vector1.Normalize();

vector2.Normalize();

double cosinus = DotProduct(vector1, vector2);

double angle = (Math.Acos(cosinus) * (180.0 / Math.PI));

XMVECTOR  XMVector3AngleBetweenVectors( XMVECTOR V1, XMVECTOR V2 ); //返回向量V1、V2间的夹角[angle, angle,angle, angle]，单位为弧度

/// Handle new body data

void CBodyBasics::ProcessBody(IBody* pBody)

{

    HRESULT hr;

    BOOLEAN bTracked = false;

    hr = pBody->get_IsTracked(&bTracked);  // Retrieves a boolean value that indicates if the body is tracked

    if (SUCCEEDED(hr) && bTracked)  // 判断是否追踪到骨骼

    {

        Joint joints[JointType_Count];

        HandState leftHandState = HandState_Unknown;

        HandState rightHandState = HandState_Unknown;

        DepthSpacePoint *depthSpacePosition = new DepthSpacePoint[_countof(joints)]; // 存储深度坐标系中的关节点位置

        pBody->get_HandLeftState(&leftHandState);  // 获取左右手状态

        pBody->get_HandRightState(&rightHandState);

        hr = pBody->GetJoints(_countof(joints), joints); // 获得25个关节点

        if (SUCCEEDED(hr))

        {

            // Filtered Joint

            filter.Update(joints);

            const DirectX::XMVECTOR* vec = filter.GetFilteredJoints();    // Retrive Filtered Joints

            float angle = Angle(vec, JointType_WristRight, JointType_ElbowRight, JointType_ShoulderRight); // Get ElbowRight joint angle

            char s[];

            sprintf_s(s, "%.0f", angle);

            std::string strAngleInfo = s;

            putText(skeletonImg, strAngleInfo, cvPoint(, ), CV_FONT_HERSHEY_COMPLEX, 0.5, cvScalar(, , )); // 屏幕上显示角度信息

            for (int type = ; type < JointType_Count; type++)

            {

                if (joints[type].TrackingState != TrackingState::TrackingState_NotTracked)

                {

                    float x = 0.0f, y = 0.0f, z = 0.0f;

                    // Retrieve the x/y/z component of an XMVECTOR Data and storing that component's value in an instance of float referred to by a pointer

                    DirectX::XMVectorGetXPtr(&x, vec[type]);

                    DirectX::XMVectorGetYPtr(&y, vec[type]);

                    DirectX::XMVectorGetZPtr(&z, vec[type]);

                    CameraSpacePoint cameraSpacePoint = { x, y, z };

                    m_pCoordinateMapper->MapCameraPointToDepthSpace(cameraSpacePoint, &depthSpacePosition[type]); //将关节点坐标从摄像机坐标系转到深度坐标系以显示

                }

            }

            DrawBody(joints, depthSpacePosition);

            DrawHandState(depthSpacePosition[JointType_HandLeft], leftHandState);

            DrawHandState(depthSpacePosition[JointType_HandRight], rightHandState);

        }

        delete[] depthSpacePosition;

    }

    cv::imshow("skeletonImg", skeletonImg);

    cv::waitKey(); // 延时5ms

}

FLOAT CBodyBasics::Angle(const DirectX::XMVECTOR* vec, JointType jointA, JointType jointB, JointType jointC)

{

    float angle = 0.0;

    XMVECTOR vBA = XMVectorSubtract(vec[jointB], vec[jointA]);

    XMVECTOR vBC = XMVectorSubtract(vec[jointB], vec[jointC]);

    XMVECTOR vAngle = XMVector3AngleBetweenVectors(vBA, vBC);

    angle = XMVectorGetX(vAngle) * 180.0 * XM_1DIVPI;    // XM_1DIVPI: An optimal representation of 1 / π

    return angle;

}