PyMandel.py

# PyMandelBrot.py
# Plot a Mandelbrot set
# And include a mouse zoom

from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from numpy import *
import sys

# If psyco isn't installed, delete the next two lines!
import psyco
psyco.full()

# Set initial window width and height
# Declare global variables
global width
global height
global hcenter
global vcenter
global axrng
global hstep
global vstep
global yinit
global xinit

width = 400
height = 400

def zap():
	global hcenter
	global vcenter
	global axrng
	hcenter = 0.0
	vcenter = 0.0
	axrng = 2.0
	init()

def init():
	# Identify the globals
	global hcenter
	global vcenter
	global axrng
	global hstep
	global vstep
	global yinit
	global xinit
	global yfinal
	global xfinal
	
	# Set the screen plotting coordinates and the step
	glClearColor(0.0, 0.0, 0.0, 0.0)
	hstep = 2*axrng/(width)
	vstep = 2*axrng/(height)
	yinit = vcenter + axrng
	xinit = hcenter - axrng
	yfinal = vcenter - axrng
	xfinal = hcenter + axrng
	
	#  Fill the entire graphics window!
	glViewport(0, 0, width, height)
	
	#  Set the projection matrix... our "view"
	glMatrixMode(GL_PROJECTION)
	glLoadIdentity()
	
	# Set the window plot coordinates
	gluOrtho2D(xinit,xfinal,yfinal,yinit)
		
	#  Set the matrix for the object we are drawing
	glMatrixMode(GL_MODELVIEW)
	glLoadIdentity()
	glutPostRedisplay()
	
def keyboard(key, x, y):
	#  Allows us to quit by pressing 'Esc' or 'q'
	if key == chr(27):
		sys.exit()
	if key == "z":
		zap()
	if key == "q":
		sys.exit()
	
def drawmandel():
	glClear(GL_COLOR_BUFFER_BIT)
	
	y = yinit
	while y > yfinal:
		y -= vstep
		x = xinit
		while x < xfinal:
			x += hstep
				
			n = 0
			z = a = complex(x,y)
			
			glBegin(GL_POINTS)
			# n < 200 is the number of iterations
			# Increase this value to show finer detail
			# However finer detail results in slower execution
			while n < 250:
				n+=1 
				z = cos(z) + a
				#print z
				#z = log(sqrt(z.real * z.real + z.imag * z.imag)+1)
				zz = abs(z)

				# zz > 2 is the critical escape value
				# Some functions require larger escape values
				# This zz > 2 conditional provides coloration for 			# points outside the M-Set set
				if zz > 40:
					# Weird colors around the M-Set
					#if abs(z.real) < 0.01 and abs(z.imag) < 0.01:
					glColor3ub(8*zz,4*zz,6*zz)
					glVertex2f(x,y)
					n = 5001
				
			# This zz < 2 conditional provides coloration for
			# points inside the M-Set.
			if zz < 40:
				# Coloration in the M-Set										
				#glColor3f(3/sin(3*zz),cos(3*z.real),2*sin(zz))
				#glColor3f(0.9, 0.2, 0.5)
				#glVertex2f(x,y)
				pass
			glEnd()
			
def mouse(button, state, x, y):
	global hcenter
	global vcenter
	global axrng
	
	# Detect the left/right mouse buttons and the click
	# Followed by resetting the origin
	# Left mouse button zooms in, right button zooms out
	if button == GLUT_LEFT_BUTTON and state == GLUT_DOWN:
		axrng = axrng/2
	if button == GLUT_RIGHT_BUTTON and state == GLUT_DOWN:
		axrng = 2*axrng
	if state == GLUT_DOWN:
		hcenter = xinit + (xfinal - xinit)*x/width
		vcenter = yinit + (yfinal - yinit)*y/height
		print hcenter, vcenter
		init()
			
def main():
	glutInit(sys.argv)
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE)
	glutInitWindowPosition(50, 50)
	glutInitWindowSize(width, height)
	glutCreateWindow("Mandelbrot Set")
	glutDisplayFunc(drawmandel)
	glutMouseFunc(mouse)
	glutKeyboardFunc(keyboard)
	zap()
	glutMainLoop()
	
main()

# End Program