C++最快获取像素值

HDC hdc, hdcTemp;
RECT rect;
BYTE* bitPointer;
int x, y;
int red, green, blue, alpha;

while(true)
{
    hdc = GetDC(HWND_DESKTOP);
    GetWindowRect(hWND_Desktop, &rect);
            int MAX_WIDTH = rect.right;
        int MAX_HEIGHT = rect.bottom;

    hdcTemp = CreateCompatibleDC(hdc);
    BITMAPINFO bitmap;
    bitmap.bmiHeader.biSize = sizeof(bitmap.bmiHeader);
    bitmap.bmiHeader.biWidth = MAX_WIDTH;
    bitmap.bmiHeader.biHeight = MAX_HEIGHT;
    bitmap.bmiHeader.biPlanes = ;
    bitmap.bmiHeader.biBitCount = ;
    bitmap.bmiHeader.biCompression = BI_RGB;
    bitmap.bmiHeader.biSizeImage = MAX_WIDTH *  * MAX_HEIGHT;
    bitmap.bmiHeader.biClrUsed = ;
    bitmap.bmiHeader.biClrImportant = ;
    HBITMAP hBitmap2 = CreateDIBSection(hdcTemp, &bitmap, DIB_RGB_COLORS, (void**)(&bitPointer), NULL, NULL);
    SelectObject(hdcTemp, hBitmap2);
    BitBlt(hdcTemp, , , MAX_WIDTH, MAX_HEIGHT, hdc, , , SRCCOPY);

    for (int i=; i<(MAX_WIDTH *  * MAX_HEIGHT); i+=)
    {
        red = (int)bitPointer[i];
        green = (int)bitPointer[i+];
        blue = (int)bitPointer[i+];
        alpha = (int)bitPointer[i+];

    }
}