cvs/fract/julia3.cgi

#!/usr/bin/python

import cgi, Image, ImageDraw, sys
from string import atoi

form= cgi.FieldStorage()

width, height= 570, 570                 # Image size
xmax, ymax = width-1, height-1          # Coordinate maximums

inx=max(0, min(atoi(form['image.x'].value), xmax))
iny=max(0, min(atoi(form['image.y'].value), ymax))
debug= form.has_key('debug')

if form.has_key('iter'):
    maxiter=atoi(form['iter'].value)
else:
    maxiter= 270

c1, c2 = (-2+2j), (2-2j)                # Corner coordinates

# Force c1 to be upper left and c2 to be lower right
c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \
        complex(max(c1.real, c2.real), min(c1.imag, c2.imag))

def constant(x, y):
    creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real
    cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag
    return complex(creal, cimag)

c= constant(inx, iny)                   # Julia set coordinate

julia= Image.new("L", (width, height))
draw= ImageDraw.Draw(julia)

def drawrect((x1, y1), (x2, y2)):
    color= plot(x1, y1)
    cut= 0
    x, y= x1+1, y1
    while x<=x2:
        if color<>plot(x, y):
            cut= 1
        x= x+1
    x, y= x2, y1+1
    while y<=y2:
        if color<>plot(x, y):
            cut= 1
        y= y+1
    x, y= x2-1, y2
    while x>=x1:
        if color<>plot(x, y):
            cut= 1
        x= x-1
    x, y= x1, y2-1
    while y>y1:
        if color<>plot(x, y):
            cut= 1
        y= y-1
    if x2-x1<=1 or y2-y1<=1:
        return
    if cut:
        if x2-x1 > y2-y1:               # If wider than high
            xc= ((x2-x1)/2)+x1
            drawrect((x1, y1), (xc, y2))
            drawrect((xc, y1), (x2, y2))
        else:                           # if higher than wide
            yc= ((y2-y1)/2)+y1
            drawrect((x1, y1), (x2, yc))
            drawrect((x1, yc), (x2, y2))
    else:
        if not debug:
            draw.rectangle([x1, y1, x2, y2], fill= color)
            if yorig >= 0: # The x axis is visible on image
                # mirror over yorig, but keep within image
                y1m= max(0, min(2*yorig-y1, ymax))
                y2m= max(0, min(2*yorig-y2, ymax))
                x1m= max(0, min(2*xorig-x1, xmax))
                x2m= max(0, min(2*xorig-x2, xmax))
                draw.rectangle([x1m, y1m, x2m, y2m], fill= color)

def plot(x, y):
    z= constant(x, y)
    i= 0
    color= julia.getpixel((x, y))
    if color<>0:
        return color
    while i<maxiter and abs(z)<2:
        z= z**2+c
        i= i+1
    color= 16*i%256
    if i>=maxiter or color==0:
        if debug:
            color= 255
        else:
            color= 1
    try:
        julia.putpixel((x, y), color)
        if yorig >= 0: # The x axis is visible on image
            ym= 2*yorig-y   # ym is y mirrored over yorig
            xm= 2*xorig-x
            if ym >= 0 and ym <= ymax and xm>=0 and xm<=xmax:
                # ym is on the image
                julia.putpixel((xm-1, ym), color)
    except IndexError, the_error:
        print "coord", x, y, xm, ym
        raise IndexError, the_error
    return color

# Initial default values
yfrom= 0
yto= ymax
yorig= -1 # The pixel coordinate of the x axis; negative means not on image
xorig= -1

# Check if we should do mirroring
if c1.imag > 0 and c2.imag < 0: # the x axis is visible
    yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis
    if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom
        yfrom= yorig # Begin at x axis
    else:
        yto= yorig # End at x axis

if c1.real < 0 and c2.real > 0:
    xorig= int((-c1.real/(c2.real-c1.real))*height)

drawrect((0, yfrom), (xmax, yto))

print "Content-type: image/png"
print
julia.save(sys.stdout, "PNG")
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")