# File:stoffractal.py
# Stoffractal, Monte Carlo methode
# Source: Lauwerier - Computer Simulatie

from graphics import * # custom graphics
import math            # math module
import random          # random numbers


#### Open a graphics window similar to SCREEN 3 in BASIC
#### 720 * 348 pixels, 2 colors
win = GraphWin("Stoffractal", 720, 348)

### Redefine the coordinate system 
win.setCoords(-1.1, -1.2, 2.1, 1.2)

#### define some constants
r1 = 0.6
a=r1*math.cos(2*math.pi/3)
b=r1*math.sin(2*math.pi/3)
r2 = 0.6
c=r2*math.cos(2*math.pi/3)
d=-r2*math.sin(2*math.pi/3)

### define functions

def rotation1():
    global x,y,a,b
    z=x
    x=a*x-b*y
    y=b*z+a*y
    return x,y

def rotation2():
    global x,y,a,c,d
    z=x
    x=c*x-d*y+1-c
    y=d*z+a*y-d
    return x,y

def spiegeling1():
    global x,y,a,b
    z=x
    x=a*x+b*y
    y=b*z-a*y
    return x,y

def spiegeling2():
    global x,y,a,c,d
    z=x
    x=c*x+d*y+1-c
    y=d*z-a*y-d
    return x,y


### starting point
x=a
y=b

### picture building
k = 1
for k in range(10000):
 
 j = random.random()
 if j < 0.5: 
  # rotation1()
  spiegeling1()
 else:
  rotation2()
  # spiegeling2()

 #### Draw a point object
 win.plot(x,y)
 
 k = k + 1

#### Wait for a signal before exiting
message = Text(Point (1,-1), "Click anywhere to quit")
message.draw(win)
win.getMouse()