拓扑多边形生成算法（C++源码）二 代码篇

 

这里主要是补充拓扑多边形生成算法（C++源码）一的代码内容和代码运行情况，希望给大家学习多边形生成算法带来帮助！

源程序下载地址：http://download.csdn.net/source/1870862

1、读入数据图像（程序中不会显示图像，图像的点和弧段信息保存在文本中）

 

2、在屏幕上输出拓扑信息

 

补充代码：

 

/**函数功能：计算两条直线逆时针方向的夹角*参数信息：start：起始点；inf：拐点；end：终止点*返回值：两条直线之间的夹角（弧度）； */double CreatePolygons::AngleOfTwoArcs(Point* start, Point* inf, Point* end){double aa = ( start->X - inf->X ) * ( start->X - inf->X ) + ( start->Y - inf->Y ) * ( start->Y - inf->Y );double bb = ( inf->X - end->X ) * ( inf->X - end->X ) + ( inf->Y - end->Y ) * ( inf->Y - end->Y );double cc = ( start->X - end->X ) * ( start->X - end->X ) + ( start->Y - end->Y ) * ( start->Y - end->Y );double cosValue = ( aa + bb - cc ) / ( 2 * sqrt( aa ) * sqrt( bb ) );double angle = acos( cosValue );double coeff1 = 0.0f, coeff2 = 0.0f;if ( start->Y != inf->Y ){coeff1 = ( double )( inf->X - start->X ) / ( double )( start->Y - inf->Y );coeff2 = ( double )( start->X * inf->Y - inf->X * start->Y ) / ( double )( start->Y - inf->Y );if ( start->Y > inf->Y ){if ( end->X + coeff1 * end->Y + coeff2 <= 0 ) {return angle;}else{return ( PI * 2 - angle );}}else if ( start->Y < inf->Y ){if ( end->X + coeff1 * end->Y + coeff2 <= 0 ){return ( PI * 2 - angle );}else{return angle;}}}else if ( start->Y == inf->Y ){if ( inf->X > start->X ){if ( end->Y < start->Y ){return angle;}else{return ( PI * 2 - angle );}}else if ( inf->X < start->X ){if ( end->Y < start->Y ){return ( PI * 2 - angle );}else{return angle;}}}return 10.0f;}void CreatePolygons::MainCreatePolygons(void){//建立点-弧段关系，而弧段-点关系在函数OpenFile已经建立this->BuildPointArcs();//多边形自动够构建算法for (int i = 0; i < (int)Arcs.size(); i++){Arc* arc = Arcs[i];if (arc->TimeOfSearch == 0){Buildpolygons(arc);}}}bool CreatePolygons::OpenFile(const char *filename){FILE* fp;char ss[20];int pNum, lNum;char lcode[20];int code;float left_x, left_y;if((fp=fopen(filename,"r"))==0) return false;//读入点fscanf(fp,"%s",ss);if(strcmp(ss,"Point:")!=0){cout << "文件格式不正确!" << endl;return false;}fscanf(fp,"%d",&pNum);for(int i=0;i<pNum;i++){fscanf(fp,"%ld%f%f",&code,&left_x,&left_y);cout << code << " " << left_x << " " << left_y << endl;Point *point = new Point;point->ID = code;point->X = left_x;point->Y = left_y;Points.push_back(point);}//读入弧段fscanf(fp,"%s",ss);if(strcmp(ss,"Line:")!=0){cout << "文件格式不正确!" << endl;return false;}fscanf(fp,"%d",&lNum);cout << "共有弧段：" << lNum << endl;for(int i=0;i<lNum;i++){Arc *arc = new Arc;fscanf(fp,"%s%d",lcode,&pNum);cout << "弧段编号：" << lcode<< "弧段上点的个数："<< pNum << endl;string str(lcode);arc->ID = str;arc->Direction = 1;arc->TimeOfSearch = 0;for(int j=0;j<pNum;j++){int pp;fscanf(fp,"%d",&pp);cout << pp << " ";Point *p = SearchPointbyID(pp);if (p != NULL){arc ->Points.push_back(p);} else{cout << "没有找到合适的点！"