Added Quaternion constructors, SetFrom(AxisAngle)

include/J3ML/LinearAlgebra/Quaternion.h

@@ -38,10 +38,13 @@ namespace J3ML::LinearAlgebra
         //void Inverse();
 
         explicit Quaternion(Vector4 vector4);
+        explicit Quaternion(const EulerAngle& angle);
+        explicit Quaternion(const AxisAngle& angle);
 
         void SetFromAxisAngle(const Vector3 &vector3, float between);
 
         void SetFromAxisAngle(const Vector4 &vector4, float between);
+        void SetFrom(const AxisAngle& angle);
 
         Quaternion Inverse() const;
 
@@ -58,6 +61,22 @@ namespace J3ML::LinearAlgebra
 
         float GetAngle() const;
 
+        EulerAngle ToEulerAngle() const
+        {
+            // roll (x-axis rotation)
+            double sinr_cosp = 2 * (w * x + y * z);
+            double cosr_cosp = 1 - 2 * (x * x + y * y);
+
+            // pitch (y-axis rotation)
+            double sinp = std::sqrt(1 + 2 * (w * y - x * z));
+            double
+
+            return {
+                .roll = std::atan2(sinr_cosp, cosr_cosp),
+                .pitch =
+            };
+        }
+
 
         Matrix3x3 ToMatrix3x3() const;