Initial Commitmaster

1 files changed, 127 insertions, 0 deletions

diff --git a/domainColoring.py b/domainColoring.py
new file mode 100644
index 0000000..0a2efca
--- a/dev/null
+++ b/domainColoring.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+import cgi
+import sys
+import Image, ImageDraw
+import math
+from cmath import *
+
+# Domain Coloring Ranges
+height = 400
+width = 400
+real_min = -4.0
+real_max = 4.0
+imag_min = -4.0
+imag_max = 4.0
+
+# Set up for safe eval
+safe_list = ['math','acos', 'asin', 'atan', 'atan2', 'ceil', 'cos', 'cosh', 'de grees', 'e', 'exp', 'fabs', 'floor', 'fmod', 'frexp', 'hypot', 'ldexp', 'log', 'log10', 'modf', 'pi', 'pow', 'radians', 'sin', 'sinh', 'sqrt', 'tan', 'tanh'] 
+safe_dict = dict([ (k, globals().get(k, None)) for k in safe_list ]) 
+safe_dict['abs'] = abs 
+
+# fun -- user defined function
+# c -- current complex value
+# x -- x coordinate of the drawing
+# y -- y coordinate of the drawing
+def evalUserFunction( fun, c, x, y ):
+   safe_dict['x'] = x
+   safe_dict['y'] = y
+   safe_dict['c'] = c 
+   safe_dict['i'] = i 
+   return eval(fun,{"__builtins__":None},safe_dict) 
+
+# Domain coloring algorithm
+def colorDomain( fun ):
+   im = Image.new('RGB', (height, width))
+   draw = ImageDraw.ImageDraw(im)
+
+   i = complex(0,1)
+   for jc in range(0,height):
+      imag = imag_max - (imag_max - imag_min) * jc /(height-1.0)
+      for ic in range(0,width):
+         real = real_max - (real_max - real_min) * ic/(width - 1.0)
+         c = complex(real, imag)
+         x = ic
+         y = jc
+         v = eval(fun)
+         m = sqrt( v.real**2 + v.imag**2 ) 
+         a = phase(c)
+         while a < 0: 
+            a += 2.0*math.pi
+         a /= 2.0*math.pi
+
+         range_start = 0.0
+         range_end = 1.0
+         while m.real > range_end:
+            range_start = range_end
+            range_end *= math.e
+         k = ( m.real - range_start) / ( range_end - range_start )
+         sat = 0.0
+         if k < .5:
+            sat = k*2.0
+         else:
+            1 - ( k - .5 )*2.0
+
+         val = sat
+         sat = 1.0 - (1.0-sat) ** (3.0) 
+         sat = .4 + sat * .6
+         val = 1.0 - val;
+         val = 1.0 - (1.0 - val) ** (3.0)
+         val = .6 + val * .4
+         r, g, b = 0, 0, 0
+         if sat == 0:
+            r = g = b = val
+         else:
+            if a == 1: 
+               a = 0
+            z = math.floor(a*6);
+            w = int(z)
+            f = a*6.0 - z
+            p = val * ( 1.0 - sat)
+            q = val * ( 1.0 - sat*f)
+            t = val * (1.0-sat * (1.0-f))
+            if w == 0:
+               r = val
+               g = t
+               b = p
+            elif w == 1:
+               r = q
+               g = val
+               b = p
+            elif w == 2:
+               r = p
+               g = val
+               b = t
+            elif w == 3:
+               r = p
+               g = q
+               b = val
+            elif w == 4:
+               r = t
+               g = p
+               b = val
+            elif w == 5:
+               r = val
+               g = p
+               b = q 
+         r *= 256
+         g *= 256
+         b *= 256
+         if r > 255: 
+            r = 255
+         if g > 255: 
+            g = 255
+         if b > 255: 
+            b = 255
+         draw.point((ic,jc), fill=( int(r), int(g), int(b) ) )
+   del draw
+   print "Content-Type: image/png\r\n"
+   im.save(sys.stdout, "PNG")
+
+# Startup code: Parse input and call domain coloring
+form = cgi.FieldStorage()
+if form.has_key("fun") and form.has_key("captcha") and form["captcha"].value == "2":
+   user_func=(form["fun"].value).replace("plus", "+")
+   colorDomain( user_func ) 
+else:
+   print "Content-Type: text/html\r\n"
+   print "Invalid Captcha, or bad input"