cvs/fract/mandel.cgi

#!/usr/bin/python

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

form= cgi.FieldStorage()

# Image size
if form.has_key('width'):
    width=atoi(form['width'].value)
else:
    width= 570
if form.has_key('height'):
    height=atoi(form['height'].value)
else:
    height= 570

xmax, ymax = width-1, height-1          # Coordinate maximums

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))

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

def drawrect((x1, y1), (x2, y2)):
    "Draw a rectangle defined by the corners (x1, y1) and (x2, y2)."
    color= plot(x1, y1) # Plot the upper left corner
    # Should we cut this rectangle and recurse into the pieces?
    cut= 0
    ## Plot the edges and at the same time check if they are all the
    ## same color.
    # Upper edge (left to right)
    x, y= x1+1, y1
    while x<=x2:
        if color<>plot(x, y):
            cut= 1
        x= x+1
    # Right edge (top to bottom)
    x, y= x2, y1+1
    while y<=y2:
        if color<>plot(x, y):
            cut= 1
        y= y+1
    # Bottom edge (right to left)
    x, y= x2-1, y2
    while x>=x1:
        if color<>plot(x, y):
            cut= 1
        x= x-1
    # Left edge (bottom to top)
    x, y= x1, y2-1
    while y>y1:
        if color<>plot(x, y):
            cut= 1
        y= y-1
    # If our rectangle is too small to have an inside, we have now
    # plotted every pixel in it.
    if x2-x1<=1 or y2-y1<=1:
        return
    if cut:                             # If we're cutting the rectangle
        if x2-x1 > y2-y1:               # If it's wider than high
            # Cut vertically
            xc= ((x2-x1)/2)+x1
            drawrect((x1, y1), (xc, y2))
            drawrect((xc, y1), (x2, y2))
        else:                           # if it's higher than wide
            # Cut horizontally
            yc= ((y2-y1)/2)+y1
            drawrect((x1, y1), (x2, yc))
            drawrect((x1, yc), (x2, y2))
    else:
        # If we're not cutting, it was the same color along the edge
        if not debug:
            # Fill in the rectangle
            draw.rectangle([x1, y1, x2, y2], fill= color)
            if yorig >= 0: # The x axis is visible on image
                # Fill in the mirror rectangle
                # Mirror y1 and y2 over yorig, but keep within image
                y1m= max(0, min(2*yorig-y1, ymax))
                y2m= max(0, min(2*yorig-y2, ymax))
                draw.rectangle([x1, y1m, x2, y2m], fill= color)

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)

def plot(x, y):
    c= constant(x, y)
    z= i= 0
    color= mandel.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:
        mandel.putpixel((x, y), color)
        if yorig >= 0: # The x axis is visible on image
            ym= 2*yorig-y   # ym is y mirrored over yorig
            if ym >= 0 and ym <= ymax:
                # ym is on the image
                mandel.putpixel((x, 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

# 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

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

print "Content-type: image/png"
print
mandel.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	# Image size
9	if form.has_key('width'):
10	width=atoi(form['width'].value)
11	else:
12	width= 570
13	if form.has_key('height'):
14	height=atoi(form['height'].value)
15	else:
16	height= 570
17
18	xmax, ymax = width-1, height-1 # Coordinate maximums
19
20	debug= form.has_key('debug')
21
22	if form.has_key('iter'):
23	maxiter=atoi(form['iter'].value)
24	else:
25	maxiter= 270
26
27	c1, c2 = (-2+2j), (2-2j) # Corner coordinates
28
29	# Force c1 to be upper left and c2 to be lower right
30	c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \
31	complex(max(c1.real, c2.real), min(c1.imag, c2.imag))
32
33	mandel= Image.new("L", (width, height))
34	draw= ImageDraw.Draw(mandel)
35
36	def drawrect((x1, y1), (x2, y2)):
37	"Draw a rectangle defined by the corners (x1, y1) and (x2, y2)."
38	color= plot(x1, y1) # Plot the upper left corner
39	# Should we cut this rectangle and recurse into the pieces?
40	cut= 0
41	## Plot the edges and at the same time check if they are all the
42	## same color.
43	# Upper edge (left to right)
44	x, y= x1+1, y1
45	while x<=x2:
46	if color<>plot(x, y):
47	cut= 1
48	x= x+1
49	# Right edge (top to bottom)
50	x, y= x2, y1+1
51	while y<=y2:
52	if color<>plot(x, y):
53	cut= 1
54	y= y+1
55	# Bottom edge (right to left)
56	x, y= x2-1, y2
57	while x>=x1:
58	if color<>plot(x, y):
59	cut= 1
60	x= x-1
61	# Left edge (bottom to top)
62	x, y= x1, y2-1
63	while y>y1:
64	if color<>plot(x, y):
65	cut= 1
66	y= y-1
67	# If our rectangle is too small to have an inside, we have now
68	# plotted every pixel in it.
69	if x2-x1<=1 or y2-y1<=1:
70	return
71	if cut: # If we're cutting the rectangle
72	if x2-x1 > y2-y1: # If it's wider than high
73	# Cut vertically
74	xc= ((x2-x1)/2)+x1
75	drawrect((x1, y1), (xc, y2))
76	drawrect((xc, y1), (x2, y2))
77	else: # if it's higher than wide
78	# Cut horizontally
79	yc= ((y2-y1)/2)+y1
80	drawrect((x1, y1), (x2, yc))
81	drawrect((x1, yc), (x2, y2))
82	else:
83	# If we're not cutting, it was the same color along the edge
84	if not debug:
85	# Fill in the rectangle
86	draw.rectangle([x1, y1, x2, y2], fill= color)
87	if yorig >= 0: # The x axis is visible on image
88	# Fill in the mirror rectangle
89	# Mirror y1 and y2 over yorig, but keep within image
90	y1m= max(0, min(2*yorig-y1, ymax))
91	y2m= max(0, min(2*yorig-y2, ymax))
92	draw.rectangle([x1, y1m, x2, y2m], fill= color)
93
94	def constant(x, y):
95	creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real
96	cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag
97	return complex(creal, cimag)
98
99	def plot(x, y):
100	c= constant(x, y)
101	z= i= 0
102	color= mandel.getpixel((x, y))
103	if color<>0:
104	return color
105	while i<maxiter and abs(z)<2:
106	z= z**2+c
107	i= i+1
108	color= 16*i%256
109	if i>=maxiter or color==0:
110	if debug:
111	color= 255
112	else:
113	color= 1
114	try:
115	mandel.putpixel((x, y), color)
116	if yorig >= 0: # The x axis is visible on image
117	ym= 2*yorig-y # ym is y mirrored over yorig
118	if ym >= 0 and ym <= ymax:
119	# ym is on the image
120	mandel.putpixel((x, ym), color)
121	except IndexError, the_error:
122	print "coord", x, y, xm, ym
123	raise IndexError, the_error
124	return color
125
126	# Initial default values
127	yfrom= 0
128	yto= ymax
129	yorig= -1 # The pixel coordinate of the x axis; negative means not on image
130
131	# Check if we should do mirroring
132	if c1.imag > 0 and c2.imag < 0: # the x axis is visible
133	yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis
134	if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom
135	yfrom= yorig # Begin at x axis
136	else:
137	yto= yorig # End at x axis
138
139	drawrect((0, yfrom), (xmax, yto))
140
141	print "Content-type: image/png"
142	print
143	mandel.save(sys.stdout, "PNG")