"""
 leaf.py

 an example for the Intro Programming course

 concepts:
    * recursion
    * objects
    * lists of objects within objects
    * dictionary (in child_color method)
    * default values
    * a bit of trig (x,y from length,angle using cos() and sin())
    * mod arithmetic (wrapping color values around at 255)
    * uses Zelle's graphics library
    * a global variable (window)

 Jim M | Nov 25 2013 | MIT License
"""
from graphics import *
from math import sin, cos, pi

window = GraphWin("leaf.py", 600, 600)
window.setCoords(0.0, 0.0, 1.0, 1.0)

class Leaf(object):

    def __init__(self, 
                 depth=0, max_depth=5,          # recursion management
                 x=0.1, y=0.1, length=0.3,      # in window coord units
                 angle=pi/30,                   # from horizontal
                 red=100, green=50, blue=25,    # 0 to 255 = black to white
                 width=25,                      # in pixels
                 red_delta=20,                  # child modifications :
                 green_delta=40,                #  |
                 blue_delta=10,                 #  |
                 angle_delta=pi/15.0,           #  |
                 length_shrink=0.7,             #  |
                 width_shrink=0.7               #  |
                 ):

        self.depth = depth
        self.max_depth = max_depth
        self.red = red
        self.green = green
        self.blue = blue
        self.width = width
        self.angle = angle
        self.length = length
        self.angle_delta = angle_delta
        self.red_delta = red_delta
        self.green_delta = green_delta
        self.blue_delta = blue_delta
        self.length_shrink = length_shrink
        self.width_shrink = width_shrink
        self.x1 = x                             # left end
        self.y1 = y
        self.x2 = x + length * cos(angle)       # right end
        self.y2 = y + length * sin(angle)
        self.line = Line(Point(self.x1, self.y1), Point(self.x2, self.y2))
        self.line.setOutline(color_rgb(red, green, blue))
        self.line.setWidth(width)

    def child_width(self):
        if self.width <= 1:
            return 1
        else:
            return self.width * self.width_shrink

    def child_color(self):
        return {'red':   (self.red + self.red_delta) % 255,
                'green': (self.green + self.green_delta) % 255,
                'blue' : (self.blue + self.blue_delta) % 255
                }
        
    def draw(self):
        self.line.draw(window)
        if self.depth < self.max_depth:
            child_color = self.child_color()
            self.child = Leaf(depth = self.depth + 1, 
                              max_depth = self.max_depth,
                              x = self.x2, 
                              y = self.y2,
                              angle = self.angle + self.angle_delta, 
                              length = self.length * self.length_shrink,
                              red = child_color['red'],         # using a 
                              green = child_color['green'],     # dictionary
                              blue = child_color['blue'],
                              width = self.child_width(),
                              red_delta = self.red_delta,
                              green_delta = self.green_delta,
                              blue_delta = self.blue_delta,
                              angle_delta = self.angle_delta,
                              length_shrink = self.length_shrink,
                              width_shrink = self.width_shrink
                )
            self.child.draw()

class Tree(object):
    def __init__(self, x=0.1, y=0.1, length=0.3, angle=pi/30):
        self.branches = [Leaf(x=x,y=y, length=length, angle=angle, max_depth=9),
                         Leaf(x=x,y=y, length=length, 
                              angle=angle+pi/10, red_delta=30),
                         Leaf(x=x,y=y, length=length, angle=angle+pi/6, 
                              angle_delta=pi/10.0, length_shrink=0.6),
                         Leaf(x=x,y=y, length=length, angle=angle+pi/4, 
                              angle_delta=pi/8.0, blue_delta=100)
                         ]
        for b in self.branches:
            b.draw()

class Forest(object):
    def __init__(self):
        self.trees = [Tree(),
                      Tree(x=0.5,y=0.7, length=0.1, angle=pi/2),
                      Tree(x=0.9,y=0.8, length=0.15, angle=pi)
                      ]

def main():
    f = Forest()
    wait = input("done? ")

if __name__ == '__main__':
    main()