From c53ef04da896b01e71840c0f511514975d1289fa Mon Sep 17 00:00:00 2001
From: Oliver Booth <me@olivr.me>
Date: Tue, 6 Dec 2022 13:28:49 +0000
Subject: [PATCH] 0 axis and +inf angle if resulting axis is NaN

---
 .../Entities/VirtualParadiseObjectBuilder.cs  |  6 +++
 VpSharp/src/Vector3d.cs                       | 42 ++++++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/VpSharp/src/Entities/VirtualParadiseObjectBuilder.cs b/VpSharp/src/Entities/VirtualParadiseObjectBuilder.cs
index d5352ec..9e9ba8a 100644
--- a/VpSharp/src/Entities/VirtualParadiseObjectBuilder.cs
+++ b/VpSharp/src/Entities/VirtualParadiseObjectBuilder.cs
@@ -186,6 +186,12 @@ public abstract class VirtualParadiseObjectBuilder
         else
         {
             TargetObject.Location.Rotation.ToAxisAngle(out Vector3d axis, out double angle);
+            if (Vector3d.IsNan(axis))
+            {
+                axis = Vector3d.Zero;
+                angle = double.PositiveInfinity;
+            }
+
             _ = vp_double_set(handle, ObjectRotationX, axis.X);
             _ = vp_double_set(handle, ObjectRotationY, axis.Y);
             _ = vp_double_set(handle, ObjectRotationZ, axis.Z);
diff --git a/VpSharp/src/Vector3d.cs b/VpSharp/src/Vector3d.cs
index 64043f1..e6db721 100644
--- a/VpSharp/src/Vector3d.cs
+++ b/VpSharp/src/Vector3d.cs
@@ -394,6 +394,46 @@ public struct Vector3d : IEquatable<Vector3d>, IFormattable
         return new Vector3d(vector.X, vector.Y, vector.Z);
     }
 
+    /// <summary>
+    ///     Returns a value that indicates whether the components in the specified vector are not a number
+    ///     (<see cref="double.NaN" />).
+    /// </summary>
+    /// <param name="vector">A double-precision vector.</param>
+    /// <returns>
+    ///     <see langword="true" /> if the components in <paramref name="vector" /> evaluate to <see cref="double.NaN" />;
+    ///     otherwise, <see langword="false" />.
+    /// </returns>
+    public static bool IsNan(in Vector3d vector)
+    {
+        return double.IsNaN(vector.X) && double.IsNaN(vector.Y) && double.IsNaN(vector.Z);
+    }
+
+    /// <summary>
+    ///     Returns a value that indicates whether the components in the specified vector evaluate to positive infinity.
+    /// </summary>
+    /// <param name="vector">A double-precision vector.</param>
+    /// <returns>
+    ///     <see langword="true" /> if the components in <paramref name="vector" /> evaluate to
+    ///     <see cref="double.PositiveInfinity" />; otherwise, <see langword="false" />.
+    /// </returns>
+    public static bool IsPositiveInfinity(in Vector3d vector)
+    {
+        return double.IsPositiveInfinity(vector.X) && double.IsPositiveInfinity(vector.Y) && double.IsPositiveInfinity(vector.Z);
+    }
+
+    /// <summary>
+    ///     Returns a value that indicates whether the components in the specified vector evaluate to negative infinity.
+    /// </summary>
+    /// <param name="vector">A double-precision vector.</param>
+    /// <returns>
+    ///     <see langword="true" /> if the components in <paramref name="vector" /> evaluate to
+    ///     <see cref="double.NegativeInfinity" />; otherwise, <see langword="false" />.
+    /// </returns>
+    public static bool IsNegativeInfinity(in Vector3d vector)
+    {
+        return double.IsNegativeInfinity(vector.X) && double.IsNegativeInfinity(vector.Y) && double.IsNegativeInfinity(vector.Z);
+    }
+
     /// <summary>
     ///     Linearly interpolates between two vectors based on the given weighting.
     /// </summary>
@@ -401,7 +441,7 @@ public struct Vector3d : IEquatable<Vector3d>, IFormattable
     /// <param name="b">The second source vector.</param>
     /// <param name="t">A value between 0 and 1 indicating the weight of <paramref name="b" />.</param>
     /// <returns>The interpolate vector.</returns>
-    public static Vector3d Lerp(Vector3d a, Vector3d b, double t)
+    public static Vector3d Lerp(in Vector3d a, in Vector3d b, double t)
     {
         Vector3d firstInfluence = a * (1.0f - t);
         Vector3d secondInfluence = b * t;