[Math/Vector] Reflected vector computation is restricted to signed types

Razakhel · Sep 23, 2023 · 3355add · 3355add
1 parent 80454bb
commit 3355add
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Showing 3 changed files with 14 additions and 12 deletions.
diff --git a/include/RaZ/Math/Vector.hpp b/include/RaZ/Math/Vector.hpp
@@ -85,7 +85,7 @@ class Vector {
   /// \image html vector_reflect.jpg "Incident vector reflection"
   /// \param normal Direction to compute the reflection over.
   /// \return Vector's reflection.
-  constexpr Vector reflect(const Vector& normal) const noexcept { return (*this - normal * dot(normal) * 2); }
+  constexpr Vector reflect(const Vector& normal) const noexcept;
   /// Computes the squared length of the vector.
   /// The squared length is equal to the dot product of the vector with itself.
   /// This calculation does not involve a square root; it is then to be preferred over computeLength() for faster operations.

diff --git a/include/RaZ/Math/Vector.inl b/include/RaZ/Math/Vector.inl
@@ -95,6 +95,13 @@ constexpr Vector<T, Size> Vector<T, Size>::cross(const Vector& vec) const noexce
   return res;
 }
 
+template <typename T, std::size_t Size>
+constexpr Vector<T, Size> Vector<T, Size>::reflect(const Vector& normal) const noexcept {
+  static_assert(std::is_signed_v<T>, "Error: The cross product can only be computed with vectors of a signed type.");
+
+  return (*this - normal * static_cast<T>(dot(normal)) * 2);
+}
+
 template <typename T, std::size_t Size>
 template <typename NormedT>
 constexpr Vector<NormedT, Size> Vector<T, Size>::normalize() const noexcept {

diff --git a/tests/src/RaZ/Math/Vector.cpp b/tests/src/RaZ/Math/Vector.cpp
@@ -157,19 +157,14 @@ TEST_CASE("Vector/matrix operations") {
   CHECK((vec4f1 * Raz::Mat4f::identity()) == vec4f1);
 }
 
-TEST_CASE("Vector manipulations") {
-  CHECK_THAT(vec3f1.normalize().computeLength(), IsNearlyEqualTo(1.f));
-  CHECK_THAT(vec4f1.normalize().computeSquaredLength(), IsNearlyEqualTo(1.f));
-  CHECK_THAT(Raz::Vec3f(0.f, 1.f, 0.f).computeLength(), IsNearlyEqualTo(1.f));
-
-  // Testing Vector::reflect():
-  //
+TEST_CASE("Vector reflection") {
   // IncVec  N  Reflection
-  //     \   |   /
-  //      \  |  /
+  //      \  ^  ^
   //       \ | /
-  //________\|/___________
-  //
+  // _______v|/_______
+
+  // The reflected vector cannot be computed for unsigned types
+
   CHECK(Raz::Vec3f(1.f, -1.f, 0.f).reflect(Raz::Vec3f(0.f, 1.f, 0.f)) == Raz::Vec3f(1.f, 1.f, 0.f));
   CHECK(vec3f1.reflect(Raz::Vec3f(0.f, 1.f, 0.f)) == Raz::Vec3f(3.18f, -42.f, 0.874f));
   CHECK(vec3f1.reflect(vec3f2) == Raz::Vec3f(-4'019'108.859'878'28f, -350'714.439'453f, -46'922.543'011'268f));