/// <summary>
/// Generates a new set of precipitation and snowfall map images.
/// </summary>
/// <param name="planet">The planet being mapped.</param>
/// <param name="winterTemperatures">A winter temperature map.</param>
/// <param name="summerTemperatues">A summer temperature map.</param>
/// <param name="resolution">The vertical resolution.</param>
/// <param name="steps">
/// The number of maps to generate internally (representing evenly spaced "seasons" during a year,
/// starting and ending at the winter solstice in the northern hemisphere).
/// </param>
/// <param name="temperatureProjection">
/// <para>
/// The map projection of the temperature maps. They must be the same.
/// </para>
/// <para>
/// If left <see langword="null"/> an equirectangular projection of the full globe is
/// assumed.
/// </para>
/// </param>
/// <param name="projection">
/// <para>
/// The map projection options used.
/// </para>
/// <para>
/// If left <see langword="null"/> an equirectangular projection of the full globe is
/// produced.
/// </para>
/// </param>
/// <returns>
/// A set of precipitation and snowfall map images. Pixel luminosity indicates
/// precipitation in mm/hr, relative to the <see cref="Atmosphere.MaxPrecipitation"/> of
/// this planet's <see cref="Atmosphere"/>.
/// </returns>
public static (Image <L16>[] precipitationMaps, Image <L16>[] snowfallMaps) GetPrecipitationAndSnowfallMaps(
this Planetoid planet,
Image <L16> winterTemperatures,
Image <L16> summerTemperatues,
int resolution,
int steps,
MapProjectionOptions?temperatureProjection = null,
MapProjectionOptions?projection = null)
{
var options = projection ?? MapProjectionOptions.Default;
var precipitationMaps = new Image <L16> [steps];
var snowMaps = new Image <L16> [steps];
if (planet.Atmosphere.MaxPrecipitation.IsNearlyZero())
{
var xResolution = (int)Math.Floor(resolution * options.AspectRatio);
for (var i = 0; i < steps; i++)
{
precipitationMaps[i] = new Image <L16>(xResolution, resolution);
snowMaps[i] = new Image <L16>(xResolution, resolution);
}
return(precipitationMaps, snowMaps);
}
var noise1 = new FastNoise(planet.Seed4, 1.0, FastNoise.NoiseType.Simplex);
var noise2 = new FastNoise(planet.Seed5, 3.0, FastNoise.NoiseType.SimplexFractal, octaves: 3);
var proportionOfYear = 1f / steps;
var proportionOfYearAtMidpoint = 0f;
var trueAnomaly = planet.WinterSolsticeTrueAnomaly;
var trueAnomalyPerSeason = DoubleConstants.TwoPi / steps;
for (var i = 0; i < steps; i++)
{
var solarDeclination = planet.GetSolarDeclination(trueAnomaly);
(precipitationMaps[i], snowMaps[i]) = SurfaceMapImage.GenerateMapImages(
new[] { winterTemperatures, summerTemperatues },
(lat, lon, temperature) =>
{
var precipitation = planet.GetPrecipitationNoise(
noise1,
noise2,
planet.LatitudeAndLongitudeToDoubleVector(lat, lon),
lat,
Planetoid.GetSeasonalLatitudeFromDeclination(lat, solarDeclination),
temperature * SurfaceMapImage.TemperatureScaleFactor,
out var snow);
return(
precipitation / planet.Atmosphere.MaxPrecipitation,
snow / planet.Atmosphere.MaxSnowfall);
},
/// <summary>
/// Calculates the atmospheric density for the given conditions, in kg/m³.
/// </summary>
/// <param name="planet">The mapped planet.</param>
/// <param name="winterTemperatures">A winter temperature map.</param>
/// <param name="summerTemperatures">A summer temperature map.</param>
/// <param name="proportionOfYear">
/// The proportion of a full year at which the map is to be generated, assuming a year
/// begins and ends at the winter solstice in the northern hemisphere.
/// </param>
/// <param name="latitude">The latitude of the object.</param>
/// <param name="longitude">The longitude of the object.</param>
/// <param name="altitude">The altitude of the object.</param>
/// <param name="surface">
/// If <see langword="true"/> the determination is made for a location
/// on the surface of the planetoid at the given elevation. Otherwise, the calculation is
/// made for an elevation above the surface.
/// </param>
/// <param name="options">The map projection used.</param>
/// <returns>The atmospheric density for the given conditions, in kg/m³.</returns>
public static double GetAtmosphericDensity(
this Planetoid planet,
Image <L16> winterTemperatures,
Image <L16> summerTemperatures,
double proportionOfYear,
double latitude,
double longitude,
double altitude,
bool surface = true,
MapProjectionOptions?options = null)
{
var surfaceTemp = SurfaceMapImage.GetSurfaceTemperature(winterTemperatures, summerTemperatures, proportionOfYear, latitude, longitude, options);
var tempAtElevation = planet.GetTemperatureAtElevation(surfaceTemp, altitude, surface);
return(planet.Atmosphere.GetAtmosphericDensity(planet, tempAtElevation, altitude));
}
/// <summary>
/// Generates an elevation map image for this planet.
/// </summary>
/// <param name="planet">The mapped planet.</param>
/// <param name="resolution">The vertical resolution of the map.</param>
/// <param name="options">
/// <para>
/// The map projection options used.
/// </para>
/// <para>
/// If left <see langword="null"/> an equirectangular projection of the full globe is
/// produced.
