/// <summary>
/// Get the distance which when added to camera position along the lookat direction will do the effect of zoom to extents (zoom to fit) operation,
/// so all the passed points will fit in the current view.
/// if the returned value is positive, the camera will move toward the lookat direction (ZoomIn).
/// if the returned value is negative, the camera will move in the reverse direction of the lookat direction (ZoomOut).
/// </summary>
/// <param name="points">The points.</param>
/// <returns>The zoom to fit distance</returns>
public float GetZoomToExtentsShiftDistance(MyVector3[] points)
{
float vAngle = (float)((Math.PI / 2.0 - Math.Acos(MyVector3.Dot(pNear.Normal, pTop.Normal))));
float vSin = (float)Math.Sin(vAngle);
float hAngle = (float)((Math.PI / 2.0 - Math.Acos(MyVector3.Dot(pNear.Normal, pLeft.Normal))));
float hSin = (float)Math.Sin(hAngle);
float horizontalToVerticalMapping = vSin / hSin;
var ioFrustrum = GetInsideOutClone();
float maxPointDist = float.MinValue;
for (int i = 0; i < points.Length; i++)
{
float pointDist = MyCollision.DistancePlanePoint(ref ioFrustrum.pTop, ref points[i]);
pointDist = Math.Max(pointDist, MyCollision.DistancePlanePoint(ref ioFrustrum.pBottom, ref points[i]));
pointDist = Math.Max(pointDist, MyCollision.DistancePlanePoint(ref ioFrustrum.pLeft, ref points[i]) * horizontalToVerticalMapping);
pointDist = Math.Max(pointDist, MyCollision.DistancePlanePoint(ref ioFrustrum.pRight, ref points[i]) * horizontalToVerticalMapping);
maxPointDist = Math.Max(maxPointDist, pointDist);
}
return(-maxPointDist / vSin);
}
