cvs/fract/mandelzoom.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 debug:
    del form['debug']

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

sys.stderr = sys.stdout
print "Content-Type: text/plain"
print ""

# If type==html, then output an HTML page, not an image
if form.has_key('type') and form['type'].value == "html":
    del form['type']
    print """Content-Type: text/html

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<HTML><HEAD>
<TITLE>Mandel Set Zoomer</TITLE>
</HEAD>
<BODY>
<H1>Mandel Set Zoomer</H1>

<FORM ACTION="mandelzoom.cgi" METHOD=GET>

<!-- implies TYPE=SUBMIT -->
    <INPUT TYPE=IMAGE NAME="image" SRC="mandelzoom.cgi?%s" ALIGN=BOTTOM
    HEIGHT="%s" WIDTH="%s">
    Iterations: <INPUT TYPE=TEXT NAME="iter" MAXLENGTH="4" SIZE="3"
    VALUE="%s">
    Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" %s>"""
    for key in form.keys():
        print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % (key, form[key].value)

    print """</FORM>
</BODY></HTML>"""
    sys.exit(0)

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	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			# 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			if debug:
22			del form['debug']
23
24			if form.has_key('iter'):
25			maxiter=atoi(form['iter'].value)
26			del form['iter']
27			else:
28			maxiter= 270
29
30			sys.stderr = sys.stdout
31			print "Content-Type: text/plain"
32			print ""
33
34			# If type==html, then output an HTML page, not an image
35			if form.has_key('type') and form['type'].value == "html":
36			del form['type']
37			print """Content-Type: text/html
38
39			<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
40			<HTML><HEAD>
41			<TITLE>Mandel Set Zoomer</TITLE>
42			</HEAD>
43			<BODY>
44			<H1>Mandel Set Zoomer</H1>
45
46			<FORM ACTION="mandelzoom.cgi" METHOD=GET>
47
48			<!-- implies TYPE=SUBMIT -->
49			<INPUT TYPE=IMAGE NAME="image" SRC="mandelzoom.cgi?%s" ALIGN=BOTTOM
50			HEIGHT="%s" WIDTH="%s">
51			Iterations: <INPUT TYPE=TEXT NAME="iter" MAXLENGTH="4" SIZE="3"
52			VALUE="%s">
53			Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" %s>"""
54			for key in form.keys():
55			print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % (key, form[key].value)
56
57			print """</FORM>
58			</BODY></HTML>"""
59			sys.exit(0)
60
61			c1, c2 = (-2+2j), (2-2j) # Corner coordinates
62
63			# Force c1 to be upper left and c2 to be lower right
64			c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \
65			complex(max(c1.real, c2.real), min(c1.imag, c2.imag))
66
67			mandel= Image.new("L", (width, height))
68			draw= ImageDraw.Draw(mandel)
69
70			def drawrect((x1, y1), (x2, y2)):
71			"Draw a rectangle defined by the corners (x1, y1) and (x2, y2)."
72			color= plot(x1, y1) # Plot the upper left corner
73			# Should we cut this rectangle and recurse into the pieces?
74			cut= 0
75			## Plot the edges and at the same time check if they are all the
76			## same color.
77			# Upper edge (left to right)
78			x, y= x1+1, y1
79			while x<=x2:
80			if color<>plot(x, y):
81			cut= 1
82			x= x+1
83			# Right edge (top to bottom)
84			x, y= x2, y1+1
85			while y<=y2:
86			if color<>plot(x, y):
87			cut= 1
88			y= y+1
89			# Bottom edge (right to left)
90			x, y= x2-1, y2
91			while x>=x1:
92			if color<>plot(x, y):
93			cut= 1
94			x= x-1
95			# Left edge (bottom to top)
96			x, y= x1, y2-1
97			while y>y1:
98			if color<>plot(x, y):
99			cut= 1
100			y= y-1
101			# If our rectangle is too small to have an inside, we have now
102			# plotted every pixel in it.
103			if x2-x1<=1 or y2-y1<=1:
104			return
105			if cut: # If we're cutting the rectangle
106			if x2-x1 > y2-y1: # If it's wider than high
107			# Cut vertically
108			xc= ((x2-x1)/2)+x1
109			drawrect((x1, y1), (xc, y2))
110			drawrect((xc, y1), (x2, y2))
111			else: # if it's higher than wide
112			# Cut horizontally
113			yc= ((y2-y1)/2)+y1
114			drawrect((x1, y1), (x2, yc))
115			drawrect((x1, yc), (x2, y2))
116			else:
117			# If we're not cutting, it was the same color along the edge
118			if not debug:
119			# Fill in the rectangle
120			draw.rectangle([x1, y1, x2, y2], fill= color)
121			if yorig >= 0: # The x axis is visible on image
122			# Fill in the mirror rectangle
123			# Mirror y1 and y2 over yorig, but keep within image
124			y1m= max(0, min(2*yorig-y1, ymax))
125			y2m= max(0, min(2*yorig-y2, ymax))
126			draw.rectangle([x1, y1m, x2, y2m], fill= color)
127
128			def constant(x, y):
129			creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real
130			cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag
131			return complex(creal, cimag)
132
133			def plot(x, y):
134			c= constant(x, y)
135			z= i= 0
136			color= mandel.getpixel((x, y))
137			if color<>0:
138			return color
139			while i<maxiter and abs(z)<2:
140			z= z**2+c
141			i= i+1
142			color= 16*i%256
143			if i>=maxiter or color==0:
144			if debug:
145			color= 255
146			else:
147			color= 1
148			try:
149			mandel.putpixel((x, y), color)
150			if yorig >= 0: # The x axis is visible on image
151			ym= 2*yorig-y # ym is y mirrored over yorig
152			if ym >= 0 and ym <= ymax:
153			# ym is on the image
154			mandel.putpixel((x, ym), color)
155			except IndexError, the_error:
156			print "coord", x, y, xm, ym
157			raise IndexError, the_error
158			return color
159
160			# Initial default values
161			yfrom= 0
162			yto= ymax
163			yorig= -1 # The pixel coordinate of the x axis; negative means not on image
164
165			# Check if we should do mirroring
166			if c1.imag > 0 and c2.imag < 0: # the x axis is visible
167			yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis
168			if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom
169			yfrom= yorig # Begin at x axis
170			else:
171			yto= yorig # End at x axis
172
173			drawrect((0, yfrom), (xmax, yto))
174
175			print "Content-type: image/png"
176			print
177			mandel.save(sys.stdout, "PNG")