dxutmisc.cpp

在GPU上实现数值模拟技术（线性方程组）的通用架构

//--------------------------------------------------------------------------------------
D3DXQUATERNION CD3DArcBall::QuatFromBallPoints(const D3DXVECTOR3 &vFrom, const D3DXVECTOR3 &vTo)
{
    D3DXVECTOR3 vPart;
    float fDot = D3DXVec3Dot(&vFrom, &vTo);
    D3DXVec3Cross(&vPart, &vFrom, &vTo);

    return D3DXQUATERNION(vPart.x, vPart.y, vPart.z, fDot);
}




//--------------------------------------------------------------------------------------
void CD3DArcBall::OnBegin( int nX, int nY )
{
    // Only enter the drag state if the click falls
    // inside the click rectangle.
    if( nX >= m_Offset.x &&
        nX < m_Offset.x + m_nWidth &&
        nY >= m_Offset.y &&
        nY < m_Offset.y + m_nHeight )
    {
        m_bDrag = true;
        m_qDown = m_qNow;
        m_vDownPt = ScreenToVector( (float)nX, (float)nY );
    }
}




//--------------------------------------------------------------------------------------
void CD3DArcBall::OnMove( int nX, int nY )
{
    if (m_bDrag) 
    { 
        m_vCurrentPt = ScreenToVector( (float)nX, (float)nY );
        m_qNow = m_qDown * QuatFromBallPoints( m_vDownPt, m_vCurrentPt );
    }
}




//--------------------------------------------------------------------------------------
void CD3DArcBall::OnEnd()
{
    m_bDrag = false;
}




//--------------------------------------------------------------------------------------
// Desc:
//--------------------------------------------------------------------------------------
LRESULT CD3DArcBall::HandleMessages( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
{
    // Current mouse position
    int iMouseX = (short)LOWORD(lParam);
    int iMouseY = (short)HIWORD(lParam);

    switch( uMsg )
    {
        case WM_LBUTTONDOWN:
        case WM_LBUTTONDBLCLK:
            SetCapture( hWnd );
            OnBegin( iMouseX, iMouseY );
            return TRUE;

        case WM_LBUTTONUP:
            ReleaseCapture();
            OnEnd();
            return TRUE;

        case WM_RBUTTONDOWN:
        case WM_RBUTTONDBLCLK:
        case WM_MBUTTONDOWN:
        case WM_MBUTTONDBLCLK:
            SetCapture( hWnd );
            // Store off the position of the cursor when the button is pressed
            m_ptLastMouse.x = iMouseX;
            m_ptLastMouse.y = iMouseY;
            return TRUE;

        case WM_RBUTTONUP:
        case WM_MBUTTONUP:
            ReleaseCapture();
            return TRUE;

        case WM_MOUSEMOVE:
            if( MK_LBUTTON&wParam )
            {
                OnMove( iMouseX, iMouseY );
            }
            else if( (MK_RBUTTON&wParam) || (MK_MBUTTON&wParam) )
            {
                // Normalize based on size of window and bounding sphere radius
                FLOAT fDeltaX = ( m_ptLastMouse.x-iMouseX ) * m_fRadiusTranslation / m_nWidth;
                FLOAT fDeltaY = ( m_ptLastMouse.y-iMouseY ) * m_fRadiusTranslation / m_nHeight;

                if( wParam & MK_RBUTTON )
                {
                    D3DXMatrixTranslation( &m_mTranslationDelta, -2*fDeltaX, 2*fDeltaY, 0.0f );
                    D3DXMatrixMultiply( &m_mTranslation, &m_mTranslation, &m_mTranslationDelta );
                }
                else  // wParam & MK_MBUTTON
                {
                    D3DXMatrixTranslation( &m_mTranslationDelta, 0.0f, 0.0f, 5*fDeltaY );
                    D3DXMatrixMultiply( &m_mTranslation, &m_mTranslation, &m_mTranslationDelta );
                }

                // Store mouse coordinate
                m_ptLastMouse.x = iMouseX;
                m_ptLastMouse.y = iMouseY;
            }
            return TRUE;
    }

    return FALSE;
}




//--------------------------------------------------------------------------------------
// Constructor
//--------------------------------------------------------------------------------------
CBaseCamera::CBaseCamera()
{
    ZeroMemory( m_aKeys, sizeof(BYTE)*CAM_MAX_KEYS );

    // Set attributes for the view matrix
    D3DXVECTOR3 vEyePt    = D3DXVECTOR3(0.0f,0.0f,0.0f);
    D3DXVECTOR3 vLookatPt = D3DXVECTOR3(0.0f,0.0f,1.0f);

