Important: The information in this document is obsolete and should not be used for new development.
GetGWorldPixMapfunction to obtain the pixel map created for an offscreen graphics world.
FUNCTION GetGWorldPixMap (offscreenGWorld: GWorldPtr): PixMapHandle;
- A pointer to an offscreen graphics world.
GetGWorldPixMapfunction returns a handle to the pixel map created for an offscreen graphics world. In the
offscreenGWorldparameter, pass the pointer returned to your application by the
NewGWorldfunction when you created the offscreen graphics world. Your application can, in turn, pass the handle returned by
GetGWorldPixMapas a parameter to other QuickDraw routines that accept a handle to a pixel map.
On a system running only basic QuickDraw, the
GetGWorldPixMapfunction returns the handle to a 1-bit pixel map that your application can supply as a parameter to the other routines related to offscreen graphics worlds. However, your application should not supply this handle to Color QuickDraw routines.
SPECIAL CONSIDERATIONSTo ensure compatibility on systems running basic QuickDraw instead of Color QuickDraw, use
GetGWorldPixMapwhenever you need to gain access to the bitmap created for a graphics world--that is, do not dereference the
GWorldPtrrecord for that graphics world.
GetGWorldPixMapfunction is not available in systems preceding System 7. You can make sure that the
GetGWorldPixMapfunction is available by using the
Gestaltfunction with the
gestaltSystemVersionselector. Test the low-order word in the
responseparameter; if the value is $0700 or greater, then
ASSEMBLY-LANGUAGE INFORMATIONThe trap macro and routine selector for the
Trap macro Selector _QDExtensions $00040017
Gestaltfunction is described in the chapter "Gestalt Manager" of Inside Macintosh: Operating System Utilities.