public KeplerElements GetElements()
{
// if there is not a change in Dv then the kepler elements wont have changed, it might be better to store them?
double myMass = OwningEntity.GetDataBlob <MassVolumeDB>().MassDry;
var sgp = OrbitMath.CalculateStandardGravityParameterInM3S2(myMass, ParentMass);
var pos = OwningEntity.GetDataBlob <PositionDB>().RelativePosition_m;
var dateTime = OwningEntity.StarSysDateTime;
var ke = OrbitMath.KeplerFromPositionAndVelocity(sgp, pos, CurrentVector_ms, dateTime);
return(ke);
}
public static double CalcDVDifference_m(Entity entity1, Entity entity2)
{
double dvDif = 0;
Entity parent;
double parentMass;
double sgp;
double r1;
double r2;
Entity soi1 = Entity.GetSOIParentEntity(entity1);
Entity soi2 = Entity.GetSOIParentEntity(entity2);
if (soi1 == soi2)
{
parent = soi1;
parentMass = parent.GetDataBlob <MassVolumeDB>().MassDry;
sgp = OrbitMath.CalculateStandardGravityParameterInM3S2(0, parentMass);
var state1 = Entity.GetRalitiveState(entity1);
var state2 = Entity.GetRalitiveState(entity2);
r1 = state1.pos.Length();
r2 = state2.pos.Length();
}
else
{
StaticRefLib.EventLog.AddEvent(new Event("Cargo calc failed, entities must have same soi parent"));
return(double.PositiveInfinity);
}
var hohmann = InterceptCalcs.Hohmann(sgp, r1, r2);
return(dvDif = hohmann[0].deltaV.Length() + hohmann[1].deltaV.Length());
}
/// <summary>
/// creates an asteroid that will collide with the given entity on the given date.
/// </summary>
/// <param name="starSys"></param>
/// <param name="target"></param>
/// <param name="collisionDate"></param>
/// <returns></returns>
public static Entity CreateAsteroid(StarSystem starSys, Entity target, DateTime collisionDate, double asteroidMass = -1.0)
{
//todo rand these a bit.
double radius = Distance.KmToAU(0.5);
double mass;
if (asteroidMass < 0)
{
mass = 1.5e+12; //about 1.5 billion tonne
}
else
{
mass = asteroidMass;
}
var speed = 40000;
Vector3 velocity = new Vector3(speed, 0, 0);
var massVolume = MassVolumeDB.NewFromMassAndRadius_AU(mass, radius);
var planetInfo = new SystemBodyInfoDB();
var name = new NameDB("Ellie");
var AsteroidDmg = new AsteroidDamageDB();
AsteroidDmg.FractureChance = new PercentValue(0.75f);
var dmgPfl = EntityDamageProfileDB.AsteroidDamageProfile(massVolume.Volume_km3, massVolume.Density, massVolume.RadiusInM, 50);
var sensorPfil = new SensorProfileDB();
planetInfo.SupportsPopulations = false;
planetInfo.BodyType = BodyType.Asteroid;
Vector3 targetPos = OrbitProcessor.GetAbsolutePosition_m(target.GetDataBlob <OrbitDB>(), collisionDate);
TimeSpan timeToCollision = collisionDate - StaticRefLib.CurrentDateTime;
var parent = target.GetDataBlob <OrbitDB>().Parent;
var parentMass = parent.GetDataBlob <MassVolumeDB>().Mass;
var myMass = massVolume.Mass;
double sgp = OrbitMath.CalculateStandardGravityParameterInM3S2(myMass, parentMass);
OrbitDB orbit = OrbitDB.FromVector(parent, myMass, parentMass, sgp, targetPos, velocity, collisionDate);
var currentpos = OrbitProcessor.GetAbsolutePosition_AU(orbit, StaticRefLib.CurrentDateTime);
var posDB = new PositionDB(currentpos.X, currentpos.Y, currentpos.Z, parent.Manager.ManagerGuid, parent);
var planetDBs = new List <BaseDataBlob>
{
posDB,
massVolume,
planetInfo,
name,
orbit,
AsteroidDmg,
dmgPfl,
sensorPfil
};
Entity newELE = new Entity(starSys, planetDBs);
return(newELE);
}
/// <summary>
/// This was designed so that fast moving objects will get interpolated a lot more than slow moving objects
/// so fast moving objects shouldn't loose positional acuracy when close to a planet,
/// and slow moving objects won't have processor time wasted on them by calulcating too often.
