/[cvs]/fract/julia3.cgi
ViewVC logotype

Annotation of /fract/julia3.cgi

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.1.1.1 - (hide annotations) (vendor branch)
Sat Feb 24 15:57:15 2001 UTC (23 years, 8 months ago) by teddy
Branch: masse
CVS Tags: start
Changes since 1.1: +0 -0 lines
Imported sources (take 2)

1 teddy 1.1 #!/usr/bin/python
2    
3     import cgi, Image, ImageDraw, sys
4     from string import atoi
5    
6     form= cgi.FieldStorage()
7    
8     width, height= 570, 570 # Image size
9     xmax, ymax = width-1, height-1 # Coordinate maximums
10    
11     inx=max(0, min(atoi(form['image.x'].value), xmax))
12     iny=max(0, min(atoi(form['image.y'].value), ymax))
13     debug= form.has_key('debug')
14    
15     if form.has_key('iter'):
16     maxiter=atoi(form['iter'].value)
17     else:
18     maxiter= 270
19    
20     c1, c2 = (-2+2j), (2-2j) # Corner coordinates
21    
22     # Force c1 to be upper left and c2 to be lower right
23     c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \
24     complex(max(c1.real, c2.real), min(c1.imag, c2.imag))
25    
26     def constant(x, y):
27     creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real
28     cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag
29     return complex(creal, cimag)
30    
31     c= constant(inx, iny) # Julia set coordinate
32    
33     julia= Image.new("L", (width, height))
34     draw= ImageDraw.Draw(julia)
35    
36     def drawrect((x1, y1), (x2, y2)):
37     color= plot(x1, y1)
38     cut= 0
39     x, y= x1+1, y1
40     while x<=x2:
41     if color<>plot(x, y):
42     cut= 1
43     x= x+1
44     x, y= x2, y1+1
45     while y<=y2:
46     if color<>plot(x, y):
47     cut= 1
48     y= y+1
49     x, y= x2-1, y2
50     while x>=x1:
51     if color<>plot(x, y):
52     cut= 1
53     x= x-1
54     x, y= x1, y2-1
55     while y>y1:
56     if color<>plot(x, y):
57     cut= 1
58     y= y-1
59     if x2-x1<=1 or y2-y1<=1:
60     return
61     if cut:
62     if x2-x1 > y2-y1: # If wider than high
63     xc= ((x2-x1)/2)+x1
64     drawrect((x1, y1), (xc, y2))
65     drawrect((xc, y1), (x2, y2))
66     else: # if higher than wide
67     yc= ((y2-y1)/2)+y1
68     drawrect((x1, y1), (x2, yc))
69     drawrect((x1, yc), (x2, y2))
70     else:
71     if not debug:
72     draw.rectangle([x1, y1, x2, y2], fill= color)
73     if yorig >= 0: # The x axis is visible on image
74     # mirror over yorig, but keep within image
75     y1m= max(0, min(2*yorig-y1, ymax))
76     y2m= max(0, min(2*yorig-y2, ymax))
77     x1m= max(0, min(2*xorig-x1, xmax))
78     x2m= max(0, min(2*xorig-x2, xmax))
79     draw.rectangle([x1m, y1m, x2m, y2m], fill= color)
80    
81     def plot(x, y):
82     z= constant(x, y)
83     i= 0
84     color= julia.getpixel((x, y))
85     if color<>0:
86     return color
87     while i<maxiter and abs(z)<2:
88     z= z**2+c
89     i= i+1
90     color= 16*i%256
91     if i>=maxiter or color==0:
92     if debug:
93     color= 255
94     else:
95     color= 1
96     try:
97     julia.putpixel((x, y), color)
98     if yorig >= 0: # The x axis is visible on image
99     ym= 2*yorig-y # ym is y mirrored over yorig
100     xm= 2*xorig-x
101     if ym >= 0 and ym <= ymax and xm>=0 and xm<=xmax:
102     # ym is on the image
103     julia.putpixel((xm-1, ym), color)
104     except IndexError, the_error:
105     print "coord", x, y, xm, ym
106     raise IndexError, the_error
107     return color
108    
109     # Initial default values
110     yfrom= 0
111     yto= ymax
112     yorig= -1 # The pixel coordinate of the x axis; negative means not on image
113     xorig= -1
114    
115     # Check if we should do mirroring
116     if c1.imag > 0 and c2.imag < 0: # the x axis is visible
117     yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis
118     if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom
119     yfrom= yorig # Begin at x axis
120     else:
121     yto= yorig # End at x axis
122    
123     if c1.real < 0 and c2.real > 0:
124     xorig= int((-c1.real/(c2.real-c1.real))*height)
125    
126     drawrect((0, yfrom), (xmax, yto))
127    
128     print "Content-type: image/png"
129     print
130     julia.save(sys.stdout, "PNG")

root@recompile.se
ViewVC Help
Powered by ViewVC 1.1.26