Mastering Perl/Tk

tkhanoi.ppl

This next PPL program is a classic Tower of Hanoi game.

#!/usr/local/bin/perl -w # # Towers of Hanoi, Perl/Tk style. 2000/06/14, [e-mail] # Global package, subroutine and data declarations. use Tk; use Tk::Dialog; use subs qw/do_hanoi fini hanoi init move_ring/; use strict; my $canvas; # the Hanoi playing field my @colors; # 24 graduated ring colors my $fly_y; # canvas Y-coord along which rings fly my $max_rings; # be nice and keep @colors count-consistent my $num_moves; # total ring moves my %pole; # tracks pole X-coord and ring count my %ring; # tracks ring canvas ID, width and pole my $ring_base; # canvas Y-coord of base of ring pile my $ring_spacing; # pixels between adjacent rings my $stopped; # 1 IFF simulation is stopped my $velocity; # pixel delta the rings move while flying my $version = '1.0, 2000/06/14'; # Main. my $mw = MainWindow->new(-use => $Plugin::brinfo{xwindow_id}); init; MainLoop; sub do_hanoi { # Initialize for a new simulation. my($n) = @_; # number of rings return unless $stopped; $stopped = 0; # start ... $num_moves = 0; # ... new simulation my $ring_height = 26; $ring_spacing = 0.67 * $ring_height; my $ring_width = 96 + $n * 12; my $canvas_width = 3 * $ring_width + 4 * 12; my $canvas_height = $ring_spacing * $n + $fly_y + 2 * $ring_height; $ring_base = $canvas_height - 32; # Remove all rings from the previous run and resize the canvas. for (my $i = 0; $i < $max_rings; $i++) { $canvas->delete($ring{$i, 'id'}) if defined $ring{$i, 'id'}; ...