/// <summary>
/// The contour segment joining vertices A and B moving from A to B. The constructed segment will
/// map the arguemnt A to either this.A or this.B and map the argument B to the other member
/// this.A or this.B such that dZ_dSinAB less or equal 0.0. Thus, the segment A-->B is always
/// compatible with a clockwise polygon (where Z is larger inside the polygon) and where A.Next is B
/// and B.Prev is A.
/// </summary>
/// <param name="A">The starting vertex.</param>
/// <param name="B">The ending vertex.</param>
public ContourSegment(IsoContours Parent, ContourVertex A, ContourVertex B)
{
this.Parent = Parent;
dx = B.x - A.x;
dy = B.y - A.y;
ds = Math.Sqrt(dx * dx + dy * dy);
dx_ds = dx / ds;
dy_ds = dy / ds;
dZ_dx = 0.5 * (A.dZ_dx + B.dZ_dx);
dZ_dy = 0.5 * (A.dZ_dy + B.dZ_dy);
dZ_dCosAB = dZ_dx * dx_ds + dZ_dy * dy_ds;
dZ_dSinAB = -dZ_dx * dy_ds + dZ_dy * dx_ds;
if (dZ_dSinAB <= 0.0)
{
this.A = A;
this.B = B;
}
else
{
this.A = B;
this.B = A;
dx = -dx;
dy = -dy;
dx_ds = -dx_ds;
dy_ds = -dy_ds;
dZ_dx = -dZ_dx;
dZ_dy = -dZ_dy;
dZ_dCosAB = -dZ_dCosAB;
dZ_dSinAB = -dZ_dSinAB;
}
this.Affinity = (1.0 + (A.dZ_dx * B.dZ_dx + A.dZ_dy * B.dZ_dy) / (A.dZ_dGradient * B.dZ_dGradient)) / ds;
//this.Affinity = 1.0/ds;
}
public ContourVertex(IsoContours Parent)
{
this.Parent = Parent;
}