private void initOrbitPosition(OrbitingEntity entity)
{
if (entity.Parent != null)
{
entity.OrbitalPeriod = EnviroUtilities.Period(entity.SemiMajorAxis, entity.Mass);
entity.LongitudeOfApogee = rnd.NextDouble(0.0, 2 * Math.PI);
entity.TimeSinceApogee = Convert.ToInt64(rnd.NextDouble(0.0, entity.OrbitalPeriod * Constants.Units.SECONDS_PER_HOUR * 24.0));
}
}
private void CalculateGases(Planet planet)
{
if (planet.SurfacePressure > 0)
{
//var amounts = new List<double>();
double totamount = 0;
var pressure = planet.SurfacePressure / Constants.Units.MILLIBARS_PER_BAR;
//bool gasesExist = false;
// create some working vars:
double yp = 0.0;
double amount = 0.0;
foreach (Molecule gas in Constants.Gases.GasLookup.Values)
//for (int i = 0; i < ElementalTable.Instance.Count; i++)
{
yp = gas.BoilingPoint /
(373.0 * ((Math.Log((pressure) + 0.001) / -5050.5) + (1.0 / 373.0)));
if ((yp >= 0 && yp < planet.LowTemperature) && (gas.AtomicWeight >= planet.MolecularWeightRetained))
{
var vrms = EnviroUtilities.RootMeanSquareVelocity(gas.AtomicWeight, planet.ExoSphericTemperature);
var pvrms = Math.Pow(1 / (1 + vrms / planet.EscapeVelocity), planet.Primary.Age / 1e9);
var abund = gas.AbundanceS; /* gases[i].abunde */
var react = 1.0D;
var fract = 1.0D;
var pres2 = 1.0D;
if (gas.Symbol == "Ar")
{
react = .15 * planet.Primary.Age / 4e9;
}
else if (gas.Symbol == "He")
{
abund = abund * (0.001 + (planet.MassOfGas / planet.Mass));
pres2 = (0.75 + pressure);
react = Math.Pow(1 / (1 + gas.Reactivity), planet.Primary.Age / 2e9 * pres2);
}
else if (((gas.Symbol == "O") || (gas.Symbol == "O2")) && (planet.Primary.Age > 2e9) && (planet.SurfaceTemperature > 270 && planet.SurfaceTemperature < 400))
{
/* pres2 = (0.65 + pressure/2); Breathable - M: .55-1.4 */
pres2 = (0.89 + pressure / 4); /* Breathable - M: .6 -1.8 */
react = Math.Pow(1 / (1 + gas.Reactivity), Math.Pow(planet.Primary.Age / 2e9, 0.25) * pres2);
}
else if ((gas.Symbol == "CO2") && (planet.Primary.Age > 2e9) && (planet.SurfaceTemperature > 270 && planet.SurfaceTemperature < 400))
{
pres2 = (0.75 + pressure);
react = Math.Pow(1 / (1 + gas.Reactivity), Math.Pow(planet.Primary.Age / 2e9, 0.5) * pres2);
react *= 1.5;
}
else
{
pres2 = (0.75 + pressure);
react = Math.Pow(1 / (1 + gas.Reactivity), planet.Primary.Age / 2e9 * pres2);
}
fract = (1 - (planet.MolecularWeightRetained / gas.AtomicWeight));
amount = abund * pvrms * react * fract;
totamount += amount;
if (amount > 0.0)
{
if (planet.Gases == null)
{
planet.Gases = new BindingList <Gas>();
}
planet.Gases.Add(new Gas()
{
MoleculeId = gas.Id,
SurfacePressure = planet.SurfacePressure * amount
});
}
}
}
if (planet.Gases != null)
{
foreach (Gas gas in planet.Gases)
{
gas.SurfacePressure /= totamount;
}
}
}
}
private bool GeneratePlanet(Planet planet)
{
planet.SurfaceTemperature = 0;
planet.HighTemperature = 0;
planet.LowTemperature = 0;
planet.MaxTemperature = 0;
planet.MinTemperature = 0;
planet.RiseInTemperatureDueToGreenhouse = 0;
planet.IsInResonantRotation = false;
planet.OrbitZone = EnviroUtilities.OrbitalZone(planet.Primary.Luminosity, planet.SolarSemiMajorAxis);
planet.AxialTilt = Inclination(planet.SolarSemiMajorAxis);
initOrbitPosition(planet);
planet.ExoSphericTemperature = Constants.Sol.Earth.EXOSPHERE_TEMP / Math.Pow(planet.SolarSemiMajorAxis / planet.Primary.EcoSphereRadius, 2.0);
planet.RootMeanSquaredVelocity = EnviroUtilities.RootMeanSquareVelocity(Constants.Gases.MolecularWeights.MOL_NITROGEN, planet.ExoSphericTemperature);
planet.RadiusOfCore = EnviroUtilities.KothariRadius(planet.MassOfDust, false, planet.OrbitZone);
// Calculate the radius as a gas giant, to verify it will retain gas.
