DRAW A CIRCLE USING MIDPOINT ALGORITHM

DRAW A CIRCLE USING MIDPOINT ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

void main()

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int x1,x2,x3,x4,xc,yc,r,y1,y2;

   char msg[15];

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "");

   /* read result of initialization */

   errorcode = graphresult();

   /* an error occurred */

   if (errorcode != grOk)

   {

      printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1);

   }

   printf("Enter the value for xc,yc,r:");

   scanf("%d%d%d",&xc,&yc,&r);

   circlemidpoint(xc,yc,r);

   getch();

   closegraph();

}

void circlemidpoint(int xc,int yc,int r)

{

int x=0,y=r,p=1-r;

void circleplotpoints(int,int,int,int);

circleplotpoints(xc,yc,x,y);

while(x<y)

{

x++;

if(p<0)

p+=2*x+1;

else

{

y--;

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

}

circleplotpoints(xc,yc,x,y);

}

}

 void circleplotpoints(int xc,int yc,int x,int y)

{

putpixel(xc+x,yc+y,YELLOW);

putpixel(xc-x,yc+y,YELLOW);

putpixel(xc+x,yc-y,GREEN);

putpixel(xc-x,yc-y,GREEN);

putpixel(xc+y,yc+x,GREEN);

putpixel(xc-y,yc+x,RED);

putpixel(xc+y,yc-x,RED);

putpixel(xc-y,yc-x,RED);

}

OUTPUT:-

Enter the value for xc, yc, r:

250

150

125