openGL— 中点Bresenham画圆

野性酷女 2022-06-17 13:48 202阅读 0赞

// aa.cpp : 定义控制台应用程序的入口点。
    
    #include "stdafx.h"
    #include <gl/glut.h> 
    
    void Init(void)    
    {
         glClearColor(0.0,0.0,0.0,0.0);    //设置背景颜色为黑色    
         glMatrixMode(GL_PROJECTION);       //对投影相关进行操作 
         gluOrtho2D(0.0, 30.0, 0.0, 30.0);
     }
     
     void CirclePoint(int x,int y)
     {
    	 glColor3f(1.0,0.0,0.0);    //设置颜色为红色
         glPointSize(4);            //设置点的大小
         glBegin(GL_POINTS);
     
         glVertex2f(15+x,15+y);     // 修正点的坐标
         glVertex2f(15+y,15+x);
         glVertex2f(15-y,15+x);
         glVertex2f(15-x,y+15);
         glVertex2f(15-x,15-y);
         glVertex2f(15-y,15-x);
         glVertex2f(15+y,15-x);
         glVertex2f(15+x,15-y);
     
         glEnd();
    	 glFlush(); 
     }
    
     void MidBresenhamCircle(int r)
     {
         int x,y,d;
         x=0;
    	 y=r;
    	 d=1-r;
         while(x<=y)
    	 {
             CirclePoint(x,y);    
             if(d<0)
                 d+=2*x+3;
             else
    		 {
                 d+=2*(x-y)+5;
                 y--;
             }
             x++;
         }
     }
    
     void display()
     {
         glClear(GL_COLOR_BUFFER_BIT);       
         MidBresenhamCircle(8);    //半径为8
     }
     
     int main(int argc,char** argv)
     {
    
         glutInit(&argc,argv);
         glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);  
         glutInitWindowSize(500,500);   
         glutInitWindowPosition(400,100);    
         glutCreateWindow("中点Bresenham画圆");   
         glutDisplayFunc(display);    
         Init();       
         glutMainLoop();   
     
         return 0;
     }

运行结果：

![Center][]

第二种方法：

// aa.cpp : 定义控制台应用程序的入口点。
    
    #include "stdafx.h"
    #include <gl/glut.h> 
    
    void init(void)    
    {
         glClearColor(0.0,0.0,0.0,0.0);    //设置背景颜色为黑色    
         glMatrixMode(GL_PROJECTION);       //对投影相关进行操作 
         gluOrtho2D(0.0, 30.0, 0.0, 30.0);
     }
    
     void putpixel(int x, int y)  
    {  
        glColor3f(1.0, 0.0, 0.0);        //设置颜色为红色
        glPointSize(2);    //设置点的大小
        glBegin(GL_POINTS);  
            glVertex2f(15+x, 15+y);  
        glEnd();  
        glFlush();  
    } 
    
     void CirclePoint(int x,int y)
     {
         putpixel(x,y);
    	 putpixel(y,x);
    	 putpixel(-y,x);
    	 putpixel(-x,y);
    	 putpixel(-x,-y);
    	 putpixel(-y,-x);
    	 putpixel(y,-x);
    	 putpixel(x,-y);
     }
    
     void MidBresenhamCircle(int r)
     {
         int x,y,d;
         x=0;
    	 y=r;
    	 d=1-r;
         while(x<=y)
    	 {
             CirclePoint(x,y);    
             if(d<0)
                 d+=2*x+3;
             else
    		 {
                 d+=2*(x-y)+5;
                 y--;
             }
             x++;
         }
     }
    
     void display()
     {
         glClear(GL_COLOR_BUFFER_BIT);       
         MidBresenhamCircle(8);    //半径为8
     }
     
     int main(int argc,char** argv)
     {
    
         glutInit(&argc,argv);
         glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);  
         glutInitWindowSize(400,400);   
         glutInitWindowPosition(0,0);    
         glutCreateWindow("中点Bresenham画圆");   
         glutDisplayFunc(display);    
         init();       
         glutMainLoop();   
     
         return 0;
     }

运行结果：  
![Center 1][]

[Center]: /images/20220617/4e936c919e5a48e8bcbe9fe2695f68b3.png
[Center 1]: /images/20220617/4ace446dd88b4824ad6f9e4364f2f628.png