// Then if mass > Earth, it's at least 5% gas and retains He, it's
// some flavor of gas giant.
planet.Density = EnviroUtilities.EmpiricalDensity(planet.Mass, planet.SolarSemiMajorAxis, planet.Primary.EcoSphereRadius, true);
planet.Radius = EnviroUtilities.VolumeRadius(planet.Mass, planet.Density);
planet.SurfaceAcceleration = EnviroUtilities.Acceleration(planet.Mass, planet.Radius);
planet.SurfaceGravity = EnviroUtilities.Gravity(planet.SurfaceAcceleration);
planet.MolecularWeightRetained = EnviroUtilities.MinMolecWeight(planet);
if (((planet.Mass * Constants.Sol.Sun.MASS_IN_EARTH_MASSES) > 1.0) &&
((planet.MassOfGas / planet.Mass) > 0.05) &&
(EnviroUtilities.MinMolecWeight(planet) <= 4.0))
{
if ((planet.MassOfGas / planet.Mass) < 0.20)
{
planet.PlanetType = PlanetTypes.GasDwarf;
}
else if ((planet.Mass * Constants.Sol.Sun.MASS_IN_EARTH_MASSES) < 20.0)
{
planet.PlanetType = PlanetTypes.IceGiant;
}
else
{
planet.PlanetType = PlanetTypes.GasGiant;
}
}
else // If not, it's rocky.
{
planet.Radius = EnviroUtilities.KothariRadius(planet.Mass, true, planet.OrbitZone);
planet.Density = EnviroUtilities.VolumeDensity(planet.Mass, planet.Radius);
if ((planet.MassOfGas / planet.Mass) > 0.000001)
{
double h2Mass = planet.MassOfGas * 0.85;
double heMass = (planet.MassOfGas - h2Mass) * 0.999;
double h2Life = EnviroUtilities.GasLife(Constants.Gases.MolecularWeights.MOL_HYDROGEN, planet);
double heLife = EnviroUtilities.GasLife(Constants.Gases.MolecularWeights.HELIUM, planet);
if (h2Life < planet.Primary.Age)
{
var h2Loss = ((1.0 - (1.0 / Math.Exp(planet.Primary.Age / h2Life))) * h2Mass);
planet.MassOfGas -= h2Loss;
//planet.Mass -= h2Loss;
//Mass of planet changed so recalculate
planet.SurfaceAcceleration = EnviroUtilities.Acceleration(planet.Mass, planet.Radius);
planet.SurfaceGravity = EnviroUtilities.Gravity(planet.SurfaceAcceleration);
}
if (heLife < planet.Primary.Age)
{
var heLoss = ((1.0 - (1.0 / Math.Exp(planet.Primary.Age / heLife))) * heMass);
planet.MassOfGas -= heLoss;
//planet.Mass -= heLoss;
//Mass of planet changed so recalculate
planet.SurfaceAcceleration = EnviroUtilities.Acceleration(planet.Mass, planet.Radius);
planet.SurfaceGravity = EnviroUtilities.Gravity(planet.SurfaceAcceleration);
}
}
}
planet.LengthOfDay = EnviroUtilities.DayLength(planet); /* Modifies planet->resonant_period */
planet.EscapeVelocity = EnviroUtilities.EscapeVel(planet.Mass, planet.Radius);
planet.MolecularWeightRetained = EnviroUtilities.MinMolecWeight(planet);
