TPrPort
TPrPort structure
#include <PrintTraps.h>
typedef struct TPrPort { Size Offset Description
GrafPort gPort; 108 0 portBits, portRect, pnSize, txFont,
...
QDProcs gProcs; 52 108 Specialized printer drawing hooks
long lGParam1; 4 160 Private storage ...
long lGParam2; 4 164 ... for the driver
long lGParam3; 4 168
long lGParam4 ; 4 172
Boolean fOurPtr; 1 176 Was this port allocated by the
driver?
Boolean fOurBits; 1 177 Was the bit map allocated by the
driver?
} TPrPort; 178
typedef TPrPort *TPPrPort;

Notes: TPrPort is a sort of "Printer Port Peek" structure. As with a
WindowRecord, its first 108 bytes contain the fields of a GrafPort into
which all drawing will occur.
This structure is used internally by the Printing Manager. A pointer to a
TPrPort is obtained via PrOpenDoc, and a is used directly in calls to
Subfields of the gProcs field can be modified to provide custom routines for
text-measuring, line- drawing, etc.