gistfile1.rb

module Bitmap
  # Logical OR between 2 bitmap having the same size.
  def self.or(bitmap, other_bitmap)
    result = []

    bitmap.each_with_index do |line, y|
      result[y] ||= []
      line.each_with_index do |bit, x|
        result[y][x] = bitmap[y][x] || other_bitmap[y][x]
      end
    end

    result
  end
end


some_bitmap = [
  [ false, false, false, false, false ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ]
]

other_bitmap = [
  [ true, false, false, false, false ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ],
  [ false, false, true, true, true ]
]


Bitmap::or(some_bitmap, other_bitmap)
# => 
# [
#   [ true, false, false, false, false ],
#   [ false, false, true, true, true ],
#   [ false, false, true, true, true ],
#   [ false, false, true, true, true ],
#   [ false, false, true, true, true ]
# ]