Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 6 - Offscreen Graphics Worlds / Offscreen Graphics Worlds Reference

Routines / Managing an Offscreen Graphics World's Pixel Image

PixMap32Bit

You can use the PixMap32Bit function to determine whether a pixel map requires 32-bit addressing mode for access to its pixel image.

FUNCTION PixMap32Bit (pmHandle: PixMapHandle): Boolean;

pmHandle

A handle to an offscreen pixel map.

DESCRIPTION

The PixMap32Bit function returns TRUE if a pixel map requires 32-bit addressing mode for access to its pixel image. If your application is in 24-bit mode, you must change to 32-bit mode.

To get a handle to an offscreen pixel map, first use the GetGWorldPixMap function, described on page 6-31. Then supply this handle for the pm parameter of PixMap32Bit.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the PixMap32Bit function are

Trap macro	Selector
_QDExtensions	$00040016

SEE ALSO

See Inside Macintosh: Memory for information about determining and setting addressing modes.