/ 
Cairo-0.03
River stage three • 27 direct dependents • 183 total dependents
/ Cairo

NAME

Cairo - Perl interface to the cairo library

SYNOPSIS

use Cairo;

my $surface = Cairo::ImageSurface->create ('argb32', 100, 100);
my $cr = Cairo::Context->create ($surface);

$cr->rectangle (10, 10, 40, 40);
$cr->set_source_rgb (0, 0, 0);
$cr->fill;

$cr->rectangle (50, 50, 40, 40);
$cr->set_source_rgb (1, 1, 1);
$cr->fill;

$cr->show_page;

$surface->write_to_png ("output.png");

ABSTRACT

Cairo provides Perl bindings for the vector graphics library cairo. It supports multiple output targets, including the X Window Systems, PDF, and PNG. Cairo produces identical output on all those targets and makes use of hardware acceleration wherever possible.

API DOCUMENTATION

Cairo::Context -- The cairo drawing context

Cairo::Context is the main object used when drawing with Cairo. To draw with Cairo, you create a Cairo::Context, set the target surface, and drawing options for the Cairo::Context, create shapes with methods like $cr-move_to> and $cr->line_to, and then draw shapes with $cr->stroke or $cr->fill.

Cairo::Context's can be pushed to a stack via $cr->save. They may then safely be changed, without loosing the current state. Use $cr->restore to restore to the saved state.

$cr = Cairo::Context->create ($surface)
$surface: Cairo::Surface
$cr->save
$cr->restore
$status = $cr->status
$surface = $cr->get_target
$cr->set_source_rgb ($red, $green, $blue)
$red: double
$green: double
$blue: double
$cr->set_source_rgba ($red, $green, $blue, $alpha)
$red: double
$green: double
$blue: double
$alpha: double
$cr->set_source ($source)
$source: Cairo::Pattern
$cr->set_source_surface ($surface, $x, $y)
$surface: Cairo::Surface
$x: double
$y: double
$source = $cr->get_source ()
$cr->set_antialias ($antialias)
$antialias: Cairo::Antialias
$antialias = $cr->get_antialias
$cr->set_dash ($offset, ...)
$offset: double
...: list of doubles
$cr->set_fill_rule ($fill_rule)
$fill_rule: Cairo::FillRule
$cr->fill_rule_t $cr->get_fill_rule
$cr->set_line_cap ($line_cap)
$line_cap: Cairo::LineCap
$line_cap = $cr->get_line_cap
$cr->set_line_join ($line_join)
$line_join: Cairo::LineJoin
$line_join = $cr->get_line_join
$cr->set_line_width ($width)
$width: double
$width = $cr->get_line_width
$cr->set_miter_limit ($ limit)
$limit: double
$limit = $cr->get_miter_limit
$cr->set_operator ($op)
$op: Cairo::Operator
$op = $cr->get_operator
$cr->set_tolerance ($tolerance)
$tolerance: double
$tolerance = $cr->get_tolerance
$cr->clip
$cr->clip_preserve
$cr->reset_clip
$cr->fill
$cr->fill_preserve
($x1, $y1, $x2, $y2) = $cr->fill_extents
$bool = $cr->in_fill ($x, $y)
$x: double
$y: double
$cr->mask ($pattern)
$pattern: Cairo::Pattern
$cr->mask_surface ($surface, $surface_x, $surface_y)
$surface: Cairo::Surface
$surface_x: double
$surface_y: double
$cr->paint
$cr->paint_with_alpha ($alpha)
$alpha: double
$cr->stroke
$cr->stroke_preserve
($x1, $y1, $x2, $y2) = $cr->stroke_extents
$bool = $cr->in_stroke ($x, $y)
$x: double
$y: double
$cr->copy_page
$cr->show_page

Paths -- Creating paths and manipulating path data

$path = [
  { type => "move-to", points => [[1, 2]] },
  { type => "line-to", points => [[3, 4]] },
  { type => "curve-to", points => [[5, 6], [7, 8], [9, 10]] },
  ...
  { type => "close-path", points => [] },
];

Cairo::Path is a data structure for holding a path. This data structure serves as the return value for $cr->copy_path_data and $cr->copy_path_data_flat as well the input value for $cr->append_path.

Cairo::Path is represented as an array reference that contains path elements, represented by hash references with two keys: type and points. The value for type can be either of the following:

move-to
line-to
curve-to
close-path

The value for points is an array reference which contains zero or more points. Points are represented as array references that contain two doubles: x and y. The necessary number of points depends on the type of the path element:

move-to: 1 point
line_to: 1 point
curve-to: 3 points
close-path: 0 points

The semantics and ordering of the coordinate values are consistent with $cr->move_to, $cr->line_to, $cr->curve_to, and $cr->close_path.

