C++ Directx鼠标输入在失去焦点后表现得很奇怪

Question

您好，在失去窗口焦点(alt+tab/windows 键)后，我的鼠标输入出现了一个小问题。

焦点回到游戏窗口后，鼠标(偏航) Action 缓慢且没有反应(出于某种原因，俯仰工作正常)。有时它会移动，有时它根本不动。

部分代码如下:

bool Game::initDirectInput(HINSTANCE hInstance)
{
    hr = DirectInput8Create(hInstance, DIRECTINPUT_VERSION, IID_IDirectInput8, (void**)&directInput, NULL); 

    hr = directInput->CreateDevice(GUID_SysKeyboard, &DIKeyboard, NULL);

    hr = directInput->CreateDevice(GUID_SysMouse, &DIMouse, NULL);

    hr = DIKeyboard->SetDataFormat(&c_dfDIKeyboard);
    hr = DIKeyboard->SetCooperativeLevel(hWnd, DISCL_FOREGROUND | DISCL_NONEXCLUSIVE);

    hr = DIMouse->SetDataFormat(&c_dfDIMouse2);
    hr = DIMouse->SetCooperativeLevel(hWnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE | DISCL_NOWINKEY);

    return true;
}

void Game::detectInput(double delta)
{
    DIMOUSESTATE2 mouseCurrState;

    BYTE keyboardState[256];

    DIKeyboard->Acquire();
    DIMouse->Acquire();

    DIMouse->GetDeviceState(sizeof(DIMOUSESTATE2), &mouseCurrState);

    DIKeyboard->GetDeviceState(sizeof(keyboardState),(LPVOID)&keyboardState);

    camera.detectInput(delta, &keyboardState[0], &mouseCurrState);
}

void Camera::detectInput(double delta, BYTE *keyboardState, DIMOUSESTATE2 *mouseCurrState){

    float speed = 16.0f * delta;


    ...


    if((mouseCurrState->lX != mouseLastState.lX) || (mouseCurrState->lY != mouseLastState.lY))
{
    camYaw += mouseCurrState->lX * 0.002f;

    camPitch += mouseCurrState->lY * 0.002f;

    if(camPitch > 0.85f)
        camPitch = 0.85f;
    if(camPitch < -0.85f)
        camPitch = -0.85f;

    mouseLastState = *mouseCurrState;
}

    update();

    return;
}

void Camera::update(){
    camRotationMatrix = XMMatrixRotationRollPitchYaw(camPitch, camYaw, 0);
    camTarget = XMVector3TransformCoord(DefaultForward, camRotationMatrix );
    camTarget = XMVector3Normalize(camTarget);

    XMMATRIX RotateYTempMatrix;
    RotateYTempMatrix = XMMatrixRotationY(camYaw);

    camRight = XMVector3TransformCoord(DefaultRight, RotateYTempMatrix);
    camForward = XMVector3TransformCoord(DefaultForward, RotateYTempMatrix);
    camUp = XMVector3Cross(camForward, camRight);

    camPosition += moveLeftRight*camRight;
    camPosition += moveBackForward*camForward;
    camPosition += moveUpDown*DefaultUp;

    moveLeftRight = 0.0f;
    moveBackForward = 0.0f;
    moveUpDown = 0.0f;

    camTarget = camPosition + camTarget;    

    camView = XMMatrixLookAtLH( camPosition, camTarget, camUp );
}

对于那些想知道的人，我刚刚开始使用本教程学习 c++ 和 directx:http://www.braynzarsoft.net/index.php?p=DX11Lessons(虽然我有相当多的使用 OpenGL + java 的经验。)

Answer 1

我通过添加一个简单的 if 语句解决了这个问题:

if(mouseLastState.lX > -10000 && mouseLastState.lX < 10000){
    camYaw += mouseLastState.lX * 0.002f;
}

问题是，当窗口重新获得焦点时，它会返回一个如此高的值，以至于偏航不再有效。