C++11: Added _htmlColor literal operator.

Allows inline specification of colors in HTML syntax.

src/OpenMesh/Core/Geometry/VectorT.hh

@@ -412,6 +412,26 @@ typedef VectorT<double,6> Vec6d;
 //=============================================================================
 } // namespace OpenMesh
 //=============================================================================
+
+
+#ifdef CPP11_ENABLED
+/**
+ * Literal operator for inline specification of colors in HTML syntax.
+ *
+ * Example:
+ * \code{.cpp}
+ * OpenMesh::Vec4f light_blue = 0x1FCFFFFF_htmlColor;
+ * \endcode
+ */
+constexpr OpenMesh::Vec4f operator"" _htmlColor(unsigned long long raw_color) {
+    return OpenMesh::Vec4f(
+            ((raw_color >> 24) & 0xFF) / 255.0f,
+            ((raw_color >> 16) & 0xFF) / 255.0f,
+            ((raw_color >>  8) & 0xFF) / 255.0f,
+            ((raw_color >>  0) & 0xFF) / 255.0f);
+}
+#endif
+
 #endif // OPENMESH_VECTOR_HH defined
 //=============================================================================
 #endif // DOXYGEN

src/Unittests/unittests_vector_type.cc

@@ -111,6 +111,18 @@ TEST_F(OpenMeshVectorTest, cpp11_constructors) {
     EXPECT_EQ(1.23, vec4d[2]);
     EXPECT_EQ(1.23, vec4d[3]);
 }
+
+TEST_F(OpenMeshVectorTest, cpp11_htmlColorLiteral) {
+    const OpenMesh::Vec4f light_blue = 0x1FCFFFFF_htmlColor;
+    EXPECT_LE((OpenMesh::Vec4f(0.1215686274f, 0.8117647058f, 1.0f, 1.0f)
+        - light_blue).sqrnorm(), 1e-10);
+
+    const auto light_blue_2 = 0x1FCFFFFF_htmlColor;
+    // Check whether auto type deduction works as expected.
+    static_assert(std::is_same<decltype(light_blue_2), decltype(light_blue)>
+        ::value, "Bad type deduced from _htmlColor literal.");
+    EXPECT_EQ(light_blue, light_blue_2);
+}
 #endif
 
 }