rowBytes
BitMap structure
#include <Quickdraw.h>
typedef struct BitMap { Size Offset Description
QDPtr baseAddr; 4 0 Address of start of bitmap data
short rowBytes; 2 4 Bytes per row in the bitmap data
Rect bounds; 8 6 Coordinates imposed over the bitmap
data
} BitMap ; 14
typedef BitMap *BitMapPtr;
typedef BitMap **BitMapHandle;

Notes: The BitMap structure is used in calls to CopyBits, CopyMask, and
SetPortBits. Each GrafPort (including the QD global thePort) contains a
BitMap identifying the memory area in which drawing will take place.
The Quickdraw global variable screenBits is a BitMap identifying the size
and location of the actual video memory.