public void KeplerVsTimeOfFlight()
{
// Need to make sure TOF < 1 period
const float mass = 100f;
GameObject star = TestSetupUtils.CreateNBody(mass, new Vector3(0, 0, 0));
NBody starNbody = star.GetComponent <NBody>();
const float orbitRadius = 10f;
GameObject planet = TestSetupUtils.CreatePlanetInOrbitUniversal(starNbody, 1f, orbitRadius);
OrbitUniversal orbitU = planet.GetComponent <OrbitUniversal>();
// Parabola (ecc=1.0 fails, need to investigate)
float[] ecc_values = { 0.0f, 0.1f, 0.5f, 0.9f, 1.2f, 1.5f };
foreach (float ecc in ecc_values)
{
Debug.LogFormat("======= ecc={0} =======", ecc);
orbitU.eccentricity = ecc;
orbitU.p = 10f;
orbitU.evolveMode = OrbitUniversal.EvolveMode.KEPLERS_EQN;
// Evolve to position r1
double time = 5.0;
TestSetupUtils.SetupGravityEngine(star, planet);
double[] r1 = new double[] { 0, 0, 0 };
// orbitU.PreEvolve(pscale, mscale);
// Ugh. Need to do this before call evolve, since it caches the value.
Vector3d r0_vec = GravityEngine.Instance().GetPositionDoubleV3(planet.GetComponent <NBody>());
orbitU.Evolve(time, ref r1);
Vector3d r1_vec = new Vector3d(ref r1);
// check time to r1
double time_test = orbitU.TimeOfFlight(r0_vec, r1_vec);
Debug.LogFormat("check r0={0} to r1={1} p ={2} after t={3} TOF => {4}",
r0_vec, r1_vec, orbitU.p, time, time_test);
Assert.IsTrue(GEUnit.DoubleEqual(time, time_test, 1E-4));
}
}