Vincent Pit

NAME

LaTeX::TikZ - Perl object model for generating PGF/TikZ code.

VERSION

Version 0.02

SYNOPSIS

    use LaTeX::TikZ;

    # A couple of lines
    my $hline = Tikz->line(-1 => 1);
    my $vline = Tikz->line([ 0, -1 ] => [ 0, 1 ]);

    # Paint them in red
    $_->mod(Tikz->color('red')) for $hline, $vline;

    # An octogon
    use Math::Complex;
    my $octo = Tikz->closed_polyline(
     map Math::Complex->emake(1, ($_ * pi)/4), 0 .. 7
    );

    # Only keep a portion of it
    $octo->clip(Tikz->rectangle(-0.5*(1+i), 2*(1+i)));

    # Fill it with dots
    $octo->mod(Tikz->pattern(class => 'Dots'));

    # Create a formatter object
    my $tikz = Tikz->formatter(scale => 5);

    # Put those objects all together and print them
    my $seq = Tikz->seq($octo, $hline, $vline);
    my ($head, $decl, $body) = $tikz->render($seq);
    print "$_\n" for map @$_, $head, $decl, $body;

DESCRIPTION

This module provides an object model for TikZ, a graphical toolkit for LaTeX. It allows you to build structures representing geometrical figures, apply a wide set of modifiers on them, transform them globally with functors, and print them in the context of an existing TeX document.

CONCEPTS

Traditionally, in TikZ, there are two ways of grouping elements, or ops, together :

  • either as a sequence, where each element is drawn in its own line :

        \draw (0cm,0cm) -- (0cm,1cm) ;
        \draw (0cm,0cm) -- (1cm,0cm) ;
  • or as a path, where elements are all drawn as one line :

        \draw (0cm,0cm) -- (0cm,1cm) (0cm,0cm) -- (1cm,0cm) ;

This distinction is important because there are some primitives that only apply to paths but not to sequences, and vice versa.

Figures are made of ops, path or sequence sets assembled together in a tree.

Modifiers can be applied onto any set to alter the way in which it is generated. The two TikZ concepts of clips and layers have been unified with the modifiers.

INTERFACE

Containers

Tikz->path(@ops)

Creates a LaTeX::TikZ::Set::Path object out of the ops @ops.

    # A path made of two circles
    Tikz->path(
           Tikz->circle(0, 1),
           Tikz->circle(1, 1),
          )
        ->mod(
           Tikz->fill('red'),
           'even odd rule',
          );

Tikz->seq(@kids)

Creates a LaTeX::TikZ::Set::Sequence object out of the sequences, paths or ops @kids.

    my $bag = Tikz->seq($sequence, $path, $circle, $raw, $point);

Elements

Those are the building blocks of your geometrical figure.

Tikz->point($point)

Creates a LaTeX::TikZ::Set::Point object by coercing $point into a LaTeX::TikZ::Point. The following rules are available :

  • If $point isn't given, the point defaults to (0, 0).

        my $origin = Tikz->point;
  • If $point is a numish Perl scalar, it is treated as ($point, 0).

        my $unit = Tikz->point(1);
  • If two numish scalars $x and $y are given, they result in the point ($x, $y).

        my $one_plus_i = Tikz->point(1, 1);
  • If $point is an array reference, it is parsed as ($point->[0], $point->[1]).

        my $i = Tikz->point([ 0, 1 ]);
  • If $point is a Math::Complex object, the LaTeX::TikZ::Point::Math::Complex class is automatically loaded and the point is coerced into ($point->Re, $point->Im).

        my $j = Tikz->point(Math::Complex->emake(1, 2*pi/3));

You can define automatic coercions from your user point types to LaTeX::TikZ::Point by writing your own LaTeX::TikZ::Point::My::User::Point class. See LaTeX::TikZ::Meta::TypeConstraint::Autocoerce for the rationale and LaTeX::TikZ::Point::Math::Complex for an example.

Tikz->line($from => $to)

Creates a LaTeX::TikZ::Set::Line object between the points $from and $to.

    my $x_axis = Tikz->line(-5 => 5);
    my $y_axis = Tikz->line([ 0, -5 ] => [ 0, 5 ]);

Tikz->polyline(@points)

Creates a LaTeX::TikZ::Set::Polyline object that links the successive elements of @points by segments.

    my $U = Tikz->polyline(
     Tikz->point(0, 1),
     Tikz->point(0, 0),
     Tikz->point(1, 0),
     Tikz->point(1, 1),
    );

Tikz->closed_polyline(@points)

Creates a LaTeX::TikZ::Set::Polyline object that cycles through successive elements of @points.

    my $diamond = Tikz->closed_polyline(
     Tikz->point(0, 1),
     Tikz->point(-1, 0),
     Tikz->point(0, -2),
     Tikz->point(1, 0),
    );

Tikz->rectangle($from => $to), Tikz->rectangle($from => { width => $width, height => $height })

Creates a LaTeX::TikZ::Set::Rectangle object with opposite corners $from and $to, or with anchor point $from and dimensions $width and $height.

    my $square = Tikz->rectangle(
     Tikz->point,
     Tikz->point(2, 1),
    );

Tikz->circle($center, $radius)

Creates a LaTeX::TikZ::Set::Circle object of center $center and radius $radius.

    my $unit_circle = Tikz->circle(0, 1);

Tikz->arc($from => $to, $center)

Creates a LaTeX::TikZ::Set structure that represents an arc going from $from to $to with center $center.

