Method GetScreenBitmap

ColorCop/ColorCopDlg.cpp:1899–1948

}

void CColorCopDlg::GetScreenBitmap(CPoint point) {
    if (hBitmap) {  // delete the old bitmap, right before we get a new one
        ::DeleteObject(hBitmap);
        hBitmap = NULL;
    }
    if (hZoomBitmap) {
        ::DeleteObject(hZoomBitmap);
        hZoomBitmap = NULL;
    }

    WindowDC hdc(NULL);  // device context to the whole desktop (RAII)

    HDC hdcMem = ::CreateCompatibleDC(hdc);
    HDC hdcZoomMem = ::CreateCompatibleDC(hdc);

    hBitmap = CreateCompatibleBitmap(hdc, magrect.Width(), magrect.Height());
    hZoomBitmap = CreateCompatibleBitmap(hdc, magrect.Width(), magrect.Height());

    ::SelectObject(hdcMem, hBitmap);
    ::SelectObject(hdcZoomMem, hZoomBitmap);
    ::SetStretchBltMode(hdc, COLORONCOLOR);

    m_MagLevel = std::clamp<int>(m_MagLevel, kMinZoom, kMaxZoom);

    const int level = m_MagLevel;
    const int magwidth = magrect.Width() / level;
    const int magheight = magrect.Height() / level;

    ::BitBlt(hdcZoomMem,                         // destination DC
             0, 0,                               // destination upper left (always 0, 0)
             magrect.Width(), magrect.Height(),  // w x h of destination
             hdc,                                // source DC
             point.x - (magrect.Width() / 2),    // x coordinate of source
             point.y - (magrect.Height() / 2),   // y coordinate of source
             SRCCOPY);                           // raster mode

    ::StretchBlt(hdcMem,                             // destination DC
                 0, 0,                               // destination upper left (always 0, 0)
                 magrect.Width(), magrect.Height(),  // w x h of destination
                 hdc,                                // source DC
                 point.x - (magwidth / 2),           // x coordinate of source
                 point.y - (magheight / 2),          // y coordinate of source
                 magwidth, magheight,                // width of source
                 SRCCOPY);                           // raster mode

    ::DeleteDC(hdcMem);
    ::DeleteDC(hdcZoomMem);
    // hdc auto‑releases via RAII
    return;
}

void CColorCopDlg::GetHistoryColor(int Cindex) {
    // this function sets the current color