3.3.1.2 Primary Drawing Order History

The Primary Drawing Order History store holds information on the fields that have been sent in primary drawing orders. There are three pieces of information that MUST be recorded:

• Last primary order type constructed

• Current bounding rectangle

• Per-order record of the last value used in each field

These records are updated as each primary drawing order is constructed, and are used to efficiently encode primary drawing orders for transmission on the wire using as few bytes as possible (see section 3.3.5.1.1.1).