Peter de Jong Attractor Visualization using PyGame in Python.

PeterdeJongAttractor.py

'''
Created on 17-Jan-2015

@author: Psycho_Coder

'''
from math import sin, cos

from PIL import Image
import pygame, sys, os
from pygame.locals import QUIT, KEYDOWN, K_ESCAPE


class Attractor():
    '''
    Class for Attractor functions and methods
    '''

    def __init__( self, constants = {"a":-0.89, "b": 1.59, "c":1.85, "d": 2.19} ):
        '''
        Constructor
        '''

        #  Useful Constants
        os.environ['SDL_VIDEO_CENTERED'] = '1'    #  Center Screen the Window

        pygame.init()
        self.size = self.width, self.height = ( 1024, 640 )
        self.screen = pygame.display.set_mode( self.size, 0, 32 )
        pygame.display.set_caption( "Peter D. Jong Attractor" )

        #  Colors
        self.bg = ( 248, 248, 248 )
        self.textshade = ( 48, 48, 48 )
        self.grayshade = ( 144, 144, 144 )

        self.constants = constants
        self.no_of_ite = 50000;
        self.xn, self.yn = 1, 1
        self.coords = []
        self.screen.fill( self.bg )
        self.count = 0
        self.str_values = "a =" + str( self.constants["a"] ) + ", b = " + str( self.constants["b"] ) + ", c = " \
                            + str( self.constants["c"] ) + ", d = " + str( self.constants["d"] )

        #  Different Font Objects
        self.font_obj = pygame.font.Font( "lunchds.ttf", 22 )
        self.font_obj2 = pygame.font.Font( "retganon.ttf", 24 )

        self.text_surf_obj1 = self.font_obj.render( "Peter D. Jong Attractor", True, self.textshade, None )
        self.text_rect_obj1 = self.text_surf_obj1.get_rect()
        self.text_rect_obj1.center = 200, 40

        self.text_surf_obj2 = self.font_obj2.render( self.str_values , True, self.textshade, None )
        self.text_rect_obj2 = self.text_surf_obj2.get_rect()
        self.text_rect_obj2.center = self.width // 2 + 60, self.height - 25

        self.screen.blit( self.text_surf_obj1, self.text_rect_obj1 )
        self.screen.blit( self.text_surf_obj2, self.text_rect_obj2 )

        self.game_loop()

    def game_loop( self ):
        while True:
            for evt in pygame.event.get():
                if evt.type == QUIT or ( evt.type == KEYDOWN and evt.key == K_ESCAPE ):
                    pygame.quit()
                    sys.exit()

            if self.count > self.no_of_ite:
                self.save_surface( "pdf1.png" )
                sys.exit()
            else:
                for i in range( 10000 ):
                    self.xn, self.yn = ( sin( self.constants["a"] * self.yn ) - cos ( self.constants["b"] \
                                    * self.xn ) ), ( sin( self.constants["c"] * self.xn ) - cos( self.constants["d"] * self.yn ) )
                    #  xn, yn = ( d * sin( a * xn ) - sin ( b * yn ) ), ( c * cos( a * xn ) + cos( b * yn ) )
                    self.coords.append( ( self.xn, self.yn ) )
                    pygame.draw.circle( self.screen, self.grayshade , ( self.width // 2 + \
                                            int( 120 * self.xn ), self.height // 2 + int( 120 * self.yn ) ), 1, 1 )
                    self.count += 1

            pygame.display.update()

    def save_surface( self, filename ):
        if filename != None:
            data = pygame.image.tostring( self.screen, 'RGBA' )
            img = Image.fromstring( 'RGBA', self.size, data )
            pygame.image.save( self.screen, filename )
        else:
            raise ValueError( "The filename is not given." )


if __name__ == "__main__":
    ins = Attractor()