cvs/fract/mandelzoom.cgi

#!/usr/bin/python

import cgi, Image, ImageDraw, sys, math, signal, errno, os
from string import atoi, atof

def handler(signum, frame):
    raise os.error, (errno.ETIME, "Timer expired")

signal.alarm(55)
signal.signal(signal.SIGALRM, handler)

# This is to get backtrace output
sys.stderr = sys.stdout

# Uncomment this to get the backtrace more readable
#print "Content-Type: text/plain"
#print ""

form= cgi.FieldStorage()

# Image size
if form.has_key('width'):
    width= atoi(form['width'].value)
else:
    width= 480
if form.has_key('height'):
    height= atoi(form['height'].value)
else:
    height= 480

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

# Complex number in center of image is (cx+cy*j)
if form.has_key('cx'):
    cx= atof(form['cx'].value)
else:
    cx= 0.0

if form.has_key('cy'):
    cy= atof(form['cy'].value)
else:
    cy= 0.0

if form.has_key('diag'):
    diag= atof(form['diag'].value)
else:
    diag= math.sqrt(32) # sqrt(4**2 + 4**2)

debug= form.has_key('debug')

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

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

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

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

<!-- implies TYPE=SUBMIT -->"""
    print '<INPUT TYPE=IMAGE NAME="image"',
    print 'WIDTH="%s"' % (str(width)),
    print 'HEIGHT="%s"' % (str(height)),
    if debug:
        ds="&debug=on"
    else:
        ds=""
    if form.has_key('image.x') and form.has_key('image.y'):
        # Adjust cx and cy
        ix= atof(form['image.x'].value)
        iy= atof(form['image.y'].value)
        owidth= atof(form['owidth'].value)
        oheight= atof(form['oheight'].value)
        diagp= math.sqrt(owidth**2 + oheight**2)
        scale= diagp/diag
        cx= (ix/scale) + (cx - (owidth / (scale*2)))
        cy= ((oheight-iy)/scale) + (cy - (oheight / (scale*2)))
    if form.has_key('zoom'):
        zoom=atof(form['zoom'].value)
        diag=diag/zoom
    else:
        # If no zoom provided, don't actually zoom
        zoom= 2.0
    print 'SRC="mandelzoom.cgi?type=image&width=%s&height=%s&iter=%s%s&diag=%s&cx=%s&cy=%s"' % (str(width), str(height), str(maxiter), ds, str(diag), str(cx), str(cy)),
    print 'ALIGN=BOTTOM HEIGHT="%s"' % (str(height)),
    print 'WIDTH="%s"><P>' % (str(width))
    print 'Zoom: <SELECT NAME="zoom">'
    for zv in [1.0/5, 1.0/3, 1.0/2, 1.0/1.5, 1.0, 1.5, 2.0, 3.0, 5.0]:
        print '<OPTION',
        if str(zv)==str(zoom):
            print 'SELECTED',
        print 'VALUE="%s"' % (str(zv))
        if zv == 1:
            print '>Pan'
        elif zv < 1:
            print '>Out �%s' % (str(1/zv))
        else:
            print '>In �%s' % (str(zv))
    print '</SELECT>'
    print """Width: <INPUT TYPE=TEXT NAME="width" MAXLENGTH="4" SIZE="3"
    VALUE="%s">
    Height: <INPUT TYPE=TEXT NAME="height" MAXLENGTH="4" SIZE="3"
    VALUE="%s">
    Iterations: <INPUT TYPE=TEXT NAME="iter" MAXLENGTH="4" SIZE="3"
    VALUE="%s">
    Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" """ % (str(width), str(height), str(maxiter)),
    if debug:
        print 'CHECKED>'
    else:
        print '>'
    print '<INPUT TYPE=SUBMIT VALUE="Apply">'
    for var in (("diag", diag), ("cx", cx), ("cy", cy), ("owidth", width),
                ("oheight", height)):
        print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % var
    print '<INPUT TYPE=HIDDEN NAME=type VALUE="html">'

    print """</FORM><P>
After changing any settings, don't forget to change the "Zoom" setting
to "Pan" if you don't want to zoom when applying them.
</BODY></HTML>"""
    sys.exit(0)

