自学教程：C++ D3DXVec3Cross函数代码示例

void Camera::lookAt(D3DXVECTOR3& pos, D3DXVECTOR3& target, D3DXVECTOR3& up){	D3DXVECTOR3 L = target - pos;	D3DXVec3Normalize(&L, &L);	D3DXVECTOR3 R;	D3DXVec3Cross(&R, &up, &L);	D3DXVec3Normalize(&R, &R);	D3DXVECTOR3 U;	D3DXVec3Cross(&U, &L, &R);	D3DXVec3Normalize(&U, &U);	m_posW = pos;	m_rightW = R;	m_upW = U;	m_lookW = L;	buildView();	buildFrustumPlanes();	m_viewProj = m_view * m_proj;}

void Geometry::setMesh(engine::Mesh* mesh){        assert( mesh->numVertices == _numVertices );    assert( mesh->numTriangles == _numTriangles );    assert( mesh->numUVs == _numUVSets );    unsigned int i,j;    for( i=0; i<_numVertices; i++ )    {        _vertices[i] = wrap( mesh->vertices[i] );    }    for( i=0; i<_numUVSets; i++ )    {        for( j=0; j<_numVertices; j++ )        {            _uvs[i][j] = wrap( mesh->uvs[i][j] );        }    }    for( i=0; i<_numTriangles; i++ )    {        _triangles[i].set(            mesh->triangles[i].vertexId[0],            mesh->triangles[i].vertexId[1],            mesh->triangles[i].vertexId[2],            mesh->triangles[i].shaderId        );    }    // calculate per-triangle normals    Vector e01, e02, n;    for( i=0; i<_numTriangles; i++ )    {        D3DXVec3Subtract(             &e01,             _vertices + mesh->triangles[i].vertexId[1],            _vertices + mesh->triangles[i].vertexId[0]        );        D3DXVec3Subtract(             &e02,             _vertices + mesh->triangles[i].vertexId[2],            _vertices + mesh->triangles[i].vertexId[0]        );        D3DXVec3Cross( &n, &e02, &e01 );        D3DXVec3Normalize( &n, &n );        _normals[mesh->triangles[i].vertexId[0]] = n;        _normals[mesh->triangles[i].vertexId[1]] = n;        _normals[mesh->triangles[i].vertexId[2]] = n;    }    instance();}

void CamerClass::GetViewMatrix(D3DXMATRIX* V){	//保持view局部坐标系，各自轴的彼此正交	D3DXVec3Normalize(&_look, &_look);	//look X right	D3DXVec3Cross(&_up, &_look, &_right);	D3DXVec3Normalize(&_up, &_up);	D3DXVec3Cross(&_right, &_up, &_look);	D3DXVec3Normalize(&_right, &_right);	// 生成view矩阵:	float x = -D3DXVec3Dot(&_right, &_pos);	float y = -D3DXVec3Dot(&_up, &_pos);	float z = -D3DXVec3Dot(&_look, &_pos);	(*V)(0,0) = _right.x; (*V)(0, 1) = _up.x; (*V)(0, 2) = _look.x; (*V)(0, 3) = 0.0f;	(*V)(1,0) = _right.y; (*V)(1, 1) = _up.y; (*V)(1, 2) = _look.y; (*V)(1, 3) = 0.0f;	(*V)(2,0) = _right.z; (*V)(2, 1) = _up.z; (*V)(2, 2) = _look.z; (*V)(2, 3) = 0.0f;	(*V)(3,0) = x;        (*V)(3, 1) = y;     (*V)(3, 2) = z;       (*V)(3, 3) = 1.0f;	return;}

void Camera::buildView(){	// Keep camera's axes orthogonal to each other and of unit length.	D3DXVec3Normalize(&mLookW, &mLookW);	D3DXVec3Cross(&mUpW, &mLookW, &mRightW);	D3DXVec3Normalize(&mUpW, &mUpW);	D3DXVec3Cross(&mRightW, &mUpW, &mLookW);	D3DXVec3Normalize(&mRightW, &mRightW);	// Fill in the view matrix entries.	float x = -D3DXVec3Dot(&mPosW, &mRightW);	float y = -D3DXVec3Dot(&mPosW, &mUpW);	float z = -D3DXVec3Dot(&mPosW, &mLookW);	mView(0,0) = mRightW.x; 	mView(1,0) = mRightW.y; 	mView(2,0) = mRightW.z; 	mView(3,0) = x;   	mView(0,1) = mUpW.x;	mView(1,1) = mUpW.y;	mView(2,1) = mUpW.z;	mView(3,1) = y;  	mView(0,2) = mLookW.x; 	mView(1,2) = mLookW.y; 	mView(2,2) = mLookW.z; 	mView(3,2) = z;   	mView(0,3) = 0.0f;	mView(1,3) = 0.0f;	mView(2,3) = 0.0f;	mView(3,3) = 1.0f;}

