Fix mix-precision quaternion conversions (#7339)

google · Nov 8, 2023 · cbc3bb3 · cbc3bb3
1 parent 0eb851f
commit cbc3bb3
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Showing 2 changed files with 110 additions and 9 deletions.
diff --git a/libs/math/include/math/TQuatHelpers.h b/libs/math/include/math/TQuatHelpers.h
@@ -58,7 +58,7 @@ class TQuatProductOperators {
 
     /* compound assignment products by a scalar
      */
-    template<typename U>
+    template<typename U, typename = std::enable_if_t<std::is_arithmetic_v<U>>>
     constexpr QUATERNION<T>& operator*=(U v) {
         QUATERNION<T>& lhs = static_cast<QUATERNION<T>&>(*this);
         for (size_t i = 0; i < QUATERNION<T>::size(); i++) {
@@ -67,7 +67,7 @@ class TQuatProductOperators {
         return lhs;
     }
 
-    template<typename U>
+    template<typename U, typename = std::enable_if_t<std::is_arithmetic_v<U>>>
     constexpr QUATERNION<T>& operator/=(U v) {
         QUATERNION<T>& lhs = static_cast<QUATERNION<T>&>(*this);
         for (size_t i = 0; i < QUATERNION<T>::size(); i++) {
@@ -125,25 +125,25 @@ class TQuatProductOperators {
      *              q.w*r.z + q.x*r.y - q.y*r.x + q.z*r.w);
      *
      */
-    template<typename U>
+    template<typename U, typename = std::enable_if_t<std::is_arithmetic_v<U>>>
     friend inline constexpr
     QUATERNION<arithmetic_result_t<T, U>> MATH_PURE operator*(QUATERNION<T> q, U scalar) {
         // don't pass q by reference because we need a copy anyway
-        return q *= scalar;
+        return QUATERNION<arithmetic_result_t<T, U>>(q *= scalar);
     }
 
-    template<typename U>
+    template<typename U, typename = std::enable_if_t<std::is_arithmetic_v<U>>>
     friend inline constexpr
-    QUATERNION<arithmetic_result_t<T, U>> MATH_PURE operator*(T scalar, QUATERNION<U> q) {
+    QUATERNION<arithmetic_result_t<T, U>> MATH_PURE operator*(U scalar, QUATERNION<T> q) {
         // don't pass q by reference because we need a copy anyway
-        return q *= scalar;
+        return QUATERNION<arithmetic_result_t<T, U>>(q *= scalar);
     }
 
-    template<typename U>
+    template<typename U, typename = std::enable_if_t<std::is_arithmetic_v<U>>>
     friend inline constexpr
     QUATERNION<arithmetic_result_t<T, U>> MATH_PURE operator/(QUATERNION<T> q, U scalar) {
         // don't pass q by reference because we need a copy anyway
-        return q /= scalar;
+        return QUATERNION<arithmetic_result_t<T, U>>(q /= scalar);
     }
 };
 

diff --git a/libs/math/tests/test_quat.cpp b/libs/math/tests/test_quat.cpp
@@ -17,6 +17,7 @@
 #include <math.h>
 #include <random>
 #include <functional>
+#include <type_traits>
 
