+=head1 CONCEPTS
+
+Traditionally, in TikZ, there are two ways of grouping paths together :
+
+=over 4
+
+=item *
+
+either as a I<sequence>, where each path is drawn in its own line :
+
+ \draw (0cm,0cm) -- (0cm,1cm) ;
+ \draw (0cm,0cm) -- (1cm,0cm) ;
+
+=item *
+
+or as an I<union>, where paths are all drawn as one line :
+
+ \draw (0cm,0cm) -- (0cm,1cm) (0cm,0cm) -- (1cm,0cm) ;
+
+=back
+
+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 path or sequence I<sets> assembled together in a tree.
+
+I<Modifiers> can be applied onto any set to alter the way in which it is generated.
+The two TikZ concepts of I<clips> and I<layers> have been unified with the modifiers.
+
+=head1 INTERFACE
+
+=head2 Containers
+
+=head3 C<union>
+
+ Tikz->union(@seq)
+
+Creates a L<LaTeX::TikZ::Set::Union> object out of the paths C<@kids>.
+
+ # A path made of two circles
+ Tikz->union(
+ Tikz->circle(0, 1),
+ Tikz->circle(1, 1),
+ )
+ ->mod(
+ Tikz->fill('red'),
+ 'even odd rule',
+ );
+
+=head3 C<join>
+
+ Tikz->join($connector, @kids)
+
+Creates a L<LaTeX::TikZ::Set::Chain> object that joins the paths C<@kinds> with the given C<$connector> which can be, according to L<LaTeX::TikZ::Set::Chain/connector>, a string, an array reference or a code reference.
+
+ # A stair
+ Tikz->join('-|', map [ $_, $_ ], 0 .. 5);
+
+=head3 C<chain>
+
+ Tikz->chain($kid0, $link0, $kid1, $link1, ... $kidn)
+
+Creates a L<LaTeX::TikZ::Set::Chain> object that chains C<$kid0> to C<$kid1> with the string C<$link0>, C<$kid1> to C<$kid2> with C<$link1>, and so on.
+
+ # An heart-like shape
+ Tikz->chain([ 0, 1 ]
+ => '.. controls (-1, 1.5) and (-0.75, 0.25) ..' => [ 0, 0 ]
+ => '.. controls (0.75, 0.25) and (1, 1.5) ..' => [ 0, 1 ]
+ );
+
+=head3 C<seq>
+
+ Tikz->seq(@kids)
+
+Creates a L<LaTeX::TikZ::Set::Sequence> object out of the sequences or paths C<@kids>.
+
+ my $bag = Tikz->seq($sequence, $path, $circle, $raw, $point);
+
+=head2 Elements
+
+Those are the building blocks of your geometrical figure.
+
+=head3 C<point>
+
+ Tikz->point($point)
+
+Creates a L<LaTeX::TikZ::Set::Point> object by coercing C<$point> into a L<LaTeX::TikZ::Point>.
+The following rules are available :
+
+=over 4
+
+=item *
+
+If C<$point> isn't given, the point defaults to C<(0, 0)>.
+
+ my $origin = Tikz->point;
+
+=item *
+
+If C<$point> is a numish Perl scalar, it is treated as C<($point, 0)>.
+
+ my $unit = Tikz->point(1);
+
+=item *
+
+If two numish scalars C<$x> and C<$y> are given, they result in the point C<($x, $y)>.
+
+ my $one_plus_i = Tikz->point(1, 1);
+
+=item *
+
+If C<$point> is an array reference, it is parsed as C<< ($point->[0], $point->[1]) >>.
+
+ my $i = Tikz->point([ 0, 1 ]);
+
+=item *
+
+If C<$point> is a L<Math::Complex> object, the L<LaTeX::TikZ::Point::Math::Complex> class is automatically loaded and the point is coerced into C<< ($point->Re, $point->Im) >>.
