Pointer Draw Routine access data structure.

typedef struct _PTRDRAWFUNCTION {
  USHORT     usReturnCode;  /*  Return Code. */
  PFN        pfnDraw;       /*  Pointer to Draw Routine Entry Point (Selector:offset). */
  PCH        pchDataSeg;    /*  Pointer to Draw Routine Data Segment Selector. */
} PTRDRAWFUNCTION;

typedef   PTRDRAWFUNCTION   * PPTRDRAWFUNCTION ;