PyMouseMandel.py

# PyMandelJulia.py
# Plot a Mandelbrot set
# And include a mouse zoom with
# Julia Set option enabled

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

# The following globals allow for the
# Julia Set options

global mandel
global tmprng
global julhcenter
global julvcenter
global julflag
global julx
global july

width = 400
height = 400

# mandel = 1 for M-Set
# mandel = 0 for Julia Set
# Start with the M-Set

mandel = 1

def zap():
	# Reset everything

	global hcenter
	global vcenter
	global axrng
	global mandel
	global julflag
	hcenter = 0.0
	vcenter = 0.0
	axrng = 2.0
	mandel = 1
	julflag = 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
	global mandel
	global julhcenter
	global julvcenter
	
	# Set the screen plotting coordinates and the step

	glClearColor(0.0, 0.0, 0.0, 0.0)

	# Dividing by (width+1) and (height+1) delays
	# the onset of screen glitches or artifacts when
	# zooming by making the hStep and vStep slightly smaller
	
	hstep = 2*axrng/(width+1)
	vstep = 2*axrng/(height+1)
	
	# if mandel == 1 then we are plotting the M-Set
	if mandel == 1:
		yinit = vcenter + axrng
		xinit = hcenter - axrng
		yfinal = vcenter - axrng
		xfinal = hcenter + axrng
	else:
		# if mandel <> 1 then we plot Julia
		# the Julia Set uses different
		# global variables so we don't forget
		# the M-Set parameters

		yinit = julvcenter + axrng
		xinit = julhcenter - axrng
		yfinal = julvcenter - axrng
		xfinal = julhcenter + 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):
	global mandel
	global tmprng
	global axrng
	global hcenter
	global vcenter
	global julflag
	
	if mandel == 1:
		# We are working with the M-Set	
		# Store the M-Set axrng zoom factor
		# So that we can restore it later if needed

		tmprng = axrng
	
	#  Allows us to quit by pressing 'Esc' or 'q'

	if key == chr(27):
		sys.exit()

	if key == "z":
		zap()

	if key == "j":
		# Toggle the Julia Set
		# and set axrng to original zoom

		mandel = 0
		axrng = 2.0

	if key == "m":
		# Toggle M-Set and restore the last
		# M-Set axrng value so the M-Set looks
		# the same as it did when we left it

		mandel = 1
		axrng = tmprng
		julflag = 0
		init()

	if key == "q":
		sys.exit()
	
def drawmandel():
	glClear(GL_COLOR_BUFFER_BIT)
	y = yinit
	
	# toggle Julia Set or M-Set
	# mandel == 0 is the Julia Set
	# julX and julY contain the Julia Set
	# seed coordinates

	if mandel == 0:
		a = complex(julx, july)
		
	while y > yfinal:
		y-= vstep
		x = xinit
		while x < xfinal:
			x+= hstep
				
			n = 0
				
			# Choose M-Set or Julia Set
			# If Julia Set is toggled, "a" already contains
			# the complex number seed

			if mandel == 1:
				z = a = complex(x,y)
			else:
				z = complex(x,y)
					
			glBegin(GL_POINTS)

			# Escape time... increase this value above 25
			# for a more detailed plot.  Decrease
			# this value for more speed.

			while n < 25:
				n+=1 
				z = z**2 + a
				zz = abs(z)

				# This is the escape distance.  For some
				# M-Set/Julia Sets such as sin() or exp() you
				# may need to set this value higher than 2
				# 50 works well for sin() functions

				if zz > 2:
					# Weird colors outside the M-Set					         
					#glColor3f(3*sin(3*z.real),cos(3*z.real),4*cos(zz))
					#glVertex2f(x,y)

					n = 5001
			
			# The same goes for this zz < 2 statement as above

			if zz < 2:
				# Coloration inside the M-Set	
				
				glColor3f(3*sin(3*zz),cos(3*z.real),2*sin(zz))
				glVertex2f(x,y)

			glEnd()
	glFlush()
			
def mouse(button, state, x, y):
	global hcenter
	global vcenter
	global axrng
	global julhcenter
	global julvcenter
	global julflag
	global julx
	global july
	
	# 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:
		if mandel == 1:
			hcenter = xinit + (xfinal - xinit)*x/width
			vcenter = yinit + (yfinal - yinit)*y/height
			axrng = axrng/2
			init()
		else:
			# We use different center point variables here
			# to keep the Julia Set and M-Set calculations
			# separate

			julhcenter = xinit + (xfinal - xinit)*x/width
			julvcenter = yinit + (yfinal - yinit)*y/height
			
			# We use a flag variable here so that the first
			# Julia Set plot is normal size regardless of the
			# Zoom factor on the M-Set.  We don't want to 
			# cause a zoom on the first Julia Set

			if julflag == 0:
				# Print the value of the Julia Set seed

				print "Julia", julhcenter, julvcenter
				
				# Store the pixel coordinates in julX and julY
				# for the Julia Set seed

				julx = julhcenter
				july = julvcenter

				# Set the following variables to zero
				# so the first Julia Set is centered in
				# the graphics display window

				julhcenter = 0.0
				julvcenter = 0.0

				# Show the Julia Set!
				init()

			else:
				# NOW we can zoom on the Julia Set

				julhcenter = xinit + (xfinal - xinit)*x/width
				julvcenter = yinit + (yfinal - yinit)*y/height
				axrng = axrng/2
				init()

			# Set the flag so subsequent mouse clicks zoom
			# into the Julia Set

			julflag = 1
			
	if button == GLUT_RIGHT_BUTTON and state == GLUT_DOWN:
		# This section is similar to the previous
		# Section except that here we zoom out!

		if mandel == 1:
			hcenter = xinit + (xfinal - xinit)*x/width
			vcenter = yinit + (yfinal - yinit)*y/height
			axrng = 2*axrng
			init()

		else:
			julhcenter = xinit + (xfinal - xinit)*x/width
			julvcenter = yinit + (yfinal - yinit)*y/height

			# Again, we don't want to initially zoom into
			# the Julia Set... we want a "normal" Julia First
			if julflag == 0:
				print "Julia", julhcenter, julvcenter
				julx = julhcenter
				july = julvcenter
				julhcenter = 0.0
				julvcenter = 0.0
				init()

			else:
				julhcenter = xinit + (xfinal - xinit)*x/width
				julvcenter = yinit + (yfinal - yinit)*y/height
				axrng = 2*axrng
				init()

			julflag = 1

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()