bool CPicking::CollisionCheckTriangle(D3DXVECTOR3 &PickPos, RAY &_ray, D3DXVECTOR3 &_v0, D3DXVECTOR3 &_v1, D3DXVECTOR3 &_v2){	float t,u,v;	t = u = v = 0.0f;	D3DXVECTOR3 v_edge1 = _v1 - _v0;	D3DXVECTOR3 v_edge2 = _v2 - _v0;	D3DXVECTOR3 tvec, pvec, qvec;	float det, inv_det;	D3DXVec3Cross(&pvec, &_ray.direction, &v_edge2);		det = D3DXVec3Dot(&v_edge1, &pvec);	if(det > -0.0001f && det < 0.0001f) return false;	inv_det = 1.0f / det;	tvec = _ray.origin - _v0;	u  = D3DXVec3Dot(&tvec, &pvec) * inv_det;	if(u < 0.0001f || u > 1.0001f) return false;		D3DXVec3Cross(&qvec, &tvec, &v_edge1);		v = D3DXVec3Dot(&_ray.direction, &qvec) * inv_det;	if(v < 0.0001f || (u+v) > 1.0001f ) return false;	_ray.fT = D3DXVec3Dot(&v_edge2, &qvec) * inv_det;	if(_ray.fT <= 0) return false;	PickPos = _v0 + (u * (_v1 - _v0)) + (v * (_v2 - _v0));	return true;}

void Camera::BuildViewMatrix(){	// Keep camera's axes orthogonal to each other and of unit length.	D3DXVec3Normalize(&m_vForward, &m_vForward);	D3DXVec3Cross(&m_vUp, &m_vForward, &m_vRight);	D3DXVec3Normalize(&m_vUp, &m_vUp);	D3DXVec3Cross(&m_vRight, &m_vUp, &m_vForward);	D3DXVec3Normalize(&m_vRight, &m_vRight);	// Fill in the view matrix entries.	float x = -D3DXVec3Dot(&m_vEyePoint, &m_vRight);	float y = -D3DXVec3Dot(&m_vEyePoint, &m_vUp);	float z = -D3DXVec3Dot(&m_vEyePoint, &m_vForward);	m_matView(0,0) = m_vRight.x; 	m_matView(1,0) = m_vRight.y; 	m_matView(2,0) = m_vRight.z; 	m_matView(3,0) = x;   	m_matView(0,1) = m_vUp.x;	m_matView(1,1) = m_vUp.y;	m_matView(2,1) = m_vUp.z;	m_matView(3,1) = y;  	m_matView(0,2) = m_vForward.x; 	m_matView(1,2) = m_vForward.y; 	m_matView(2,2) = m_vForward.z; 	m_matView(3,2) = z;   	m_matView(0,3) = 0.0f;	m_matView(1,3) = 0.0f;	m_matView(2,3) = 0.0f;	m_matView(3,3) = 1.0f;}

void AVCamera::walk(float units){	if( units == 0 ) return;	if(m_type == CAMERA_TYPE_LANDOBJECT)	{		D3DXVECTOR3 dir;		D3DXVec3Cross(&dir, &m_right, &D3DXVECTOR3(0,1,0));		m_pos += D3DXVECTOR3(dir.x, 0.f, dir.z) * units;	}	//type == air	else		m_pos += m_look * units;}

D3DXQUATERNION ArcBall::QuatFromBallPoints(D3DXVECTOR3& start_point, D3DXVECTOR3& end_point){    // Calculate rotate angle    float angle = D3DXVec3Dot(&start_point, &end_point);    // Calculate rotate axis    D3DXVECTOR3 axis;    D3DXVec3Cross(&axis, &start_point, &end_point);    // Build and Normalize the Quaternion    D3DXQUATERNION quat(axis.x, axis.y, axis.z, angle);    D3DXQuaternionNormalize(&quat, &quat);    return quat;}