# Figure out c1 and c2 from width, height, diag, cx, and cy.
# Diagonal in pixels
diagp= math.sqrt(width**2 + height**2)
# Scale between pixels and coordinates
scale= diagp/diag
x= (width/2.0)/scale
y= (height/2.0)/scale

c1= cx - x + (cy - y) * (0+1j)
c2= cx + x + (cy + y) * (0+1j)

#print width, height, diag, cx, cy, diagp, scale, x, y, c1, c2
#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

try:
    drawrect((0, yfrom), (xmax, yto))
except os.error, the_error:
    if the_error[0] != errno.ETIME:
        raise os.error, the_error
        
signal.alarm(0)

print "Content-type: image/png"
print
mandel.save(sys.stdout, "PNG")
1	teddy	1.1	#!/usr/bin/python
2
3	teddy	1.9	import cgi, Image, ImageDraw, sys, math, signal, errno, os
4	teddy	1.2	from string import atoi, atof
5
6	teddy	1.9	def handler(signum, frame):
7			raise os.error, (errno.ETIME, "Timer expired")
8
9			signal.alarm(55)
10			signal.signal(signal.SIGALRM, handler)
11
12	teddy	1.3	# This is to get backtrace output
13	teddy	1.2	sys.stderr = sys.stdout
14	teddy	1.1
15	teddy	1.3	# Uncomment this to get the backtrace more readable
16			#print "Content-Type: text/plain"
17			#print ""
18
19	teddy	1.1	form= cgi.FieldStorage()
20
21			# Image size
22			if form.has_key('width'):
23	teddy	1.2	width= atoi(form['width'].value)
24	teddy	1.1	else:
25	teddy	1.3	width= 480
26	teddy	1.1	if form.has_key('height'):
27	teddy	1.2	height= atoi(form['height'].value)
28	teddy	1.1	else:
29	teddy	1.3	height= 480
30	teddy	1.1
31			xmax, ymax = width-1, height-1 # Coordinate maximums
32
33	teddy	1.2	# Complex number in center of image is (cx+cy*j)
34			if form.has_key('cx'):
35			cx= atof(form['cx'].value)
36			else:
37	teddy	1.6	cx= 0.0
38	teddy	1.2
39			if form.has_key('cy'):
40			cy= atof(form['cy'].value)
41			else:
42	teddy	1.6	cy= 0.0
43	teddy	1.2
44			if form.has_key('diag'):
45			diag= atof(form['diag'].value)
46			else:
47	teddy	1.5	diag= math.sqrt(32) # sqrt(42 + 42)
48	teddy	1.2
49	teddy	1.1	debug= form.has_key('debug')
50
51			if form.has_key('iter'):
52	teddy	1.2	maxiter= atoi(form['iter'].value)
53	teddy	1.1	else:
54	teddy	1.5	maxiter= 270
55	teddy	1.1
56	teddy	1.2	# If type!=image, then output an HTML page, not an image
57			if not (form.has_key('type') and form['type'].value == "image"):
58	teddy	1.1	print """Content-Type: text/html
59
60			<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
61			<HTML><HEAD>
62	teddy	1.6	<TITLE>Mandelbrot Set Zoomer</TITLE>
63	teddy	1.1	</HEAD>
64			<BODY>
65	teddy	1.6	<H1>Mandelbrot Set Zoomer</H1>
66	teddy	1.1
67			<FORM ACTION="mandelzoom.cgi" METHOD=GET>
68
69	teddy	1.2	<!-- implies TYPE=SUBMIT -->"""
70			print '<INPUT TYPE=IMAGE NAME="image"',
71			print 'WIDTH="%s"' % (str(width)),
72			print 'HEIGHT="%s"' % (str(height)),
73			if debug:
74			ds="&debug=on"
75			else:
76			ds=""
77	teddy	1.6	if form.has_key('image.x') and form.has_key('image.y'):
78			# Adjust cx and cy
79			ix= atof(form['image.x'].value)
80			iy= atof(form['image.y'].value)
81			owidth= atof(form['owidth'].value)
82			oheight= atof(form['oheight'].value)
83	teddy	1.7	diagp= math.sqrt(owidth2 + oheight2)
84	teddy	1.6	scale= diagp/diag
