Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 2 - Basic QuickDraw / Basic QuickDraw Reference

Routines / Managing Bitmaps, Port Rectangles, and Clipping Regions

SetPortBits

Although you should never need to do so, you can set the bitmap for the current basic graphics port by using the SetPortBits procedure.

PROCEDURE SetPortBits (bm:\xDDBitMap); 

bm

A BitMap record.

DESCRIPTION

The SetPortBits procedure sets the portBits field of the current graphics port to any previously defined bitmap. Be sure to prepare all fields of the BitMap record before you call SetPortBits.

SPECIAL CONSIDERATIONS

The SetPortBits procedure, created in early versions of QuickDraw, allows you to perform all normal drawing and calculations on a buffer other than the screen--for example, copying a small offscreen image onto the screen with the CopyBits procedure. However, instead of using SetPortBits, you should use the more powerful offscreen graphics capabilities described in the chapter "Offscreen Graphics Worlds."