    # An arc. The points are automatically coerced into LaTeX::TikZ::Set::Point objects
    my $quarter = Tikz->arc(
     [ 1, 0 ] => [ 0, 1 ],
     [ 0, 0 ]
    );

Tikz->arrow($from => $to), Tikz->arrow($from => dir => $dir)

Creates a LaTeX::TikZ::Set structure that represents an arrow going from $from towards $to, or starting at $from in direction $dir.

    # An horizontal arrow
    my $arrow = Tikz->arrow(0 => 1);

Tikz->raw($content)

Creates a LaTeX::TikZ::Set::Raw object that will instantiate to the raw TikZ code $content.

Modifiers

Modifiers are applied onto sets by calling the ->mod method, like in $set->mod($mod). This method returns the $set object, so it can be chained.

Tikz->clip($path)

Creates a LaTeX::TikZ::Mod::Clip object that can be used to clip a given sequence by the (closed) path $path.

    my $box = Tikz->clip(
     Tikz->rectangle(0 => [ 1, 1 ]),
    );

Clips can also be directly applied to sets with the ->clip method.

    my $set = Tikz->circle(0, 1.5)
                  ->clip(Tikz->rectangle([-1, -1] => [1, 1]));

Tikz->layer($name, above => \@above, below => \@below)

Creates a LaTeX::TikZ::Mod::Layer object with name $name and optional relative positions @above and @below.

    my $layer = Tikz->layer(
     'top'
     above => [ 'main' ],
    );

The default layer is main.

Layers are stored into a global hash, so that when you refer to them by their name, you get the existing layer object.

Layers can also be directly applied to sets with the ->layer method.

    my $dots = Tikz->rectangle(0 => [ 1, 1 ])
                   ->mod(Tikz->pattern(class => 'Dots'))
                   ->layer('top');

Tikz->width($line_width)

Creates a LaTeX::TikZ::Mod::Width object that sets the line width to $line_width when applied.

    my $thick_arrow = Tikz->arrow(0 => 1)
                          ->mod(Tikz->width(5));

Tikz->color($color)

Creates a LaTeX::TikZ::Mod::Colorobject that sets the line color to $color (given in the xcolor syntax).

    # Paint the previous $thick_arrow in red.
    $thick_arrow->mod(Tikz->color('red'));

Tikz->fill($color)

Creates a LaTeX::TikZ::Mod::Fill object that fills the interior of a path with the solid color $color (given in the xcolor syntax).

    my $red_box = Tikz->rectangle(0 => { width => 1, height => 1 })
                      ->mod(Tikz->fill('red'));

Tikz->pattern(class => $class, %args)

Creates a LaTeX::TikZ::Mod::Pattern object of class $class and arguments %args that fills the interior of a path with the specified pattern. $class is prepended with LaTeX::TikZ::Mod::Pattern when it doesn't contain ::. See LaTeX::TikZ::Mod::Pattern::Dots and LaTeX::TikZ::Mod::Pattern::Lines for two examples of pattern classes.

    my $hatched_circle = Tikz->circle(0 => 1)
                             ->mod(Tikz->pattern(class => 'Lines'));

Tikz->raw_mod($content)

Creates a LaTeX::TikZ::Mod::Raw object that will instantiate to the raw TikZ mod code $content.

    my $homemade_arrow = Tikz->line(0 => 1)
                             ->mod(Tikz->raw_mod('->')) # or just ->mod('->')

Helpers

Tikz->formatter(%args)

Creates a LaTeX::TikZ::Formatter object that can render a LaTeX::TikZ::Set tree.

    my $tikz = Tikz->formatter;
    my ($header, $declarations, $seq1_body, $seq2_body) = $tikz->render($set1, $set2);

Tikz->functor(@rules)

Creates a LaTeX::TikZ::Functor anonymous subroutine that can be called against LaTeX::TikZ::Set trees to clone them according to the given rules. @rules should be a list of array references whose first element is the class/role to match against and the second the handler to execute.

    # The default is a clone method
    my $clone = Tikz->functor;
    my $dup = $set->$clone;

    # A translator
    my $translate = Tikz->functor(
     'LaTeX::TikZ::Set::Point' => sub {
      my ($functor, $set, $x, $y) = @_;

      $set->new(
       point => [
        $set->x + $x,
        $set->y + $y,
       ],
       label => $set->label,
       pos   => $set->pos,
      );
     },
    );
    my $shifted = $set->$translate(1, 1);

    # A mod stripper
    my $strip = Tikz->functor(
     '+LaTeX::TikZ::Mod' => sub { return },
    );
    my $naked = $set->$strip;

DEPENDENCIES

Any::Moose with Mouse 0.63 or greater.

Sub::Name.

Scope::Guard.

Math::Complex, Math::Trig.

Scalar::Util, List::Util, Task::Weaken.

SEE ALSO

PGF/TikZ - http://pgf.sourceforge.net.

AUTHOR

Vincent Pit, <perl at profvince.com>, http://www.profvince.com.

You can contact me by mail or on irc.perl.org (vincent).

BUGS

Please report any bugs or feature requests to bug-latex-tikz at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=LaTeX-TikZ. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc LaTeX::TikZ

COPYRIGHT & LICENSE

Copyright 2010 Vincent Pit, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.




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