#!/usr/bin/python
# -*- coding: iso-8859-2 -*-

########################################################################
# Turtle drawer
#
# Copyright (C) 2006 Gergõ ÉRDI
# http://cactus.rulez.org/
#
# Published under the terms of the GNU General Public License 2.0
# $Id: turtle.py 188 2006-03-12 11:59:46Z cactus $
########################################################################

import libxml2;

########################################################################
# Infrastructure
########################################################################
class Point:
    def __init__ (self, x, y):
        self.x = x
        self.y = y

    def __add__ (p1, p2):
        return Point(p1.x + p2.x, p1.y + p2.y)

    def __sub__ (p1, p2):
        return Point(p1.x - p2.x, p1.y - p2.y)

    def __div__ (p, q):
        return Point(p.x / q, p.y / q)

    def __mul__ (p, q):
        return Point(p.x * q, p.y * q)


class Turtle:
    def __init__ (self):
        self.p = Point (0.0, 0.0)
        self.heading = Point (1.0, 0.0)


class Canvas:
    def __init__ (self):
        self.turtle = Turtle()
        self.segments = []

    def draw (self, path):
        map (lambda i: i(self), path);

    def draw_line (self, p1, p2):
        self.segments.append ((p1, p2))

    def render_to_svg (self, svg_root, p0, size):
        svg = svg_root.newChild(None, "svg", None);
        ns = svg.newNs ("http://www.w3.org/2000/svg", None);
        svg.setNs(ns)
        
        for (p1, p2) in self.segments:
            p1_ = (p1 * size + p0)
            p2_ = (p2 * size + p0)
            
            line_node = svg.newChild(ns, "line", None)
            line_node.setProp("style", "stroke:rgb(99,99,99);stroke-width:2")
            
            line_node.setProp("x1", "%f" % p1_.x)
            line_node.setProp("y1", "%f" % p1_.y)
            
            line_node.setProp("x2", "%f" % p2_.x)
            line_node.setProp("y2", "%f" % p2_.y)


def create_svg (filename, shrink, path):
    canvas = Canvas ()
    canvas.draw (path)

    doc = libxml2.newDoc("1.0")
    canvas.render_to_svg (doc, Point(100.0, 100.0), 100.0 / shrink)
    doc.saveFile(filename)
    doc.freeDoc()    


########################################################################
# Drawing alphabet
########################################################################
def f (canvas):
    canvas.turtle.p += canvas.turtle.heading

def F (canvas):
    p1 = canvas.turtle.p
    f (canvas)
    p2 = canvas.turtle.p
    canvas.draw_line (p1, p2)

def l (canvas):
    heading = canvas.turtle.heading;
    (heading.x, heading.y) = (-heading.y, heading.x)
    
def r (canvas):
    heading = canvas.turtle.heading;
    (heading.x, heading.y) = (heading.y, -heading.x)


########################################################################
# Sequence transformation
########################################################################
def map_concat(func, l):
    ret = []
    for i in l: ret += func(i)
    return ret

def draw_iterate(l, func, factor, n):
    name = func.__name__
    shrink = 1
    create_svg("%s-0.svg" % name, shrink, l)
    for i in range(1, n + 1):
        shrink = shrink * factor
        l = map_concat (func, l)
        create_svg("%s-%d.svg" % (name, i), shrink, l)

########################################################################
# Test sequences
########################################################################
def Koch():
    square = [F, l, F, l, F, l, F, l]
    def koch(x):
        if x == F: return [F, l, F, r, F, r, F, F, l, F, l, F, r, F]
        return [x]
    draw_iterate(square, koch, 4, 4)


def Unnamed():
    line = [F, F, F, F]
    def unnamed(x):
        if x == F: return [F,
                           r, f, l,
                           F,
                           F, r, F, r, F, F, r, F,
                           f, r, F,
                           F, l, f, r,
                           F, F, l, F, l, F, F, l, F, f,
                           F, F, F]
        if x == f: return [f, f, f, f, f, f]
        return [x]
    draw_iterate(line, unnamed, 3, 2)

Koch()
#Unnamed()