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