#!/usr/bin/env ruby

Dir.chdir(File.dirname(__FILE__))

require 'shellwords'

palettes = [64]
side = 256

palettes.each do |palette|
  IO.popen(%W[
    convert
    -depth 8
    -size #{side}x#{side}
    -strip
    rgb:-
    PNG24:#{palette}.png
  ].shelljoin, 'w') do |f|
    (side * side).times do |i|
      color = i * palette / (side * side) * 0x10000 / palette
      f << [color / 0x100, color % 0x100, 0].pack('C*')
    end
  end
  system "identify -format 'Wrote %f with %k unique colors\n' #{palette}.png"
end