PROSRGNDATA FASTCALL REGION_AllocRgnWithHandle(INT n);
PROSRGNDATA FASTCALL REGION_AllocUserRgnWithHandle(INT n);
VOID FASTCALL REGION_UnionRectWithRgn(ROSRGNDATA *rgn, const RECTL *rect);
+INT FASTCALL REGION_SubtractRectFromRgn(PREGION prgnDest, PREGION prgnSrc, const RECTL *prcl);
INT FASTCALL REGION_GetRgnBox(PROSRGNDATA Rgn, RECTL *pRect);
BOOL FASTCALL REGION_RectInRegion(PROSRGNDATA Rgn, const RECTL *rc);
BOOL FASTCALL REGION_PtInRegion(PREGION, INT, INT);