我写的一个模拟管道算法

//在很多组态软件上都 管道图元，可以根据模拟出 管道内流动的效果。

//这个算法只是模拟起来看是向管道流动，其实还是有些不完美。 但是基本也是够用。利用部分直角三角形的特点，如勾股定理，正弦，余弦函数。其它人估计看不懂。

自己留个记念。借用Flex 中的线段工具 起点端点移动，产生类似管道流动的效果。加油，努力 。奋斗 。

///初始化            if (FlexBox->PointCount>1&&tempPre->ControlType==8)            {                    Flexpath::TPointArray APoints;                    Flexpath::TPointTypeArray ATypes;                           FlexBox->GetPointsEx(APoints,ATypes);                    int PointCount= FlexBox->PointCount;                    int EndPointIndex=FlexBox->PointCount-1;                    int penwidth=FlexBox->PenProp->Width;                    /*以下根据三角型 勾股定理计算                    */                    double Y_0=APoints[0].y;                    double X_0=APoints[0].x;                    double Y_1=APoints[1].y;                    double X_1=APoints[1].x;                   //  double AB=Y_1-Y_0;    COSa =AB/AB                    double Big_AB=Y_1-Y_0;                    tempPre->IS__Yopposite_direction=false;                    tempPre->IS__Xopposite_direction=false;                    if (Big_AB<0)                    {                         Big_AB=abs(Big_AB);                         tempPre->IS__Yopposite_direction=true;//                    }                    double Big_AD=Big_AB;                    double Big_BC=X_1-X_0;                    if (Big_BC<0)                    {                         Big_BC=abs(Big_BC);                         tempPre->IS__Xopposite_direction=true;//                    }                    double Big_AC=sqrt(Big_AB*Big_AB+Big_BC*Big_BC);                    double Big_AF=0;                    if ((Big_BC*Big_AB)!=0)                    {                         Big_AF=Big_AB/Big_AC*Big_AD;                    }                    double Big_FD=sqrt(Big_AD*Big_AD-Big_AF*Big_AF);                    double Use_CosA=0;                    if (Big_AC!=0)                    {                         Use_CosA=Big_AB/Big_AC;                    }                    //以上为算出斜边长度，余弦值 ，                   //  double AB=Y_1-Y_0;    COSa =AB/AB                    double AB=penwidth*3;                    double AD=AB;                    double AC=0 ;                    if (Use_CosA!=0)                    {                         AC=AB/Use_CosA ;                    }                    double BC=sqrt(AC*AC-AB*AB);                    double AF=0;                    if ((BC*AB)!=0)                    {                         AF=AB/AC*AD;                    }                    double FD=sqrt(AD*AD-AF*AF);                    if (tempPre->IS__Xopposite_direction)//                    {                        tempPre->PipingX_Step=0-abs(FD/10);                    }                    else                    {                        tempPre->PipingX_Step=abs(FD/10);                                        }                     //以上为算出一个最大移动曲间。如果第二点的 的坐标小于第一点，则算出绝对值 。在运行中反向移动即可。                    if (tempPre->IS__Yopposite_direction)//                    {                        tempPre->PipingY_Step=0-abs(AF/10);                    }                    else                    {                        tempPre->PipingY_Step=abs(AF/10);                    }

//运行，变化

                            TFlexCurve*tempcurve=(TFlexCurve*)Road;                          //  tempcurve->                            TPoint AnchorPoint=tempcurve->AnchorPoint;                            int dddd=tempcurve-> NodeCount;                            //int dddd=tempcurve->NodeCount;                            int PointCount= tempcurve->PointCount;                            int EndPointIndex=tempcurve->PointCount-1;                            TPoint temppp;                            Flexpath::TPointArray APoints;                            Flexpath::TPointTypeArray ATypes;                            tempcurve->PenProp->Width;                            tempcurve->GetPointsEx(APoints,ATypes);                             if (tempPre->PipingMoveForWord==1)                             {                                  if (tempPre->PipingStep<10)                                  {                                       APoints[0].y+=tempPre->PipingY_Step;                                       APoints[0].x+=tempPre->PipingX_Step;                                       tempPre->PipingLoadAllLenY_Change+=tempPre->PipingY_Step;                                       tempPre->PipingLoadAllLenX_Change+=tempPre->PipingX_Step;                                       tempPre->PipingStep++;                                  }                                  else                                  {                                       APoints[0].y-=tempPre->PipingLoadAllLenY_Change;                                       APoints[0].x-=tempPre->PipingLoadAllLenX_Change;                                       tempPre->PipingLoadAllLenY_Change=0;                                       tempPre->PipingLoadAllLenX_Change=0;;                                       tempPre->PipingStep=0;                                  }                             }                             else  if (tempPre->PipingMoveForWord==2)                             {                                  if (tempPre->PipingStep<10)                                  {                                       APoints[0].y-=tempPre->PipingY_Step;                                       APoints[0].x-=tempPre->PipingX_Step;                                       tempPre->PipingLoadAllLenY_Change-=tempPre->PipingY_Step;                                       tempPre->PipingLoadAllLenX_Change-=tempPre->PipingX_Step;                                       tempPre->PipingStep++;                                  }                                  else                                  {                                       APoints[0].y+=tempPre->PipingLoadAllLenY_Change;                                       APoints[0].x+=tempPre->PipingLoadAllLenX_Change;                                       tempPre->PipingLoadAllLenY_Change=0;                                       tempPre->PipingLoadAllLenX_Change=0;                                       tempPre->PipingStep=0;                                  }                             }                             tempcurve->SetPoints(APoints);