1#!/usr/bin/env ruby
2require 'tk'
3require 'tkextlib/blt'
4
5file = File.join(File.dirname(File.expand_path(__FILE__)),
6                 'images', 'sample.gif')
7if File.exist?(file)
8  src = TkPhotoImage.new(:file=>file)
9else
10  fail RuntimeError, 'no image file'
11end
12
13width = src.width
14height = src.height
15
16TkOption.add('*Label.font', '*helvetica*10*')
17TkOption.add('*Label.background', 'white')
18
19l_img0 = TkLabel.new(:image=>src)
20l_hdr0 = TkLabel.new(:text=>"#{width} x #{height}")
21l_ftr0 = TkLabel.new(:text=>'100%')
22Tk.root.background('white')
23
24(2..10).each{|i|
25  iw = width/i
26  ih = height/i
27  r = '%6g'%(100.0/i)
28  dst = TkPhotoImage.new(:width=>iw, :height=>ih)
29  Tk::BLT::Winop.image_resample(src, dst, :sinc)
30  l_hdr = TkLabel.new(:text=>"#{iw} x #{ih}")
31  l_ftr = TkLabel.new(:text=>"#{r}%")
32  l_img = TkLabel.new(:image=>dst)
33  Tk::BLT::Table.add(Tk.root,
34                     [0,i], l_hdr,
35                     [1,i], l_img,
36                     [2,i], l_ftr)
37  Tk.update
38}
39
40Tk.mainloop
41