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#!/usr/bin/python |
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|
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import sys |
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sys.stderr = sys.stdout |
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#print "Content-Type: text/plain" |
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#print |
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import cgi, Image, ImageDraw |
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from string import atoi |
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from Drawrect import drawrect |
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|
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form= cgi.FieldStorage() |
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|
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# Image size |
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if form.has_key('width'): |
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width=atoi(form['width'].value) |
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else: |
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width= 570 |
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if form.has_key('height'): |
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height=atoi(form['height'].value) |
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else: |
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height= 570 |
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|
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xmax, ymax = width-1, height-1 # Coordinate maximums |
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|
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inx=max(0, min(atoi(form['image.x'].value), xmax)) |
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iny=max(0, min(atoi(form['image.y'].value), ymax)) |
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debug= form.has_key('debug') |
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|
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if form.has_key('iter'): |
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maxiter=atoi(form['iter'].value) |
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else: |
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maxiter= 270 |
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|
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c1, c2 = (-2+2j), (2-2j) # Corner coordinates |
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|
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# Force c1 to be upper left and c2 to be lower right |
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c1, c2= complex(min(c1.real, c2.real), max(c1.imag, c2.imag)), \ |
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complex(max(c1.real, c2.real), min(c1.imag, c2.imag)) |
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|
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def constant(x, y): |
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creal= (float(x)/xmax)*(c2.real - c1.real)+c1.real |
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cimag= (float(y)/ymax)*(c2.imag - c1.imag)+c1.imag |
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return complex(creal, cimag) |
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|
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c= constant(inx, iny) # Julia set coordinate |
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|
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julia= Image.new("L", (width, height)) |
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draw= ImageDraw.Draw(julia) |
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|
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def plot(x, y): |
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z= constant(x, y) |
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i= 0 |
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color= julia.getpixel((x, y)) |
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if color<>0: |
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return color |
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while i<maxiter and abs(z)<2: |
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z= z**2+c |
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i= i+1 |
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color= 16*i%256 |
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if i>=maxiter or color==0: |
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if debug: |
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color= 255 |
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else: |
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color= 1 |
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try: |
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julia.putpixel((x, y), color) |
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if yorig >= 0: # The x axis is visible on image |
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ym= 2*yorig-y # ym is y mirrored over yorig |
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xm= 2*xorig-x |
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if ym >= 0 and ym <= ymax and xm>=0 and xm<=xmax: |
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# ym is on the image |
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julia.putpixel((xm-1, ym), color) |
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except IndexError, the_error: |
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print "coord", x, y, xm, ym |
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raise IndexError, the_error |
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return color |
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|
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|
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|
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# Initial default values |
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yfrom= 0 |
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yto= ymax |
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yorig= -1 # The pixel coordinate of the x axis; negative means not on image |
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xorig= -1 |
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|
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|
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def fillrect(x1, y1, x2, y2, color): |
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draw.rectangle([x1, y1, x2, y2], fill= color) |
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if yorig >= 0: # The x axis is visible on image |
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# mirror over yorig, but keep within image |
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y1m= max(0, min(2*yorig-y1, ymax)) |
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y2m= max(0, min(2*yorig-y2, ymax)) |
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x1m= max(0, min(2*xorig-x1, xmax)) |
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x2m= max(0, min(2*xorig-x2, xmax)) |
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draw.rectangle([x1m, y1m, x2m, y2m], fill= color) |
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|
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|
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# Check if we should do mirroring |
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if c1.imag > 0 and c2.imag < 0: # the x axis is visible |
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yorig= int((-c1.imag/(c2.imag-c1.imag))*height) # pixel pos. of x axis |
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if c1.imag < abs(c2.imag): # the x axis is closer to top than bottom |
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yfrom= yorig # Begin at x axis |
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else: |
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yto= yorig # End at x axis |
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|
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if c1.real < 0 and c2.real > 0: |
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xorig= int((-c1.real/(c2.real-c1.real))*height) |
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|
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if not debug: |
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funcpoint= fillrect |
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else: |
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funcpoint= lambda x1, y1, x2, y2, color: x1+y1+x2+y2+color |
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drawrect((0, yfrom), (xmax, yto), plot, funcpoint) |
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|
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print "Content-type: image/png" |
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print |
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julia.save(sys.stdout, "PNG") |
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