from visual import *

a=complex(-0.75,0)

#faces() runs better on VPython/Python 2.4 

scene=display(
            title="a=-3/4 Julia set",
            height=600,width=600,x=0,y=000,fov=1e-8,
            foreground=color.black, background=color.white,
            userspin=0,userzoom=0,
            center=vector(0,0,0),range=(4,4,4))
screen = faces()

number=100 #width in pixels
MAX=2.0    #half-width in complex plane
MAXITS=20


####calculate the julia map
bins=zeros(((number+1),(number+1)))
for i in arange (0,number+1):
    for j in arange (0,number+1):
        x=-MAX+2*(MAX/number)*i
        y=-MAX+2*(MAX/number)*j
        iter=0
        
        z=complex(x,y)
        while ( (abs(z) < 2.0) and (iter<MAXITS) ):
             z = z*z + a  #JULIA
             iter += 1

        if(iter==MAXITS):
            bins[i,j]=1




####draw the region
nrm=vector(0,0,1)
side=2*float(MAX)/float(number)
for i in arange (0,number+1):
    for j in arange (0,number+1):
        x=-MAX+2*(MAX/number)*i
        y=-MAX+2*(MAX/number)*j
        B=float(bins[i,j])

        if B>0 :
            colorcode=color.black
            screen.append (pos = (x, y, 0.0), color = colorcode, normal=nrm)
            screen.append (pos = (x, y - side, 0.0), color = colorcode, normal=nrm)
            screen.append (pos = (x + side, y, 0.0), color = colorcode, normal=nrm)
            screen.append (pos = (x + side, y, 0.0), color = colorcode, normal=nrm)
            screen.append (pos = (x, y - side, 0.0), color = colorcode, normal=nrm)
            screen.append (pos = (x + side, y - side, 0.0), color = colorcode, normal=nrm)