    // Setup the view matrix
    SetViewParams( &vEyePt, &vLookatPt );

    // Setup the projection matrix
    SetProjParams( D3DX_PI/4, 1.0f, 1.0f, 1000.0f );

    GetCursorPos( &m_ptLastMousePosition );
    m_bMouseLButtonDown = false;
    m_bMouseMButtonDown = false;
    m_bMouseRButtonDown = false;
    m_nCurrentButtonMask = 0;
    m_nMouseWheelDelta = 0;

    m_fCameraYawAngle = 0.0f;
    m_fCameraPitchAngle = 0.0f;

    SetRect( &m_rcDrag, LONG_MIN, LONG_MIN, LONG_MAX, LONG_MAX );
    m_vVelocity     = D3DXVECTOR3(0,0,0);
    m_bMovementDrag = false;
    m_vVelocityDrag = D3DXVECTOR3(0,0,0);
    m_fDragTimer    = 0.0f;
    m_fTotalDragTimeToZero = 0.25;
    m_vRotVelocity = D3DXVECTOR2(0,0);

    m_fRotationScaler = 0.01f;           
    m_fMoveScaler = 5.0f;           

    m_bInvertPitch = false;
    m_bEnableYAxisMovement = true;
    m_bEnablePositionMovement = true;

    m_vMouseDelta   = D3DXVECTOR2(0,0);
    m_fFramesToSmoothMouseData = 2.0f;

    m_bClipToBoundary = false;
    m_vMinBoundary = D3DXVECTOR3(-1,-1,-1);
    m_vMaxBoundary = D3DXVECTOR3(1,1,1);

    m_bResetCursorAfterMove = false;
}


//--------------------------------------------------------------------------------------
// Client can call this to change the position and direction of camera
//--------------------------------------------------------------------------------------
VOID CBaseCamera::SetViewParams( D3DXVECTOR3* pvEyePt, D3DXVECTOR3* pvLookatPt )
{
    if( NULL == pvEyePt || NULL == pvLookatPt )
        return;

    m_vDefaultEye = m_vEye = *pvEyePt;
    m_vDefaultLookAt = m_vLookAt = *pvLookatPt;

    // Calc the view matrix
    D3DXVECTOR3 vUp(0,1,0);
    D3DXMatrixLookAtLH( &m_mView, pvEyePt, pvLookatPt, &vUp );

    D3DXMATRIX mInvView;
    D3DXMatrixInverse( &mInvView, NULL, &m_mView );

    // The axis basis vectors and camera position are stored inside the 
    // position matrix in the 4 rows of the camera's world matrix.
    // To figure out the yaw/pitch of the camera, we just need the Z basis vector
    D3DXVECTOR3* pZBasis = (D3DXVECTOR3*) &mInvView._31;

    m_fCameraYawAngle   = atan2f( pZBasis->x, pZBasis->z );
    float fLen = sqrtf(pZBasis->z*pZBasis->z + pZBasis->x*pZBasis->x);
    m_fCameraPitchAngle = -atan2f( pZBasis->y, fLen );
}




//--------------------------------------------------------------------------------------
// Calculates the projection matrix based on input params
//--------------------------------------------------------------------------------------
VOID CBaseCamera::SetProjParams( FLOAT fFOV, FLOAT fAspect, FLOAT fNearPlane,
                                   FLOAT fFarPlane )
{
    // Set attributes for the projection matrix
    m_fFOV        = fFOV;
    m_fAspect     = fAspect;
    m_fNearPlane  = fNearPlane;
    m_fFarPlane   = fFarPlane;

    D3DXMatrixPerspectiveFovLH( &m_mProj, fFOV, fAspect, fNearPlane, fFarPlane );
}




//--------------------------------------------------------------------------------------
// Call this from your message proc so this class can handle window messages
//--------------------------------------------------------------------------------------
LRESULT CBaseCamera::HandleMessages( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam )
{
    UNREFERENCED_PARAMETER( hWnd );
    UNREFERENCED_PARAMETER( lParam );

    switch( uMsg )
    {
        case WM_KEYDOWN:
        {
            // Map this key to a D3DUtil_CameraKeys enum and update the
            // state of m_aKeys[] by adding the KEY_WAS_DOWN_MASK|KEY_IS_DOWN_MASK mask
            // only if the key is not down
            D3DUtil_CameraKeys mappedKey = MapKey( (UINT)wParam );
            if( mappedKey != CAM_UNKNOWN )
            {
                if( FALSE == IsKeyDown(m_aKeys[mappedKey]) )
                    m_aKeys[ mappedKey ] = KEY_WAS_DOWN_MASK | KEY_IS_DOWN_MASK;
            }
            break;
        }

