DR: Performance test array splat/instance var access

performance_test.rb

class MyTile
  def initialize(x, y, r, g, b)
    @x = x * 16
    @y = y * 16
    @w = 16
    @h = 16
    @path = 'tile'
    @a = 255
    @r = r
    @g = g
    @b = b
  end

  def draw(ffi_draw)
    ffi_draw.draw_sprite_4 @x, @y, @w, @h, @path, nil, @a, @r, @g, @b,
                           nil, nil, nil, nil,
                           nil, nil,
                           nil, nil,
                           nil, nil, nil, nil,
                           nil
  end
end

class InstanceVarAccessStrategy
  def self.build_element(x, y, r, g, b)
    MyTile.new(x, y, r, g, b)
  end

  def self.draw(ffi_draw, elements)
    index = 0
    len = elements.size
    while index < len
      elements[index].draw(ffi_draw)
      index += 1
    end
  end
end


class ArraySplatStrategy
  def self.build_element(x, y, r, g, b)
    [x * 16, y * 16, 16, 16, 'tile', 255, r, g, b]
  end

  def self.draw(ffi_draw, elements)
    index = 0
    len = elements.size
    while index < len
      x, y, w, h, path, a, r, g, b = elements[index]
      ffi_draw.draw_sprite_4 x, y, w, h, path, nil, a, r, g, b,
                             nil, nil, nil, nil,
                             nil, nil,
                             nil, nil,
                             nil, nil, nil, nil,
                             nil
      index += 1
    end
  end
end

class MyTileMapRenderer
  def initialize(strategy)
    build_tile
    @strategy = strategy
    @elements = 80.times.flat_map { |x|
      43.times.map { |y|
        @strategy.build_element(x, y, rand * 255, rand * 255, rand * 255)
      }
    }
  end


  def draw_override(ffi_draw)
    start = Time.now.to_f
    @strategy.draw(ffi_draw, @elements)
    $last_frame_time = ((Time.now.to_f - start) * 1000)
  end

  def primitive_marker
    :sprite
  end

  def build_tile
    $args.outputs[:tile].width = 16
    $args.outputs[:tile].height = 16
    $args.outputs[:tile].solids << [0, 0, 16, 16, 255, 255, 255]
  end
end

def tick(args)
  # Change the commented out tile map renderer to try out the other strategy
  $tilemap_renderer = MyTileMapRenderer.new(InstanceVarAccessStrategy) if args.tick_count.zero?
  # $tilemap_renderer = MyTileMapRenderer.new(ArraySplatStrategy) if args.tick_count.zero?
  args.outputs.primitives << $tilemap_renderer
  args.outputs.primitives << [0, 720, $gtk.current_framerate.to_i.to_s].label
  args.outputs.primitives << [200, 720, "#{$last_frame_time}ms"].label
end