 #include <gtest/gtest.h>
 
@@ -324,3 +325,103 @@ TEST_F(QuatTest, NaN) {
     EXPECT_NEAR(qs[2], 0.5, 0.1);
     EXPECT_NEAR(qs[3], 0.5, 0.1);
 }
+
+TEST_F(QuatTest, Conversions) {
+    quat qd;
+    quatf qf;
+    float3 vf;
+    double3 vd;
+    double d = 0.0;
+    float f = 0.0f;
+
+    static_assert(std::is_same<details::arithmetic_result_t<float, float>, float>::value);
+    static_assert(std::is_same<details::arithmetic_result_t<float, double>, double>::value);
+    static_assert(std::is_same<details::arithmetic_result_t<double, float>, double>::value);
+    static_assert(std::is_same<details::arithmetic_result_t<double, double>, double>::value);
+
+    {
+        auto r1 = qd * d;
+        auto r2 = qd * f;
+        auto r3 = qf * d;
+        auto r4 = qf * f;
+        static_assert(std::is_same<decltype(r1), quat>::value);
+        static_assert(std::is_same<decltype(r2), quat>::value);
+        static_assert(std::is_same<decltype(r3), quat>::value);
+        static_assert(std::is_same<decltype(r4), quatf>::value);
+    }
+    {
+        auto r1 = qd / d;
+        auto r2 = qd / f;
+        auto r3 = qf / d;
+        auto r4 = qf / f;
+        static_assert(std::is_same<decltype(r1), quat>::value);
+        static_assert(std::is_same<decltype(r2), quat>::value);
+        static_assert(std::is_same<decltype(r3), quat>::value);
+        static_assert(std::is_same<decltype(r4), quatf>::value);
+    }
+    {
+        auto r1 = d * qd;
+        auto r2 = f * qd;
+        auto r3 = d * qf;
+        auto r4 = f * qf;
+        static_assert(std::is_same<decltype(r1), quat>::value);
+        static_assert(std::is_same<decltype(r2), quat>::value);
+        static_assert(std::is_same<decltype(r3), quat>::value);
+        static_assert(std::is_same<decltype(r4), quatf>::value);
+    }
+    {
+        auto r1 = qd * vd;
+        auto r2 = qf * vd;
+        auto r3 = qd * vf;
+        auto r4 = qf * vf;
+        static_assert(std::is_same<decltype(r1), double3>::value);
+        static_assert(std::is_same<decltype(r2), double3>::value);
+        static_assert(std::is_same<decltype(r3), double3>::value);
+        static_assert(std::is_same<decltype(r4), float3>::value);
+    }
+    {
+        auto r1 = qd * qd;
+        auto r2 = qf * qd;
+        auto r3 = qd * qf;
+        auto r4 = qf * qf;
+        static_assert(std::is_same<decltype(r1), quat>::value);
+        static_assert(std::is_same<decltype(r2), quat>::value);
+        static_assert(std::is_same<decltype(r3), quat>::value);
+        static_assert(std::is_same<decltype(r4), quatf>::value);
+    }
+    {
+        auto r1 = dot(qd, qd);
+        auto r2 = dot(qf, qd);
+        auto r3 = dot(qd, qf);
+        auto r4 = dot(qf, qf);
+        static_assert(std::is_same<decltype(r1), double>::value);
+        static_assert(std::is_same<decltype(r2), double>::value);
+        static_assert(std::is_same<decltype(r3), double>::value);
+        static_assert(std::is_same<decltype(r4), float>::value);
+    }
+    {
+        auto r1 = cross(qd, qd);
+        auto r2 = cross(qf, qd);
+        auto r3 = cross(qd, qf);
+        auto r4 = cross(qf, qf);
+        static_assert(std::is_same<decltype(r1), quat>::value);
+        static_assert(std::is_same<decltype(r2), quat>::value);
+        static_assert(std::is_same<decltype(r3), quat>::value);
+        static_assert(std::is_same<decltype(r4), quatf>::value);
+    }
+}
+
+template <typename L, typename R, typename = void>
+struct has_divide_assign : std::false_type {};
+
+template <typename L, typename R>
+struct has_divide_assign<L, R,
+        decltype(std::declval<L&>() /= std::declval<R>(), void())> : std::true_type {};
+
+// Static assertions to validate the availability of the /= operator for specific type
+// combinations. The first static_assert checks that the quat does not have a /= operator with Foo.
+// This ensures that quat does not provide an inappropriate overload that could be erroneously
+// selected.
+struct Foo {};
+static_assert(!has_divide_assign<quat, Foo>::value);
+static_assert(has_divide_assign<quat, float>::value);