lib/img2zpl/image.rb in img2zpl-0.1.1 vs lib/img2zpl/image.rb in img2zpl-0.1.2

@@ -1,32 +1,61 @@
 class Img2Zpl::Image < MiniMagick::Image
 
-  def to_zpl(black_threshold: 0.5)
+  def to_zpl(black_threshold: 0.5, compress: true)
     bytes_per_row = (width % 8).positive? ? (width / 8) + 1 : (width / 8)
     byte_count = bytes_per_row * height
     data, line, previous_line, byte = '', '', '', ''
 
     get_pixels.each do |row|
-
       row.each_with_index do |column, i|
         r, g, b = column.map(&:to_i)
         byte << ((r + g + b) > (black_threshold * 765) ? '0' : '1')
         if (i % 8).zero?
           line << byte.to_i(2).to_s(16).upcase.rjust(2, '0')
           byte = ''
         end
       end
-      data << (line == previous_line ? ':' : line.gsub(/0+$/, ',').gsub(/F+$/, '!'))
+
+      data << if compress
+        (line == previous_line ? ':' : line.gsub(/0+$/, ',').gsub(/F+$/, '!'))
+      else
+        line
+      end
+
       previous_line = line
       line = ''
     end
 
-    "^FO0,0^GFA,#{byte_count},#{byte_count},#{bytes_per_row},#{data}^FS"
+    _compress(data) if compress
+    "^GFA,#{byte_count},#{byte_count},#{bytes_per_row},#{data}^FS"
   end
 
   private
 
   def _compression_map
-    # TODO: finish compression map
+    map = {}
+    start = 'G'.ord
+    19.times { |i| map[i + 1] = (start+i).chr }
+    start = 'g'.ord
+    (20..400).step(20).each_with_index { |i, j| map[i] = (start+j).chr }
+    map
+  end
+
+  def _reduce(n)
+    str = ''
+    counts = _compression_map.keys.sort.reverse
+    counts.each do |c|
+      if c <= n
+        str << (_compression_map[c])
+        n -= c
+      end
+    end
+    str
+  end
+
+  def _compress(data)
+    data.gsub!(/([\da-zA-Z])(\1+)/) do |m|
+      "#{_reduce(m.length)}#{$1}"
+    end
   end
 
 end