# -*- encoding: big5 -*-
#
# ColorSpiral.py
#
#	- jshin@csie.ncnu.edu.tw // shin@nlp.csie.ncnu.edu.tw // shin.jsc@gmail.com
#

#
# Sierpinski_triangle
#
#
#	Author: Jing-Shin Chang
#	Emails: jshin@csie.ncnu.edu.tw // shin@nlp.csie.ncnu.edu.tw // shin.jsc@gmail.com
#	Last Update: 2019/11/22 (v1.0)
#
# https://zh.wikipedia.org/wiki/%E8%AC%9D%E7%88%BE%E8%B3%93%E6%96%AF%E5%9F%BA%E4%B8%89%E8%A7%92%E5%BD%A2
#

"""
這條曲線以L系統來記述為：

變數: A , B
常數: + , -
公理: A
規則:
A → B-A-B
B → A+B+A
A,B ： 向前
- ： 左轉60°
+ ： 右轉60°
"""

""" IF NOT PART OF TURTLEDEMO ...
import turtle
t = turtle.Turtle()
wn = turtle.Screen()
"""

#+1 from turtle import *		# including mainloop
#+2 
from turtle import Turtle, Screen, mainloop
from time import clock

#- t = Turtle()		# Globals ewlated to other modules must be declared in main when included by TURTLEDEMO
#- wn = Screen()

#- wn.bgcolor("black")
#- t.speed(0)

sides = 6

colors0 = ["yellow", "magenta", "yellow", "magenta", "yellow", "magenta"]
colors1 = ["yellow", "magenta", "red", "magenta", "blue", "magenta"]

def colorSpiral(nMoves = 60, degRotation = 1, wider = True, constFwd = 0, fwdMore = True, colors = colors1):

	# gotoOrigin() 
	for x in range(nMoves):
		t.pencolor(colors[x % sides])	# the number of colors must be >= sides

		if ( constFwd != 0 ):
			t.forward(constFwd)		# constant move step
		elif (not fwdMore):
			t.forward(x)			# step size increase as x
		else:
			t.forward(x * 3/sides + x)	# [0, 0, 1, 1, 2, 2, 3, 3, ...] + x

		t.left(360/sides + degRotation)
			# 360/sides: make a complete rotation every #side left turns
			# +degRotation = 0: without rotation
			# +degRotation = 1: with a little rotation 

		if ( wider ):
			t.width(x*sides/200)	# incresingly wider

def gotoOrigin(x=0,y=0):
    t.penup()
    t.goto(x,y)
    t.pendown()

def Sierpinski_triangle(level=10, fwd=50):
    # A(level,fwd)		# A=> 'B'-'A'-'B': bottom-left B first then top A, then bottom-right B
    B(level,fwd)		# B=> 'A'+'B'+'A': bottom-left A first then top B, then bottom-right A

def A(level,fwd,colors = colors1):

    if ( level <= 0 ):
        return "Done! with Level A(%d)" % level

    t.pencolor(colors[level % sides])

    B(level-1,fwd)

    t.forward(fwd)
    t.left(60)
    print("f-",end='')

    A(level-1,fwd)

    t.forward(fwd)
    t.left(60)
    print("f-",end='')

    B(level-1,fwd)

    print("\nDone! with Level A(%d)" % level)
    return "Done! with Level A(%d)" % level

def B(level,fwd,colors = colors0):

    if ( level <= 0 ):
        return "Done! with Level B(%d)" % level

    t.pencolor(colors[level % sides])

    A(level-1,fwd)

    t.forward(fwd)
    t.right(60)
    print("f+",end='')

    B(level-1,fwd)

    t.forward(fwd)
    t.right(60)
    print("f+",end='')

    A(level-1,fwd)

    print("\nDone! with Level B(%d)" % level)
    return "Done! with Level B(%d)" % level

#
# Try different parameter passing options
#
def main():
	global t, wn

	t = Turtle()		# Global must be declared in main when included in TURTLEDEMO
	wn = Screen()
	wn.bgcolor("black")
	t.speed(0)		# doesn't look like speeding by this arg

	t0 = clock()

	gotoOrigin(-200,-100)
	t.hideturtle()

	# colorSpiral()			# default

	# colorSpiral(constFwd=60)
	# colorSpiral(colors=colors0)
	# colorSpiral(nMoves=80)
	# colorSpiral(degRotation=0)
	# colorSpiral(wider=False)
	# colorSpiral(fwdMore=False)

	# colorSpiral(degRotation=0, wider=False)
	# colorSpiral(120, 10, False)

	Sierpinski_triangle(level=6, fwd=5)
	
	t1 = clock()
	return "Done! in %.2f Seconds" % (t1-t0)

if __name__ == "__main__":
    msg = main()
    print(msg)
    mainloop()		# keep alive until closed by user
# FIN