Bresenham’s Circle Drawing Algorithm

The centre of the circle and the starting points are assumed to be located precisely at pixel elements. The radius is also assumed to be an integer.

1. Insert the radius r of the circle.
2. Initialize the decision variable d=3-(2*r)
3. x=0, y=r then (x₀, y₀)= (0,r)
4. If we are using octant symmetric to plot the pixel then until (x< y)

if(d< 0) then

d=d+4x+6
x=x-1
else
d=d+4(x-y)+10
y=y-1
x=x+1
5. Plot(x,y)
6. Determine the symmetric points of the other octants also.
7. STOP