if ((planet.PlanetType == PlanetTypes.GasGiant) || (planet.PlanetType == PlanetTypes.IceGiant) || (planet.PlanetType == PlanetTypes.GasDwarf))
{
planet.HasGreenhouseEffect = false;
planet.VolatileGasInventory = Constants.Units.INCREDIBLY_LARGE_NUMBER;
planet.SurfacePressure = Constants.Units.INCREDIBLY_LARGE_NUMBER;
planet.BoilingPoint = Constants.Units.INCREDIBLY_LARGE_NUMBER;
planet.SurfaceTemperature = Constants.Units.INCREDIBLY_LARGE_NUMBER;
planet.RiseInTemperatureDueToGreenhouse = 0;
planet.Albedo = rnd.About(Constants.Units.GAS_GIANT_ALBEDO, 0.1);
planet.HydrosphereCover = 1.0;
planet.CloudCover = 1.0;
planet.IceCover = 0.0;
planet.SurfaceGravity = Constants.Units.INCREDIBLY_LARGE_NUMBER;
planet.EstimatedTemperature = EnviroUtilities.EstTemp(planet.Primary.EcoSphereRadius, planet.SolarSemiMajorAxis, planet.Albedo);
planet.EstimatedTerrestrialTemperature = EnviroUtilities.EstTemp(planet.Primary.EcoSphereRadius, planet.SolarSemiMajorAxis, Constants.Sol.Earth.ALBEDO);
}
else
{
planet.EstimatedTemperature = EnviroUtilities.EstTemp(planet.Primary.EcoSphereRadius, planet.SolarSemiMajorAxis, Constants.Sol.Earth.ALBEDO);
planet.SurfaceGravity = EnviroUtilities.Gravity(planet.SurfaceAcceleration);
planet.HasGreenhouseEffect = EnviroUtilities.Greenhouse(planet.Primary.EcoSphereRadius, planet.SolarSemiMajorAxis);
planet.VolatileGasInventory = EnviroUtilities.VolInventory(planet.Mass, planet.EscapeVelocity, planet.RootMeanSquaredVelocity,
planet.Primary.Mass, planet.OrbitZone, planet.HasGreenhouseEffect,
(planet.MassOfGas / planet.Mass) > 0.000001);
planet.SurfacePressure = EnviroUtilities.Pressure(planet.VolatileGasInventory, planet.Radius, planet.SurfaceGravity);
if (planet.SurfacePressure == 0.0D)
{
planet.BoilingPoint = 0.0;
}
else
{
planet.BoilingPoint = EnviroUtilities.BoilingPoint(planet.SurfacePressure);
}
EnviroUtilities.IterateSurfaceTemp(planet);
if ((planet.MaxTemperature >= Constants.Sol.Earth.FREEZING_POINT_OF_WATER) && (planet.MinTemperature <= planet.BoilingPoint))
{
CalculateGases(planet);
}
/*
* Next we assign a type to the planet.
*/
if (planet.SurfacePressure < 1.0)
{
if (!planet.IsMoon && ((planet.Mass * Constants.Sol.Sun.MASS_IN_EARTH_MASSES) < Constants.Stargen.ASTEROID_MASS_LIMIT))
{
planet.PlanetType = PlanetTypes.Asteroid;
}
else
{
planet.PlanetType = PlanetTypes.Rock;
}
}
else if ((planet.SurfacePressure > 6000.0) && (planet.MolecularWeightRetained <= 2.0)) // Retains Hydrogen
{
planet.PlanetType = PlanetTypes.GasDwarf;
planet.Gases.Clear(); //TODO: Do we really want to clear the atmosphere just because it is a gas dwarf?
