TGB: GetVideoAccelerationLevel (code inside)

   static int GetVideoAccelerationLevel(void);

int WinDisplayDevice::GetVideoAccelerationLevel()
{
    // Open HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\VIDEO
    // Get Content of \Device\Video0 key
    // Take the GUID from the end and open HKLM\System\CurrentControlSet\Control\Video\{GUID}\0000
    // Now, look for "Acceleration.Level"
    // If the key is NOT present, the level is on full HW assist
    // If the key is present, the level is 1 to 5 with 5 being the NO HW Support, and 1 being almost full HW support!
    //
    HKEY hKey;
    int nRet = -1;              
    if (ERROR_SUCCESS == RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("HARDWARE\\DEVICEMAP\\VIDEO"), 0, KEY_QUERY_VALUE , &hKey))
    {
        LPSTR lpszBuffer = NULL;
        DWORD dwType, dwSize;
        LPCSTR lpszSearchKey = "\\Device\\Video0";                            
        dwType = dwSize = 0;
        if (ERROR_SUCCESS == RegQueryValueExA(hKey, lpszSearchKey, 0, &dwType, (LPBYTE)lpszBuffer, &dwSize))
        {
            HANDLE hHeap = GetProcessHeap(); 
            if (lpszBuffer = (LPSTR)HeapAlloc(hHeap, HEAP_ZERO_MEMORY, dwSize))
            {
                dwType = REG_SZ;
                if (ERROR_SUCCESS == RegQueryValueExA(hKey, lpszSearchKey, 0, &dwType, (LPBYTE)lpszBuffer, &dwSize))
                {                                              
                    LPCSTR lpszRet = dStrchr(lpszBuffer, '{');
                    HKEY hKeyVideo;
                    char tszRegKey[128] = {"SYSTEM\\CurrentControlSet\\Control\\Video\\"};
                    lstrcpyA(&tszRegKey[39], lpszRet);
                    if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_LOCAL_MACHINE, tszRegKey, 0, KEY_QUERY_VALUE , &hKeyVideo))
                    {
                        DWORD dwAccelVal;
                        LPCTSTR lpszOutputMsg;
                        dwType = REG_DWORD;
                        nRet   = 5;            // Set the return to 5 here to use to invert the level in the registry. 
                        if (ERROR_SUCCESS == RegQueryValueEx(hKeyVideo, TEXT("Acceleration.Level"), 0, &dwType, (LPBYTE)&dwAccelVal, &dwSize))
                        {
                            nRet -= dwAccelVal;
                         }
                        RegCloseKey(hKeyVideo);
                    }
                    else
                    {
                        // Set the default to '1' here to reflect that the hardware is on... the default, which is provided when no key is present.
                        nRet = 1;
                    }
                } 
                HeapFree(hHeap, 0, lpszBuffer);
            }
        }                
        RegCloseKey(hKey);
    }
    return nRet;
}

//--------------------------------------
// Returns VideoAccelerationLevel:
// The range is 1 to 5 with 1 being the NO HW Support, and 5 being full HW support.
//--------------------------------------
ConsoleFunction( GetVideoAccelerationLevel, int, 1, 1, "int GetVideoAccelerationLevel(void)" )
{
    return WinDisplayDevice::GetVideoAccelerationLevel();
}