Implement rotation_mat function on hlsl

Author: kevyuu

include/nbl/builtin/hlsl/math/linalg/transform.hlsl

@@ -0,0 +1,57 @@
+// Copyright (C) 2018-2024 - DevSH Graphics Programming Sp. z O.O.
+// This file is part of the "Nabla Engine".
+// For conditions of distribution and use, see copyright notice in nabla.h
+#ifndef _NBL_BUILTIN_HLSL_MATH_LINALG_TRANSFORM_INCLUDED_
+#define _NBL_BUILTIN_HLSL_MATH_LINALG_TRANSFORM_INCLUDED_
+
+
+#include <nbl/builtin/hlsl/mpl.hlsl>
+#include <nbl/builtin/hlsl/cpp_compat/intrinsics.hlsl>
+#include <nbl/builtin/hlsl/concepts.hlsl>
+
+
+namespace nbl
+{
+namespace hlsl
+{
+namespace math
+{
+namespace linalg
+{
+
+/// Builds a rotation 4 * 4 matrix created from an axis vector and an angle.
+///
+/// @param angle Rotation angle expressed in radians.
+/// @param axis Rotation axis, must be normalized.
+///
+/// @tparam T A floating-point scalar type
+template <typename T>
+matrix<T, 4, 4> rotation_mat(T angle, vector<T, 3> const& axis)
+{
+  T const a = angle;
+  T const c = cos(a);
+  T const s = sin(a);
+
+  vector<T, 3> temp((T(1) - c) * axis);
+
+  matrix<T, 4, 4> rotation;
+  rotation[0][0] = c + temp[0] * axis[0];
+  rotation[0][1] = temp[1] * axis[0] - s * axis[2];
+  rotation[0][2] = temp[2] * axis[0] + s * axis[1];
+
+  rotation[1][0] = temp[0] * axis[1] + s * axis[2];
+  rotation[1][1] = c + temp[1] * axis[1];
+  rotation[1][2] = temp[2] * axis[1] - s * axis[0];
+
+  rotation[2][0] = temp[0] * axis[2] - s * axis[1];
+  rotation[2][1] = temp[1] * axis[2] + s * axis[0];
+  rotation[2][2] = c + temp[2] * axis[2];
+
+  return rotation;
+}
+
+}
+}
+}
+}
+#endif