fast algorithm for drawing filled circles?

Question

I am using Bresenham\'s circle algorithm for fast circle drawing. However, I also want to (at the request of the user) draw a filled circle.

Is there a fast and effi

Answer 1

Just use brute force. This method iterates over a few too many pixels, but it only uses integer multiplications and additions. You completely avoid the complexity of Bresenham and the possible bottleneck of sqrt.

for(int y=-radius; y<=radius; y++)
    for(int x=-radius; x<=radius; x++)
        if(x*x+y*y <= radius*radius)
            setpixel(origin.x+x, origin.y+y);