private PointF EvaluatePolynomial(SplinePolynomial SP, double s)
{
PointF Pt = new PointF();
Pt.X = (float)(SP.Ax * s * s * s + SP.Bx * s * s + SP.Cx * s + SP.Dx);
Pt.Y = (float)(SP.Ay * s * s * s + SP.By * s * s + SP.Cy * s + SP.Dy);
return(Pt);
}
public List <SplinePolynomial> CalculatePolynomialSpline(List <PointF> ListOfPoints, Func <PointF, PointF> convert = null, string[] SVGCode = null, bool isarea = false)
{
int i;
int n = ListOfPoints.Count;
double c = 0.19;
List <SplinePolynomial> ListSP = new List <SplinePolynomial>();
for (i = 0; i < n - 1; i++)
{
SplinePolynomial SP = new SplinePolynomial();
// 1
double x0 = (i == 0) ? ListOfPoints[0].X : ListOfPoints[i - 1].X;
double x1 = ListOfPoints[i].X;
double x2 = ListOfPoints[i + 1].X;
double x3 = (i == n - 2) ? ListOfPoints[n - 1].X : ListOfPoints[i + 2].X;
double y0 = (i == 0) ? ListOfPoints[0].Y : ListOfPoints[i - 1].Y;
double y1 = ListOfPoints[i].Y;
double y2 = ListOfPoints[i + 1].Y;
double y3 = (i == n - 2) ? ListOfPoints[n - 1].Y : ListOfPoints[i + 2].Y;
if (isarea)
{
x0 = (i == 0) ? ListOfPoints[n - 2].X : ListOfPoints[i - 1].X;
x3 = (i == n - 2) ? ListOfPoints[1].X : ListOfPoints[i + 2].X;
y0 = (i == 0) ? ListOfPoints[n - 2].Y : ListOfPoints[i - 1].Y;
y3 = (i == n - 2) ? ListOfPoints[1].Y : ListOfPoints[i + 2].Y;
}
if (SVGCode != null)
{
PointF XY0 = convert(new PointF((float)x0, (float)y0));
PointF XY1 = convert(new PointF((float)x1, (float)y1));
PointF XY2 = convert(new PointF((float)x2, (float)y2));
PointF XY3 = convert(new PointF((float)x3, (float)y3));
x0 = XY0.X;
x1 = XY1.X;
x2 = XY2.X;
x3 = XY3.X;
y0 = XY0.Y;
y1 = XY1.Y;
y2 = XY2.Y;
y3 = XY3.Y;
}
// 2
double m1x = x1 + c * (x2 - x0);
double m2x = x2 - c * (x3 - x1);
double m1y = y1 + c * (y2 - y0);
double m2y = y2 - c * (y3 - y1);
SP.Ax = -3 * m2x + 3 * m1x + x2 - x1;
SP.Bx = -6 * m1x + 3 * m2x + 3 * x1;
SP.Cx = 3 * m1x - 3 * x1;
SP.Dx = x1;
SP.Ay = -3 * m2y + 3 * m1y + y2 - y1;
SP.By = -6 * m1y + 3 * m2y + 3 * y1;
SP.Cy = 3 * m1y - 3 * y1;
SP.Dy = y1;
if (SVGCode != null)
{
if (i == 0)
{
SVGCode[0] += "M " + x1.ToString() + " " + y1.ToString() + " ";
}
SVGCode[0] += " c "
+ (m1x - x1).ToString() + " " + (m1y - y1).ToString() + ", "
+ (m2x - x1).ToString() + " " + (m2y - y1).ToString() + ", "
+ (x2 - x1).ToString() + " " + (y2 - y1).ToString() + " ";
}
ListSP.Add(SP);
}
return(ListSP);
}
