new-horizons/NewHorizons/External/Modules/OrbitModule.cs

using System.ComponentModel;
using NewHorizons.Components.Orbital;
using NewHorizons.Utility;

namespace NewHorizons.External.Modules
{
    public class OrbitModule : IOrbitalParameters
    {
        /// <summary>
        /// The name of the body this one will orbit around
        /// </summary>
        public string PrimaryBody { get; set; }

        /// <summary>
        /// Is this the moon of a planet? Used for determining when its name is shown on the map.
        /// </summary>
        public bool IsMoon { get; set; }

        /// <summary>
        /// The angle between the normal to the orbital plane and its axis of rotation.
        /// </summary>
        public float AxialTilt { get; set; }

        /// <summary>
        /// Rotation period in minutes.
        /// </summary>
        public float SiderealPeriod { get; set; }

        /// <summary>
        /// Should the body always have one side facing its primary?
        /// </summary>
        public bool IsTidallyLocked { get; set; }

        /// <summary>
        /// If it is tidally locked, this direction will face towards the primary. Ex: Interloper uses `0, -1, 0`. Most planets
        /// will want something like `-1, 0, 0`.
        /// </summary>
        public MVector3 AlignmentAxis { get; set; }

        /// <summary>
        /// Referring to the orbit line in the map screen.
        /// </summary>
        [DefaultValue(true)]
        public bool ShowOrbitLine { get; set; } = true;

        /// <summary>
        /// Should the orbit line be dotted?
        /// </summary>
        public bool DottedOrbitLine { get; set; } = false;

        /// <summary>
        /// Is the body meant to stay in one place without moving?
        /// </summary>
        public bool IsStatic { get; set; }

        /// <summary>
        /// Colour of the orbit-line in the map view.
        /// </summary>
        public MColor Tint { get; set; }

        /// <summary>
        /// Should we just draw a line behind its orbit instead of the entire circle/ellipse?
        /// </summary>
        public bool TrackingOrbitLine { get; set; }

        /// <summary>
        /// The semi-major axis of the ellipse that is the body's orbit. For a circular orbit this is the radius.
        /// </summary>
        public float SemiMajorAxis { get; set; }

        /// <summary>
        /// The angle (in degrees) between the body's orbit and the plane of the star system
        /// </summary>
        public float Inclination { get; set; }

        /// <summary>
        /// An angle (in degrees) defining the point where the orbit of the body rises above the orbital plane if it has
        /// nonzero inclination.
        /// </summary>
        public float LongitudeOfAscendingNode { get; set; }

        /// <summary>
        /// At 0 the orbit is a circle. The closer to 1 it is, the more oval-shaped the orbit is.
        /// </summary>
        // FIXME: Needs Min & Max!
        public float Eccentricity { get; set; }

        /// <summary>
        /// An angle (in degrees) defining the location of the periapsis (the closest distance to it's primary body) if it has
        /// nonzero eccentricity.
        /// </summary>
        public float ArgumentOfPeriapsis { get; set; }

        /// <summary>
        /// Where the planet should start off in its orbit in terms of the central angle.
        /// </summary>
        public float TrueAnomaly { get; set; }

        public OrbitalParameters GetOrbitalParameters(Gravity primaryGravity, Gravity secondaryGravity)
        {
            return OrbitalParameters.FromTrueAnomaly(primaryGravity, secondaryGravity, Eccentricity, SemiMajorAxis,
                Inclination, ArgumentOfPeriapsis, LongitudeOfAscendingNode, TrueAnomaly);
        }
    }
}