139.图形法绘制圆

  

   

    

     

    
    

     

      #include <stdio.h>
     
    
   

    

     

    
    

     

      #include <graphics.h>
     
    
   

    

     

    
    

     

      #include <dos.h>
     
    
   

    

     

    
    

     

      /*这是根据给出的圆心坐标和点坐标分别在八个象限画点的子程序*/
     
    
   

    

     

    
    

     

      void circlePoint( int xCenter, int yCenter, int x, int y )
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	putpixel( xCenter + x, yCenter + y, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter - x, yCenter + y, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter + x, yCenter - y, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter - x, yCenter - y, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter + y, yCenter + x, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter - y, yCenter + x, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter + y, yCenter - x, YELLOW );
     
    
   

    

     

    
    

     
	putpixel( xCenter - y, yCenter - x, YELLOW );
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      void myCircle(int xCenter,int yCenter,int radius)
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	int x, y, p;
     
    
   

    

     

    
    

     

      /*初始化各个参数*/
     
    
   

    

     

    
    

     

      	x = 0;
     
    
   

    

     

    
    

     

      	y = radius;
     
    
   

    

     

    
    

     

      	p = 1 - radius;
     
    
   

    

     

    
    

     
	circlePoint(xCenter, yCenter, x, y);
     
    
   

    

     

    
    

     

      /*循环中计算圆上的各点坐标*/
     
    
   

    

     

    
    

     
	while( x < y ) {
     
    
   

    

     

    
    

     

      		x++;
     
    
   

    

     

    
    

     
		if( p < 0 )
     
    
   

    

     

    
    

     

      			p += 2*x+1;
     
    
   

    

     

    
    

     
		else
     
    
   

    

     

    
    

     

      		{
     
    
   

    

     

    
    

     

      			y--;
     
    
   

    

     

    
    

     

      			p+=2*(x-y)+1;
     
    
   

    

     

    
    

     

      		}
     
    
   

    

     

    
    

     
		circlePoint( xCenter, yCenter, x, y);
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      void main()
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	int gdriver=DETECT, gmode;  /*这是用c画图时必须要使用的图像入口*/
     
    
   

    

     

    
    

     
	int i;
     
    
   

    

     

    
    

     
	int xCenter, yCenter, radius;
     
    
   

    

     

    
    

     
	printf("Please input center coordinate :(x,y) ");
     
    
   

    

     

    
    

     
	scanf("%d,%d", &xCenter, &yCenter );
     
    
   

    

     

    
    

     
	printf("Please input radius : ");
     
    
   

    

     

    
    

     
	scanf("%d", &radius );
     
    
   

    

     

    
    

     

      /*这条语句初始化整个屏幕并把入口传给gdriver,注意引号中是tc中bgi目录的完整路径*/
     
    
   

    

     

    
    

     
	registerbgidriver(EGAVGA_driver);
     
    
   

    

     

    
    

     
	initgraph(&gdriver, &gmode, "..\\bgi");  
     
    
   

    

     

    
    

     
	setcolor( BLUE );
     
    
   

    

     

    
    

     
	myCircle(xCenter, yCenter, radius);
     
    
   

    

     

    
    

     
	sleep(3);
     
    
   

    

     

    
    

     
	closegraph();
     
    
   

    

     

    
    

     
	return;
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: blog.csdn.net，作者：程序员编程指南，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/weixin_41055260/article/details/124665484