void Camera::lookAt(const D3DXVECTOR3 &eye, const D3DXVECTOR3 &target, const D3DXVECTOR3 &up){    m_eye = eye;    m_zAxis = target - eye;    D3DXVec3Normalize(&m_zAxis, &m_zAxis);    m_viewDir = m_zAxis;    D3DXVec3Cross(&m_xAxis, &up, &m_zAxis);    D3DXVec3Normalize(&m_xAxis, &m_xAxis);    D3DXVec3Cross(&m_yAxis, &m_zAxis, &m_xAxis);    D3DXVec3Normalize(&m_yAxis, &m_yAxis);    D3DXVec3Normalize(&m_xAxis, &m_xAxis);    D3DXMatrixIdentity(&m_viewMatrix);    m_viewMatrix(0,0) = m_xAxis.x;    m_viewMatrix(1,0) = m_xAxis.y;    m_viewMatrix(2,0) = m_xAxis.z;    m_viewMatrix(3,0) = -D3DXVec3Dot(&m_xAxis, &eye);    m_viewMatrix(0,1) = m_yAxis.x;    m_viewMatrix(1,1) = m_yAxis.y;    m_viewMatrix(2,1) = m_yAxis.z;    m_viewMatrix(3,1) = -D3DXVec3Dot(&m_yAxis, &eye);    m_viewMatrix(0,2) = m_zAxis.x;    m_viewMatrix(1,2) = m_zAxis.y;    m_viewMatrix(2,2) = m_zAxis.z;    m_viewMatrix(3,2) = -D3DXVec3Dot(&m_zAxis, &eye);    // Extract the pitch angle from the view matrix.    m_accumPitchDegrees = D3DXToDegree(-asinf(m_viewMatrix(1,2)));}

void Camera::UpdateView(){    D3DXMatrixRotationYawPitchRoll(&rotationMatrix, yaw, pitch, 0);    D3DXVec3TransformCoord(&view, &v, &rotationMatrix);    D3DXVec3TransformCoord(&up, &u, &rotationMatrix);    D3DXVec3Normalize(&forward, &view);    D3DXVec3Cross(&right, &up, &view);    D3DXVec3Normalize(&right, &right);    view = eye + view;    D3DXMatrixLookAtLH(&viewMatrix, &eye, &view, &up);}

void Camera::updateView(float dt){	//rotation	D3DXMatrixRotationYawPitchRoll(&rotationMatrix, heading, pitch, 0);	D3DXVec3TransformCoord(&view,&dV,&rotationMatrix);	D3DXVec3TransformCoord(&up,&dU,&rotationMatrix);	D3DXVec3Normalize(&forward,&view);	D3DXVec3Cross(&strafeRight,&up,&view);	D3DXVec3Normalize(&strafeRight,&strafeRight);	view = eye + view;	D3DXMatrixLookAtLH(&viewMatrix,&eye,&view,&up);}

void CCameraKernel::CalculateViewMatrix(D3DXMATRIX *pMatrix){	//规范化三个向量使之成为正交矩阵	//规范化观察向量	D3DXVec3Normalize(&m_vLookVector, &m_vLookVector);	//使上向量与观察向量垂直	D3DXVec3Cross(&m_vUpVector, &m_vLookVector, &m_vRightVector);	//规范化上向量	D3DXVec3Normalize(&m_vUpVector, &m_vUpVector);	//右向量与上向量垂直	D3DXVec3Cross(&m_vRightVector, &m_vUpVector, &m_vLookVector);	//规范化右向量	D3DXVec3Normalize(&m_vRightVector, &m_vRightVector);	//创建取景变换矩阵	pMatrix->_11 = m_vRightVector.x;	pMatrix->_12 = m_vUpVector.x;	pMatrix->_13 = m_vLookVector.x;	pMatrix->_14 = 0.0f;	pMatrix->_21 = m_vRightVector.y;	pMatrix->_22 = m_vUpVector.y;	pMatrix->_23 = m_vLookVector.y;	pMatrix->_24 = 0.0f;	pMatrix->_31 = m_vRightVector.z;	pMatrix->_32 = m_vUpVector.z;	pMatrix->_33 = m_vLookVector.z;	pMatrix->_34 = 0.0f;	pMatrix->_41 = -D3DXVec3Dot(&m_vRightVector, &m_vCameraPosition);	pMatrix->_42 = -D3DXVec3Dot(&m_vUpVector, &m_vCameraPosition);	pMatrix->_43 = -D3DXVec3Dot(&m_vLookVector, &m_vCameraPosition);	pMatrix->_44 = 1.0f;}

