一、bresenham算法画直线#include<glut.h>#include<math.h>#include<stdio.h>void draw_pixel(int ix,int iy){glBegin(GL_POINTS);glVertex2i(ix,iy);glEnd();}void Bresenham(int x1,int y1,int xEnd,int yEnd) {int dx=abs(xEnd-x1),dy=abs(yEnd-y1);int p=2*dy-dx;int twoDy=2*dy,twoDyMinusDx=2*dy-2*dx;int x,y;if (x1>xEnd){x=xEnd;y=yEnd;xEnd=x1;}else{x=x1;y=y1;}draw_pixel(x,y);while(x<xEnd){x++;if(p<0)p+=twoDy;else{y++;p+=twoDyMinusDx;draw_pixel(x,y);}}}void display(){glClear(GL_COLOR_BUFFER_BIT);Bresenham(0,0,400,400);glFlush();}void myinit(){glClearColor(0.8,1.0,1.0,1.0);glColor3f(0.0,0.0,1.0);glPointSize(1.0);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0,500.0,0.0,500.0);}void main(int argc,char **argv ){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(500,500);glutInitWindowPosition(200.0,200.0);glutCreateWindow("CG_test_Bresenham_Line example");glutDisplayFunc(display);myinit();glutMainLoop();}二、中点法绘制椭圆#include<glut.h>#include<math.h>#include<stdio.h>inline int round(const float a){return int (a+0.5);}void setPixel(GLint xCoord,GLint yCoord){glBegin(GL_POINTS);glVertex2i(xCoord,yCoord);glEnd();}void ellipseMidpoint(int xCenter,int yCenter,int Rx,int Ry) {int Rx2=Rx*Rx;int Ry2=Ry*Ry;int twoRx2=2*Rx2;int twoRy2=2*Ry2;int p;int x=0;int y=Ry;int px=0;int py=twoRx2*y;void ellipsePlotPoints(int,int,int,int);ellipsePlotPoints(xCenter,yCenter,x,y);p=round(Ry2-(Rx2*Ry)+(0.25*Rx2));while(px<py){x++;px+=twoRy2;if(p<0)p+=Ry2+px;else{y--;py-=twoRx2;p+=Ry2+px-py;}ellipsePlotPoints(xCenter,yCenter,x,y);}p=round(Ry2*(x+0.5)*(x+0.5)+Rx2*(y-1)*(y-1)-Rx2*Ry2);while(y>0){y--;py-=twoRx2;if(p>0)p+=Rx2-py;else{x++;px+=twoRy2;p+=Rx2-py+px;}ellipsePlotPoints(xCenter,yCenter,x,y);}}void ellipsePlotPoints(int xCenter,int yCenter,int x,int y) {setPixel(xCenter+x,yCenter+y);setPixel(xCenter-x,yCenter+y);setPixel(xCenter+x,yCenter-y);setPixel(xCenter-x,yCenter-y);}void display(){glClear(GL_COLOR_BUFFER_BIT);ellipseMidpoint(200,200,50,30);glFlush();}void myinit(){glClearColor(0.8,1.0,1.0,1.0);glColor3f(0.0,0.0,1.0);glPointSize(1.0);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0,300.0,0.0,300.0);}void main(int argc,char **argv ){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(300,300);glutInitWindowPosition(200.0,200.0);glutCreateWindow("circleMId example");glutDisplayFunc(display);myinit();glutMainLoop();}三、抛物线#include<glut.h>#include<math.h>#include<stdio.h>inline int round(const float a){return int (a+0.5);}void setPixel(GLint xCoord,GLint yCoord){glBegin(GL_POINTS);glVertex2i(xCoord,yCoord);glEnd();}void ellipseMidpoint(int xCenter,int yCenter,int a,int b){int p;int x=xCenter;int y=yCenter;int px=0,py=0;void