# Strange Attractors 0.0.1
# Copyright 2003 Lja MultiMedia
# May be used under the GNU GPL

# Algorithims from 'Fractal Programming in C'

"""strange.py : Draws two examples of strange attractors."""

import pygame, math

Xmax = Ymax = 2.8
Xmin = Ymin = -2.8
X = Y = Z = 0
a = 2.24
b = 0.43
c = -0.65
d = -2.43
e = 1.0
max_col = 640
max_row = 480
max_iterations = 50000

white = (255, 255, 255)
black = (000, 000, 000)

pygame.init()
screen = pygame.display.set_mode((max_col, max_row))
deltaX = max_col / (Xmax - Xmin)
deltaY = max_row / (Ymax - Ymin)
for j in range(2):
 screen.fill(white)
 pygame.display.update()
 for i in range(max_iterations):
  Xtemp = math.sin(a * Y) - Z * math.cos(b * X)
  Ytemp = Z * math.sin(c * X) - math.cos(d * Y)
  Z = e * math.sin(X)
  X = Xtemp
  Y = Ytemp
  if j:
   col = (Y - Xmin) * deltaX
   row = (Z - Ymin) * deltaY
  else:
   col = (X - Xmin) * deltaX
   row = (Y - Ymin) * deltaY
  if 0 <= col < max_col and 0 <= row < max_row:
   screen.set_at((col, row), black)
  if not (i % 100):
   pygame.display.update()
 pygame.display.update()
 while pygame.event.wait().type != pygame.KEYUP:
  pass