RPG Maker VX ACE Sample HUD

class Scene_Map
  alias start_custom_hud start
  def start
    start_custom_hud
    create_hud
  end

  def create_hud
    @actor = $game_party.members.first
    h = 104
    @hud_viewport = Viewport.new(0, Graphics.height-h, Graphics.width, h)
    @face = Sprite.new(@hud_viewport)
    @face.bitmap = Cache.picture('Face')
    @face.x, @face.y = 4, 4

    @hp_bar_back = Sprite.new(@hud_viewport)
    @hp_bar_back.bitmap = Cache.picture('HpBar_Back')
    @hp_bar_back.x = (Graphics.width-@hp_bar_back.bitmap.width)/2
    @hp_bar_back.y = 65

    @hp_bar = Sprite.new(@hud_viewport)
    @hp_bar.bitmap = Cache.picture('HpBar')
    @hp_bar.x, @hp_bar.y = @hp_bar_back.x, @hp_bar_back.y
    @hp_bar.z = @hp_bar_back.z + 1
    @hp_bar.src_rect = Rect.new(0, 0,
    (@hp_bar.bitmap.width*@actor.hp_rate).to_i, @hp_bar.bitmap.height)

    @hp_text = Sprite.new(@hud_viewport)
    @hp_text.bitmap = Bitmap.new(@hp_bar.bitmap.width, @hp_bar.bitmap.height)
    @hp_text.x, @hp_text.y, @hp_text.z = @hp_bar.x, @hp_bar.y, @hp_bar.z+1
    draw_hp_value

    @mp_bar = Sprite.new(@hud_viewport)
    @mp_bar.bitmap = Cache.picture('MpBar')
    @mp_bar.x = @hp_bar.x + 1
    @mp_bar.y = @hp_bar.y + 25
    @mp_bar.src_rect = Rect.new(0, 0,
    (@mp_bar.bitmap.width*@actor.mp_rate).to_i, @mp_bar.bitmap.height)
  end

  def update_hp
    current_length = @hp_bar.src_rect.width
    target_length = (@hp_bar.bitmap.width * @actor.hp_rate).to_i
    return if current_length == target_length
    update_gauge(@hp_bar, current_length, target_length, 10)
    draw_hp_value
  end

  def draw_hp_value
    bitmap = @hp_text.bitmap
    bitmap.clear
    rect = Rect.new(0, 0, bitmap.width-5, bitmap.height)
    bitmap.font.outline = true
    bitmap.font.bold = true
    bitmap.font.size = 14
    mhp_size = bitmap.text_size(@actor.mhp.to_s).width
    bitmap.draw_text(rect, @actor.mhp.to_i.to_s ,2)
    rect = Rect.new(0, 0, bitmap.width - 5 - mhp_size, bitmap.height)
    bitmap.font.size = 20
    bitmap.draw_text(rect, @actor.hp.to_i.to_s + "/", 2)
  end

  def update_mp
    current_length = @mp_bar.src_rect.width
    target_length = (@mp_bar.bitmap.width * @actor.mp_rate).to_i
    return if current_length == target_length
    update_gauge(@mp_bar, current_length, target_length, 10)
  end

  def update_gauge(spr, current_length, target_length, speed)
    dw = target_length - current_length
    dw = dw.abs > speed ? (dw>0? speed : -speed) : dw
    spr.src_rect = Rect.new(0, 0, spr.src_rect.width+dw, spr.src_rect.height)
  end

  def update_hud
    update_hp
    update_mp
  end

  alias update_custom_hud update
  def update
    update_custom_hud
    update_hud
  end

  alias terminate_custom_hud terminate
  def terminate
    terminate_custom_hud
    dispose_hud
  end

  def dispose_hud
    [@face, @hp_bar, @hp_bar_back, @mp_bar, @hp_text].each{|item|
      item.bitmap.dispose if item.bitmap
      item.dispose
    }
    @hud_viewport.dispose
  end
end