/// However this seems to be unstable and looses energy, unsure why. currently set it to just itterate/interpolate every second.
/// so currently will be using more time to get through this than neccisary.
/// </summary>
/// <param name="entity">Entity.</param>
/// <param name="deltaSeconds">Delta seconds.</param>
public static void NewtonMove(Entity entity, int deltaSeconds)
{
NewtonMoveDB newtonMoveDB = entity.GetDataBlob <NewtonMoveDB>();
NewtonThrustAbilityDB newtonThrust = entity.GetDataBlob <NewtonThrustAbilityDB>();
PositionDB positionDB = entity.GetDataBlob <PositionDB>();
double mass_Kg = entity.GetDataBlob <MassVolumeDB>().MassDry;
double parentMass_kg = newtonMoveDB.ParentMass;
var manager = entity.Manager;
DateTime dateTimeFrom = newtonMoveDB.LastProcessDateTime;
DateTime dateTimeNow = manager.ManagerSubpulses.StarSysDateTime;
DateTime dateTimeFuture = dateTimeNow + TimeSpan.FromSeconds(deltaSeconds);
double deltaT = (dateTimeFuture - dateTimeFrom).TotalSeconds;
double sgp = OrbitMath.CalculateStandardGravityParameterInM3S2(mass_Kg, parentMass_kg);
double secondsToItterate = deltaT;
while (secondsToItterate > 0)
{
//double timeStep = Math.Max(secondsToItterate / speed_kms, 1);
//timeStep = Math.Min(timeStep, secondsToItterate);
double timeStepInSeconds = 1;//because the above seems unstable and looses energy.
double distanceToParent_m = positionDB.GetDistanceTo_m(newtonMoveDB.SOIParent.GetDataBlob <PositionDB>());
distanceToParent_m = Math.Max(distanceToParent_m, 0.1); //don't let the distance be 0 (once collision is in this will likely never happen anyway)
double gravForce = GameConstants.Science.GravitationalConstant * (mass_Kg * parentMass_kg / Math.Pow(distanceToParent_m, 2));
Vector3 gravForceVector = gravForce * -Vector3.Normalise(positionDB.RelativePosition_m);
Vector3 totalDVFromGrav = (gravForceVector / mass_Kg) * timeStepInSeconds;
//double maxAccelFromThrust1 = newtonThrust.ExhaustVelocity * Math.Log(mass_Kg / (mass_Kg - newtonThrust.FuelBurnRate));//per second
//double maxAccelFromThrust = newtonThrust.ThrustInNewtons / mass_Kg; //per second
Vector3 manuverDV = newtonMoveDB.DeltaVForManuver_FoRO_m; //how much dv needed to complete the manuver.
Vector3 totalDVFromThrust = new Vector3(0, 0, 0);
if (manuverDV.Length() > 0)
{
double dryMass = mass_Kg - newtonThrust.FuelBurnRate * timeStepInSeconds; //how much our ship weighs after a timestep of fuel is used.
//how much dv can we get in this timestep.
double deltaVThisStep = OrbitMath.TsiolkovskyRocketEquation(mass_Kg, dryMass, newtonThrust.ExhaustVelocity);
deltaVThisStep = Math.Min(manuverDV.Length(), deltaVThisStep); //don't use more Dv than what is called for.
deltaVThisStep = Math.Min(newtonThrust.DeltaV, deltaVThisStep); //check we've got the deltaV to spend.
totalDVFromThrust = Vector3.Normalise(manuverDV) * deltaVThisStep;
//remove the deltaV we're expending from the max (TODO: Remove fuel from cargo, change mass of ship)
newtonThrust.BurnDeltaV(deltaVThisStep);
//remove the vectorDV from the amount needed to fully complete the manuver.
