This section describes the format of the graphics orders.
Graphics orders are used in the following circumstances:
When primitive or attribute functions (plus certain other functions) are specified at the programming interface, and the drawing mode (see GpiSetDrawingMode) is set to drawandretain, graphics orders are constructed and placed in the current graphics segment. One API call often causes a single order to be generated. Sometimes, however, several orders are necessary: an example of this is where a GpiPolyLine call is issued, which specifies more strokes than there is room for, in a single order.
In either case, the order or orders generated by a single API call comprise a single element, unless the application specifically starts an element using the GpiBeginElement function. In this case the element consists of all of the orders generated between this and the following GpiEndElement function. A GpiQueryElement function returns the orders that comprise an element; the application may edit these, and return them to the segment with GpiElement. The Begin Element - End Element orders that surround a multi-order element in the segment are never passed between the application and the system on GpiQueryElement and GpiElement functions.
No double word or word alignment can be assumed for orders either within segments or during editing.