# C++ > Computer Graphics Code Examples

## Program to implement Circle Drawing Algorithm

``` Program to implement Circle Drawing Algorithm #include<iostream.h> #include<graphics.h> #include<conio.h> #include<math.h> #include<dos.h> #include<stdlib.h> #include<stdio.h> class myCircle { private: int x,y,r,d,x1,y1; public: myCircle(); //Constructor void showCircle(); }; myCircle::myCircle() { x=0;y=0; cout<<" "Enter The Co-Ordinates Of The Circle ":="; cin>>x>>y; cout<<" "Enter The Radius Of The Circle ":="; cin>>r; } void myCircle::showCircle() { char *s; x1=0;y1=r; d=3-2*r; while(x1<=y1) { putpixel((x+x1+320),(y+y1+240),5); putpixel((x-x1+320),(y+y1+240),5); putpixel((x+x1+320),(y-y1+240),5); putpixel((x-x1+320),(y-y1+240),5); putpixel((x+y1+320),(y+x1+240),5); putpixel((x-y1+320),(y+x1+240),5); putpixel((x+y1+320),(y-x1+240),5); putpixel((x-y1+320),(y-x1+240),5); if(d<0) d+=4*x1+6; else { d+=4*(x1-y1)+10; y1--; } x1++; } setcolor(5); outtextxy(318+x,235+y,"."); setcolor(15); sprintf(s,"Center(%d,%d)",x,y); outtextxy(20,10,"The Center Is At"); outtextxy(20,20,s); sprintf(s,"Radius=%d",r); outtextxy(20,30,s); getch(); } void main() { int gd=DETECT,gm,i,j,xx=190,xxx=480; clrscr(); myCircle a; char *mess[]={"B","R","E","S","E","N","H","A","M","'","S"," ","C","I","R","C","L","E"," ","A","L","G","O","R","I","T","H","M"}; initgraph(&gd,&gm,"..\bgi"); cleardevice(); rectangle(120,40,320,240); rectangle(320,40,520,240); rectangle(120,240,320,440); rectangle(320,240,520,440); for(i=0,j=27;i<16,j>=14;i++,j--) { xx+=10; outtextxy(xx,10,mess[i]); xxx-=10; outtextxy(xxx,10,mess[j]); delay(100); } for(i=130;i<=510;i+=10) for(j=50;j<=430;j+=10) putpixel(i,j,15); for(i=130;i<=510;i+=10) { if(i==320) continue; outtextxy(i,237,"+"); } for(i=50;i<=430;i+=10) { if(i==240) continue; outtextxy(317,i,"-"); } outtextxy(310,230,"O"); outtextxy(530,240,"X"); outtextxy(320,450,"-Y"); outtextxy(100,240,"-X"); outtextxy(320,30,"Y"); a.showCircle(); // closegraph(); } ```