ellipsePlotPoints(int,int,int,int);ellipsePlotPoints(xCenter,yCenter,px,py);p=yCenter+a*(x+1-xCenter)*(x+1-xCenter)+b*(x+1-xCenter)-y-0.5;do{if(p<0){x=x+1;y=y;p=yCenter+a*(x+1-xCenter)*(x+1-xCenter)+b*(x+1-xCenter)-y-0.5;}else{x=x+1;y=y-1;p=yCenter+a*(x+1-xCenter)*(x+1-xCenter)+b*(x+1-xCenter)-y-0.5;}px=x-xCenter;py=y-yCenter;ellipsePlotPoints(xCenter,yCenter,px,py);}while(px<py);for(;;){if(p<0){x=x-1;y=y+1;p=yCenter+a*(x+0.5-xCenter)*(x+0.5-xCenter)+b*(x+0.5-xCenter)-y-1;}else{x=x;y=y+1;p=yCenter+a*(x+0.5-xCenter)*(x+0.5-xCenter)+b*(x+0.5-xCenter)-y-1;}px=x-xCenter;py=y-yCenter;ellipsePlotPoints(xCenter,yCenter,px,py);};}void ellipsePlotPoints(int xCenter,int yCenter,int x,int y){setPixel(xCenter+x,yCenter+y);setPixel(xCenter-x,yCenter+y);}void display(){glClear(GL_COLOR_BUFFER_BIT);ellipseMidpoint(150,150,1,0);glFlush();}void myinit(){glClearColor(0.8,1.0,1.0,1.0);glColor3f(0.0,0.0,1.0);glPointSize(1.0);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0,300.0,0.0,300.0);}void main(int argc,char **argv ){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(500,500);glutInitWindowPosition(200.0,200.0);glutCreateWindow("circleMId example");glutDisplayFunc(display);myinit();glutMainLoop();}四、基本图元输出#include<glut.h>#include<math.h>#include<stdio.h>void Polygon(int*p1,int*p2,int*p3,int*p4,int*p5,int*p6) {glBegin(GL_POLYGON);glVertex2iv(p1);glVertex2iv(p2);glVertex2iv(p3);glVertex2iv(p4);glVertex2iv(p5);glVertex2iv(p6);glEnd();}void Triangles(int*p1,int*p2,int*p3,int*p4,int*p5,int*p6) {glBegin(GL_TRIANGLES);glVertex2iv(p1);glVertex2iv(p2);glVertex2iv(p6);glVertex2iv(p3);glVertex2iv(p4);glVertex2iv(p5);glEnd();}void Trianglefan(int*p1,int*p2,int*p3,int*p4,int*p5,int*p6) {glBegin(GL_TRIANGLE_FAN);glVertex2iv(p1);glVertex2iv(p2);glVertex2iv(p3);glVertex2iv(p4);glVertex2iv(p5);glVertex2iv(p6);glEnd();}void Trianglestrip(int*p1,int*p2,int*p3,int*p4,int*p5,int*p6) {glBegin(GL_TRIANGLE_STRIP);glVertex2iv(p1);glVertex2iv(p2);glVertex2iv(p6);glVertex2iv(p3);glVertex2iv(p5);glVertex2iv(p4);glEnd();}void glRect_s(GLint a,GLint b,GLint c,GLint d){glRecti(a,b,c,d);}void display(){int p1[]={60,170};int p2[]={100,100};int p3[]={180,100};int p4[]={220,170};int p5[]={180,240};int p6[]={100,240};int p7[]={60,100};glClear(GL_COLOR_BUFFER_BIT);//Triangles(p1,p2,p3,p4,p5,p6);//Polygon(p1,p2,p3,p4,p5,p6);//glRect_s(160,30,10,100);Trianglestrip(p1,p2,p3,p4,p5,p6);//Trianglefan(p1,p2,p3,p4,p5,p6);glFlush();}void myinit(){glClearColor(0.8,1.0,1.0,1.0);glColor3f(0.0,0.0,1.0);glPointSize(1.0);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0,300.0,0.0,300.0);}void main(int argc,char **argv ){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(500,500);glutInitWindowPosition(300.0,300.0);glutCreateWindow("circleMId example");glutDisplayFunc(display);myinit();glutMainLoop();}五、区域填充#include"glut.h"#include"windows.h"const int POINTNUM=7; //多边形点数.