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| 1 | +#!/usr/bin/env python |
| 2 | +# life.py -- A curses-based version of Conway's Game of Life. |
| 3 | +# Contributed by A.M. Kuchling <[email protected]> |
| 4 | +# |
| 5 | +# An empty board will be displayed, and the following commands are available: |
| 6 | +# E : Erase the board |
| 7 | +# R : Fill the board randomly |
| 8 | +# S : Step for a single generation |
| 9 | +# C : Update continuously until a key is struck |
| 10 | +# Q : Quit |
| 11 | +# Cursor keys : Move the cursor around the board |
| 12 | +# Space or Enter : Toggle the contents of the cursor's position |
| 13 | +# |
| 14 | +# TODO : |
| 15 | +# Support the mouse |
| 16 | +# Use colour if available |
| 17 | +# Make board updates faster |
| 18 | +# |
| 19 | + |
| 20 | +class LifeBoard: |
| 21 | + """Encapsulates a Life board |
| 22 | +
|
| 23 | + Attributes: |
| 24 | + X,Y : horizontal and vertical size of the board |
| 25 | + state : dictionary mapping (x,y) to 0 or 1 |
| 26 | + |
| 27 | + Methods: |
| 28 | + display(update_board) -- If update_board is true, compute the |
| 29 | + next generation. Then display the state |
| 30 | + of the board and refresh the screen. |
| 31 | + erase() -- clear the entire board |
| 32 | + makeRandom() -- fill the board randomly |
| 33 | + set(y,x) -- set the given cell to Live; doesn't refresh the screen |
| 34 | + toggle(y,x) -- change the given cell from live to dead, or vice |
| 35 | + versa, and refresh the screen display |
| 36 | +
|
| 37 | + """ |
| 38 | + def __init__(self, scr, char=ord('*')): |
| 39 | + """Create a new LifeBoard instance. |
| 40 | +
|
| 41 | + scr -- curses screen object to use for display |
| 42 | + char -- character used to render live cells (default: '*') |
| 43 | + """ |
| 44 | + self.state={} ; self.scr=scr |
| 45 | + Y, X = self.scr.getmaxyx() |
| 46 | + self.X, self.Y = X-2, Y-2-1 |
| 47 | + self.char = char |
| 48 | + self.scr.clear() |
| 49 | + |
| 50 | + # Draw a border around the board |
| 51 | + border_line='+'+(self.X*'-')+'+' |
| 52 | + self.scr.addstr(0, 0, border_line) |
| 53 | + self.scr.addstr(self.Y+1,0, border_line) |
| 54 | + for y in range(0, self.Y): |
| 55 | + self.scr.addstr(1+y, 0, '|') |
| 56 | + self.scr.addstr(1+y, self.X+1, '|') |
| 57 | + self.scr.refresh() |
| 58 | + |
| 59 | + def set(self, y, x): |
| 60 | + """Set a cell to the live state""" |
| 61 | + if x<0 or self.X<=x or y<0 or self.Y<=y: |
| 62 | + raise ValueError, "Coordinates out of range %i,%i"% (y,x) |
| 63 | + self.state[x,y] = 1 |
| 64 | + |
| 65 | + def toggle(self, y, x): |
| 66 | + """Toggle a cell's state between live and dead""" |
| 67 | + if x<0 or self.X<=x or y<0 or self.Y<=y: |
| 68 | + raise ValueError, "Coordinates out of range %i,%i"% (y,x) |
| 69 | + if self.state.has_key( (x,y) ): |
| 70 | + del self.state[x,y] |
| 71 | + self.scr.addch(y+1, x+1, ' ') |
| 72 | + else: |
| 73 | + self.state[x,y]=1 |
| 74 | + self.scr.addch(y+1, x+1, self.char) |
| 75 | + self.scr.refresh() |
| 76 | + |
| 77 | + def erase(self): |
| 78 | + """Clear the entire board and update the board display""" |
| 79 | + self.state={} |
| 80 | + self.display(update_board=0) |
| 81 | + |
| 82 | + def display(self, update_board=1): |
| 83 | + """Display the whole board, optionally computing one generation""" |
| 84 | + M,N = self.X, self.Y |
| 85 | + if not update_board: |
| 86 | + for i in range(0, M): |
| 87 | + for j in range(0, N): |
| 88 | + if self.state.has_key( (i,j) ): |
| 89 | + self.scr.addch(j+1, i+1, self.char) |
| 90 | + else: |
| 91 | + self.scr.addch(j+1, i+1, ' ') |
| 92 | + self.scr.refresh() |
| 93 | + return |
| 94 | + |
| 95 | + d={} ; self.boring=1 |
| 96 | + for i in range(0, M): |
| 97 | + L=range( max(0, i-1), min(M, i+2) ) |
| 98 | + for j in range(0, N): |
| 99 | + s=0 |
| 100 | + live=self.state.has_key( (i,j) ) |
| 101 | + for k in range( max(0, j-1), min(N, j+2) ): |
| 102 | + for l in L: |
| 103 | + if self.state.has_key( (l,k) ): |
| 104 | + s=s+1 |
| 105 | + s=s-live |
| 106 | + if s==3: |
| 107 | + # Birth |
| 108 | + d[i,j]=1 |
| 109 | + self.scr.addch(j+1, i+1, self.char) |
| 110 | + if not live: self.boring=0 |
| 111 | + elif s==2 and live: d[i,j]=1 # Survival |
| 112 | + elif live: |
| 113 | + # Death |
| 114 | + self.scr.addch(j+1, i+1, ' ') |
