C# Orbit.NextClosestApproachTime方法代码示例

        public override ManeuverParameters MakeNodeImpl(Orbit o, double UT, MechJebModuleTargetController target)
        {
            if (!target.NormalTargetExists)
                throw new OperationException("must select a target for the course correction.");

            Orbit correctionPatch = o;
            while (correctionPatch != null)
            {
                if (correctionPatch.referenceBody == target.TargetOrbit.referenceBody)
                {
                    o = correctionPatch;
                    UT = correctionPatch.StartUT;
                    break;
                }
                correctionPatch = target.core.vessel.GetNextPatch(correctionPatch);
            }

            if (correctionPatch == null || correctionPatch.referenceBody != target.TargetOrbit.referenceBody)
                throw new OperationException("target for course correction must be in the same sphere of influence");

            if (o.NextClosestApproachTime(target.TargetOrbit, UT) < UT + 1 ||
                    o.NextClosestApproachDistance(target.TargetOrbit, UT) > target.TargetOrbit.semiMajorAxis * 0.2)
            {
                errorMessage = "Warning: orbit before course correction doesn't seem to approach target very closely. Planned course correction may be extreme. Recommend plotting an approximate intercept orbit and then plotting a course correction.";
            }

            CelestialBody targetBody = target.Target as CelestialBody;
            Vector3d dV = targetBody != null ?
                OrbitalManeuverCalculator.DeltaVAndTimeForCheapestCourseCorrection(o, UT, target.TargetOrbit, targetBody, targetBody.Radius + courseCorrectFinalPeA, out UT):
                OrbitalManeuverCalculator.DeltaVAndTimeForCheapestCourseCorrection(o, UT, target.TargetOrbit, interceptDistance, out UT);


            return new ManeuverParameters(dV, UT);
        }

        public static Vector3d DeltaVAndTimeForCheapestCourseCorrection(Orbit o, double UT, Orbit target, out double burnUT)
        {
            double closestApproachTime = o.NextClosestApproachTime(target, UT + 2); //+2 so that closestApproachTime is definitely > UT

            burnUT = UT;
            Vector3d dV = DeltaVToInterceptAtTime(o, burnUT, target, closestApproachTime);

            int fineness = 20;
            for (double step = 0.5; step < fineness; step += 1.0)
            {
                double testUT = UT + (closestApproachTime - UT) * step / fineness;
                Vector3d testDV = DeltaVToInterceptAtTime(o, testUT, target, closestApproachTime);

                if (testDV.magnitude < dV.magnitude)
                {
                    dV = testDV;
                    burnUT = testUT;
                }
            }

            return dV;
        }

 //First finds the time of closest approach to the target during the next orbit after the
 //time UT. Then returns the delta-V of a burn at UT that will change the separation at
 //that closest approach time to zero.
 //This will likely only return sensible results when the given orbit is already an
 //approximate intercept trajectory.
 public static Vector3d DeltaVForCourseCorrection(Orbit o, double UT, Orbit target)
 {
     double closestApproachTime = o.NextClosestApproachTime(target, UT + 1); //+1 so that closestApproachTime is definitely > UT
     Vector3d dV = DeltaVToInterceptAtTime(o, UT, target, closestApproachTime);
     return dV;
 }

        public double ComputeManeuverTime(Orbit o, double UT, MechJebModuleTargetController target)
        {
            switch (allowedTimeRef[currentTimeRef])
            {
            case TimeReference.X_FROM_NOW:
                UT += leadTime.val;
                break;

            case TimeReference.APOAPSIS:
                if (o.eccentricity < 1)
                {
                    UT = o.NextApoapsisTime(UT);
                }
                else
                {
                    throw new OperationException("Warning: orbit is hyperbolic, so apoapsis doesn't exist.");
                }
                break;

            case TimeReference.PERIAPSIS:
                UT = o.NextPeriapsisTime(UT);
                break;

            case TimeReference.CLOSEST_APPROACH:
                if (target.NormalTargetExists)
                {
                    UT = o.NextClosestApproachTime(target.TargetOrbit, UT);
                }
                else
                {
                    throw new OperationException("Warning: no target selected.");
                }
                break;

            case TimeReference.ALTITUDE:
                if (circularizeAltitude > o.PeA && (circularizeAltitude < o.ApA || o.eccentricity >= 1))
                {
                    UT = o.NextTimeOfRadius(UT, o.referenceBody.Radius + circularizeAltitude);
                }
                else
                {
                    throw new OperationException("Warning: can't circularize at this altitude, since current orbit does not reach it.");
                }
                break;

            case TimeReference.EQ_ASCENDING:
                if (o.AscendingNodeEquatorialExists())
                {
                    UT = o.TimeOfAscendingNodeEquatorial(UT);
                }
                else
                {
                    throw new OperationException("Warning: equatorial ascending node doesn't exist.");
                }
                break;

            case TimeReference.EQ_DESCENDING:
                if (o.DescendingNodeEquatorialExists())
                {
                    UT = o.TimeOfDescendingNodeEquatorial(UT);
                }
                else
                {
                    throw new OperationException("Warning: equatorial descending node doesn't exist.");
                }
                break;
            
