CIRCLE DRAWING USING MIDPOINT ALGORITHM

Ex no:3  CIRCLE  DRAWING  USING MIDPOINT ALGO.

Date:       

Aim:

     To write a C++ Program to draw a circle using MIdpoint algorithm.

Algorithm:

Step1: Start the program.

Step2: Initialize the variables.

Step3: Call the initgraph() function

Step4: Get the values for centre end points for drawing a circle

Step5: Calculate the distance to be traveled by the circle.

Step6: Put the pixels in the given color to draw the circle.

Step7: Display the output.

Step8:   Stop the program

PROGRAM

#include "stdio.h"

#include "conio.h"

#include "math.h"

#include "graphics.h"

main()

{

intgd=DETECT,gm;

intxcenter,ycenter,radius;

intp,x,y;

initgraph(&gd,&gm,"c:\\tc\\bgi");

x=0;

printf("Enter The Radius Value:\n");

scanf("%d",&radius);

y=radius;

printf("Enter The xcenter and ycenter Values:\n");

scanf("%d%d",&xcenter,&ycenter);

plotpoints(xcenter,ycenter,x,y);

p=1-radius;

while(x<y)

{

if(p<0)

x=x+1;

else

{

x=x+1;

y=y-1;

}

if(p<0)

p=p+2*x+1;

else

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

plotpoints(xcenter,ycenter,x,y);

}

getch();

return(0);

}

intplotpoints(intxcenter,intycenter,intx,int y)

{

putpixel(xcenter+x,ycenter+y,1);

putpixel(xcenter-x,ycenter+y,1);

putpixel(xcenter+x,ycenter-y,1);

putpixel(xcenter-x,ycenter-y,1);

putpixel(xcenter+y,ycenter+x,1);

putpixel(xcenter-y,ycenter+x,1);

putpixel(xcenter+y,ycenter-x,1);

putpixel(xcenter-y,ycenter-x,1);

return(0);

}

OUTPUT

Enter the Radius Value                       :             80                            

Enter The xcenter and ycenterValues :           230         260