<<endl;}}cout << endl;Arcs.push_back(arc);}fclose(fp);return true;}Arc* CreatePolygons::GetNextArc(Arc* cuarc){Point *start, *start0;PointArcs* PtArcs;double hudu;Arc* NextArc = cuarc;Angles.clear();//清空所有的角度if (cuarc->Direction == 1){start0 = *(cuarc->Points.end() -2);//起始点start = *(cuarc->Points.end() - 1);PtArcs = SearchPtArcsByPt(start);for (int i = 0; i < (int)PtArcs->arcs.size(); i++){if ((strcmp(cuarc->ID.c_str(),PtArcs->arcs[i]->ID.c_str())!= 0) && (PtArcs->arcs[i]->TimeOfSearch < 2)){Angle angle;Point *sta, *end;sta = *(PtArcs->arcs[i]->Points.begin());end = *(PtArcs->arcs[i]->Points.end() - 1);//确认扩展弧段if (sta->ID == start->ID)//准扩展弧段以第一记录开始,方向与当前弧段相反{sta = *(PtArcs->arcs[i]->Points.begin() + 1);hudu = AngleOfTwoArcs(start0, start, sta);angle.Direction = 1;}else if(end->ID == start->ID)//准扩展弧段以最后记录开始，方向与当前弧段一样{end = *(PtArcs->arcs[i]->Points.end() - 2);hudu = AngleOfTwoArcs(start0, start, end);angle.Direction = -1;}//angle.Direction = cuarc->Direction;angle.angle = hudu;angle.arcs = PtArcs->arcs[i];Angles.push_back(angle);}}} else if(cuarc->Direction == -1){start0 = *(cuarc->Points.begin() + 1);//起始点start = *(cuarc->Points.begin());PtArcs = SearchPtArcsByPt(start);for (int i = 0; i < (int)PtArcs->arcs.size(); i++){if ((strcmp(cuarc->ID.c_str(), PtArcs->arcs[i]->ID.c_str()) != 0) && (PtArcs->arcs[i]->TimeOfSearch < 2)){Angle angle;Point *sta, *end;sta = *(PtArcs->arcs[i]->Points.begin());end = *(PtArcs->arcs[i]->Points.end() - 1);//确认扩展弧段if (sta->ID == start->ID)//准扩展弧段以第一记录开始,方向与当前弧段相反{sta = *(PtArcs->arcs[i]->Points.begin() + 1);hudu = AngleOfTwoArcs(start0, start, sta);angle.Direction = 1;}else if(end->ID == start->ID)//准扩展弧段以最后记录开始，方向与当前弧段一样{end = *(PtArcs->arcs[i]->Points.end() - 2);hudu = AngleOfTwoArcs(start0, start, end);angle.Direction = -1;}angle.angle = hudu;angle.arcs = PtArcs->arcs[i];Angles.push_back(angle);}}}else{cout << "弧段的方向错误！" << endl;}if (Angles.size() == 0){return NextArc;//没有任何夹角时返回弧段本身}MinAngle = GetMinAngle(Angles);//得到扩展弧段的IDNextArc = MinAngle.arcs;return NextArc;}void CreatePolygons::Createpolygons(Arc* cuarc){vector<Polygon*> polygons;//记录多边形图Polygon* polygon = BuildOnePolygon(cuarc);vector<Point*> lpoints;lpoints = GetPlPoints(polygon);polygon->Points = lpoints;polygon->area = abs(GetArea(lpoints));//计算面积polygons.push_back(polygon);for (int i = 0; i < (int)Arcs.size(); i++){if (Arcs[i]->TimeOfSearch == 1){Arcs[i]->Direction *= -1;polygon = BuildOnePolygon(Arcs[i]);if (polygon == NULL){return;}//计算多边形面积vector<Point*> points;points = GetPlPoints(polygon);polygon->area = abs(GetArea(points));polygon->Points = points;polygons.push_back(polygon);i = 0;//每次都从第一个弧段搜索}}//一个多边形图构建完毕，还要去除面积最大的多边形（不符合）this->RemoveMaxPolygon(polygons);for (int i = 0; i < (int)polygons.size(); i++){polygons[i]->ID = Pid;Pid++;Polygons.push_back(polygons[i]);}}Polygon* CreatePolygons::CreateOnePolygon(Arc* cuarc){Polygon* polygon = new Polygon;Arc * NextArc;NextArc = GetNextArc(cuarc);ArcDir *arcpoint0 = new ArcDir;arcpoint0->arcs = cuarc;arcpoint0->Direction = cuarc->Direction;//将多边形的起始弧段添加到多边形中polygon->ArcPts.push_back(arcpoint0);if (NextArc == NULL){delete polygon;return NULL;}while (1){if ((NextArc != cuarc) && (NextArc->TimeOfSearch < 2)){NextArc->Direction = MinAngle.Direction;//扩展弧段的遍历次数增加,除去对第二次起始弧段的遍历NextArc->TimeOfSearch += 1;ArcDir *arcpoint = new ArcDir;arcpoint->arcs = NextArc;arcpoint->Direction = NextArc->Direction;polygon->ArcPts.push_back(arcpoint);NextArc = GetNextArc(NextArc);}else{break;//一个多边形构建完毕}}cuarc->TimeOfSearch += 1;//起始弧段的遍历次数增加return polygon;}void CreatePolygons::RemoveMaxPolygon(vector<Polygon*>& Polygons){vector<Polygon*>::iterator maxiter;double max;maxiter = Polygons.begin();max = (*maxiter)->area;for(vector<Polygon*>::iterator iter = Polygons.begin()+1; iter != Polygons.end(); iter++ ) {if (max <= (*iter)->area){maxiter = iter;max = (*iter)->area;}}Polygons.erase(maxiter);}//面积为正可以判断多边型正面，面积为负表示多边形背面double CreatePolygons::GetArea(vector<Point*> pPoint){double S = 0;int nNum = (int)pPoint.size();for(int i = 0; i < nNum - 1; i++)S+=pPoint[i]->X * pPoint[i+1]->Y - pPoint[i+1]->X * pPoint[i]->Y;S += pPoint[nNum-1]->X * pPoint[0]->Y - pPoint[0]->X * pPoint[nNum-1]->Y;S /= 2.0;return S;}void CreateTopology::CreatePolArc(vector<Polygon*> Polygons){for (int i = 0; i < (int)Polygons.size(); i++){TPolArc* tpolarc = new TPolArc;tpolarc->PolID = Polygons[i]->ID;for (int j = 0; j < (int)Polygons[i]->ArcPts.size();j++){string id = Polygons[i]->ArcPts[j]->arcs->ID;tpolarc->ArcID.push_back(id);}if ((int)Polygons[i]->ArcPts.size() == 1){Arc * arc = Polygons[i]->ArcPts[0]->arcs;//仅有一多边形可能为岛//取多边形上任意一点，判断是否在其他多边形中if (PtInisland(Polygons, Polygons[i])){ModifyPol(islandinfo.OutPolID);}}PolArc.push_back(tpolarc);}}bool CreateTopology::PtInisland(std::vector<Polygon*> Polygons, Polygon* polygon){bool flag = false;Point* point = polygon->ArcPts[0]->arcs->Points[0];for (int i = 0; i < (int)Polygons.size(); i++){if (polygon->ID != Polygons[i]->ID){vector<Point*> points = Polygons[i]->Points;bool n = PtInRegion(point, points);if (n)//在多边形内部的情况{string id("-");id += polygon->ArcPts[0]->arcs->ID;islandinfo.BeforeID = polygon->ArcPts[0]->arcs->ID;islandinfo.AfterID = id;islandinfo.OutPolID = Polygons[i]->ID;islandinfo.InPolID = polygon->ID;flag = true;break;}}}return flag;}//判断出岛，需要将岛的弧段添加到包含的多边形弧段关系中void CreateTopology::ModifyPol(char PolID){TPolArc * polarc;for (int i = 0; i < (int)PolArc.size(); i++){if (PolID == PolArc[i]->PolID){polarc = PolArc[i];polarc->ArcID.push_back(islandinfo.AfterID);}}}//判断点是否在多边形中bool CreateTopology::PtInRegion(Point* point, vector<Point*> pllPoint) { int wn = 0; // the winding number counterstd::vector<Point *>::iterator it;// loop through all edges of the polygonfor (it=pllPoint.begin(); it<pllPoint.end()-1; it++)// edge from V[i] to V[i+1]{if ((*(it))->Y <= point->Y) { // start Y <= pt->Yif ((*(it+1))->Y > point->Y) // an upward crossingif (IsLeft( *it, *(it+1), point) > 0) // P left of edge++wn; // have a valid up intersect}else { // start Y > P.Y (no test needed)if ((*(it+1))->Y <= point->Y) // a downward crossingif (IsLeft( *it, *(it+1), point) < 0) // P right of edge--wn; // have a valid down intersect}}if (wn==0)return false;return true;} double CreateTopology::IsLeft(Point *P0, Point *P1, Point *P2 ){return ( (P1->X - P0->X) * (P2->Y - P0->Y)- (P2->X - P0->X) * (P1->Y - P0->Y) );}void CreateTopology::BuildArcPol(vector<Arc*> arcs, vector<Polygon*> Polygons){vector<Arc*>::iterator iterA;for (iterA = arcs.begin(); iterA != arcs.end(); iterA++){TArcPol* tarcpol = new TArcPol;tarcpol->ArcID = (*iterA)->ID;vector<Point*>::iterator iterB;vector<Point*>::iterator iterE;iterB = (*iterA)->Points.begin();iterE = (*iterA)->Points.end()-1;tarcpol->StartID = (*iterB)->ID;tarcpol->EndID = (*iterE)->ID;vector<Polygon*>::iterator iterP;bool right = false, left = false;//判断是否为岛（即单弧段）,目前只能可以判断一个岛，没有考虑多个岛的情况if (strcmp((*iterA)->ID.c_str(),islandinfo.BeforeID.c_str()) ==0){tarcpol->RightP = islandinfo.InPolID;tarcpol->LeftP = islandinfo.OutPolID;right = true;left = true;}else{for ( iterP = Polygons.begin(); iterP != Polygons.end(); iterP++){for (int i = 0; i < (int)(*iterP)->ArcPts.size(); i++){ArcDir* arcpoint = (*iterP)->ArcPts[i];Arc * arc = arcpoint->arcs;if (strcmp((*iterA)->ID.c_str(), arc->ID.c_str()) == 0){if (arcpoint->Direction == 1){tarcpol->RightP = (*iterP)->ID;right = true;}else if (arcpoint->Direction == -1){tarcpol->LeftP = (*iterP)->ID;left = true;}}}}}if (right == true && left == false){tarcpol->LeftP = 'Q';}if (right == false && left == true){tarcpol->LeftP = 'Q';}ArcPol.push_back(tarcpol);}}void CreateTopology::PrintTopTables(void){cout << "/n/n" << "点的坐标文件" << endl;cout <<"点号"<< " "<< "坐标" << " " << "点号"<< " "<< "坐标"<< endl;for (int i = 0; i < (int)Points.size(); i++){cout << " " << this->Points[i]->ID << " " << "(" << this->Points[i]->X << "," << this->Points[i]->Y << ")" << " ";if (i < (int)Points.size() -1){i++;cout << " " << this->Points[i]->ID << " " << "(" << this->Points[i]->X << "," << this->Points[i]->Y << ")" << endl;}}cout << "/n/n" << "弧段-点文件" << endl;cout << "多边形ID" << " " << "弧段号"<< endl;for (int i = 0; i < (int)Arcpoints.size(); i++){cout << " " << Arcpoints[i]->ArcID.c_str() << " " ;for (int j = 0; j < (int)Arcpoints[i]->PointID.size(); j++){cout<< Arcpoints[i]->PointID[j] << " ";}cout << endl;}cout << endl << "多边形拓扑文件" << endl;cout << "弧段ID" << " " << "点号"<< endl;for (int i = 0; i < (int)PolArc.size(); i++){cout << " " << PolArc[i]->PolID << " ";for (int j = 0; j < (int)PolArc[i]->ArcID.size(); j++){cout << PolArc[i]->ArcID[j].c_str()<< " ";}cout <<endl;}cout << endl << "弧段拓扑文件" << endl;cout << "弧段ID"<<" "<< "起始点"<<" " << "终结点"<<" " << "左多边形"<<" "<<"右多边形" << endl;for (int i = 0; i < (int)ArcPol.size(); i++){cout << " "<<ArcPol[i]->ArcID.c_str()<< setw(9) << right << ArcPol[i]->StartID << setw(8) << right <<ArcPol[i]->EndID << setw(8) << right<< ArcPol[i]->LeftP<<setw(10) << right<< ArcPol[i]->RightP <<endl;}}