read individual vertices and components of vertices in attributes

src/Attributes.hpp

@@ -210,6 +210,21 @@ namespace sb
             add({std::initializer_list<XType>({coordinate_0, coordinate_1, coordinates ...})});
         }
 
+        /* Return a const reference to the vertex at the specified index in the attributes vector. */
+        template<typename VertexType>
+        const VertexType& read(std::size_t index) const
+        {
+            return std::get<std::vector<VertexType>>(vertices)[index];
+        }
+
+        /* 2D lookup of a value in the attributes. Return a const reference to the coordinate value at inner index
+         * within a vertex at outer index in the attributes vector. */
+        template<typename VertexType, typename CoordinateType = float>
+        const CoordinateType& read(std::size_t outer, std::size_t inner)
+        {
+            return std::get<std::vector<VertexType>>(vertices)[outer][inner];
+        }
+
         /* Return the attributes as a reference to a typed vector. If the type is not the alternative in use by the
          * attributes, std::bad_variant_access will be thrown. */
         template<typename VertexType>