+ /**
+ * Depending on the type of the draw call (indexed or non-indexed),
+ * is the value of \c basevertex passed to \c glDrawElementsBaseVertex and
+ * similar, or is the value of \c first passed to \c glDrawArrays and
+ * similar.
+ *
+ * \note
+ * It can be used to calculate the \c SYSTEM_VALUE_VERTEX_ID as
+ * \c SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus \c SYSTEM_VALUE_FIRST_VERTEX.
+ *
+ * \sa SYSTEM_VALUE_VERTEX_ID_ZERO_BASE, SYSTEM_VALUE_VERTEX_ID
+ */
+ SYSTEM_VALUE_FIRST_VERTEX,
+
+ /**
+ * If the Draw command used to start the rendering was an indexed draw
+ * or not (~0/0). Useful to calculate \c SYSTEM_VALUE_BASE_VERTEX as
+ * \c SYSTEM_VALUE_IS_INDEXED_DRAW & \c SYSTEM_VALUE_FIRST_VERTEX.
+ */
+ SYSTEM_VALUE_IS_INDEXED_DRAW,
+