2dreprap.rb

require 'RMagick'
import Magick

if(ARGV.length < 2)
  puts "call with image filename and gcode filename"
  exit(1)
end

XSTEP = 5
YSTEP = 5
ZSTEP = 10

img = Image.read(ARGV[0])
pixels = img.export_pixels
scanlines = pixels.each_slice(img.columns).to_a

File.open(ARGV[1]) do |f|
  f.puts('G28') # zero
  f.puts('G91') # set to relative positioning
  scanlines.each do |line|
    line.each do |px|
      if(not_white(px))
        f.puts("G1 Z-#{ZSTEP}") # lower pen
        f.puts("G1 Z#{ZSTEP}") # raise pen
      end
      f.puts("G1 X#{XSTEP}") # move to next px
    end
    f.puts("G1 Y#{YSTEP}") # move to next lime
    f.puts('G28 X0') # zero X
  end
end