Simulation support:

This function is mandatory for display drivers that want to be DCAF-enabled.

Description GreGetScreenChangeArea takes an SCA handle and, for the identified SCA, adds its rectangles to the region pointed to by the phrgn field. The SCA is reset to NULL as a result of this call.

#define INCL_GRE_SCREEN
#include <os2.h>
#include <pmddi.h>

HDC      hdc;     /*  Any valid device context. */
HSCA     hsca;    /*  Handle of the SCA to be queried. */
PHRGN    phrgn;   /*  Pointer to a region handle. */
PDC      pdcArg;  /*  Pointer to instance data. */
ULONG    FunN;    /*  High-order word=Flags; Low-order word=NGreGetScreenArea. */
LONG     rc;

rc = GreGetScreenChangeArea(hdc, hsca, phrgn,
       pdcArg, FunN);