Math: added component-wise equal()/notEqual() for vectors.

doc/changelog.dox

@@ -160,6 +160,9 @@ See also:
     @ref Math::IsFloatingPoint and @ref Math::IsUnitless type traits and a
     @ref Math::UnderlyingTypeOf utility
 -   Added batch versions of @ref Math::isInf() and @ref Math::isNan()
+-   @ref Math::equal() and @ref Math::notEqual() for component-wise comparison
+    of @ref Math::Vector, as the equality/non-equality operators return a
+    single @cpp bool @ce
 
 @subsubsection changelog-latest-new-meshtools MeshTools library
 

src/Magnum/Math/Test/VectorTest.cpp

@@ -343,6 +343,16 @@ void VectorTest::compare() {
 
 void VectorTest::compareComponentWise() {
     typedef BoolVector<3> BoolVector3;
+    typedef BoolVector<4> BoolVector4;
+
+    Vector4 a{1.0f, -3.5f, 5.0f, -10.0f};
+    Vector4 b{1.0f + TypeTraits<Float>::epsilon()/2, -3.5f, 5.0f - TypeTraits<Float>::epsilon()*2, -10.0f};
+    Vector4 c{1.0f + TypeTraits<Float>::epsilon()*2, -3.5f, 5.0f - TypeTraits<Float>::epsilon()*10, -10.0f};
+    CORRADE_COMPARE(equal(a, b), BoolVector4{0xf});
+    CORRADE_COMPARE(equal(a, c), BoolVector4{0xa});
+    CORRADE_COMPARE(notEqual(a, b), BoolVector4{0x0});
+    CORRADE_COMPARE(notEqual(a, c), BoolVector4{0x5});
+
     CORRADE_COMPARE(Vector3(1.0f, -1.0f, 5.0f) < Vector3(1.1f, -1.0f, 3.0f), BoolVector3(0x1));
     CORRADE_COMPARE(Vector3(1.0f, -1.0f, 5.0f) <= Vector3(1.1f, -1.0f, 3.0f), BoolVector3(0x3));
     CORRADE_COMPARE(Vector3(1.0f, -1.0f, 5.0f) >= Vector3(1.1f, -1.0f, 3.0f), BoolVector3(0x6));

src/Magnum/Math/Vector.h

@@ -48,13 +48,13 @@ namespace Magnum { namespace Math {
 template<class T> inline typename std::enable_if<IsScalar<T>::value, bool>::type isNan(T value) {
     return std::isnan(UnderlyingTypeOf<T>(value));
 }
-
+/* Keeping the same parameter names as in Functions.h so the note about
-template<class T> constexpr typename std::enable_if<IsScalar<T>::value, T>::type min(T a, T b) {
+   NaN propagation works here too */
-    return b < a ? b : a;
+template<class T> constexpr typename std::enable_if<IsScalar<T>::value, T>::type min(T value, T min) {
+    return min < value ? min : value;
 }
-
+template<class T> constexpr typename std::enable_if<IsScalar<T>::value, T>::type max(T value, T max) {
-template<class T> constexpr typename std::enable_if<IsScalar<T>::value, T>::type max(T a, T b) {
+    return value < max ? max : value;
-    return a < b ? b : a;
 }
 #endif
 
@@ -237,7 +237,11 @@ template<std::size_t size, class T> class Vector {
         T& operator[](std::size_t pos) { return _data[pos]; }
         constexpr T operator[](std::size_t pos) const { return _data[pos]; } /**< @overload */
 
-        /** @brief Equality comparison */
+        /**
+         * @brief Equality comparison
+         *
+         * @see @ref Math::equal()
+         */
         bool operator==(const Vector<size, T>& other) const {
             for(std::size_t i = 0; i != size; ++i)
                 if(!TypeTraits<T>::equals(_data[i], other._data[i])) return false;
@@ -245,7 +249,11 @@ template<std::size_t size, class T> class Vector {
             return true;
         }
 
-        /** @brief Non-equality comparison */
+        /**
+         * @brief Non-equality comparison
+         *
+         * @see @ref Math::notEqual()
+         */
         bool operator!=(const Vector<size, T>& other) const {
             return !operator==(other);
         }
@@ -640,6 +648,11 @@ template<std::size_t size, class T> class Vector {
         template<std::size_t, class> friend class Matrix;
         template<std::size_t, class> friend struct Implementation::MatrixDeterminant;
 
+        /* So the out-of-class comparators can access data directly to avoid
+           function call overhead */
+        template<std::size_t size_, class T_> friend BoolVector<size_> equal(const Vector<size_, T_>&, const Vector<size_, T_>&);
+        template<std::size_t size_, class T_> friend BoolVector<size_> notEqual(const Vector<size_, T_>&, const Vector<size_, T_>&);
+
         /* Implementation for Vector<size, T>::Vector(const Vector<size, U>&) */
         template<class U, std::size_t ...sequence> constexpr explicit Vector(Implementation::Sequence<sequence...>, const Vector<size, U>& vector) noexcept: _data{T(vector._data[sequence])...} {}
 
@@ -655,6 +668,36 @@ template<std::size_t size, class T> class Vector {
         }
 };
 
+/** @relatesalso Vector
+@brief Component-wise equality comparison
+
+Unlike @ref Vector::operator==() returns a @ref BoolVector instead of a single
+value.
+*/
+template<std::size_t size, class T> inline BoolVector<size> equal(const Vector<size, T>& a, const Vector<size, T>& b) {
+    BoolVector<size> out;
+
+    for(std::size_t i = 0; i != size; ++i)
+        out.set(i, TypeTraits<T>::equals(a._data[i], b._data[i]));
+
+    return out;
+}
+
+/** @relatesalso Vector
+@brief Component-wise non-equality comparison
+
+Unlike @ref Vector::operator!=() returns a @ref BoolVector instead of a single
+value.
+*/
+template<std::size_t size, class T> inline BoolVector<size> notEqual(const Vector<size, T>& a, const Vector<size, T>& b) {
+    BoolVector<size> out;
+
+    for(std::size_t i = 0; i != size; ++i)
+        out.set(i, !TypeTraits<T>::equals(a._data[i], b._data[i]));
+
+    return out;
+}
+
 /** @relates Vector
 @brief Multiply a scalar with a vector