+
+ my $j = Tikz->point(Math::Complex->emake(1, 2*pi/3));
+
+=back
+
+You can define automatic coercions from your user point types to L<LaTeX::TikZ::Point> by writing your own C<LaTeX::TikZ::Point::My::User::Point> class.
+See L<LaTeX::TikZ::Meta::TypeConstraint::Autocoerce> for the rationale and L<LaTeX::TikZ::Point::Math::Complex> for an example.
+
+=head3 C<line>
+
+ Tikz->line($from => $to)
+
+Creates a L<LaTeX::TikZ::Set::Line> object between the points C<$from> and C<$to>.
+
+ my $x_axis = Tikz->line(-5 => 5);
+ my $y_axis = Tikz->line([ 0, -5 ] => [ 0, 5 ]);
+
+=head3 C<polyline>
+
+ Tikz->polyline(@points)
+
+Creates a L<LaTeX::TikZ::Set::Polyline> object that links the successive elements of C<@points> by segments.
+
+ my $U = Tikz->polyline(
+ Tikz->point(0, 1),
+ Tikz->point(0, 0),
+ Tikz->point(1, 0),
+ Tikz->point(1, 1),
+ );
+
+=head3 C<closed_polyline>
+
+ Tikz->closed_polyline(@points)
+
+Creates a L<LaTeX::TikZ::Set::Polyline> object that cycles through successive elements of C<@points>.
+
+ my $diamond = Tikz->closed_polyline(
+ Tikz->point(0, 1),
+ Tikz->point(-1, 0),
+ Tikz->point(0, -2),
+ Tikz->point(1, 0),
+ );
+
+=head3 C<rectangle>
+
+ Tikz->rectangle($from => $to)
+ Tikz->rectangle($from => { width => $width, height => $height })
+
+Creates a L<LaTeX::TikZ::Set::Rectangle> object with opposite corners C<$from> and C<$to>, or with anchor point C<$from> and dimensions C<$width> and C<$height>.
+
+ my $square = Tikz->rectangle(
+ Tikz->point,
+ Tikz->point(2, 1),
+ );
+
+=head3 C<circle>
+
+ Tikz->circle($center, $radius)
+
+Creates a L<LaTeX::TikZ::Set::Circle> object of center C<$center> and radius C<$radius>.
+
+ my $unit_circle = Tikz->circle(0, 1);
+
+=head3 C<arc>
+
+ Tikz->arc($from => $to, $center)
+
+Creates a L<LaTeX::TikZ::Set> structure that represents an arc going from C<$from> to C<$to> with center C<$center>.
+
+ # An arc. The points are automatically coerced into LaTeX::TikZ::Set::Point objects
+ my $quarter = Tikz->arc(
+ [ 1, 0 ] => [ 0, 1 ],
+ [ 0, 0 ]
+ );
+
+=head3 C<arrow>
+
+ Tikz->arrow($from => $to)
+ Tikz->arrow($from => dir => $dir)
+
+Creates a L<LaTeX::TikZ::Set> structure that represents an arrow going from C<$from> towards C<$to>, or starting at C<$from> in direction C<$dir>.
+
+ # An horizontal arrow
+ my $arrow = Tikz->arrow(0 => 1);
+
+=head3 C<raw>
+
+ Tikz->raw($content)
+
+Creates a L<LaTeX::TikZ::Set::Raw> object that will instantiate to the raw TikZ code C<$content>.
+
+=head2 Modifiers
+
+Modifiers are applied onto sets by calling the C<< ->mod >> method, like in C<< $set->mod($mod) >>.
+This method returns the C<$set> object, so it can be chained.
+
+=head3 C<clip>
+
+ Tikz->clip($path)
+
+Creates a L<LaTeX::TikZ::Mod::Clip> object that can be used to clip a given sequence by the (closed) path C<$path>.
+
+ my $box = Tikz->clip(
+ Tikz->rectangle(0 => [ 1, 1 ]),
+ );
+
+Clips can also be directly applied to sets with the C<< ->clip >> method.
