L-System

import copy
import os, sys
import traceback

from math import *

with open(os.devnull, "w") as f:
    oldstdout=sys.stdout; sys.stdout=f; import pygame; sys.stdout=oldstdout
from pygame.locals import *

from OpenGL.GL import *
from OpenGL.GLU import *


if sys.platform in ["win32","win64"]: os.environ["SDL_VIDEO_CENTERED"]="1"

pygame.display.init()
pygame.font.init()


screen_size = [1024,1024]

icon = pygame.Surface((1,1)); icon.set_alpha(0); pygame.display.set_icon(icon)
pygame.display.set_caption("[Program] - [Author] - [Version] - [Date]")

multisample = 16
if multisample:
    pygame.display.gl_set_attribute(GL_MULTISAMPLEBUFFERS,1)
    pygame.display.gl_set_attribute(GL_MULTISAMPLESAMPLES,multisample)

pygame.display.set_mode(screen_size,OPENGL|DOUBLEBUF)


glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA)

glEnable(GL_TEXTURE_2D)
glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE)
glTexEnvi(GL_POINT_SPRITE,GL_COORD_REPLACE,GL_TRUE)

glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST)
glEnable(GL_DEPTH_TEST)


def lerp(x,y,t):
    return x*(1.0-t) + y*t


data =  [ (1/2-sqrt(2)/4,0), ((0.5,0),(3/4,1/4)), (0.5,0), ((0.5,1/8),(1/2,1/4)), (3/8,1/4),
          (1/4,1/8), (3/8,0), ((3/8,-1/8),(3/8,-1/4)), (5/8,-1/4), (5/8,-1/8), (1/2,-1/8),
          ((5/8,-1/8),(3/4,-1/8)), (1,0) ]
##data = [ (1/4,0), ((1/2,0),(1/2,1/4)), (1/2,-1/4), ((1/2,0),(3/4,0)), (1,0) ]
##data = [ (1/4,0), ((1/2,0),(1/2,1/4)), (3/4,0), (1/2,0), ((3/4,0),(1,-0.001)) ]
##data = [ (1/2-sqrt(2)/4,0), ((0.5,0),(3/4,1/4)), (1/2,1/8), (1/2,-1/4), (1,0) ]
class Line(object):
    def __init__(self,p0,p1):
        self.p0 = p0
        self.p1 = p1
        vec = ( self.p1[0]-self.p0[0], self.p1[1]-self.p0[1] )
        self.angle = degrees(atan2(vec[1],vec[0]))
        self.length = hypot(vec[1],vec[0])
        self.children = None
    def apply_rules(self,axiom):
        if self.children == None:
            self.children = copy.deepcopy(axiom)
        else:
            for child in self.children:
                child.apply_rules(axiom)
    def push(self):
        glPushMatrix()
        glTranslatef(self.p0[0],self.p0[1],0.0)
        glRotatef(self.angle,0,0,1)
        glScalef(*((self.length,)*3))
    def pop(self):
        glPopMatrix()
    def draw(self):
        if self.children == None:
            glColor3f(1,1,0)
            glBegin(GL_LINES)
            glVertex2f(*self.p0)
            glVertex2f(*self.p1)
            glEnd()
        else:
            self.push()
            for child in self.children: child.draw()
            self.pop()
class Arc(object):
    def __init__(self,p0,center,p1):
        self.center = center
        vec0 = (p0[0]-center[0],p0[1]-center[1])
        vec1 = (p1[0]-center[0],p1[1]-center[1])
        self.radius = hypot(vec0[0],vec0[1])
        angle0 = degrees(atan2(vec0[1],vec0[0]))
        angle1 = degrees(atan2(vec1[1],vec1[0]))
        while angle0<0.0: angle0+=360.0
        while angle1<0.0: angle1+=360.0
        if   angle1>angle0 and angle1-angle0>180: angle1-=360.0
        elif angle1<angle0 and angle0-angle1>180: angle1+=360.0
        self.angle0 = radians(angle0)
        self.angle1 = radians(angle1)
    def apply_rules(self,axiom):
        pass
    def draw(self):
        glColor3f(1,0,0)
        glBegin(GL_LINE_STRIP)
        for i in range(100):
            angle = lerp(self.angle0,self.angle1,i/99.0)
            glVertex2f(self.center[0]+self.radius*cos(angle),self.center[1]+self.radius*sin(angle))
        glEnd()
axiom = []
pos = (0,0)
for elem in data:
    if type(elem[0]) == tuple:
        #arc
        axiom.append(Arc( pos, elem[0], elem[1] ))
        pos = elem[1]
    else:
        #line
        axiom.append(Line( pos, elem ))
        pos = elem

def apply_rule(system):
    for elem in system:
        elem.apply_rules(axiom)

systems = [copy.deepcopy(axiom)]
for i in range(3):
    system = copy.deepcopy(systems[-1])
    apply_rule(system)
    systems.append(system)

dllists = [ glGenLists(1) for i in range(len(systems)) ]
for i in range(len(systems)):
    glNewList(dllists[i],GL_COMPILE)
    for elem in systems[i]:
        elem.draw()
    glEndList()


idisplay = 3
def get_input():
    global idisplay
    for event in pygame.event.get():
        if   event.type == QUIT: return False
        elif event.type == KEYDOWN:
            if   event.key == K_ESCAPE: return False
            elif event.key==K_0: idisplay=0
            elif event.key==K_1: idisplay=1
            elif event.key==K_2: idisplay=2
            elif event.key==K_3: idisplay=3
            elif event.key==K_4: idisplay=4
            elif event.key==K_5: idisplay=5
            elif event.key==K_6: idisplay=6
            elif event.key==K_7: idisplay=7
            elif event.key==K_8: idisplay=8
            elif event.key==K_9: idisplay=9
    return True

def draw():
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)

    glViewport(0,0,screen_size[0],screen_size[1])

    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho( -0.1,1.1, -0.6,0.6, -1.0,1.0 )

    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    glCallList(dllists[idisplay])

    pygame.display.flip()

def main():
    clock = pygame.time.Clock()
    while True:
        if not get_input(): break
        draw()
        clock.tick(60)
    pygame.quit()

if __name__ == "__main__":
    try:
        main()
    except:
        traceback.print_exc()
        pygame.quit()
        input()