Convert print dumpfile from VICE C64 emulator to a real image.

convert.rb

#!/usr/bin/env ruby

require "logger"
require "rmagick"

class Input
  attr_reader :filename
  
  def initialize(filename)
    @filename = filename
  end
  
  def max_line_length
    lines.map(&:length).max
  end
  
  def lines
    @lines ||= File.readlines(filename)
  end
end

class Output
  BG_PIXEL = Magick::Pixel.new(Magick::QuantumRange, Magick::QuantumRange, Magick::QuantumRange)
  FG_PIXEL = Magick::Pixel.new(0, 0, 0)
  
  attr_reader :filename, :input, :img, :log
  
  def initialize(filename, input, log)
    @filename = filename
    @input    = input
    @log   = log
  end
  
  def convert
    log.debug "Converting #{width}x#{height} image:"
    input.lines.each_with_index do |line, i|
      log.debug("Line #{i} ...") if i % 1000 == 0
      convert_line i, line
    end
    log.debug "Saving image."
    save_image
  end
  
  def width
    @width ||= input.max_line_length
  end
  
  def height
    @height ||= input.lines.count
  end
  
  def img
    @img ||= Magick::Image.new(width, height) do |img|
      img.background_color = BG_PIXEL
    end
  end
  
  def convert_line(y, data)
    pixels = data.each_char.map do |c|
      c == " " ? BG_PIXEL : FG_PIXEL
    end
    img.store_pixels(0, y, pixels.size, 1, pixels)
  end
  
  def save_image
    img.write(filename)
  end
end

def usage
  puts "Usage: #{$0} INPUTFILE OUTPUTFILE"
  exit
end

input_file = ARGV[0] || usage
output_file = ARGV[1] || usage
logger = Logger.new(STDERR)
logger.formatter = ->(severity, datetime, progname, msg){ "#{msg}\n" }

input = Input.new(input_file)
output = Output.new(output_file, input, logger)

output.convert