/// <summary> /// Calculates the approximate area of a point on a map projection with the given /// characteristics, by transforming the point and its nearest neighbors to latitude and /// longitude, calculating the midpoints between them, and calculating the area of the /// region enclosed within those midpoints. /// </summary> /// <param name="region">The mapped region.</param> /// <param name="planet">The mapped planet.</param> /// <param name="x">The x coordinate of a point on a map projection, with zero as the /// westernmost point.</param> /// <param name="y">The y coordinate of a point on a map projection, with zero as the /// northernmost point.</param> /// <param name="resolution">The vertical resolution of the projection.</param> /// <param name="options"> /// The map projection options used to generate the map used. /// </param> /// <returns>The area of the given point, in m².</returns> public static HugeNumber GetAreaOfLocalPoint( this SurfaceRegion region, Planetoid planet, int x, int y, int resolution, MapProjectionOptions options) => SurfaceMap.GetAreaOfPointFromRadiusSquared( planet.RadiusSquared, x, y, (int)Math.Floor(resolution * options.AspectRatio), resolution, region.GetProjection(planet, options.EqualArea));
/// <summary> /// Gets the elevation at the given <paramref name="latitude"/> and <paramref /// name="longitude"/>, in meters. /// </summary> /// <param name="region">The mapped region.</param> /// <param name="planet">The mapped planet.</param> /// <param name="elevationMap">An elevation map.</param> /// <param name="latitude">The latitude at which to determine elevation.</param> /// <param name="longitude">The longitude at which to determine elevation.</param> /// <param name="equalArea"> /// If <see langword="true"/> the projection is a cylindrical equal-area projection. /// Otherwise, an equirectangular projection will be used. /// </param> /// <returns> /// The elevation at the given <paramref name="latitude"/> and <paramref name="longitude"/>, /// in meters. Or <see cref="double.NaN"/> if the given <paramref name="latitude"/> and /// <paramref name="longitude"/> are not contained within this region. /// </returns> public static double GetElevationAt( this SurfaceRegion region, Planetoid planet, Image <L16> elevationMap, double latitude, double longitude, bool equalArea = false) => region.IsPositionWithin(planet, latitude, longitude) ? (elevationMap.GetValueFromImage( latitude, longitude, region.GetProjection(planet, equalArea), true) - planet.NormalizedSeaLevel) * planet.MaxElevation : double.NaN;
/// <summary> /// Produces an elevation map projection of this region. /// </summary> /// <param name="region">The mapped region.</param> /// <param name="planet">The planet being mapped.</param> /// <param name="resolution">The vertical resolution of the projection.</param> /// <param name="equalArea"> /// If <see langword="true"/> the projection will be a cylindrical equal-area projection. /// Otherwise, an equirectangular projection will be used. /// </param> /// <returns> /// A projected map of elevation. Pixel luminosity indicates elevation relative to <see /// cref="Planetoid.MaxElevation"/>, with values below the midpoint indicating elevations /// below the mean surface. /// </returns> public static Image <L16> GetElevationMap( this SurfaceRegion region, Planetoid planet, int resolution, bool equalArea = false) => planet.GetElevationMap(resolution, region.GetProjection(planet, equalArea));