1 files changed, 30 insertions, 0 deletions

diff --git a/src/common/quaternion.h b/src/common/quaternion.h
index da44f35cd..4d0871eb4 100644
--- a/src/common/quaternion.h
+++ b/src/common/quaternion.h
@@ -36,6 +36,36 @@ public:
         T length = std::sqrt(xyz.Length2() + w * w);
         return {xyz / length, w / length};
     }
+
+    [[nodiscard]] std::array<decltype(-T{}), 16> ToMatrix() const {
+        const T x2 = xyz[0] * xyz[0];
+        const T y2 = xyz[1] * xyz[1];
+        const T z2 = xyz[2] * xyz[2];
+
+        const T xy = xyz[0] * xyz[1];
+        const T wz = w * xyz[2];
+        const T xz = xyz[0] * xyz[2];
+        const T wy = w * xyz[1];
+        const T yz = xyz[1] * xyz[2];
+        const T wx = w * xyz[0];
+
+        return {1.0f - 2.0f * (y2 + z2),
+                2.0f * (xy + wz),
+                2.0f * (xz - wy),
+                0.0f,
+                2.0f * (xy - wz),
+                1.0f - 2.0f * (x2 + z2),
+                2.0f * (yz + wx),
+                0.0f,
+                2.0f * (xz + wy),
+                2.0f * (yz - wx),
+                1.0f - 2.0f * (x2 + y2),
+                0.0f,
+                0.0f,
+                0.0f,
+                0.0f,
+                1.0f};
+    }
 };
 
 template <typename T>