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QuickDraw 3D RAVE / QuickDraw 3D RAVE Reference

QuickDraw 3D RAVE Routines / Manipulating Draw Contexts

QARenderEnd

You can use the QARenderEnd function to signal the end of any rendering into a draw context.

#define QARenderEnd(drawContext,modifiedRect) \
            (drawContext)->renderEnd (drawContext,modifiedRect)

drawContext

A draw context.

modifiedRect

The minimum area of the back buffer of the specified draw context to display, or the value NULL.

DESCRIPTION

The QARenderEnd function performs any operations necessary to display an image rendered into the draw context specified by the drawContext parameter. If the draw context is double buffered, QARenderEnd displays the back buffer. If the draw context is single buffered, QARenderEnd calls QAFlush.

The modifiedRect parameter indicates the minimum area of the back buffer of the specified draw context that should be displayed. If the value of the modifiedRect parameter is NULL, the entire back buffer is displayed. If the value of the modifiedRect parameter is not NULL, it indicates the rectangle in the back buffer to display. Some drawing engines may exhibit improved performance when an area that is smaller than the entire draw context rectangle is passed (to avoid unnecessary pixel copying). However, the interpretation of the modifiedRect parameter is dependent on the drawing engine, which may choose to draw the entire back buffer.

The QARenderEnd function returns a result code (of type TQAError) indicating whether any errors have occurred since the previous call to QARenderStart. If all rendering commands completed successfully, the value kQANoErr is returned. If any other value is returned, you should assume that the rendered image is incorrect.

SPECIAL CONSIDERATIONS

You should call QARenderStart before performing any rendering operations in the specified draw context, and you should call either QARenderEnd to signal the end of rendering operations or QARenderAbort to cancel rendering operations. Once you have called QARenderEnd, you should not submit any drawing requests until you have called QARenderStart again.