int MultiFormMgr::GetUpdateRectCount() { int c = 0; for (int n = 0; n < m_cfrmm; n++) { UpdateMap *pupd = m_apfrmm[n]->GetUpdateMap(); Size sizMap; pupd->GetMapSize(&sizMap); int cb = sizMap.cx * sizMap.cy; bool *pfInvalid = pupd->GetInvalidMap(); while (cb-- != 0) { if (*pfInvalid++) c++; } } return c; }