Inspector tests

Nerfed.Runtime/Util/MathEx.cs

@@ -1,3 +1,5 @@
+using System.Numerics;
+
 namespace Nerfed.Runtime;
 
 public static class MathEx
@@ -17,4 +19,51 @@ public static class MathEx
     public static float Remap(float value, float oldMin, float oldMax, float newMin, float newMax) {
         return (value - oldMin) / (oldMax - oldMin) * (newMax - newMin) + newMin;
     }
-}
+    
+    // https://stackoverflow.com/questions/70462758/c-sharp-how-to-convert-quaternions-to-euler-angles-xyz
+    public static Quaternion ToQuaternion(Vector3 v)
+    {
+        float cy = (float)Math.Cos(v.Z * 0.5);
+        float sy = (float)Math.Sin(v.Z * 0.5);
+        float cp = (float)Math.Cos(v.Y * 0.5);
+        float sp = (float)Math.Sin(v.Y * 0.5);
+        float cr = (float)Math.Cos(v.X * 0.5);
+        float sr = (float)Math.Sin(v.X * 0.5);
+
+        return new Quaternion
+        {
+            W = (cr * cp * cy + sr * sp * sy),
+            X = (sr * cp * cy - cr * sp * sy),
+            Y = (cr * sp * cy + sr * cp * sy),
+            Z = (cr * cp * sy - sr * sp * cy),
+        };
+    }
+
+    public static Vector3 ToEulerAngles(Quaternion q)
+    {
+        Vector3 angles = new();
+
+        // roll / x
+        double sinrCosp = 2 * (q.W * q.X + q.Y * q.Z);
+        double cosrCosp = 1 - 2 * (q.X * q.X + q.Y * q.Y);
+        angles.X = (float)Math.Atan2(sinrCosp, cosrCosp);
+
+        // pitch / y
+        double sinp = 2 * (q.W * q.Y - q.Z * q.X);
+        if (Math.Abs(sinp) >= 1)
+        {
+            angles.Y = (float)Math.CopySign(Math.PI / 2, sinp);
+        }
+        else
+        {
+            angles.Y = (float)Math.Asin(sinp);
+        }
+
+        // yaw / z
+        double sinyCosp = 2 * (q.W * q.Z + q.X * q.Y);
+        double cosyCosp = 1 - 2 * (q.Y * q.Y + q.Z * q.Z);
+        angles.Z = (float)Math.Atan2(sinyCosp, cosyCosp);
+
+        return angles;
+    }
+}