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QuickDraw 3D RAVE / QuickDraw 3D RAVE Reference

QuickDraw 3D RAVE Routines / Public Draw Context Methods

TQAFlush

A drawing engine must define a method to flush a draw context.

typedef TQAError (*TQAFlush) (const TQADrawContext *drawContext);

drawContext

A draw context.

DESCRIPTION

Your TQAFlush function should cause your drawing engine to begin rendering all drawing commands that are queued in a buffer awaiting processing for the draw context specified by the drawContext parameter. QuickDraw 3D RAVE allows a drawing engine to buffer as many drawing commands as desired. Accordingly, the successful completion of a drawing command (such as QADrawPoint) does not guarantee that the specified object is visible on the screen. An application can call QAFlush to have your drawing engine start processing queued commands. Note, however, that QAFlush is not a blocking call--that is, the successful completion of QAFlush does not guarantee that all buffered commands have been processed. Calling QAFlush guarantees only that all queued commands will eventually be processed.

Typically, applications should occasionally call QAFlush to update the screen image during a lengthy set of rendering operations in a single-buffered draw context. QAFlush has no visible effect when called on a double-buffered draw context, but it does initiate rendering to the back buffer.

Your TQAFlush function should return a result code (of type TQAError) indicating whether any errors have occurred since the previous call to your TQARenderStart function. If all rendering commands completed successfully, you should return the value kQANoErr. If you return any other value, the code that called QAFlush should assume that the rendered image is incorrect.