/// <summary> /// calculates, sets and returns DV. /// </summary> /// <param name="parentEntity"></param> /// <returns></returns> public static double CalcDeltaV(Entity parentEntity) { var db = parentEntity.GetDataBlob <NewtonThrustAbilityDB>(); var ft = db.FuelType; var ev = db.ExhaustVelocity; var wetmass = parentEntity.GetDataBlob <MassVolumeDB>().Mass; ProcessedMaterialSD fuel = StaticRefLib.StaticData.CargoGoods.GetMaterials()[ft]; var cargo = parentEntity.GetDataBlob <CargoStorageDB>(); var fuelAmount = StorageSpaceProcessor.GetAmount(cargo, fuel); var dryMass = wetmass - fuelAmount; return(db.DeltaV = OrbitMath.TsiolkovskyRocketEquation(wetmass, dryMass, ev)); }
/// <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>().Mass; 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 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_m; //how much dv needed to complete the manuver. 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. Vector3 totalDVFromThrust = Vector3.Normalise(manuverDV) * deltaVThisStep; //remove the deltaV we're expending from the max (TODO: Remove fuel from cargo, change mass of ship) newtonThrust.DeltaV -= deltaVThisStep; //remove the vectorDV from the amount needed to fully complete the manuver. newtonMoveDB.DeltaVForManuver_m -= totalDVFromThrust; Vector3 totalDV = totalDVFromGrav + totalDVFromThrust; 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>().Mass; 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_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 { 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; }
/// <summary> /// removes fuel and correct amount of DV. /// </summary> /// <param name="fuel">in kg</param> internal void BurnFuel(double fuel) { TotalFuel_kg -= fuel; DeltaV = OrbitMath.TsiolkovskyRocketEquation(TotalFuel_kg, DryMass_kg, ExhaustVelocity); }