85	teddy	1.7	cx= (ix/scale) + (cx - (owidth / (scale*2)))
86			cy= ((oheight-iy)/scale) + (cy - (oheight / (scale*2)))
87	teddy	1.2	if form.has_key('zoom'):
88	teddy	1.5	zoom=atof(form['zoom'].value)
89	teddy	1.2	diag=diag/zoom
90			else:
91			# If no zoom provided, don't actually zoom
92	teddy	1.6	zoom= 2.0
93	teddy	1.2	print 'SRC="mandelzoom.cgi?type=image&width=%s&height=%s&iter=%s%s&diag=%s&cx=%s&cy=%s"' % (str(width), str(height), str(maxiter), ds, str(diag), str(cx), str(cy)),
94			print 'ALIGN=BOTTOM HEIGHT="%s"' % (str(height)),
95			print 'WIDTH="%s"><P>' % (str(width))
96			print 'Zoom: <SELECT NAME="zoom">'
97	teddy	1.5	for zv in [1.0/5, 1.0/3, 1.0/2, 1.0/1.5, 1.0, 1.5, 2.0, 3.0, 5.0]:
98	teddy	1.2	print '<OPTION',
99	teddy	1.5	if str(zv)==str(zoom):
100	teddy	1.2	print 'SELECTED',
101			print 'VALUE="%s"' % (str(zv))
102	teddy	1.3	if zv == 1:
103			print '>Pan'
104			elif zv < 1:
105	teddy	1.6	print '>Out �%s' % (str(1/zv))
106	teddy	1.2	else:
107	teddy	1.3	print '>In �%s' % (str(zv))
108	teddy	1.2	print '</SELECT>'
109			print """Width: <INPUT TYPE=TEXT NAME="width" MAXLENGTH="4" SIZE="3"
110			VALUE="%s">
111			Height: <INPUT TYPE=TEXT NAME="height" MAXLENGTH="4" SIZE="3"
112			VALUE="%s">
113	teddy	1.1	Iterations: <INPUT TYPE=TEXT NAME="iter" MAXLENGTH="4" SIZE="3"
114			VALUE="%s">
115	teddy	1.3	Debug mode: <INPUT TYPE=CHECKBOX NAME="debug" """ % (str(width), str(height), str(maxiter)),
116	teddy	1.2	if debug:
117			print 'CHECKED>'
118			else:
119			print '>'
120	teddy	1.3	print '<INPUT TYPE=SUBMIT VALUE="Apply">'
121	teddy	1.6	for var in (("diag", diag), ("cx", cx), ("cy", cy), ("owidth", width),
122			("oheight", height)):
123	teddy	1.5	print '<INPUT TYPE=HIDDEN NAME="%s" VALUE="%s">' % var
124	teddy	1.2	print '<INPUT TYPE=HIDDEN NAME=type VALUE="html">'
125	teddy	1.1
126	teddy	1.8	print """</FORM><P>
127			After changing any settings, don't forget to change the "Zoom" setting
128			to "Pan" if you don't want to zoom when applying them.
129	teddy	1.1	</BODY></HTML>"""
130			sys.exit(0)
131
132	teddy	1.5	# Figure out c1 and c2 from width, height, diag, cx, and cy.
133			# Diagonal in pixels
134			diagp= math.sqrt(width2 + height2)
135			# Scale between pixels and coordinates
136			scale= diagp/diag
137			x= (width/2.0)/scale
138			y= (height/2.0)/scale
139
140	teddy	1.6	c1= cx - x + (cy - y) * (0+1j)
141			c2= cx + x + (cy + y) * (0+1j)
142	teddy	1.5
143			#print width, height, diag, cx, cy, diagp, scale, x, y, c1, c2
144			#sys.exit(0)
145
146			#c1, c2 = (-2+2j), (2-2j) # Corner coordinates
147	teddy	1.1
148			# Force c1 to be upper left and c2 to be lower right
149			c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \
150			complex(max(c1.real, c2.real), min(c1.imag, c2.imag))
151
152			mandel= Image.new("L", (width, height))
153			draw= ImageDraw.Draw(mandel)
154
155			def drawrect((x1, y1), (x2, y2)):
156			"Draw a rectangle defined by the corners (x1, y1) and (x2, y2)."
157			color= plot(x1, y1) # Plot the upper left corner
158			# Should we cut this rectangle and recurse into the pieces?
159			cut= 0
160			## Plot the edges and at the same time check if they are all the