}
else
{ // Atmospheres:
//if (((int)planet.Day == (int)(planet.OrbitalPeriod * 24.0) || (planet.IsInResonantRotation)))
// planet.PlanetType = PlanetTypes.Face;
//else
if (planet.HydrosphereCover >= 0.95)
{
planet.PlanetType = PlanetTypes.Water; // >95% water
}
else if (planet.IceCover >= 0.95)
{
planet.PlanetType = PlanetTypes.Ice; // >95% ice
}
else if (planet.HydrosphereCover > 0.05)
{
planet.PlanetType = PlanetTypes.Terrestrial; // Terrestrial
// else <5% water
}
else if (planet.MaxTemperature > planet.BoilingPoint)
{
planet.PlanetType = PlanetTypes.Venusian; // Hot = Venusian
}
else if ((planet.MassOfGas / planet.Mass) > 0.0001)
{
// Accreted gas, But no Greenhouse, or liquid water, Make it an Ice World
planet.PlanetType = PlanetTypes.Ice;
planet.IceCover = 1.0;
}
else if (planet.SurfacePressure <= 250.0)
{
// Thin air = Martian
planet.PlanetType = PlanetTypes.Martian;
}
else if (planet.SurfaceTemperature < Constants.Sol.Earth.FREEZING_POINT_OF_WATER)
{
planet.PlanetType = PlanetTypes.Ice;
}
else
{
planet.PlanetType = PlanetTypes.Unknown;
}
}
}
if (_generateMoons && !planet.IsMoon)
{
if (planet.Moons != null)
{
// Sort moons
planet.Moons = new BindingList <Planet>(planet.Moons.OrderBy(x => x.SemiMajorAxis).ToList());
// Create a copy of the moons list
var moonList = planet.Moons.ToList();
var count = 0;
var hillSphere = planet.SemiMajorAxis * (1.0 - planet.Eccentricity) * Constants.Units.KM_PER_AU * Math.Pow((planet.Mass / (3.0 * planet.Primary.Mass)), (1.0 / 3.0)) / Constants.Units.KM_PER_AU;
for (int n = 0; n < moonList.Count; n++)
{
bool pass = true;
var moon = moonList[n];
if (moon.Mass * Constants.Sol.Sun.MASS_IN_EARTH_MASSES > .000001)
{
//moon.SemiMajorAxis = planet.SemiMajorAxis;
//moon.Eccentricity = planet.Eccentricity;
moon.Id = Guid.NewGuid();
moon.Name = string.Format("{0}.{1}", planet.Name, count + 1);
moon.Primary = planet.Primary;
GeneratePlanet(moon);
//TODO: Look at adding atmosphere call to this
var rocheLimit = 2.44 * planet.Radius * Math.Pow((planet.Density / moon.Density), (1.0 / 3.0)) / Constants.Units.KM_PER_AU;
//if ((rocheLimit * 3.0) < hillSphere)
if (moon.SemiMajorAxis < rocheLimit)
{
// Moon too close.
// TODO: Turn moon into rings
planet.Moons.Remove(moon);
pass = false;
//return false;
//#if LOG4NET_ENABLED
//logger.Debug(string.Format("Moon of planet {0} inside Roche limit", planet.Name));
//#endif
}
if (moon.SemiMajorAxis > hillSphere)
{
// Moon too far
planet.Moons.Remove(moon);
pass = false;
//return false;
//#if LOG4NET_ENABLED
//logger.Debug(string.Format("Moon of planet {0} outside hill radius", planet.Name));
//#endif
}
}
else
{
// Moon too small
planet.Moons.Remove(moon);
pass = false;
//return false;
//#if LOG4NET_ENABLED
//logger.Debug(string.Format("Moon of planet {0} too small", planet.Name));
//#endif
}
if (pass)
{
count++;
}
}
}
}
return(true);
}