Remove unused BasicVector4::isEqual()

This functionality is implemented for Vector4 by math::isNear(), which is now
tested by an additional unit test.

libs/math/Vector4.h

@@ -291,19 +291,6 @@ class BasicVector4
     const BasicVector3<Element>& getVector3() const {
         return *reinterpret_cast<const BasicVector3<Element>*>(_v);
     }
-
-    /**
-     * Equality check with tolerance epsilon.
-     */
-    template<typename OtherElement>
-    bool isEqual(const BasicVector4<OtherElement>& other, Element epsilon) const
-    {
-        return float_equal_epsilon(x(), other.x(), epsilon) &&
-               float_equal_epsilon(y(), other.y(), epsilon) &&
-               float_equal_epsilon(z(), other.z(), epsilon) &&
-               float_equal_epsilon(w(), other.w(), epsilon);
-    }
-
 }; // BasicVector4
 
 /// Multiply BasicVector4 with a scalar

test/math/Vector.cpp

@@ -96,7 +96,7 @@ TEST(MathTest, Vector3EqualityComparison)
     EXPECT_NE(v1, v2);
 }
 
-TEST(MathTest, VectorEpsilonComparison)
+TEST(MathTest, Vector3EpsilonComparison)
 {
     const Vector3 v(1, 8, 320);
     const Vector3 increment(1e-8, 1e-7, 1e-8);
@@ -120,6 +120,19 @@ TEST(MathTest, Vector4EqualityComparison)
     EXPECT_NE(v1, v2);
 }
 
+TEST(MathTest, Vector4EpsilonComparison)
+{
+    const Vector4 v(256, -18, -0.5);
+    const Vector4 increment(1e-8, 1e-8, 1e-8, 1e-8);
+
+    EXPECT_NE(v, v + increment);
+    EXPECT_TRUE(math::isNear(v, v, 1e-10));
+    EXPECT_TRUE(math::isNear(v, v + increment, 1e-6));
+    EXPECT_TRUE(math::isNear(v, v - increment, 1e-6));
+    EXPECT_FALSE(math::isNear(v, v + increment, 1e-10));
+    EXPECT_FALSE(math::isNear(v, v - increment, 1e-10));
+}
+
 TEST(MathTest, NegateVector3)
 {
     Vector3 vec(5, 10, 125);