from kandinsky import set_pixel import math a = 50 r = 20 cx = 160 cy = 111 xmin = max(0, cx - a - r) xmax = min(320, cx + a + r) ymin = max(0, cy - r) ymax = min(222, cy + r) for x in range(xmin, xmax): for y in range(ymin, ymax): dx = x - cx dy = y - cy qx = max(abs(dx) - a, 0) d = math.sqrt(qx*qx + dy*dy) - r if d <= 0: set_pixel(x, y, (255, 0, 0))