//定义结构体用于活性边表AET和新边表NETtypedef struct XET{float x;float dx,ymax;XET* next;}AET,NET;//定义点结构体pointstruct point{float x;float y;}polypoint[POINTNUM]={250,50,350,150,50,40,250,20,200,30,100,100,10,300};//多边形顶点void PolyScan(){//计算最高点的y坐标(扫描到此结束)int MaxY=0;int i;for(i=0;i<POINTNUM;i++)if(polypoint[i].y>MaxY)MaxY=polypoint[i].y;//初始化AET表AET *pAET=new AET;pAET->next=NULL;//初始化NET表NET *pNET[1024];for(i=0;i<=MaxY;i++){pNET[i]=new NET;pNET[i]->next=NULL;}glClear(GL_COLOR_BUFFER_BIT); //赋值的窗口显示.glColor3f(0.9,1.0,0.0); //设置直线的颜色红色glBegin(GL_POINTS);//扫描并建立NET表，注：构建一个图形for(i=0;i<=MaxY;i++){for(int j=0;j<POINTNUM;j++)if(polypoint[j].y==i){ //一个点跟前面的一个点形成一条线段，跟后面的点也形成线段if(polypoint[(j-1+POINTNUM)%POINTNUM].y>polypoint[j].y){NET *p=new NET;p->x=polypoint[j].x;p->ymax=polypoint[(j-1+POINTNUM)%POINTNUM].y;p->dx=(polypoint[(j-1+POINTNUM)%POINTNUM].x-polypoint[j].x)/(polypoint[(j- 1+POINTNUM)%POINTNUM].y-polypoint[j].y);p->next=pNET[i]->next;pNET[i]->next=p;}if(polypoint[(j+1+POINTNUM)%POINTNUM].y>polypoint[j].y){NET *p=new NET;p->x=polypoint[j].x;p->ymax=polypoint[(j+1+POINTNUM)%POINTNUM].y;p->dx=(polypoint[(j+1+POINTNUM)%POINTNUM].x-polypoint[j].x)/(polypoint[(j+1+POINTNUM)%POINTNUM].y-polypoint[j].y);p->next=pNET[i]->next;pNET[i]->next=p;}}}for(i=0;i<=MaxY;i++){//计算新的交点x,更新AETNET *p=pAET->next;while(p){p->x=p->x + p->dx;p=p->next;}AET *tq=pAET;p=pAET->next;tq->next=NULL;while(p){while(tq->next && p->x >= tq->next->x)tq=tq->next;NET *s=p->next;p->next=tq->next;tq->next=p;p=s;tq=pAET;}//(改进算法)先从AET表中删除ymax==i的结点* AET *q=pAET;p=q->next;while(p){if(p->ymax==i){q->next=p->next;delete p;p=q->next;}else{q=q->next;p=q->next;}}//将NET中的新点加入AET,并用插入法按X值递增排序p=pNET[i]->next;q=pAET;while(p){while(q->next && p->x >= q->next->x)q=q->next;NET *s=p->next;p->next=q->next;q->next=p;p=s;q=pAET;}//配对填充颜色p=pAET->next;while(p && p->next){for(float j=p->x;j<=p->next->x;j++)glVertex2i(static_cast<int>(j),i);p=p->next->next;//考虑端点情况}}glEnd();glFlush();}void init(void){glClearColor(1.0,1.0,1.0,0.0);//窗口的背景颜色设置为白色glMatrixMode(GL_PROJECTION);gluOrtho2D(0.0,600.0,0.0,450.0);}void lineSegment(void){glClear(GL_COLOR_BUFFER_BIT); //赋值的窗口显示.glColor3f(0.0,1.0,0.0); //设置直线的颜色红色glBegin(GL_LINES);glVertex2i(180,15); //Specify line-segment geometry.glVertex2i(10,145);glEnd();glFlush(); //Process all OpenGL routines as quickly as possible.}void main(int argc,char* argv){glutInit(&argc,&argv); //I初始化GLUT.glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); //设置显示模式：单个缓存和使用RGB模型glutInitWindowPosition(50,100); //设置窗口的顶部和左边位置glutInitWindowSize(400,300); //设置窗口的高度和宽度glutCreateWindow("扫描线填充算法"); //创建显示窗口init(); //调用初始化过程glutDisplayFunc(PolyScan); //图形的定义传递glutMainLoop(); //显示所有的图形并等待}11。