+
+ my $set = Tikz->circle(0, 1.5)
+ ->clip(Tikz->rectangle([-1, -1] => [1, 1]));
+
+=head3 C<layer>
+
+ Tikz->layer($name, above => \@above, below => \@below)
+
+Creates a L<LaTeX::TikZ::Mod::Layer> object with name C<$name> and optional relative positions C<@above> and C<@below>.
+
+ my $layer = Tikz->layer(
+ 'top'
+ above => [ 'main' ],
+ );
+
+The default layer is C<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 C<< ->layer >> method.
+
+ my $dots = Tikz->rectangle(0 => [ 1, 1 ])
+ ->mod(Tikz->pattern(class => 'Dots'))
+ ->layer('top');
+
+=head3 C<scale>
+
+ Tikz->scale($factor)
+
+Creates a L<LaTeX::TikZ::Mod::Scale> object that scales the sets onto which it apply by the given C<$factor>.
+
+ my $circle_of_radius_2 = Tikz->circle(0 => 1)
+ ->mod(Tikz->scale(2));
+
+=head3 C<width>
+
+ Tikz->width($line_width)
+
+Creates a L<LaTeX::TikZ::Mod::Width> object that sets the line width to C<$line_width> when applied.
+
+ my $thick_arrow = Tikz->arrow(0 => 1)
+ ->mod(Tikz->width(5));
+
+=head3 C<color>
+
+ Tikz->color($color)
+
+Creates a L<LaTeX::TikZ::Mod::Color> object that sets the line color to C<$color> (given in the C<xcolor> syntax).
+
+ # Paint the previous $thick_arrow in red.
+ $thick_arrow->mod(Tikz->color('red'));
+
+=head3 C<fill>
+
+ Tikz->fill($color)
+
+Creates a L<LaTeX::TikZ::Mod::Fill> object that fills the interior of a path with the solid color C<$color> (given in the C<xcolor> syntax).
+
+ my $red_box = Tikz->rectangle(0 => { width => 1, height => 1 })
+ ->mod(Tikz->fill('red'));
+
+=head3 C<pattern>
+
+ Tikz->pattern(class => $class, %args)
+
+Creates a L<LaTeX::TikZ::Mod::Pattern> object of class C<$class> and arguments C<%args> that fills the interior of a path with the specified pattern.
+C<$class> is prepended with C<LaTeX::TikZ::Mod::Pattern> when it doesn't contain C<::>.
+See L<LaTeX::TikZ::Mod::Pattern::Dots> and L<LaTeX::TikZ::Mod::Pattern::Lines> for two examples of pattern classes.
+
+ my $hatched_circle = Tikz->circle(0 => 1)
+ ->mod(Tikz->pattern(class => 'Lines'));
+
+=head3 C<raw_mod>
+
+ Tikz->raw_mod($content)
+
+Creates a L<LaTeX::TikZ::Mod::Raw> object that will instantiate to the raw TikZ mod code C<$content>.
+
+ my $homemade_arrow = Tikz->line(0 => 1)
+ ->mod(Tikz->raw_mod('->')) # or just ->mod('->')
+
+=head2 Helpers
+
+=head3 C<formatter>
+
+ Tikz->formatter(%args)
+
+Creates a L<LaTeX::TikZ::Formatter> object that can render a L<LaTeX::TikZ::Set> tree.
+
+ my $tikz = Tikz->formatter;
+ my ($header, $declarations, $seq1_body, $seq2_body) = $tikz->render($set1, $set2);
+
+=head3 C<functor>
+
+ Tikz->functor(@rules)
+
+Creates a L<LaTeX::TikZ::Functor> anonymous subroutine that can be called against L<LaTeX::TikZ::Set> trees to clone them according to the given rules.
+C<@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;
+
projects / perl / modules / LaTeX-TikZ.git / blobdiff