Pygame demo of the Fourier series

fourier-demo-pygame.py

import pygame, time, sys, pygame.gfxdraw, math
print("Fourier Example thingy by Noorquacker. https://www.nqind.com")
pygame.init()
clock = pygame.time.Clock()
w = pygame.display.set_mode((1500,1000))
pygame.font.init()
pygame.display.set_caption("fourier example thingy")
font = pygame.font.SysFont("Times New Roman", 18)
iter = 5
circ_outs = [0]*500
ys = list([0]*750)
tick = 0
rate = 300
while True:
        tick += 1
        w.fill((0,0,0))
        w.blit(font.render("FPS: " + str(round(clock.get_fps(),2)), True, (255,255,255), None),(2,2))
        w.blit(font.render("Iterations: " + str(iter), True, (255,255,255), None), (2,20))
        for i in range(0,iter):
                rx, ry = 0, 0
                if i != 0:
                        rx, ry = circ_outs[i-1]
                color = int((iter-i)/iter*255)
                pygame.gfxdraw.aacircle(w, round(rx+500), round(ry+500), round(400/((2*i+1)*math.pi)), (0,color,color))
                theta = (2*i+1)*tick/rate
                circ_outs[i] = (rx + 400*math.cos(theta)/((2*i+1)*math.pi), ry + 400*math.sin(theta)/((2*i+1)*math.pi))
                pygame.gfxdraw.line(w, round(rx+500), round(ry+500), round(circ_outs[i][0]+500), round(circ_outs[i][1]+500), (color,color,color))
                if i == iter-1:
                        x, y = int(circ_outs[i][0]), int(circ_outs[i][1])
                        pygame.gfxdraw.line(w, 700, y+500, x+500, y+500, (255,0,0))
        if tick % int(rate/100) == 0:
                ys.insert(0, circ_outs[iter-1][1])
                del ys[-1]
        for i in range(0,len(ys)):
                pygame.gfxdraw.pixel(w, i+700, round(ys[i])+500, (0,255,0))
        for event in pygame.event.get():
                if event.type == pygame.QUIT:
                        pygame.quit()
                        sys.exit()
                if event.type == pygame.KEYDOWN:
                        if event.key == pygame.K_UP and iter < 500:
                                iter += 1
                        if event.key == pygame.K_DOWN and iter > 1:
                                iter -= 1
        clock.tick(rate)
        pygame.display.flip()