string2png_util.rb

require 'ftools'
require 'fileutils'
require 'rubygems'
require 'RMagick'
include Magick

require 'open3'

def merge( files = [] )
  merged_file = ""
  files.each do |file|
    File.open( file, "r") { |f| 
      merged_file += f.read + "\n" 
    }
  end
  merged_file
end

def minify( string = '', type = 'js' )
  cmd = "java -jar bin/yuicompressor-2.4.2.jar --type #{type}"
  stdin, stdout, stderr = Open3.popen3( cmd )
  stdin.write string
  stdin.close
  stdout.read
end

def minify_to_file( string, type, output )
  cmd = "java -jar bin/yuicompressor-2.4.2.jar -v --type #{type} -o #{output} --charset utf-8"
  # puts cmd
  stdin, stdout, stderr = Open3.popen3( cmd )
  stdin.write string
  stdin.close
  puts stderr.read
end

def string2png( string, output )
  image = Magick::Image.new 1,string.length
  for i in 0 .. string.length
    color = '#%02X0000' % string[i]
    pixel = Magick::Pixel.from_color color
    image.pixel_color 0, i, pixel
  end
  image.compression = ZipCompression
  image.write("png8:"+ output)
  
  image = nil
end

def png2string(image)
  string = ''
  Image.read(File.open( image, "r" )).first.each_pixel do |px,x,y|
    string += (px.red % 256).chr
  end
  string
end


def string2pngs( string, output )
  puts "original string length #{string.length}"
  limit = 8192 #8192 # IE9 max for getImageData
  images_count = (string.length * 1.0 / limit ).ceil
  
  files = []
  
  for i in 0 ... images_count
    
    filename = output.split('.')
    filename[ filename.length - 2 ] += i.to_s
    filename = filename.join('.')
    
    files << filename
    
    from = i * limit
    to   = from + [ limit, string.length - from ].min
    
    puts "output from #{from} to #{to}"
    string2png string[from,to], filename
  end
  
  # verify 
  # s = ''
  # files.each{ |file| s += png2string(file) }
  # raise ('invalid string, expecting ' + s + "\n\n---but got---\n\n " + string) unless s == string
  
  # total_size = 0
  # files.each{ |file|  puts "#{"%-20.20s" % file} #{"%30s" % File.stat( file ).size}"; total_size += File.stat( file ).size }
  # puts total_size
end