The Labs.Com Issue_09_GD_L-systems

TPJ: Issue_09_GD_L-systems

This is a collection of programs published by The Perl Journal. You can download all source-code also from TPJ: Programs.

1. Turtle.pm
2. lsys.pl.txt
3. diagram.gif
4. diagram2.gif
5. flower.gif
6. flower2.gif
7. flower3.gif
8. tree1.gif
9. tree10.gif
10. tree11.gif
11. tree2.gif
12. tree3.gif
13. tree4.gif
14. tree5.gif
15. tree6.gif
16. tree7.gif
17. tree8.gif
18. tree9.gif
19. More Samples on GD_L-systems

Download Turtle.pm

package Turtle;

sub new

{

my $class=shift;

my $self={};

@{$self}{qw(x y theta mirror)}=@_;

bless $self, $class;

}

sub forward

{

my $self=shift;

my ($r, $what)=@_;

my ($newx, $newy)=($self->{x}+$r* sin($self->{theta}),

$self->{y}+$r*-cos($self->{theta}));

if ($what)

{

&$what($self->{x}, $self->{y}, $newx, $newy);        # D\

o something related to motion

}                                                             \

# According to the coderef passed i\

n

($self->{x}, $self->{y})=($newx, $newy);                        \

# And change the old coords

}

sub turn

{

my $self=shift;

my $dtheta=shift;

$self->{theta}+=$dtheta*$self->{mirror};

}

sub state

{

my $self=shift;

@{$self}{qw(x y theta mirror)};

}

sub setstate

{

my $self=shift;

@{$self}{qw(x y theta mirror)}=@_;

}

sub mirror

{

my $self=shift;

$self->{mirror}*=-1;

}

"Turtle.pm";

Issue_09_GD_L-systems 2. lsys.pl.txt

Download lsys.pl.txt

#!/usr/bin/perl

use GD;

use Turtle;

sub flower

{

my $flower=shift;

my ($width, $height)=$flower->getBounds();

my ($x,$y)=$turtle->state();

$im->copy($flower, $x-$width/2, $y-$height/2, 0, 0, $width, $height\

);

}

####################################

# This hash translates from turtle

# symbols into actual Perl code.

####################################

# S => Step Forward

# - => Turn Counter-clockwise

# + => Turn Clockwise

# f,g,h => Flower

# M => Mirror

# [ => Begin Branch

# ] => End Branch

# { => Begin polygon

# } => End polygon

%translate=(

'S' => sub{$turtle->forward($changes->{"distance"}, $changes-\

>{"motionsub"});},

'-' => sub{$turtle->turn(-$changes->{"dtheta"});},

'+' => sub{$turtle->turn($changes->{"dtheta"});},

'M' => sub{$turtle->mirror();},

'[' => sub{push(@statestack, [$turtle->state()]);},

']' => sub{$turtle->setstate(@{pop(@statestack)});},

'{' => sub{$poly=new GD::Polygon; $changes=\%polychanges;},

'}' => sub{$im->filledPolygon($poly, $light_green); undef $poly;\

$changes=\%stemchanges;},

'f' => sub{flower($flower);},

'g' => sub{flower($flower2);},

'h' => sub{flower($flower3);},

);

######################################

# And this one controls the actual

# development of the L-system itself

######################################

%rule=(

'A'=>'GS[---fA][++MB]',

'B'=>'C',

'C'=>'A',

'f'=>'g',

'g'=>'h',

'h'=>'',

'G'=>'HS',

'H'=>'IS',

'I'=>'GLMS',

'L'=>'[{S+S+S+S+S+S}]',

);

# Set some parameters

%stemchanges=(distance => 2.8, dtheta => .06, motionsub => su\

b{$im->line(@_, $dark_green);});

%polychanges=(distance => 3, dtheta =>  .4, motionsub => sub{\

$poly->addPt(@_[0..1]);});

$changes=\%stemchanges;

$repetitions=10;

$imagesize=400;

# Create the main image

$im=new GD::Image($imagesize, $imagesize);

# Allocate some colors for it

$white=$im->colorAllocate(255,255,255);

$dark_green=$im->colorAllocate(0,128,0);

$light_green=$im->colorAllocate(0,192,0);

# Create the flower images

open(IN, "flower.gif") or die $!;

$flower=newFromGif GD::Image(IN);

close(IN);

open(IN, "flower2.gif") or die $!;

$flower2=newFromGif GD::Image(IN);

close(IN);

open(IN, "flower3.gif") or die $!;

$flower3=newFromGif GD::Image(IN);

close(IN);

# Create the turtle, at the midpoint of the bottom

# edge of the image, pointing up.

$turtle=new Turtle($imagesize/2, $imagesize, 0, 1);

# Finally, actually apply the rules to the axiom

$string="A"; # Axiom

for (1..$repetitions)

{

$string =~ s/./defined ($rule{$&}) ? $rule{$&} : $&/eg;

print "Finished pass $_...\n";

}

foreach $cmd (split(//, $string))

{

if ($translate{$cmd}) {&{$translate{$cmd}}();}

}

print "Executed...\n";

#$im->transparent($white);

open(OUT, ">tree.gif") or die $!;

print OUT $im->gif;

close(OUT);

print "Done.\n";

Issue_09_GD_L-systems 3. diagram.gif

Issue_09_GD_L-systems 4. diagram2.gif

Issue_09_GD_L-systems 5. flower.gif

Issue_09_GD_L-systems 6. flower2.gif

Issue_09_GD_L-systems 7. flower3.gif

Issue_09_GD_L-systems 8. tree1.gif

Issue_09_GD_L-systems 9. tree10.gif

Issue_09_GD_L-systems 10. tree11.gif

Issue_09_GD_L-systems 11. tree2.gif

Issue_09_GD_L-systems 12. tree3.gif

Issue_09_GD_L-systems 13. tree4.gif

Issue_09_GD_L-systems 14. tree5.gif

Issue_09_GD_L-systems 15. tree6.gif

Issue_09_GD_L-systems 16. tree7.gif

Issue_09_GD_L-systems 17. tree8.gif

Issue_09_GD_L-systems 18. tree9.gif

Issue_09_GD_L-systems 19. More Samples on GD_L-systems

• Issue_09_GD_L-systems