NAME
Image::CairoSVG - render SVG into a Cairo surface
SYNOPSIS
This example converts an SVG into a PNG:
use Cairo;
use Image::CairoSVG;
my $cairosvg = Image::CairoSVG->new ();
my $surface = $cairosvg->render ("$Bin/locust.svg");
$surface->write_to_png ("$Bin/locust.png");This renders the following image:
(This example is included as synopsis.pl in the distribution. The input and output files are also included.)
VERSION
This documents Image::CairoSVG version 0.08 corresponding to git commit 8a1a43a62d43974ff62f93a9e803fa068e386307 released on Mon Aug 14 14:30:58 2017 +0900.
DESCRIPTION
This module renders some kinds of SVG ("Scalable Vector Graphics") instructions into a Cairo surface.
METHODS
new
my $cairosvg = Image::CairoSVG->new ();The user can supply a Cairo surface:
my $cairosvg = Image::CairoSVG->new (surface => $surface);For example,
my $cairosvg = Image::CairoSVG->new (
surface => Cairo::ImageSurface->create ('argb32', 100, 100)
);The user can also supply a Cairo context:
my $cairosvg = Image::CairoSVG->new (context => $cr);If a Cairo context is supplied, the value of surface is ignored, and the image is written using the context value.
render
my $surface = $cairosvg->render ('some.svg');Draw an SVG file into a Cairo surface. The return value is the surface drawn into. If the user does not supply a context or surface in "new", a new Cairo::ImageSurface object is generated from the attributes of the <svg> element, either the width and height attributes, or the width and height specified in the viewBox attribute. If the user supplied a context with "new", the return value should be ignored. If the user supplied a surface with "new", the return value is just that surface.
If the call value is a scalar containing what looks like XML, it is parsed from the scalar instead.
Calling with a scalar containing XML was added in version 0.08.
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 line element, you can parse its attributes with an XML parser, then send the hash of key/value pairs in the attributes to "line".
line
$cairosvg->line (%attr);Render an SVG line onto the surface specified by $cairosvg. Given SVG input of the form <line >, this renders it onto the Cairo surface.
path
$cairosvg->path (%attr);Given an SVG path element, send its attribute key / value pairs as %attr to render into the Cairo surface of $cairosvg. This uses Image::SVG::Path to render the "d" attibute of the path. It also converts quadratic bezier curves into cubic bezier curves.
rect
$cairosvg->rect (%attr);ellipse
$cairosvg->ellipse (%attr);circle
$cairosvg->circle (%attr);polygon
$cairosvg->polygon (%attr);DEPENDENCIES
- Cairo
-
Cairo is used for rendering the image.
- Carp
-
Carp is used for reporting errors.
- Image::SVG::Path
-
Image::SVG::Path is used for parsing the "path" information of the SVG.
- XML::Parser
-
XML::Parser is used for parsing SVG files.
SEE ALSO
- CairoSVG
-
CairoSVG is a Python SVG renderer in Cairo. Parts of the code here are based on it.
Other CPAN modules related to SVG
- Image::SVG::Path
-
This is for reading the "d" attribute of SVG paths.
- MarpaX::Languages::SVG::Parser
-
This extends the Marpa::R2 parser to parse SVG.
- SVG
-
This is for generating SVG documents.
- Image::LibRSVG
-
Perl extension for a Gnome library called librsvg which converts SVG to PNG or JPEG, etc. I have not tested this library.
- SVG::Rasterize
-
Rasterize SVG content to pixel graphics.
More information
- Perl Maven article
-
SVG - Scalable Vector Graphics with Perl - article at Perl Maven
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.
AUTHOR
Ben Bullock, <bkb@cpan.org>
COPYRIGHT & LICENCE
This package and associated files are copyright (C) 2014-2017 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.
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.