wince支持液晶翻转

wince系统的GDI提供了支持液晶翻转的接口，需要在驱动层实现。在应用层只需修改注册表[HKEY_LOCAL_MACHINE\System\GDI\ROTATION]即可。

代码段如下：

HKEY    hRegKey;
    DWORD   status;
    DWORD   ValType;
    DWORD   ValLen;

    DWORD Rotation = 0;
    DEVMODE devmode = {0};
    devmode.dmSize = sizeof(DEVMODE);
    devmode.dmFields = DM_DISPLAYORIENTATION;
    ChangeDisplaySettingsEx(NULL, &devmode, 0, CDS_TEST, NULL);

    switch(devmode.dmDisplayOrientation)
    {
    case DMDO_0:
        devmode.dmDisplayOrientation = DMDO_90; //????
        Rotation = 90;
        break;
    case DMDO_90:
        devmode.dmDisplayOrientation = DMDO_180;
        Rotation = 180;
        break;
    case DMDO_180:
        devmode.dmDisplayOrientation = DMDO_270;
        Rotation = 270;
        break;
    case DMDO_270:
        devmode.dmDisplayOrientation = DMDO_0;
        Rotation = 0;
        break;
    default :
        devmode.dmDisplayOrientation = DMDO_0;
        Rotation = 0;
    }

    devmode.dmFields = DM_DISPLAYORIENTATION;
    ChangeDisplaySettingsEx(NULL, &devmode, NULL, 0, NULL);

    status = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
                TEXT("System\\GDI\\Rotation"),
                0, 0, &hRegKey);

    if (ERROR_SUCCESS == status)
    {
        ValLen = sizeof(DWORD);
        if (ERROR_SUCCESS == RegSetValueEx (hRegKey, TEXT("Angle"), NULL, REG_DWORD, (PBYTE)&Rotation, ValLen))
        RegCloseKey(hRegKey);
    }
    RegFlushKey(HKEY_LOCAL_MACHINE);

关于驱动中如何去支持，得因处理器而异了，AM3517上使能液晶翻转需要操作vrfb模块，具体操作可参见：http://blog.csdn.net/savage_sdj/article/details/8975927