I am representing my 2D space (consider a window), where each pixel is shown as a cell in a 2D array. i.e. a 100x100 window is represented by the array of same dimensions. 

Now given a point in the window, if I draw a circle of radius `r`, I want to find all the points lying in that circle.

I was thinking I'd check for the each point in the square region around the radius, with `side = 2*r`, if it lies in the circle or not. I'll use the normal distance formula maybe?

Hence, maybe the following:

```
for (x=center-radius ; x<center+radius ; x++){
    for (y=center-radius ; y<center+radius; y++) {
        if (inside) {
            // Do something
        }
    }
}

```

Will it serve my purpose? Can I make it faster?