$path = $cr->copy_path
$path = $cr->copy_path_flat
$cr->append_path ($path)
$path: Cairo::Path
($x, $y) = $cr->get_current_point
$cr->new_path
$cr->close_path
$cr->arc ($xc, $yc, $radius, $angle1, $angle2)
$xc: double
$yc: double
$radius: double
$angle1: double
$angle2: double
$cr->arc_negative ($xc, $yc, $radius, $angle1, $angle2)
$xc: double
$yc: double
$radius: double
$angle1: double
$angle2: double
$cr->curve_to ($x1, $y1, $x2, $y2, $x3, $y3)
$x1: double
$y1: double
$x2: double
$y2: double
$x3: double
$y3: double
$cr->line_to ($x, $y)
$x: double
$y: double
$cr->move_to ($x, $y)
$x: double
$y: double
$cr->rectangle ($x, $y, $width, $height)
$x: double
$y: double
$width: double
$height: double
$cr->glyph_path (...)
...: list of Cairo::Glyph's
$cr->text_path ($utf8)
$utf8: string in utf8 encoding
$cr->rel_curve_to ($dx1, $dy1, $dx2, $dy2, $dx3, $dy3)
$dx1: double
$dy1: double
$dx2: double
$dy2: double
$dx3: double
$dy3: double
$cr->rel_line_to ($dx, $dy)
$dx: double
$dy: double
$cr->rel_move_to ($dx, $dy)
$dx: double
$dy: double

Patterns -- Gradients and filtered sources

$status = $pattern->status
$pattern->set_matrix ($matrix)
$matrix: Cairo::Matrix
$matrix = $pattern->get_matrix
$pattern = Cairo::SolidPattern->create_rgb ($red, $green, $blue)
$red: double
$green: double
$blue: double
$pattern = Cairo::SolidPattern->create_rgba ($red, $green, $blue, $alpha)
$red: double
$green: double
$blue: double
$alpha: double
$matrix = $pattern->get_matrix
$pattern = Cairo::SurfacePattern->create ($surface)
$surface: Cairo::Surface
$pattern->set_extend ($extend)
$extend: Cairo::Extend
$extend = $pattern->get_extend
$pattern->set_filter ($filter)
$filter: Cairo::Filter
$filter = $pattern->get_filter
$pattern = Cairo::LinearGradient->create ($x0, $y0, $x1, $y1)
$x0: double
$y0: double
$x1: double
$y1: double
$pattern = Cairo::RadialGradient->create ($cx0, $cy0, $radius0, $cx1, $cy1, $radius1)
$cx0: double
$cy0: double
$radius0: double
$cx1: double
$cy1: double
$radius1: double
$pattern->add_color_stop_rgb (double offset, double red, double green, double blue)
$offset: double
$red: double
$green: double
$blue: double
$pattern->add_color_stop_rgba (double offset, double red, double green, double blue, double alpha)
$offset: double
$red: double
$green: double
$blue: double
$alpha: double

Transformations -- Manipulating the current transformation matrix

$cr->translate ($tx, $ty)
$tx: double
$ty: double
$cr->scale ($sx, $sy)
$sx: double
$sy: double
$cr->rotate ($angle)
$angle: double
$cr->transform ($matrix)
$matrix: Cairo::Matrix
$cr->set_matrix ($matrix)
$matrix: Cairo::Matrix
$matrix = $cr->get_matrix
$cr->identity_matrix
($x, $y) = $cr->user_to_device ($x, $y)
$x: double
$y: double
($dx, $dy) = $cr->user_to_device_distance ($dx, $dy)
$dx: double
$dy: double
($x, $y) = $cr->device_to_user ($x, $y)
$x: double
$y: double
($dx, $dy) = $cr->device_to_user_distance ($dx, $dy)
$dx: double
$dy: double

Text -- Rendering text and sets of glyphs

Glyphs are represented as anonymous hash references with three keys: index, x and y. Example:

my @glyphs = ({ index => 1, x => 2, y => 3 },
              { index => 2, x => 3, y => 4 },
              { index => 3, x => 4, y => 5 });
$cr->select_font_face ($family, $slant, $weight)
$family: string
$slant: Cairo::FontSlant
$weight: Cairo::FontWeight
$cr->set_font_size ($size)
$size: double
$cr->set_font_matrix ($matrix)
$matrix: Cairo::Matrix
$matrix = $cr->get_font_matrix
$cr->set_font_options ($options)
$options: Cairo::FontOptions
$options = $cr->get_font_options
$cr->show_text ($utf8)
$utf8: string
$cr->show_glyphs (...)
...: list of glyphs
$face = $cr->get_font_face
$extents = $cr->font_extents
$cr->set_font_face ($font_face)
$font_face: Cairo::FontFace
$extents = $cr->text_extents ($utf8)
$utf8: string
$extents = $cr->glyph_extents (...)
...: list of glyphs

SEE ALSO

http://cairographics.org/documentation

Lists many available resources including tutorials and examples

http://cairographics.org/manual/

Contains the reference manual

AUTHORS

Ross McFarland <rwmcfa1 at neces dot com>
Torsten Schoenfeld <kaffeetisch at gmx dot de>

COPYRIGHT

Copyright (C) 2005 by the cairo perl team