bgneal@46: """ Code example from Complexity and Computation, a book about
bgneal@46: exploring complexity science with Python.  Available free from
bgneal@46: 
bgneal@46: http://greenteapress.com/complexity
bgneal@46: 
bgneal@46: Copyright 2011 Allen B. Downey.
bgneal@46: Distributed under the GNU General Public License at gnu.org/licenses/gpl.html.
bgneal@46: """
bgneal@46: 
bgneal@46: import numpy
bgneal@46: 
bgneal@46: 
bgneal@46: class UnimplementedMethodException(Exception):
bgneal@46:     """Used to indicate that a child class has not implemented an
bgneal@46:     abstract method."""
bgneal@46: 
bgneal@46: 
bgneal@46: class Drawer(object):
bgneal@46:     """Drawer is an abstract class that should not be instantiated.
bgneal@46:     It defines the interface for a CA drawer; child classes of Drawer
bgneal@46:     should implement draw, show and save.
bgneal@46: 
bgneal@46:     If draw_array is not overridden, the child class should provide
bgneal@46:     draw_cell.
bgneal@46:     """
bgneal@46:     def __init__(self):
bgneal@46:         msg = 'CADrawer is an abstract type and should not be instantiated.'
bgneal@46:         raise UnimplementedMethodException, msg
bgneal@46: 
bgneal@46:     def draw(self, ca):
bgneal@46:         """Draws a representation of cellular automaton (CA).
bgneal@46:         This function generally has no visible effect."""
bgneal@46:         raise UnimplementedMethodException
bgneal@46:     
bgneal@46:     def draw_array(self, a):
bgneal@46:         """Iterate through array (a) and draws any non-zero cells."""
bgneal@46:         for i in xrange(self.rows):
bgneal@46:             for j in xrange(self.cols):
bgneal@46:                 if a[i,j]:
bgneal@46:                     self.draw_cell(j, self.rows-i-1)
bgneal@46: 
bgneal@46:     def draw_cell(self, ca):
bgneal@46:         """Draws a single cell.
bgneal@46:         Not required for all implementations."""
bgneal@46:         raise UnimplementedMethodException
bgneal@46:     
bgneal@46:     def show(self):
bgneal@46:         """Displays the representation on the screen, if possible."""
bgneal@46:         raise UnimplementedMethodException
bgneal@46: 
bgneal@46:     def save(self, filename):
bgneal@46:         """Saves the representation of the CA in filename."""
bgneal@46:         raise UnimplementedMethodException
bgneal@46:         
bgneal@46: 
bgneal@46: class PyplotDrawer(Drawer):
bgneal@46:     """Implementation of Drawer using matplotlib."""
bgneal@46: 
bgneal@46:     def __init__(self):
bgneal@46:         # we only need to import pyplot if a PyplotDrawer
bgneal@46:         # gets instantiated
bgneal@46:         global pyplot
bgneal@46:         import matplotlib.pyplot as pyplot
bgneal@46: 
bgneal@46:     def draw(self, ca, start=0, end=None):
bgneal@46:         """Draws the CA using pyplot.pcolor."""
bgneal@46:         pyplot.gray()
bgneal@46:         a = ca.get_array(start, end)
bgneal@46:         rows, cols = a.shape
bgneal@46: 
bgneal@46:         # flipud puts the first row at the top; 
bgneal@46:         # negating it makes the non-zero cells black.
bgneal@46:         pyplot.pcolor(-numpy.flipud(a))
bgneal@46:         pyplot.axis([0, cols, 0, rows])
bgneal@46: 
bgneal@46:         # empty lists draw no ticks
bgneal@46:         pyplot.xticks([])
bgneal@46:         pyplot.yticks([])
bgneal@46: 
bgneal@46:     def show(self):
bgneal@46:         """display the pseudocolor representation of the CA"""
bgneal@46:         pyplot.show()
bgneal@46: 
bgneal@46:     def save(self, filename='ca.png'):
bgneal@46:         """save the pseudocolor representation of the CA in (filename)."""
bgneal@46:         pyplot.savefig(filename)
bgneal@46:     
bgneal@46: 
bgneal@46: class PILDrawer(Drawer):
bgneal@46:     """Implementation of Drawer using PIL and Swampy."""
