require 'bundler'

Bundler::require

require 'rmagick'
include Magick

IMAGE_DIR='video/128_128'
OUTPUT_NAME='video/128_128/apple.bin'

COLOR_STEP=(Magick::QuantumRange + 1) / 16

def convert_image(filename)
    im = Image.read(filename)
    pix_ary = Array.new(8192, 0)
    im[0].each_pixel do |pix, col, row|
        if col.even? then # Low nibble
                pix_ary[row * 64 + col / 2] &= 0xF0
                pix_ary[row * 64 + col / 2] |= pix.intensity / COLOR_STEP
        else # High nibble
            pix_ary[row * 64 + col / 2] &= 0x0F
            pix_ary[row * 64 + col / 2] |= (pix.intensity / COLOR_STEP) << 4
        end
    end
    pix_ary
end

File.open(OUTPUT_NAME, "w+") do |f|
    Dir.glob("#{IMAGE_DIR}/*.bmp").each_with_index do |img, i|
        puts "#{i} image processed."
        f.write(convert_image(img).pack("C*"))
    end
end