67 lines
1.7 KiB
Ruby
67 lines
1.7 KiB
Ruby
|
=begin
|
||
|
|
cairo.rb - Ruby/Pango with cairo sample script.
|
||
|
|
|
||
|
|
Copyright (c) 2005 Ruby-GNOME2 Project
|
||
|
|
This program is licenced under the same licence as Ruby-GNOME2.
|
||
|
|
|
||
|
|
$Id: pango_cairo.rb,v 1.1 2005/10/15 07:57:52 mutoh Exp $
|
||
|
|
=end
|
||
|
|
|
||
|
|
require 'pango'
|
||
|
|
|
||
|
|
unless Pango.cairo_available?
|
||
|
|
STDERR.puts "This sample requires Pango 1.0.0 or later and cairo support"
|
||
|
|
exit 1
|
||
|
|
end
|
||
|
|
|
||
|
|
filename = ARGV.shift
|
||
|
|
filename ||= "cairo.png"
|
||
|
|
|
||
|
|
RADIUS = 150
|
||
|
|
N_WORDS = 10
|
||
|
|
FONT = "Sans Bold 27"
|
||
|
|
|
||
|
|
def draw_text(cr)
|
||
|
|
# Center coordinates on the middle of the region we are drawing
|
||
|
|
cr.translate(RADIUS, RADIUS);
|
||
|
|
|
||
|
|
# Create a PangoLayout, set the font and text
|
||
|
|
layout = cr.create_pango_layout
|
||
|
|
|
||
|
|
layout.set_text("Text")
|
||
|
|
desc = Pango::FontDescription.new(FONT)
|
||
|
|
layout.set_font_description(desc)
|
||
|
|
|
||
|
|
# Draw the layout N_WORDS times in a circle
|
||
|
|
N_WORDS.times do |i|
|
||
|
|
angle = (360.0 * i) / N_WORDS;
|
||
|
|
cr.save do
|
||
|
|
# Gradient from red at angle == 60 to blue at angle == 300
|
||
|
|
red = (1 + Math.cos((angle - 60) * Math::PI / 180.0)) / 2
|
||
|
|
cr.set_source_rgb(red, 0, 1.0 - red)
|
||
|
|
cr.rotate(angle * Math::PI / 180.0)
|
||
|
|
|
||
|
|
# Inform Pango to re-layout the text with the new transformation
|
||
|
|
cr.update_pango_layout(layout)
|
||
|
|
|
||
|
|
width, height = layout.size
|
||
|
|
cr.move_to(-(width.to_f / Pango::SCALE) / 2, -RADIUS)
|
||
|
|
cr.show_pango_layout(layout)
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
diameter = 2 * RADIUS
|
||
|
|
surface = Cairo::ImageSurface.new(Cairo::FORMAT_ARGB32, diameter, diameter)
|
||
|
|
cr = Cairo::Context.new(surface)
|
||
|
|
cr.set_source_rgb(1.0, 1.0, 1.0)
|
||
|
|
cr.rectangle(0, 0, diameter, diameter);
|
||
|
|
cr.fill
|
||
|
|
draw_text(cr)
|
||
|
|
|
||
|
|
File.open(filename, "wb") do |f|
|
||
|
|
cr.target.write_to_png(f)
|
||
|
|
end
|
||
|
|
# or
|
||
|
|
# cr.target.write_to_png(filename)
|