps);
if (!success)
return null;
}
#if DEBUG
printTime("SplinePreparation", false);
#endif
spline = new BezierSpline(start, start + startDir * param, end + endDir * param, end);
resPoints = spline.GetResampledByDistance(lengths, true);
#if DEBUG
printTime("Resample", false);
#endif
#if DEBUG
printTime("Finished", true);
#endif
return resPoints;
}
