C++ Directx 鼠标输入在失去焦点后表现怪异

Posted 2023-02-22

【中文标题】C++ Directx 鼠标输入在失去焦点后表现怪异

【英文标题】：C++ Directx mouse input acting weird after focus lost

【发布时间】：2014-06-11 17:12:39

【问题描述】：

您好，在我失去窗口焦点（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）动作缓慢且没有响应（由于某种原因，俯仰工作正常）。有时它会动，有时它根本不动。

以下是部分代码：

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。）

【问题讨论】：

不要将 DirectInput 用于鼠标或键盘。 在 Windows XP 或更高版本上，DirectInput 是对现有 Win32 消息 WM_MOUSE*、@987654324 之上的一点破解@，使用挂钩 API，因此只需自己使用 Win32 消息。目前 DirectInput 的唯一用途是使用 HID 操纵杆/控制器。

【参考方案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。