GetPixelsState

GetPixelsState
Header:	QDOffscreen.h		Carbon status:	Supported

Saves the current information about the memory allocated for an offscreen pixel image.

GWorldFlags GetPixelsState (
    PixMapHandle pm
);

Parameter descriptions

pm: A handle to an offscreen pixel map. To get a handle to an offscreen pixel map, use the GetGWorldPixMap function.

function result: Information about the memory allocated for the base address for an offscreen pixel image. This result can be either of the constants, pixelsPurgeable or pixelsLocked. If the pixelsPurgeable flag is not returned, then the base address for the offscreen pixel image is unpurgeable. If the pixelsLocked flag is not returned, then the base address for the offscreen pixel image is unlocked.

DISCUSSION

After using GetPixelsState to save this state information, use the SetPixelsState function to restore this state to the offscreen graphics world.

After using GetPixelsState and before using SetPixelsState, temporarily use the AllowPurgePixels function to make the base address for an offscreen pixel image purgeable, the NoPurgePixels function to make it unpurgeable, the LockPixels function to prevent it from being moved, and the UnlockPixels function to allow it to be moved.

SPECIAL CONSIDERATIONS

The GetPixelsState function may move or purge memory blocks in the application heap; do 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.