        case WM_KEYUP:
        {
            // Map this key to a D3DUtil_CameraKeys enum and update the
            // state of m_aKeys[] by removing the KEY_IS_DOWN_MASK mask.
            D3DUtil_CameraKeys mappedKey = MapKey( (UINT)wParam );
            if( mappedKey != CAM_UNKNOWN )
                m_aKeys[ mappedKey ] &= ~KEY_IS_DOWN_MASK;
            break;
        }

        case WM_RBUTTONDOWN:
        case WM_MBUTTONDOWN:
        case WM_LBUTTONDOWN:
        case WM_RBUTTONDBLCLK:
        case WM_MBUTTONDBLCLK:
        case WM_LBUTTONDBLCLK:
        {
            // Compute the drag rectangle in screen coord.
            POINT ptCursor = { (short)LOWORD(lParam), (short)HIWORD(lParam) };

            // Update member var state
            if( ( uMsg == WM_LBUTTONDOWN || uMsg == WM_LBUTTONDBLCLK ) && PtInRect( &m_rcDrag, ptCursor ) )
                { m_bMouseLButtonDown = true; m_nCurrentButtonMask |= MOUSE_LEFT_BUTTON; }
            if( ( uMsg == WM_MBUTTONDOWN || uMsg == WM_MBUTTONDBLCLK ) && PtInRect( &m_rcDrag, ptCursor ) )
                { m_bMouseMButtonDown = true; m_nCurrentButtonMask |= MOUSE_MIDDLE_BUTTON; }
            if( ( uMsg == WM_RBUTTONDOWN || uMsg == WM_RBUTTONDBLCLK ) && PtInRect( &m_rcDrag, ptCursor ) )
                { m_bMouseRButtonDown = true; m_nCurrentButtonMask |= MOUSE_RIGHT_BUTTON; }

            // Capture the mouse, so if the mouse button is 
            // released outside the window, we'll get the WM_LBUTTONUP message
            SetCapture(hWnd);
            GetCursorPos( &m_ptLastMousePosition );
            return TRUE;
        }

        case WM_RBUTTONUP: 
        case WM_MBUTTONUP: 
        case WM_LBUTTONUP:   
        {
            // Update member var state
            if( uMsg == WM_LBUTTONUP ) { m_bMouseLButtonDown = false; m_nCurrentButtonMask &= ~MOUSE_LEFT_BUTTON; }
            if( uMsg == WM_MBUTTONUP ) { m_bMouseMButtonDown = false; m_nCurrentButtonMask &= ~MOUSE_MIDDLE_BUTTON; }
            if( uMsg == WM_RBUTTONUP ) { m_bMouseRButtonDown = false; m_nCurrentButtonMask &= ~MOUSE_RIGHT_BUTTON; }

            // Release the capture if no mouse buttons down
            if( !m_bMouseLButtonDown  && 
                !m_bMouseRButtonDown &&
                !m_bMouseMButtonDown )
            {
                ReleaseCapture();
            }
            break;
        }

        case WM_MOUSEWHEEL: 
            // Update member var state
            m_nMouseWheelDelta = (short)HIWORD(wParam) / 120;
            break;
    }

    return FALSE;
}




//--------------------------------------------------------------------------------------
// Figure out the mouse delta based on mouse movement
//--------------------------------------------------------------------------------------
void CBaseCamera::UpdateMouseDelta( float fElapsedTime )
{
    UNREFERENCED_PARAMETER( fElapsedTime );

    POINT ptCurMouseDelta;
    POINT ptCurMousePos;
    
    // Get current position of mouse
    GetCursorPos( &ptCurMousePos );

    // Calc how far it's moved since last frame
    ptCurMouseDelta.x = ptCurMousePos.x - m_ptLastMousePosition.x;
    ptCurMouseDelta.y = ptCurMousePos.y - m_ptLastMousePosition.y;

    // Record current position for next time
    m_ptLastMousePosition = ptCurMousePos;

    if( m_bResetCursorAfterMove )
    {
        // Set position of camera to center of desktop, 
        // so it always has room to move.  This is very useful
        // if the cursor is hidden.  If this isn't done and cursor is hidden, 
        // then invisible cursor will hit the edge of the screen 
        // and the user can't tell what happened
        POINT ptCenter;
        RECT rcDesktop;
        GetWindowRect( GetDesktopWindow(), &rcDesktop );