public CometOrbit(Comet comet, int division)
{
this.Division = division;
Orbit = new Xyz[division + 1];
if (comet.e < 1.0 - TOLERANCE)
{
GetOrbitEllip(comet);
}
else if (comet.e > 1.0 + TOLERANCE)
{
GetOrbitHyper(comet);
}
else
{
GetOrbitPara(comet);
}
Matrix vec = comet.VectorConstant;
Matrix prec = Matrix.PrecMatrix(comet.EquinoxJD, Astro.JD2000);
for (int i = 0; i <= division; i++)
{
Orbit[i] = Orbit[i].Rotate(vec).Rotate(prec);
}
}
public void LoadPanel(Comet comet, ATime atime)
{
Comet = comet;
ATime = atime;
ObjectOrbit = new CometOrbit(Comet, 1000);
UpdatePositions(atime);
UpdatePlanetOrbit(atime);
UpdateRotationMatrix(atime);
}
private void UpdatePositions(ATime atime)
{
if (PaintEnabled)
{
ObjectPos = Comet.GetPos(atime.JD);
for (int i = 0; i < 9; i++)
{
PlanetPos[i] = Planet.GetPos(Planet.MERCURY + i, atime);
}
}
}
/// <summary>
/// Parabolic Orbit
/// </summary>
/// <param name="comet"></param>
private void GetOrbitPara(Comet comet)
{
int idx1, idx2;
idx1 = idx2 = this.Division / 2;
double dV = (Math.Atan(Math.Sqrt(MAXORBIT / comet.q - 1.0)) * 2.0) / (this.Division / 2);
double V = 0.0;
for (int i = 0; i <= (this.Division / 2); i++, V += dV)
{
double TanV2 = Math.Sin(V / 2.0) / Math.Cos(V / 2.0);
double RCosV = comet.q * (1.0 - TanV2 * TanV2);
double RSinV = 2.0 * comet.q * TanV2;
Orbit[idx1++] = new Xyz(RCosV, RSinV, 0.0);
Orbit[idx2--] = new Xyz(RCosV, -RSinV, 0.0);
}
}
/// <summary>
/// Hyperbolic Orbit
/// </summary>
/// <param name="comet"></param>
private void GetOrbitHyper(Comet comet)
{
int idx1, idx2;
idx1 = idx2 = this.Division / 2;
double t = Math.Sqrt(comet.e * comet.e - 1.0);
double axis = comet.q / (comet.e - 1.0);
double dF = UdMath.arccosh((MAXORBIT + axis) / (axis * comet.e)) / (this.Division / 2);
double F = 0.0;
for (int i = 0; i <= (this.Division / 2); i++, F += dF)
{
double RCosV = axis * (comet.e - UdMath.cosh(F));
double RSinV = axis * t * UdMath.sinh(F);
Orbit[idx1++] = new Xyz(RCosV, RSinV, 0.0);
Orbit[idx2--] = new Xyz(RCosV, -RSinV, 0.0);
}
}
/// <summary>
/// Elliptical Orbit
/// </summary>
/// <param name="comet"></param>
private void GetOrbitEllip(Comet comet)
{
double axis = comet.q / (1.0 - comet.e);
double ae2 = -2.0 * axis * comet.e;
double t = Math.Sqrt(1.0 - comet.e * comet.e);
if (axis * (1.0 + comet.e) > MAXORBIT)
{
double dE = Math.Acos((1.0 - MAXORBIT / axis) / comet.e) / ((this.Division / 2) * (this.Division / 2));
int idx1, idx2;
idx1 = idx2 = this.Division / 2;
for (int i = 0; i <= (this.Division / 2); i++)
{
double E = dE * i * i;
double RCosV = axis * (Math.Cos(E) - comet.e);
double RSinV = axis * t * Math.Sin(E);
Orbit[idx1++] = new Xyz(RCosV, RSinV, 0.0);
Orbit[idx2--] = new Xyz(RCosV, -RSinV, 0.0);
}
}
else
{
int idx1, idx2, idx3, idx4;
idx1 = 0;
idx2 = idx3 = this.Division / 2;
idx4 = this.Division;
double E = 0.0;
for (int i = 0; i <= (this.Division / 4); i++, E += (2.0 * Math.PI / this.Division))
{
double RCosV = axis * (Math.Cos(E) - comet.e);
double RSinV = axis * t * Math.Sin(E);
Orbit[idx1++] = new Xyz(RCosV, RSinV, 0.0);
Orbit[idx2--] = new Xyz(ae2 - RCosV, RSinV, 0.0);
Orbit[idx3++] = new Xyz(ae2 - RCosV, -RSinV, 0.0);
Orbit[idx4--] = new Xyz(RCosV, -RSinV, 0.0);
}
}
}
