Поиск наличия расхождения координат

bool __fastcall TFCrdCheckForm::Check() {
  HMAP map = mapOpenMap(mapName, GENERIC_READ);
  // паспорт
  MAPREGISTER mr = {0};
  LISTREGISTER lr = {0};
  mapGetMapInfo(map, 1, &mr, &lr);
  // рамка 91000000
  HOBJ obj = mapCreateSiteObject(map, map, IDDOUBLE2, 0);
  mapGetListFrameObject(map, 1, obj);
  LINT pcnt = mapPointCount(obj, 0);
  // углы рамки
  DOUBLEPOINT dp[4] = {0};
  mapGetPlanePoint(obj, &(dp[0]), 1, 0);            // SW
  mapGetPlanePoint(obj, &(dp[1]), 2, 0);            // NW
  int stepCnt = (pcnt - 5) / 2;
  int nePos = stepCnt + 2 + 1;                      // индексы с 1
  mapGetPlanePoint(obj, &(dp[2]), nePos, 0);        // NE
  mapGetPlanePoint(obj, &(dp[3]), nePos + 1, 0);    // SE
  //-------------------------------------------------------------------------
  mapFreeObject(obj);
  mapCloseMap(map);
  //-------------------------------------------------------------------------
  double delta[8];
  delta[0] = fabs(dp[0].x - lr.XSouthWest);
  delta[1] = fabs(dp[0].y - lr.YSouthWest);
  delta[2] = fabs(dp[1].x - lr.XNorthWest);
  delta[3] = fabs(dp[1].y - lr.YNorthWest);
  delta[4] = fabs(dp[2].x - lr.XNorthEast);
  delta[5] = fabs(dp[2].y - lr.YNorthEast);
  delta[6] = fabs(dp[3].x - lr.XSouthEast);
  delta[7] = fabs(dp[3].y - lr.YSouthEast);
  for (int i = 0; i < 8; i++)
    if (delta[i] > DOUBLENULL)                      // ??????????????????????
      return false;
  return true;
}