cvs/fract/julia2.cgi

#!/usr/bin/python

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

form= cgi.FieldStorage()

maxiter= 270

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))

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

debug= 0

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:
        xc= ((x2-x1)/2)+x1
        yc= ((y2-y1)/2)+y1
        drawrect((x1+1, y1+1), (xc, yc)) # upper left
        drawrect((xc+1, y1+1), (x2-1, yc)) # upper right
        drawrect((x1+1, yc+1), (xc, y2-1)) # lower left
        drawrect((xc+1, yc+1), (x2-1, y2-1)) # lower right
    else:
        if not debug:
            draw.rectangle([x1+1, y1+1, x2-1, y2-1], 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+1), ymax))
                y2m= max(0, min(2*yorig-(y2-1), ymax))
                x1m= max(0, min(2*xorig-(x1+1), xmax))
                x2m= max(0, min(2*xorig-(x2-1), xmax))
                draw.rectangle([x1m, y1m, x2m, y2m], fill= color)

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