/// </para>
/// </param>
/// <returns>An elevation map image for this planet.</returns>
public static Image <L16> GetElevationMap(
this Planetoid planet,
int resolution,
MapProjectionOptions?options = null)
{
if (planet.MaxElevation.IsNearlyZero())
{
return(SurfaceMapImage.GenerateZeroMapImage(resolution, options, true));
}
var noise1 = new FastNoise(planet.Seed1, 0.8, FastNoise.NoiseType.SimplexFractal, octaves: 6);
var noise2 = new FastNoise(planet.Seed2, 0.6, FastNoise.NoiseType.SimplexFractal, FastNoise.FractalType.Billow, octaves: 6);
var noise3 = new FastNoise(planet.Seed3, 1.2, FastNoise.NoiseType.Simplex);
return(SurfaceMapImage.GenerateMapImage(
(lat, lon) => GetElevationNoise(noise1, noise2, noise3, planet.LatitudeAndLongitudeToDoubleVector(lat, lon)),
resolution,
options,
true));
}
public void EarthlikePlanet()
{
// First run to ensure timed runs do not include any one-time initialization costs.
_ = Planetoid.GetPlanetForSunlikeStar(out _);
var stopwatch = new Stopwatch();
stopwatch.Start();
var planet = Planetoid.GetPlanetForSunlikeStar(out _);
stopwatch.Stop();
Assert.IsNotNull(planet);
Console.WriteLine($"Planet generation time: {stopwatch.Elapsed:s'.'FFF} s");
Console.WriteLine($"Radius: {planet!.Shape.ContainingRadius / 1000:N0} km");
Console.WriteLine($"Surface area: {planet!.Shape.ContainingRadius.Square() * HugeNumberConstants.FourPi / 1000000:N0} km²");
stopwatch.Restart();
using (var elevationMap = planet.GetElevationMap(MapResolution))
{
var(winterTemperatureMap, summerTemperatureMap) = planet.GetTemperatureMaps(elevationMap, MapResolution);
var(precipitationMaps, snowfallMaps) = planet
.GetPrecipitationAndSnowfallMaps(winterTemperatureMap, summerTemperatureMap, MapResolution, Seasons);
for (var i = 0; i < snowfallMaps.Length; i++)
{
snowfallMaps[i].Dispose();
}
using var precipitationMap = SurfaceMapImage.AverageImages(precipitationMaps);
for (var i = 0; i < precipitationMaps.Length; i++)
{
precipitationMaps[i].Dispose();
}
_ = new WeatherMaps(
planet,
elevationMap,
winterTemperatureMap,
summerTemperatureMap,
precipitationMap,
MapResolution,
MapProjectionOptions.Default);
winterTemperatureMap.Dispose();
summerTemperatureMap.Dispose();
}
stopwatch.Stop();
Console.WriteLine($"Equirectangular surface map generation time: {stopwatch.Elapsed:s'.'FFF} s");
var projection = new MapProjectionOptions(equalArea: true);
stopwatch.Restart();
using var elevationMapEA = planet.GetElevationMap(MapResolution, projection);
var(winterTemperatureMapEA, summerTemperatureMapEA) = planet.GetTemperatureMaps(elevationMapEA, MapResolution, projection, projection);
using var temperatureMapEA = SurfaceMapImage.AverageImages(winterTemperatureMapEA, summerTemperatureMapEA);
var(precipitationMapsEA, snowfallMapsEA) = planet
.GetPrecipitationAndSnowfallMaps(winterTemperatureMapEA, summerTemperatureMapEA, MapResolution, Seasons, projection, projection);
for (var i = 0; i < snowfallMapsEA.Length; i++)
{
snowfallMapsEA[i].Dispose();
}
using var precipitationMapEA = SurfaceMapImage.AverageImages(precipitationMapsEA);
for (var i = 0; i < precipitationMapsEA.Length; i++)
{
precipitationMapsEA[i].Dispose();
}
var climateMapsEA = new WeatherMaps(
planet,
elevationMapEA,
winterTemperatureMapEA,
summerTemperatureMapEA,
precipitationMapEA,
MapResolution,
projection);
winterTemperatureMapEA.Dispose();
summerTemperatureMapEA.Dispose();
stopwatch.Stop();
Console.WriteLine($"Cylindrical equal-area surface map generation time: {stopwatch.Elapsed:s'.'FFF} s");
var normalizedSeaLevel = planet.SeaLevel / planet.MaxElevation;
var elevationRange = planet.GetElevationRange(elevationMapEA);
var landCoords = 0;
if (planet.Hydrosphere?.IsEmpty == false)
{
for (var x = 0; x < elevationMapEA.Width; x++)
{
for (var y = 0; y < elevationMapEA.Height; y++)
{
var value = (2.0 * elevationMapEA[x, y].PackedValue / ushort.MaxValue) - 1;
if (value - normalizedSeaLevel > 0)
{
landCoords++;
}
}
}
}
var sb = new StringBuilder();
AddTempString(sb, temperatureMapEA);
sb.AppendLine();
AddTerrainString(sb, planet, elevationMapEA, landCoords);
sb.AppendLine();
AddClimateString(sb, elevationMapEA, normalizedSeaLevel, landCoords, climateMapsEA);
sb.AppendLine();
AddPrecipitationString(sb, planet, elevationMapEA, precipitationMapEA, normalizedSeaLevel, landCoords, climateMapsEA);
Console.WriteLine(sb.ToString());
}