Step by step Procedure Algorithm
1. Include the graphics header file and obtain graphics mode and driver.
2. Get the center point (x,y) and radius(r) of a circle.
3. Initialize the variables
i. a=0;b=r;d=3-(2*r);
4. If(d>=0) then
i. b--;
ii. d=d+10+4*(a-b);
b. else
i. d=d+(4*a)+6
5. Repeat step 4 until a<=b and Increment a by 1 each time.
6. Plot the pixel to display the circle using put pixel function.
7. Display the circle. BRESENHAM’S CIRCLE DRAWING ALGORITHM
Source Code Programming Bresenham’s Algorithm
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
int r,x,y;
float a,b,d;
void bresan();
void pixel(float a,float b);
void main()
{
int gm,gr;
clrscr();
detectgraph(&gm,&gr);
initgraph(&gm,&gr,"d:\\tc\\BGI");
printf("Enter the center point:\n");
scanf("%d%d",&x,&y);
printf("Enter the radius :\n");
scanf("%d",&r);
bresan();
getch();
}
void bresan()
{
a=0;
b=r;
d=3-(2*r);
while(a<=b)
{
a++;
if(d>=0)
{
b--;
d=d+10+4*(a-b);
}
else
d=d+(4*a)+6;
pixel(a,b);
}
}
void pixel(float a,float b)
{
putpixel(x+a,y+b,10);
putpixel(x-a,y-b,10);
putpixel(x+a,y-b,10);
putpixel(x-a,y+b,10);
putpixel(x+b,y+a,10);
putpixel(x-b,y-a,10);
putpixel(x+b,y-a,10);
putpixel(x-b,y+a,10);
}
Example Result Output Computer Graphics
Enter the center point:
400
200
Enter the radius:
100