161			## same color.
162			# Upper edge (left to right)
163			x, y= x1+1, y1
164			while x<=x2:
165			if color<>plot(x, y):
166			cut= 1
167			x= x+1
168			# Right edge (top to bottom)
169			x, y= x2, y1+1
170			while y<=y2:
171			if color<>plot(x, y):
172			cut= 1
173			y= y+1
174			# Bottom edge (right to left)
175			x, y= x2-1, y2
176			while x>=x1:
177			if color<>plot(x, y):
178			cut= 1
179			x= x-1
180			# Left edge (bottom to top)
181			x, y= x1, y2-1
182			while y>y1:
183			if color<>plot(x, y):
184			cut= 1
185			y= y-1
186			# If our rectangle is too small to have an inside, we have now
187			# plotted every pixel in it.
188			if x2-x1<=1 or y2-y1<=1:
189			return
190			if cut: # If we're cutting the rectangle
191			if x2-x1 > y2-y1: # If it's wider than high
192			# Cut vertically
193			xc= ((x2-x1)/2)+x1
194			drawrect((x1, y1), (xc, y2))
195			drawrect((xc, y1), (x2, y2))
196			else: # if it's higher than wide
197			# Cut horizontally
198			yc= ((y2-y1)/2)+y1
199			drawrect((x1, y1), (x2, yc))
200			drawrect((x1, yc), (x2, y2))
201			else:
202			# If we're not cutting, it was the same color along the edge
203			if not debug:
204			# Fill in the rectangle
205			draw.rectangle([x1, y1, x2, y2], fill= color)
206			if yorig >= 0: # The x axis is visible on image
207			# Fill in the mirror rectangle
208			# Mirror y1 and y2 over yorig, but keep within image
209			y1m= max(0, min(2*yorig-y1, ymax))
210			y2m= max(0, min(2*yorig-y2, ymax))
211			draw.rectangle([x1, y1m, x2, y2m], fill= color)
212
213			def constant(x, y):
214			creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real
215			cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag
216			return complex(creal, cimag)
217
218			def plot(x, y):
219			c= constant(x, y)
220			z= i= 0
221			color= mandel.getpixel((x, y))
222			if color<>0:
223			return color
224			while i<maxiter and abs(z)<2:
225			z= z**2+c
226			i= i+1
227			color= 16*i%256
228			if i>=maxiter or color==0:
229			if debug:
230			color= 255
231			else:
232			color= 1
233			try:
234			mandel.putpixel((x, y), color)
235			if yorig >= 0: # The x axis is visible on image
236			ym= 2*yorig-y # ym is y mirrored over yorig
237			if ym >= 0 and ym <= ymax:
238			# ym is on the image
239			mandel.putpixel((x, ym), color)
240			except IndexError, the_error:
241			print "coord", x, y, xm, ym
242			raise IndexError, the_error
243			return color
244
245			# Initial default values
246			yfrom= 0
247			yto= ymax
248			yorig= -1 # The pixel coordinate of the x axis; negative means not on image
249
250			# Check if we should do mirroring
251			if c1.imag > 0 and c2.imag < 0: # the x axis is visible
252			yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis
253			if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom
254			yfrom= yorig # Begin at x axis
255			else:
256			yto= yorig # End at x axis
257
258	teddy	1.9	try:
259			drawrect((0, yfrom), (xmax, yto))
260			except os.error, the_error:
261			if the_error[0] != errno.ETIME:
262			raise os.error, the_error
263
264			signal.alarm(0)
265	teddy	1.1
266			print "Content-type: image/png"
267			print
268			mandel.save(sys.stdout, "PNG")