            case TimeReference.EQ_NEAREST_AD:
                if(o.AscendingNodeEquatorialExists())
                {
                    UT = o.DescendingNodeEquatorialExists()
                        ? System.Math.Min(o.TimeOfAscendingNodeEquatorial(UT), o.TimeOfDescendingNodeEquatorial(UT))
                        : o.TimeOfAscendingNodeEquatorial(UT);
                }
                else if(o.DescendingNodeEquatorialExists())
                {
                    UT = o.TimeOfDescendingNodeEquatorial(UT);
                }
                else
                {
                    throw new OperationException("Warning: neither ascending nor descending node exists.");
                }
                break;

            case TimeReference.EQ_HIGHEST_AD:
                if(o.AscendingNodeEquatorialExists())
                {
                    if(o.DescendingNodeEquatorialExists())
                    {
                        var anTime = o.TimeOfAscendingNodeEquatorial(UT);
                        var dnTime = o.TimeOfDescendingNodeEquatorial(UT);
                        UT = o.getOrbitalVelocityAtUT(anTime).magnitude <= o.getOrbitalVelocityAtUT(dnTime).magnitude
                            ? anTime
                            : dnTime;
                    }
                    else
                    {
                        UT = o.TimeOfAscendingNodeEquatorial(UT);
                    }
                }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                        errorMessage = "target for Hohmann transfer must be in the same sphere of influence.";
                    }
                    else if (o.eccentricity > 1)
                    {
                        error = true;
                        errorMessage = "starting orbit for Hohmann transfer must not be hyperbolic.";
                    }
                    else if (core.target.Orbit.eccentricity > 1)
                    {
                        error = true;
                        errorMessage = "target orbit for Hohmann transfer must not be hyperbolic.";
                    }
                    else if (o.RelativeInclination(core.target.Orbit) > 30 && o.RelativeInclination(core.target.Orbit) < 150)
                    {
                        errorMessage = "Warning: target's orbital plane is at a " + o.RelativeInclination(core.target.Orbit).ToString("F0") + "º angle to starting orbit's plane (recommend at most 30º). Planned transfer may not intercept target properly.";
                    }
                    else if (o.eccentricity > 0.2)
                    {
                        errorMessage = "Warning: Recommend starting Hohmann transfers from a near-circular orbit (eccentricity < 0.2). Planned transfer is starting from an orbit with eccentricity " + o.eccentricity.ToString("F2") + " and so may not intercept target properly.";
                    }
                    break;

                case Operation.COURSE_CORRECTION:
                    if (!core.target.NormalTargetExists)
                    {
                        error = true;
                        errorMessage = "must select a target for the course correction.";
                    }
                    else if (o.referenceBody != core.target.Orbit.referenceBody)
                    {
                        error = true;
                        errorMessage = "target for course correction must be in the same sphere of influence";
                    }
                    else if (o.NextClosestApproachTime(core.target.Orbit, UT) < UT + 1 ||
                        o.NextClosestApproachDistance(core.target.Orbit, UT) > core.target.Orbit.semiMajorAxis * 0.2)
                    {
                        errorMessage = "Warning: orbit before course correction doesn't seem to approach target very closely. Planned course correction may be extreme. Recommend plotting an approximate intercept orbit and then plotting a course correction.";
                    }
                    break;

                case Operation.INTERPLANETARY_TRANSFER:
                    if (!core.target.NormalTargetExists)
                    {
                        error = true;
                        errorMessage = "must select a target for the interplanetary transfer.";
                    }
                    else if (o.referenceBody.referenceBody == null)
                    {
                        error = true;
                        errorMessage = "doesn't make sense to plot an interplanetary transfer from an orbit around " + o.referenceBody.theName + ".";
                    }
                    else if (o.referenceBody.referenceBody != core.target.Orbit.referenceBody)
                    {
                        error = true;
                        if (o.referenceBody == core.target.Orbit.referenceBody) errorMessage = "use regular Hohmann transfer function to intercept another body orbiting " + o.referenceBody.theName + ".";
                        else errorMessage = "an interplanetary transfer from within " + o.referenceBody.theName + "'s sphere of influence must target a body that orbits " + o.referenceBody.theName + "'s parent, " + o.referenceBody.referenceBody.theName + ".";
                    }
                    else if (o.referenceBody.orbit.RelativeInclination(core.target.Orbit) > 30)
                    {
                        errorMessage = "Warning: target's orbital plane is at a " + o.RelativeInclination(core.target.Orbit).ToString("F0") + "º angle to " + o.referenceBody.theName + "'s orbital plane (recommend at most 30º). Planned interplanetary transfer may not intercept target properly.";
                    }
                    else
                    {
                        double relativeInclination = Vector3d.Angle(o.SwappedOrbitNormal(), o.referenceBody.orbit.SwappedOrbitNormal());
                        if (relativeInclination > 10)
                        {