RosettaCodeData/Task/Simple-turtle-graphics/Perl/simple-turtle-graphics.pl

138 lines
2.3 KiB
Perl

#!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Simple_turtle_graphics
use warnings;
use Tk;
use List::Util qw( max );
my $c; # the canvas
# turtle routines
my $pen = 1; # true for pendown, false for penup
my @location = (0, 0); # upper left corner
my $direction = 0; # 0 for East, increasing clockwise
my @stack;
my $radian = 180 / atan2 0, -1;
sub dsin { sin $_[0] / $radian }
sub dcos { cos $_[0] / $radian }
sub save { push @stack, [ $direction, @location ] }
sub restore { ($direction, @location) = @{ pop @stack } }
sub turn { $direction += shift }
sub right { turn shift }
sub left { turn -shift }
sub forward
{
my $x = $location[0] + $_[0] * dcos $direction;
my $y = $location[1] + $_[0] * dsin $direction;
$pen and $c->createLine( @location, $x, $y, -width => 3 );
@location = ($x, $y);
}
sub back { turn 180; forward shift; turn 180 }
sub penup { $pen = 0 }
sub pendown { $pen = 1 }
sub text { $c->createText( @location, -text => shift ) }
# make window
my $mw = MainWindow->new;
$c = $mw->Canvas(
-width => 900, -height => 900,
)->pack;
$mw->Button(-text => 'Exit', -command => sub {$mw->destroy},
)->pack(-fill => 'x');
$mw->after(0, \&run);
MainLoop;
-M $0 < 0 and exec $0;
sub box
{
my ($w, $h) = @_;
for (1 .. 2)
{
forward $w;
left 90;
forward $h;
left 90;
}
}
sub house
{
my $size = shift;
box $size, $size;
right 90;
for ( 1 .. 3 )
{
right 120;
forward $size;
}
penup;
left 90;
forward $size;
left 90;
save;
forward $size * 1 / 4;
pendown;
box $size / 4, $size / 2;
penup;
forward $size * 3 / 8;
left 90;
forward $size / 4;
right 90;
pendown;
box $size / 4, $size / 4;
penup;
restore;
save;
forward $size / 2;
left 90;
forward $size + 40;
right 90;
pendown;
for (1 .. 8)
{
forward 15;
left 45;
forward 15;
}
restore;
penup;
}
sub graph
{
save;
my $size = shift;
my $width = $size / @_;
my $hscale = $size / max @_;
for ( @_ )
{
box $width, $hscale * $_;
save;
penup;
forward $width / 2;
left 90;
forward 10;
text $_;
pendown;
restore;
forward $width;
}
restore;
}
sub run
{
penup;
forward 50;
right 90;
forward 400;
pendown;
house(300);
penup;
forward 400;
pendown;
graph( 400, 2,7,4,5,1,8,6 );
}