#!/usr/bin/env python
from math import *
from random import *
import cairo
from cairo import Context
Black = (0, 0, 0)
White = (1, 1, 1)
def rand():
return random()*2 - 1
def rotate(theta, x, y):
x, y = x*cos(theta)-y*sin(theta), x*sin(theta)+y*cos(theta)
return x, y
def star(ctx, n=5, r0=0.4):
for c in range(2):
ctx.set_source_rgba(*(White, Black)[c])
x, y = 0, 1
ctx.move_to(x, y)
theta = 2*pi / n
for i in range(n):
x1, y1 = rotate(theta/2, x, y)
ctx.line_to(r0*x1, r0*y1)
x, y = rotate(theta/2, x1, y1)
ctx.line_to(x, y)
ctx.close_path()
(ctx.fill, ctx.stroke)[c]()
class ScribeCall(object):
def __init__(self, scribe, name):
self.scribe = scribe
self.name = name
def __call__(self, *args, **kw):
self.args = args
self.kw = kw
self.scribe.calls.append(self)
class Scribe(object):
def __init__(self):
self.calls = []
__getattr__ = ScribeCall
def run(self, ctx):
for call in self.calls:
#print "ctx.%s(%s)" % (call.name, ', '.join(str(x) for x
in call.args))
getattr(ctx, call.name)(*call.args, **call.kw)
def orbit(dx, dy, w, h):
x = -2*w
while x < 2*w:
y = -2*h
while y < 2*h:
yield x, y
y += dy
x += dx
def main_stars(w=800, h=1000):
seed(0)
surface = cairo.PSSurface('stars.ps', w, h)
ctx = Context(surface)
ctx.set_source_rgba(*White)
ctx.rectangle(0, 0, w, h)
ctx.fill()
ctx.set_line_width(1./30)
scribe = Scribe()
for i in range(10):
scribe.save()
scribe.translate(w*random(), h*random())
scribe.scale(20, 20)
scribe.rotate(random() * 2 * pi)
r = exp(random())
scribe.scale(r, r)
star(scribe, 5)
scribe.scale(1./r, 1./r)
scribe.translate(rand(), rand())
scribe.restore()
for x, y in orbit(120, 240, w, h):
ctx.save()
ctx.translate(x, y)
scribe.run(ctx)
ctx.restore()
if __name__=="__main__":
main_stars()
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