bool U2IntectRayBox3D::Test(){	float aWdU[3], aAWdU[3], aDdU[3], aADdU[3], aAWxDdU[3], fRhs;	D3DXVECTOR3 diff = m_pRay->m_vOrigin - m_pBox->m_vCenter;	aWdU[0] = D3DXVec3Dot(&m_pRay->m_vDir, &m_pBox->m_avAxis[0]);	aAWdU[0] = U2Math::FAbs(aWdU[0]);	aDdU[0] = D3DXVec3Dot(&diff, &m_pBox->m_avAxis[0]);	aADdU[0] = U2Math::FAbs(aDdU[0]);	if(aADdU[0] > m_pBox->m_afExtent[0] && aDdU[0] * aWdU[0] >= 0.f)		return false;	aWdU[1] = D3DXVec3Dot(&m_pRay->m_vDir, &m_pBox->m_avAxis[1]);	aAWdU[1] = U2Math::FAbs(aWdU[1]);	aDdU[1] = D3DXVec3Dot(&diff, &m_pBox->m_avAxis[1]);	aADdU[1] = U2Math::FAbs(aDdU[1]);	if(aADdU[1] > m_pBox->m_afExtent[1] && aDdU[1] * aWdU[1] >= 0.f)		return false;	aWdU[2] = D3DXVec3Dot(&m_pRay->m_vDir, &m_pBox->m_avAxis[2]);	aAWdU[2] = U2Math::FAbs(aWdU[2]);	aDdU[2] = D3DXVec3Dot(&diff, &m_pBox->m_avAxis[2]);	aADdU[2] = U2Math::FAbs(aDdU[2]);	if(aADdU[2] > m_pBox->m_afExtent[2] && aDdU[2] * aWdU[2] >= 0.f)		return false;	D3DXVECTOR3 WxD;	D3DXVec3Cross(&WxD, &m_pRay->m_vDir, &diff);		aAWxDdU[0] = U2Math::FAbs(D3DXVec3Dot(&WxD, &m_pBox->m_avAxis[0]));	fRhs = m_pBox->m_afExtent[1] *aAWdU[2] + m_pBox->m_afExtent[2]*aAWdU[1];	if(aAWxDdU[0] > fRhs)		return false;	aAWxDdU[1] = U2Math::FAbs(D3DXVec3Dot(&WxD, &m_pBox->m_avAxis[1]));	fRhs = m_pBox->m_afExtent[0] *aAWdU[2] + m_pBox->m_afExtent[2]*aAWdU[0];	if(aAWxDdU[1] > fRhs)		return false;	aAWxDdU[2] = U2Math::FAbs(D3DXVec3Dot(&WxD, &m_pBox->m_avAxis[2]));	fRhs = m_pBox->m_afExtent[0] *aAWdU[1] + m_pBox->m_afExtent[1]*aAWdU[0];	if(aAWxDdU[2] > fRhs)		return false;	return true;}

OcTreeSector* RayIntersection::collideBSPOcTreeSector(OcTreeSector* ocTreeSector){    if( ocTreeSector->_triangles.size() )    {        // collide octree sector triangles        Triangle* triangle;        Vector    v0v1, v0v2, n;        Vector    hitPoint;        for( unsigned int i=0; i<ocTreeSector->_triangles.size(); i++ )        {            triangle = _triangles + ocTreeSector->_triangles[i];            if( ::intersectionRayTriangle(                      &_ray,                       _vertices + triangle->vertexId[0],                      _vertices + triangle->vertexId[1],                      _vertices + triangle->vertexId[2],                      &hitPoint,                      &_collisionTriangle.distance              ))            {                _collisionTriangle.vertices[0] = wrap( _vertices[triangle->vertexId[0]] );                _collisionTriangle.vertices[1] = wrap( _vertices[triangle->vertexId[1]] );                _collisionTriangle.vertices[2] = wrap( _vertices[triangle->vertexId[2]] );                v0v1 = _vertices[triangle->vertexId[1]] - _vertices[triangle->vertexId[0]];                v0v2 = _vertices[triangle->vertexId[2]] - _vertices[triangle->vertexId[0]];                D3DXVec3Cross( &n, &v0v1, &v0v2 );                D3DXVec3Normalize( &n, &n );                _collisionTriangle.normal = wrap( n );                _collisionTriangle.collisionPoint = wrap( hitPoint );                _collisionTriangle.shader = _geometry->shader( triangle->shaderId );                _collisionTriangle.triangleId = ocTreeSector->_triangles[i];                if( !_callBack( &_collisionTriangle, _bspSector, NULL, _callBackData ) ) return NULL;                return ocTreeSector;            }        }    }    else if( ocTreeSector->_subtree[0] )    {        for( unsigned int i=0; i<8; i++ )        {            if( intersectionRayAABB( &_ray, &ocTreeSector->_subtree[i]->_boundingBox ) )            {                if( !collideBSPOcTreeSector( ocTreeSector->_subtree[i] ) ) return NULL;            }        }    }    return ocTreeSector;}

/// 
C++ D3DXVec3Dot函数代码示例
C++ D3DXVECTOR4函数代码示例