/// <summary>
/// Gets the orbit sample points without unnecessary memory alloc for resulting array.
/// However, memory allocation may occur if resulting array has not correct lenght.
/// </summary>
/// <param name="orbitPoints">The orbit points.</param>
/// <param name="pointsCount">The points count.</param>
/// <param name="origin">The origin.</param>
/// <param name="maxDistance">The maximum distance.</param>
public void GetOrbitPointsNoAlloc(ref Vector3d[] orbitPoints, int pointsCount, Vector3d origin, float maxDistance = 1000f)
{
if (pointsCount < 2)
{
orbitPoints = new Vector3d[0];
return;
}
if (Eccentricity < 1)
{
if (orbitPoints == null || orbitPoints.Length != pointsCount)
{
orbitPoints = new Vector3d[pointsCount];
}
if (ApoapsisDistance < maxDistance)
{
for (int i = 0; i < pointsCount; i++)
{
orbitPoints[i] = GetFocalPositionAtEccentricAnomaly(i * KeplerOrbitUtils.PI_2 / (pointsCount - 1d)) + origin;
}
}
else
{
double maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis, PeriapsisDistance);
for (int i = 0; i < pointsCount; i++)
{
orbitPoints[i] = GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
}
else
{
if (maxDistance < PeriapsisDistance)
{
orbitPoints = new Vector3d[0];
return;
}
if (orbitPoints == null || orbitPoints.Length != pointsCount)
{
orbitPoints = new Vector3d[pointsCount];
}
double maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis, PeriapsisDistance);
for (int i = 0; i < pointsCount; i++)
{
orbitPoints[i] = GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
}
/// <summary>
/// Gets orbit sample points with defined precision.
/// </summary>
/// <param name="pointsCount">The points count.</param>
/// <param name="origin">The origin.</param>
/// <param name="maxDistance">The maximum distance.</param>
/// <returns>Array of orbit curve points.</returns>
public Vector3d[] GetOrbitPoints(int pointsCount, Vector3d origin, double maxDistance = 1000d)
{
if (pointsCount < 2)
{
return(new Vector3d[0]);
}
Vector3d[] result = new Vector3d[pointsCount];
if (Eccentricity < 1.0)
{
if (ApoapsisDistance < maxDistance)
{
for (int i = 0; i < pointsCount; i++)
{
result[i] = GetFocalPositionAtEccentricAnomaly(i * KeplerOrbitUtils.PI_2 / (pointsCount - 1d)) + origin;
}
}
else if (Eccentricity > 1.0)
{
double maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis, PeriapsisDistance);
for (int i = 0; i < pointsCount; i++)
{
result[i] = GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
else
{
double maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, PeriapsisDistance, PeriapsisDistance);
for (int i = 0; i < pointsCount; i++)
{
result[i] = GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
}
else
{
if (maxDistance < PeriapsisDistance)
{
return(new Vector3d[0]);
}
double maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis, PeriapsisDistance);
for (int i = 0; i < pointsCount; i++)
{
result[i] = GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
return(result);
}
/// <summary>
/// Gets calculated orbit points with defined precision.
/// </summary>
/// <param name="pointsCount">The points count.</param>
/// <param name="origin">The origin.</param>
/// <param name="maxDistance">The maximum distance.</param>
/// <returns>Array of orbit curve points.</returns>
public Vector3[] GetOrbitPoints(int pointsCount, Vector3 origin, float maxDistance = 1000f)
{
if (pointsCount < 2)
{
return(new Vector3[0]);
}
var result = new Vector3[pointsCount];
if (Eccentricity < 1)
{
if (ApoapsisDistance < maxDistance)
{
for (var i = 0; i < pointsCount; i++)
{
result[i] = (Vector3)GetFocalPositionAtEccentricAnomaly(i * KeplerOrbitUtils.PI_2 / (pointsCount - 1d)) + origin;
}
}
else
{
var maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis);
for (int i = 0; i < pointsCount; i++)
{
result[i] = (Vector3)GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
}
else
{
if (maxDistance < PeriapsisDistance)
{
return(new Vector3[0]);
}
var maxAngle = KeplerOrbitUtils.CalcTrueAnomalyForDistance(maxDistance, Eccentricity, SemiMajorAxis);
for (int i = 0; i < pointsCount; i++)
{
result[i] = (Vector3)GetFocalPositionAtTrueAnomaly(-maxAngle + i * 2d * maxAngle / (pointsCount - 1)) + origin;
}
}
return(result);
}