newtonMoveDB.DeltaVForManuver_FoRO_m -= totalDVFromThrust;
}
//convert prograde to global frame of reference for thrust direction
Vector3 globalCoordDVFromThrust = OrbitMath.ProgradeToParentVector(sgp, totalDVFromThrust,
positionDB.RelativePosition_m,
newtonMoveDB.CurrentVector_ms);
Vector3 totalDV = totalDVFromGrav + globalCoordDVFromThrust;
Vector3 newVelocity = totalDV + newtonMoveDB.CurrentVector_ms;
newtonMoveDB.CurrentVector_ms = newVelocity;
Vector3 deltaPos = (newtonMoveDB.CurrentVector_ms + newVelocity) / 2 * timeStepInSeconds;
positionDB.RelativePosition_m += deltaPos;
double sOIRadius = OrbitProcessor.GetSOI_m(newtonMoveDB.SOIParent);
if (positionDB.RelativePosition_m.Length() >= sOIRadius)
{
Entity newParent;
Vector3 parentRalitiveVector;
//if our parent is a regular kepler object (normaly this is the case)
if (newtonMoveDB.SOIParent.HasDataBlob <OrbitDB>())
{
var orbitDB = newtonMoveDB.SOIParent.GetDataBlob <OrbitDB>();
newParent = orbitDB.Parent;
var parentVelocity = OrbitProcessor.InstantaneousOrbitalVelocityVector_m(orbitDB, entity.StarSysDateTime);
parentRalitiveVector = newtonMoveDB.CurrentVector_ms + parentVelocity;
}
else //if (newtonMoveDB.SOIParent.HasDataBlob<NewtonMoveDB>())
{ //this will pretty much never happen.
newParent = newtonMoveDB.SOIParent.GetDataBlob <NewtonMoveDB>().SOIParent;
var parentVelocity = newtonMoveDB.SOIParent.GetDataBlob <NewtonMoveDB>().CurrentVector_ms;
parentRalitiveVector = newtonMoveDB.CurrentVector_ms + parentVelocity;
}
parentMass_kg = newParent.GetDataBlob <MassVolumeDB>().MassDry;
Vector3 posRalitiveToNewParent = positionDB.AbsolutePosition_m - newParent.GetDataBlob <PositionDB>().AbsolutePosition_m;
var dateTime = dateTimeNow + TimeSpan.FromSeconds(deltaSeconds - secondsToItterate);
//double sgp = GMath.StandardGravitationalParameter(parentMass_kg + mass_Kg);
var kE = OrbitMath.KeplerFromPositionAndVelocity(sgp, posRalitiveToNewParent, parentRalitiveVector, dateTime);
positionDB.SetParent(newParent);
newtonMoveDB.ParentMass = parentMass_kg;
newtonMoveDB.SOIParent = newParent;
newtonMoveDB.CurrentVector_ms = parentRalitiveVector;
}
if (newtonMoveDB.DeltaVForManuver_FoRO_m.Length() <= 0) //if we've completed the manuver.
{
var dateTime = dateTimeNow + TimeSpan.FromSeconds(deltaSeconds - secondsToItterate);
//double sgp = GMath.StandardGravitationalParameter(parentMass_kg + mass_Kg);
KeplerElements kE = OrbitMath.KeplerFromPositionAndVelocity(sgp, positionDB.RelativePosition_m, newtonMoveDB.CurrentVector_ms, dateTime);
var parentEntity = Entity.GetSOIParentEntity(entity, positionDB);
if (kE.Eccentricity < 1) //if we're going to end up in a regular orbit around our new parent
{
if (entity.HasDataBlob <ProjectileInfoDB>()) //this feels a bit hacky.
{
var newOrbit = OrbitDB.FromKeplerElements(parentEntity, mass_Kg, kE, dateTime);
var fastOrbit = new OrbitUpdateOftenDB(newOrbit);
entity.RemoveDataBlob <NewtonMoveDB>();
entity.SetDataBlob(fastOrbit);
positionDB.SetParent(parentEntity);
var newPos = OrbitProcessor.GetPosition_m(fastOrbit, dateTime);
positionDB.RelativePosition_m = newPos;
}
else
{
var newOrbit = OrbitDB.FromKeplerElements(parentEntity, mass_Kg, kE, dateTime);
entity.RemoveDataBlob <NewtonMoveDB>();
entity.SetDataBlob(newOrbit);
positionDB.SetParent(parentEntity);
var newPos = OrbitProcessor.GetPosition_m(newOrbit, dateTime);
positionDB.RelativePosition_m = newPos;
}
}
break;
}
secondsToItterate -= timeStepInSeconds;
}
newtonMoveDB.LastProcessDateTime = dateTimeFuture;
}