bgneal@46: 
bgneal@46:     def __init__(self, csize=4, color='black'):
bgneal@46:         # we only need to import these modules if a PILDrawer
bgneal@46:         # gets instantiated
bgneal@46:         global Image, ImageDraw, ImageTk, Gui
bgneal@46:         import Image
bgneal@46:         import ImageDraw
bgneal@46:         import ImageTk
bgneal@46:         try:
bgneal@46:             import Gui
bgneal@46:         except ImportError:
bgneal@46:             import swampy.Gui
bgneal@46:         self.csize = csize
bgneal@46:         self.color = color
bgneal@46: 
bgneal@46:     def draw(self, ca, start=0, end=None):
bgneal@46:         a = ca.get_array(start, end)
bgneal@46:         self.rows, self.cols = a.shape
bgneal@46:         size = [self.cols * self.csize, self.rows * self.csize]
bgneal@46: 
bgneal@46:         self.gui = Gui.Gui()
bgneal@46:         self.button = self.gui.bu(command=self.gui.quit)
bgneal@46: 
bgneal@46:         self.image = Image.new(mode='1', size=size, color='white')
bgneal@46:         self.drawable = ImageDraw.Draw(self.image)
bgneal@46:         self.draw_array(numpy.flipud(a))
bgneal@46: 
bgneal@46:     def draw_cell(self, i, j):
bgneal@46:         size = self.csize
bgneal@46:         x, y = i*size, j*size
bgneal@46:         self.drawable.rectangle([x, y, x+size, y+size], fill=self.color)
bgneal@46: 
bgneal@46:     def show(self):
bgneal@46:         self.tkpi = ImageTk.PhotoImage(self.image)
bgneal@46:         self.button.config(image=self.tkpi)
bgneal@46:         self.gui.mainloop()
bgneal@46:  
bgneal@46:     def save(self, filename='ca.gif'):
bgneal@46:         self.image.save(filename)
bgneal@46: 
bgneal@46: 
bgneal@46: class EPSDrawer(Drawer):
bgneal@46:     """Implementation of Drawer using encapsulated Postscript (EPS)."""
bgneal@46: 
bgneal@46:     def __init__(self):
bgneal@46:         self.cells = []
bgneal@46: 
bgneal@46:     def draw(self, ca, start=0, end=None):
bgneal@46:         a = ca.get_array(start, end)
bgneal@46:         self.rows, self.cols = a.shape
bgneal@46:         self.draw_array(a)
bgneal@46: 
bgneal@46:     def draw_cell(self, i, j):
bgneal@46:         self.cells.append((i,j))
bgneal@46:         
bgneal@46:     def show(self):
bgneal@46:         raise UnimplementedMethodException
bgneal@46: 
bgneal@46:     def save(self, filename='ca.eps'):
bgneal@46:         fp = open(filename, 'w')
bgneal@46:         self.print_header(fp)
bgneal@46:         self.print_outline(fp)
bgneal@46:         self.print_cells(fp)
bgneal@46:         self.print_footer(fp)
bgneal@46: 
bgneal@46:     def print_cells(self, fp):
bgneal@46:         for i, j in self.cells:
bgneal@46:             fp.write('%s %s c\n' % (i, j))
bgneal@46: 
bgneal@46:     def print_header(self, fp, size=0.9):
bgneal@46:         fp.write('%!PS-Adobe-3.0 EPSF-3.0\n')
bgneal@46:         fp.write('%%%%BoundingBox: -2 -2 %s %s\n' % (self.cols+2, self.rows+2))
bgneal@46: 
bgneal@46:         fp.write('/c {\n')
bgneal@46:         fp.write('   newpath moveto\n')
bgneal@46:         fp.write('   0 %g rlineto\n' % size)
bgneal@46:         fp.write('   %g 0 rlineto\n' % size)
bgneal@46:         fp.write('   0 -%g rlineto\n' % size)
bgneal@46:         fp.write('   closepath fill\n')
bgneal@46:         fp.write('} def\n')
bgneal@46: 
bgneal@46:     def print_outline(self, fp):
bgneal@46:         fp.write('newpath 0.1 setlinewidth 0 0 moveto\n')
bgneal@46:         fp.write('0 %s rlineto\n' % self.rows)
bgneal@46:         fp.write('%s 0 rlineto\n' % self.cols)
bgneal@46:         fp.write('0 -%s rlineto\n' % self.rows)
bgneal@46:         fp.write('closepath stroke\n')
bgneal@46: 
bgneal@46:     def print_footer(self, fp):
bgneal@46:         fp.write('%%EOF\n')
bgneal@46: