ROFLBALT Screen

screen.rb

class Screen
  OFFSET = -20
  def initialize width, height, world
    @width = width
    @height = height
    @world = world
    @background = world.background
    create_frame_buffer
    %x{stty -icanon -echo}
    print "\033[0m" # reset
    print "\033[2J" # clear screen
    print "\x1B[?25l" # disable cursor
  end
  attr_reader :width, :height, :world
  def create_frame_buffer
    @fb = Framebuffer.new @background
  end
  def draw renderable
    renderable.each_pixel(world.ticks) do |x, y, pixel|
      @fb.set x, y, pixel
    end
  end
  def render start_time
    print "\e[H"
    buffer = ''
    previous_pixel = nil
    (0...height).each do |y|
      (OFFSET...(width + OFFSET)).each do |x|
        pixel = @fb.get(x, y)
        if Pixel === previous_pixel && Pixel === pixel && pixel.color_equal?(previous_pixel)
          buffer << pixel.char
        else
          buffer << pixel.to_s
        end
        previous_pixel = pixel
      end
      buffer << "\n"
    end
    print "\033[0m"

    dt = Time.new.to_f - start_time;
    target_time = 0.04
    sleep target_time - dt if dt < target_time

    print buffer
    create_frame_buffer
  end
  def on_exit
    print "\033[0m" # reset colours
    print "\x1B[?25h" # re-enable cursor
    print "\n"
  end
end