| 115 | + self.boring=0 |
| 116 | + self.state=d |
| 117 | + self.scr.refresh() |
| 118 | + |
| 119 | + def makeRandom(self): |
| 120 | + "Fill the board with a random pattern" |
| 121 | + import whrandom |
| 122 | + self.state={} |
| 123 | + for i in range(0, self.X): |
| 124 | + for j in range(0, self.Y): |
| 125 | + if whrandom.random()*10>5.0: self.set(j,i) |
| 126 | + |
| 127 | + |
| 128 | +def erase_menu(stdscr, menu_y): |
| 129 | + "Clear the space where the menu resides" |
| 130 | + stdscr.move(menu_y, 0) ; stdscr.clrtoeol() |
| 131 | + stdscr.move(menu_y+1, 0) ; stdscr.clrtoeol() |
| 132 | + |
| 133 | +def display_menu(stdscr, menu_y): |
| 134 | + "Display the menu of possible keystroke commands" |
| 135 | + erase_menu(stdscr, menu_y) |
| 136 | + stdscr.addstr(menu_y, 4, |
| 137 | + 'Use the cursor keys to move, and space or Enter to toggle a cell.') |
| 138 | + stdscr.addstr(menu_y+1, 4, |
| 139 | + 'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit') |
| 140 | + |
| 141 | +def main(stdscr): |
| 142 | + import string, curses |
| 143 | + |
| 144 | + # Clear the screen and display the menu of keys |
| 145 | + stdscr.clear() |
| 146 | + stdscr_y, stdscr_x = stdscr.getmaxyx() |
| 147 | + menu_y=(stdscr_y-3)-1 |
| 148 | + display_menu(stdscr, menu_y) |
| 149 | + |
| 150 | + # Allocate a subwindow for the Life board and create the board object |
| 151 | + subwin=stdscr.subwin(stdscr_y-3, stdscr_x, 0, 0) |
| 152 | + board=LifeBoard(subwin, char=ord('*')) |
| 153 | + board.display(update_board=0) |
| 154 | + |
| 155 | + # xpos, ypos are the cursor's position |
| 156 | + xpos, ypos = board.X/2, board.Y/2 |
| 157 | + |
| 158 | + # Main loop: |
| 159 | + while (1): |
| 160 | + stdscr.move(1+ypos, 1+xpos) # Move the cursor |
| 161 | + c=stdscr.getch() # Get a keystroke |
| 162 | + if 0<c<256: |
| 163 | + c=chr(c) |
| 164 | + if c in ' \n': |
| 165 | + board.toggle(ypos, xpos) |
| 166 | + elif c in 'Cc': |
| 167 | + erase_menu(stdscr, menu_y) |
| 168 | + stdscr.addstr(menu_y, 6, ' Hit any key to stop continuously ' |
| 169 | + 'updating the screen.') |
| 170 | + stdscr.refresh() |
| 171 | + # Activate nodelay mode; getch() will return -1 |
| 172 | + # if no keystroke is available, instead of waiting. |
| 173 | + stdscr.nodelay(1) |
| 174 | + while (1): |
| 175 | + c=stdscr.getch() |
| 176 | + if c!=-1: break |
| 177 | + stdscr.addstr(0,0, '/'); stdscr.refresh() |
| 178 | + board.display() |
| 179 | + stdscr.addstr(0,0, '+'); stdscr.refresh() |
| 180 | + |
| 181 | + stdscr.nodelay(0) # Disable nodelay mode |
| 182 | + display_menu(stdscr, menu_y) |
| 183 | + |
| 184 | + elif c in 'Ee': board.erase() |
| 185 | + elif c in 'Qq': break |
| 186 | + elif c in 'Rr': |
| 187 | + board.makeRandom() |
| 188 | + board.display(update_board=0) |
| 189 | + elif c in 'Ss': |
| 190 | + board.display() |
| 191 | + else: pass # Ignore incorrect keys |
| 192 | + elif c==curses.KEY_UP and ypos>0: ypos=ypos-1 |
| 193 | + elif c==curses.KEY_DOWN and ypos<board.Y-1: ypos=ypos+1 |
| 194 | + elif c==curses.KEY_LEFT and xpos>0: xpos=xpos-1 |
| 195 | + elif c==curses.KEY_RIGHT and xpos<board.X-1: xpos=xpos+1 |
| 196 | + else: pass # Ignore incorrect keys |
| 197 | + |
| 198 | +if __name__=='__main__': |
| 199 | + import curses, traceback |
| 200 | + try: |
| 201 | + # Initialize curses |
| 202 | + stdscr=curses.initscr() |
| 203 | + # Turn off echoing of keys, and enter cbreak mode, |
| 204 | + # where no buffering is performed on keyboard input |
| 205 | + curses.noecho() ; curses.cbreak() |
| 206 | + |
| 207 | + # In keypad mode, escape sequences for special keys |
| 208 | + # (like the cursor keys) will be interpreted and |
| 209 | + # a special value like curses.KEY_LEFT will be returned |
| 210 | + stdscr.keypad(1) |
| 211 | + main(stdscr) # Enter the main loop |
| 212 | + # Set everything back to normal |
| 213 | + stdscr.keypad(0) |
| 214 | + curses.echo() ; curses.nocbreak() |
| 215 | + curses.endwin() # Terminate curses |
| 216 | + except: |
| 217 | + # In the event of an error, restore the terminal |
| 218 | + # to a sane state. |
| 219 | + stdscr.keypad(0) |
| 220 | + curses.echo() ; curses.nocbreak() |
| 221 | + curses.endwin() |
| 222 | + traceback.print_exc() # Print the exception |
| 223 | + |
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