中国地质大学（武汉）课题：计算机图形学班级：191113姓名：杨耀鹏源程序#include<gl/glut.h>#include<iostream.h>#include<stdlib.h>typedef struct dePt{int x;int y;}dePt;void fill(GLint x1,GLint y1,GLint z1) {glBegin(GL_POINTS);glVertex3f(x1,y1,0.0f);glEnd();}typedef struct Edge{int yUpper;float xIntersect, dxPerScan;struct Edge *next;}Edge;void insertEdge(Edge *list, Edge *edge) {Edge *p,*q=list;p=q->next;while(p!=NULL){if(edge->xIntersect<p->xIntersect)p=NULL;else{q=p;p=p->next;}}edge->next=q->next;q->next=edge;}int yNext(int k, int cnt, dePt*pts){int j;if((k+1)>(cnt-1))j=0;elsej=k+1;while(pts[k].y==pts[j].y)if((j+1)>(cnt-1))j=0;else j++;return (pts[j].y);}void makeEdgeRec(dePt lower, dePt upper,int yComp,Edge *edge,Edge *edges[]) {edge->dxPerScan=(float)(upper.x-lower.x)/(upper.y-lower.y);edge->xIntersect=lower.x;if(upper.y<yComp)edge->yUpper=upper.y-1;elseedge->yUpper=upper.y;insertEdge(edges[lower.y],edge);}void buildEdgeList(int cnt,dePt *pts,Edge *edges[]){Edge *edge;dePt v1,v2;int i,yPrev=pts[cnt-2].y;v1.x=pts[cnt-1].x;v1.y=pts[cnt-1].y;for(i=0;i<cnt;i++){v2=pts[i];if(v1.y!=v2.y){edge=(Edge *)malloc(sizeof(Edge));if(v1.y<v2.y)makeEdgeRec(v1,v2,yNext(i,cnt,pts),edge,edges);elsemakeEdgeRec(v2,v1,yPrev,edge,edges);}yPrev=v1.y;v1=v2;}}void buildActiveList(int scan,Edge *active,Edge *edges[]){Edge *p,*q;p=edges[scan]->next;while(p)q=p->next;insertEdge(active,p);p=q;}}void fillScan(int scan,Edge *active){Edge *p1,*p2;int i;p1=active->next;while(p1){p2=p1->next;for(i=p1->xIntersect;i<p2->xIntersect;i++) fill((int)i,scan,3);p1=p2->next;}}void deleteAfter(Edge *q){Edge *p=q->next;q->next=p->next;free(p);}void updateActiveList(int scan,Edge *active) {Edge *q=active, *p=active->next;while(p)if(scan>=p->yUpper){p=p->next;deleteAfter(q);}else{p->xIntersect=p->xIntersect+p->dxPerScan; q=p;p=p->next;}void resortActiveList(Edge *active) {Edge *q,*p=active->next;active->next=NULL;while(p){q=p->next;insertEdge(active,p);p=q;}}void scanFill(int cnt,dePt *pts){Edge *edges[1024],*active;int i,scan;for(i=0;i<1024;i++){edges[i]=(Edge *)malloc(sizeof(Edge)); edges[i]->next=NULL;}buildEdgeList(cnt,pts,edges);active=(Edge *)malloc(sizeof(Edge)); active->next=NULL;for(scan=0;scan<1024;scan++){buildActiveList(scan,active,edges);if(active->next){fillScan(scan,active); updateActiveList(scan,active); resortActiveList(active);}}}void ChangeSize(GLsizei w,GLsizei h) {GLfloat nRange=400.0f;if(h==0) h=1;glViewport(0,0,w,h);glMatrixMode(GL_PROJECTION);glLoadIdentity();if(w<=h)glOrtho(-nRange,nRange,-nRange*h/w,nRange*h/w,-nRange,nRange);elseglOrtho(-nRange*h/w,nRange*h/w,-nRange,nRange,-nRange,nRange); glMatrixMode(GL_MODELVIEW);glLoadIdentity();}void Display(void){int n,x,y,i;cout<<"请输入多边形顶点数："<<endl;cin>>n;dePt *t=new dePt[n];for(i=0;i<n;i++){cout<<"请输入第"<<i+1<<"个顶点坐标"<<endl;cin>>x>>y;t[i].x=x;t[i].y=y;glVertex2i(t[i].x,t[i].y);}glEnd();glFlush();scanFill(n,t);glFlush();glutPostRedisplay();}void Initial(void){glClearColor(2.0f,2.0f,2.0f,2.0f);glMatrixMode(GL_PROJECTION); //指定设置投影参数gluOrtho2D(-100.0,200.0,-100.0,150.0); //设置投影参数}void main(int argc,char*argv[]){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); //初始化窗口的显示模式glutInitWindowSize(400,300); //设置窗口的尺寸glutInitWindowPosition(100,120); //设置窗口的位置glutCreateWindow("多边形的扫描转换与填充"); //设置一个名为多边形的扫描转换与填充的窗口glutDisplayFunc(Display); //设置当前窗口的显示调用函数Initial(); //完成窗口初始化glutMainLoop(); //启动主GLUT事件处理循环}运行结果。
