2 files changed, 23 insertions, 0 deletions
diff --git a/Source/Core/Common/Matrix.cpp b/Source/Core/Common/Matrix.cpp
index 7efac12f78..9581a5a4ce 100644
--- a/Source/Core/Common/Matrix.cpp
+++ b/Source/Core/Common/Matrix.cpp
@@ -84,6 +84,23 @@ Matrix33 Matrix33::RotateZ(float rad)
   return mtx;
 }
 
+Matrix33 Matrix33::Rotate(float rad, const Vec3& axis)
+{
+  const float s = std::sin(rad);
+  const float c = std::cos(rad);
+  Matrix33 mtx;
+  mtx.data[0] = axis.x * axis.x * (1 - c) + c;
+  mtx.data[1] = axis.x * axis.y * (1 - c) - axis.z * s;
+  mtx.data[2] = axis.x * axis.z * (1 - c) + axis.y * s;
+  mtx.data[3] = axis.y * axis.x * (1 - c) + axis.z * s;
+  mtx.data[4] = axis.y * axis.y * (1 - c) + c;
+  mtx.data[5] = axis.y * axis.z * (1 - c) - axis.x * s;
+  mtx.data[6] = axis.z * axis.x * (1 - c) - axis.y * s;
+  mtx.data[7] = axis.z * axis.y * (1 - c) + axis.x * s;
+  mtx.data[8] = axis.z * axis.z * (1 - c) + c;
+  return mtx;
+}
+
 Matrix33 Matrix33::Scale(const Vec3& vec)
 {
   Matrix33 mtx = {};
diff --git a/Source/Core/Common/Matrix.h b/Source/Core/Common/Matrix.h
index bf23963b3d..ed58abdccb 100644
--- a/Source/Core/Common/Matrix.h
+++ b/Source/Core/Common/Matrix.h
@@ -20,6 +20,10 @@ union TVec3
   TVec3() = default;
   TVec3(T _x, T _y, T _z) : data{_x, _y, _z} {}
 
+  TVec3 Cross(const TVec3& rhs) const
+  {
+    return {(y * rhs.z) - (rhs.y * z), (z * rhs.x) - (rhs.z * x), (x * rhs.y) - (rhs.x * y)};
+  }
   T Dot(const TVec3& other) const { return x * other.x + y * other.y + z * other.z; }
   T LengthSquared() const { return Dot(*this); }
   T Length() const { return std::sqrt(LengthSquared()); }
@@ -275,6 +279,8 @@ public:
   static Matrix33 RotateY(float rad);
   static Matrix33 RotateZ(float rad);
 
+  static Matrix33 Rotate(float rad, const Vec3& axis);
+
   static Matrix33 Scale(const Vec3& vec);
 
   // set result = a x b