

=encoding UTF-8

=head1 NAME

Image::CairoSVG - render SVG into a Cairo surface

=head1 SYNOPSIS

This example converts an SVG into a PNG:

    use Cairo;
    use Image::CairoSVG;
    my $surface = Cairo::ImageSurface->new ();
    my $cairosvg = Image::CairoSVG->new (
        surface => $surface,
    );
    $cairosvg->render ('file.svg');
    $surface->write_to_png ($tempout);

=head1 DESCRIPTION

This module renders some kinds of SVG ("Scalable Vector Graphics")
instructions into a Cairo surface.

=head1 METHODS

=head2 new

    my $cairosvg = Image::CairoSVG->new ();

If a surface is not provided, this creates a L<Cairo::ImageSurface> of
dimensions 100 by 100 of rgba format.

The user can supply a surface:

    my $cairosvg = Image::CairoSVG->new (surface => $surface);

For example,

    my $cairosvg = Image::CairoSVG->new (
        surface => Cairo::ImageSurface->create ('argb32', 100, 100)
    );

=head2 render

    $cairosvg->render ('some.svg');

Draw an SVG file into a Cairo surface.

=head1 DRAWING METHODS

All of these methods take the attributes of the specific element after
which they're named. So, for example, if you have an SVG C<line>
element, you can parse its attributes with an XML parser, then send
the hash of key/value pairs in the attributes to L</line>.

=head2 line

    $cairosvg->line (%attr);

Render an SVG line onto the surface specified by C<$cairosvg>.  Given
SVG input of the form C<< <line > >>, this renders it onto the Cairo
surface.

=head2 path

    $cairosvg->path (%attr);

Given an SVG path element, send its attribute key / value pairs as
C<%attr> to render into the Cairo surface of C<$cairosvg>. This uses
L<Image::SVG::Path> to render the "d" attibute of the path. It also
converts quadratic bezier curves into cubic bezier curves.

=head2 rect

    $cairosvg->rect (%attr);

=head2 ellipse

    $cairosvg->ellipse (%attr);

=head2 circle

    $cairosvg->circle (%attr);

=head2 polygon

    $cairosvg->polygon (%attr);

=head1 DEPENDENCIES

=over

=item L<Cairo>

Cairo is used for rendering the image.

=item L<Carp>

Carp is used for reporting errors.

=item L<Image::SVG::Path>

Image::SVG::Path is used for parsing the "path" information of the SVG.

=item L<XML::Parser>

XML::Parser is used for parsing SVG files.

=back

=head1 SEE ALSO

=over

=item CairoSVG

L<CairoSVG|http://cairosvg.org/> is a Python SVG renderer in
Cairo. Parts of the code here are based on it.

=back

=head2 Other CPAN modules related to SVG

=over

=item L<Image::SVG::Path>

This is for reading the "d" attribute of SVG paths.

=item L<MarpaX::Languages::SVG::Parser>

This extends the L<Marpa::R2> parser to parse SVG.

=item L<SVG>

This is for generating SVG documents.

=item L<Image::LibRSVG>

Perl extension for a Gnome library called librsvg which converts SVG
to PNG or JPEG, etc. I have not tested this library.

=item L<SVG::Rasterize>

Rasterize SVG content to pixel graphics.

=back

=head2 More information

=over

=item Perl Maven article

L<SVG - Scalable Vector Graphics with Perl|http://perlmaven.com/scalable-vector-graphics-with-perl> - article at Perl Maven

=back

=head1 BUGS

This module is a "least effort" attempt to get the parts of SVG which
the author needs rendered, rendered. It doesn't even pretend to be a
full SVG renderer. So, if you find the module doesn't do some part of
SVG which you want done, please add that to the module, and contribute
your addition to this module via the github repository.


=head1 AUTHOR

Ben Bullock, <bkb@cpan.org>

=head2 Request

If you'd like to see this module continued, let me know that you're
using it. For example, send an email, write a bug report, star the
project's github repository, add a patch, add a C<++> on Metacpan.org,
or write a rating at CPAN ratings. It really does make a
difference. Thanks.

=head1 COPYRIGHT & LICENCE

This package and associated files are copyright (C) 
2014-2015
Ben Bullock.

You can use, copy, modify and redistribute this package and associated
files under the Perl Artistic Licence or the GNU General Public
Licence.




=head2 cairosvg licence

Some parts of the module (specifically the SVG arc drawing code) are
translations from the above-mentioned Python program "cairosvg", which
is under the "GNU LESSER GENERAL PUBLIC LICENSE Version 3, 29 June
2007". I'm not really sure how or if this affects the code, but just
in case it causes legal issues for someone downstream, I'm mentioning
it here.

=head1 TERMINOLOGY

This defines the terminology used in this document.

=over

=item Convenience function

In this document, a "convenience function" indicates a function which
solves some of the problems, some of the time, for some of the people,
but which may not be good enough for all envisaged uses. A convenience
function is an 80/20 solution, something which solves (about) 80% of
the problems with 20% of the effort. Something which does the obvious
things, but may not do all the things you might want, a time-saver for
the most basic usage cases.

=item BUGS

In this document, the section BUGS describes possible deficiencies,
problems, and workarounds with the module. It's not a guide to bug
reporting, or even a list of actual bugs. The name "BUGS" is the
traditional name for this sort of section in a Unix manual page.

=back


