Anti-aliased Arc Pygame

Question

I am trying to code a simple circle timer in Python using Pygame. At the moment it looks like this:

As you can see, the blue line is very wavy and has white dots in it. I am achieving this blue line by using pygame.draw.arc() function, but it is not anti-aliased and looks bad. I would like it to be anti-aliased, but gfxdraw module which should let me achieve this, doesn't support arc width selection. Here's code snippet:

pygame.draw.arc(screen, blue, [center[0] - 120, center[1] - 120, 240, 240], pi/2, pi/2+pi*i*koef, 15)
pygame.gfxdraw.aacircle(screen, center[0], center[1], 105, black)
pygame.gfxdraw.aacircle(screen, center[0], center[1], 120, black)

Answer 1

I did it creating the arc with a polygon.

def drawArc(surface, x, y, r, th, start, stop, color):
    points_outer = []
    points_inner = []
    n = round(r*abs(stop-start)/20)
    if n<2:
        n = 2
    for i in range(n):
        delta = i/(n-1)
        phi0 = start + (stop-start)*delta
        x0 = round(x+r*math.cos(phi0))
        y0 = round(y+r*math.sin(phi0))
        points_outer.append([x0,y0])
        phi1 = stop + (start-stop)*delta
        x1 = round(x+(r-th)*math.cos(phi1))
        y1 = round(y+(r-th)*math.sin(phi1))
        points_inner.append([x1,y1])
    points = points_outer + points_inner        
    pygame.gfxdraw.aapolygon(surface, points, color)
    pygame.gfxdraw.filled_polygon(surface, points, color)

The for loop could certainly be created more elegantly with a generator, but I am not very sophisticated with python.

The arc definitely looks nicer than pygame.draw.arc, but when I compare it to the screen rendering on my mac, there is room for improvement.