Creates an offscreen PixMap structure and allocate temporary memory for the base address of its pixel image; applications generally don’t need to use NewTempScreenBuffer.

QDErr NewTempScreenBuffer (
    const Rect *globalRect, 
    Boolean purgeable, 
    GDHandle *gdh, 
    PixMapHandle *offscreenPixMap
);

Parameter descriptions

globalRect

The boundary rectangle, in global coordinates, for the offscreen pixel map.

purgeable

A value of TRUE to make the memory block for the offscreen pixel map purgeable, or a value of FALSE to make it unpurgeable.

gdh

On return, a pointer to the handle to the GDevice structure for the graphics device with the greatest pixel depth among all graphics devices whose boundary rectangles intersect the rectangle specified in the globalRect parameter.

offscreenPixMap

On return, a pointer to the handle to the new offscreen PixMap structure.

DISCUSSION

The NewTempScreenBuffer function performs the same functions as NewScreenBuffer except that it creates the base address for the offscreen pixel image in temporary memory. When an application passes it the useTempMem flag, the NewGWorld function uses NewTempScreenBuffer instead of NewScreenBuffer.

Your application should not need to use this function.

SPECIAL CONSIDERATIONS

The NewTempScreenBuffer function may move or purge memory blocks in the application heap. Your application should not call this function at interrupt time.

AVAILABILITY

Supported in Carbon. Available in Carbon 1.0.2 and later when running Mac OS 8.1 or later.

© 2000 Apple Computer, Inc. (Last Updated 6/30/2000)