Code:
=begin
#==============================================================================
# RGSS3 - Sword Art Online Heads Up Display
# ** Author: SoulPour777
# Web URL: http://www.infinitytears.wordpress.com
#------------------------------------------------------------------------------
#  Description: This is a script that creates a HUD same with that of the 
#  light novel and anime Sword Art Online.
   Terms of Use:
   - You are free to use the script on any non-commercial projects.
   - Credits to SoulPour777 for the script.
   - Preserve this script header.
   
   Important Rule:
    - You are not allowed to claim this script as your own.
    - if you are going to use this on your project, it is a rule to include
    the scripter's name in the game.
    
    Version History:
    ** Version 1 - Has only the safe bar.
    ** Version 2 - Created the different bars
    
    Instructions of Using:
     - Place the script below Materials above Main.
     - Place the graphics on the Systems folder.
     
     ** if there are suggestions or errors about the script, please don't
     forget to mail the author at the given web url above.
    
    Known Compatibility Issues:
     - None.
    
#==============================================================================
=end
# ---------------------------------------------------------------------------- #
# This module contains all variables needed to display the hud and its traits.
# ---------------------------------------------------------------------------- #
module SOULPOUR777
  #------------------------------------
  SAFE_BAR = "sao_hud_life_bar.png" #safe bar image
  #------------------------------------
  DANGER_BAR = "sao_hud_life_danger_bar.png" #danger bar image
  #------------------------------------
  HUD_BACK = "sao_hud_back.png" #back image of the hud
  #------------------------------------
  NEAR_DEATH = "sao_hud_near_death" #near death image
  #------------------------------------
  SAO_HUD_Z = 150 # sao_hud.z
  #------------------------------------
  BAR_Z = 149 #bar z
  #------------------------------------
  OLD_VALUES = 0
  HUD_RECOGNIZED_NUMBER = 0
  RANGE_A = 126
  RANGE_B = 335
  RANGE_C = 27
  RANGE_D = 43
  #------------------------------------
end
# ---------------------------------------------------------------------------- #
# This module holds the state traits for the HUD. It displays:
# Green - The character is safe.
# Orange - The character is dying.
# Red - The character is in the verge of death.
# ---------------------------------------------------------------------------- #
module SAO_HUD
  include SOULPOUR777
# ---------------------------------------------------------------------------- #
# Creates the actual hud.
# ---------------------------------------------------------------------------- #
  def soulpour_make_sao_hud
    @SOULPOUR_SAO_HUD = Sprite.new(nil)
    @SOULPOUR_SAO_HUD.z = SAO_HUD_Z
    @SOULPOUR_SAO_HUD.bitmap =Bitmap.new("Graphics/System/" + HUD_BACK)
    @SAO_HUD_SOULPOUR_BAR = Sprite.new(nil)
    @SAO_HUD_SOULPOUR_BAR.z = BAR_Z
    @SAO_HUD_SOULPOUR_BAR.bitmap = Bitmap.new("Graphics/System/" + SAFE_BAR)
    @old_name = ""
    @old_hp = OLD_VALUES
    @old_max_hp = OLD_VALUES
    @old_level = OLD_VALUES
  end
# ---------------------------------------------------------------------------- #
# Dispose HUD
# Disposes the hud when the HUD is deactivated.
# ---------------------------------------------------------------------------- #
  def sao_hud_soulpour_dispose_hud
    @SOULPOUR_SAO_HUD.dispose
    @SAO_HUD_SOULPOUR_BAR.dispose
  end  
# ---------------------------------------------------------------------------- #
# Update Hud
# This method updates the hud, meaning when the actor ($leader) is damaged or
# healed, the hud updates itself to show the accurate hud graphic.
# ---------------------------------------------------------------------------- #
  def sao_hud_soulpour_update
    @SOULPOUR_SAO_HUD.bitmap.clear
    @SOULPOUR_SAO_HUD.bitmap = Bitmap.new("Graphics/System/" + HUD_BACK)
    @SOULPOUR_SAO_HUD.bitmap.draw_text(45, 22, 80, 30, $game_party.members[0].name)
    @SOULPOUR_SAO_HUD.bitmap.font.size = 16
    @SOULPOUR_SAO_HUD.bitmap.draw_text(241, 45, 70, 20, $game_party.members[0].hp.to_s + "/" +$game_party.members[0].mhp.to_s, 1)
    @SOULPOUR_SAO_HUD.bitmap.draw_text(311, 45, 30, 20, "Lv " + $game_party.members[0].level.to_s, 1)
    #when the character is still safe:
    @SAO_HUD_SOULPOUR_BAR.bitmap = Bitmap.new("Graphics/System/" + SAFE_BAR) if $game_party.members[0].hp >= $game_party.members[0].mhp / 2
    #when the character is in danger:
    @SAO_HUD_SOULPOUR_BAR.bitmap = Bitmap.new("Graphics/System/" + DANGER_BAR) if $game_party.members[0].hp <= 150
    #when the character is in the verge of death:
    @SAO_HUD_SOULPOUR_BAR.bitmap = Bitmap.new("Graphics/System/" + NEAR_DEATH) if $game_party.members[0].hp <= 100
     for x in RANGE_A..RANGE_B
      for y in RANGE_C..RANGE_D
        if y>-3*x/2+313*$game_party.members[0].hp/$game_party.members[0].mhp+218
          @SAO_HUD_SOULPOUR_BAR.bitmap.set_pixel(x,y,Color.new(0,0,0,0))
        end
      end
    end
    @old_level = $game_party.members[HUD_RECOGNIZED_NUMBER].level
    @old_hp = $game_party.members[HUD_RECOGNIZED_NUMBER].hp
    @old_max_hp = $game_party.members[HUD_RECOGNIZED_NUMBER].mhp
    @old_name = $game_party.members[HUD_RECOGNIZED_NUMBER].name  
  end
  
end
# ---------------------------------------------------------------------------- #
# Spriteset Map
# ---------------------------------------------------------------------------- #
class Spriteset_Map
  include SAO_HUD
  alias initialize_HUD initialize
  def initialize
    soulpour_make_sao_hud
    initialize_HUD
  end
# ---------------------------------------------------------------------------- #
# Dispose
# ---------------------------------------------------------------------------- #
  alias sao_hud_soulpour_dispose dispose
  def dispose
    sao_hud_soulpour_dispose_hud
    sao_hud_soulpour_dispose
  end
# ---------------------------------------------------------------------------- #
# Update
# ---------------------------------------------------------------------------- #
  alias update_HUD update
  def update
    sao_hud_soulpour_update if @old_name != $game_party.members[0].name or @old_hp != $game_party.members[0].hp or @old_max_hp != $game_party.members[0].mhp or @old_level != $game_party.members[0].level
    update_HUD
  end
end
# ---------------------------------------------------------------------------- #
$soulpour777_rgss3_sao_hud = true
# ---------------------------------------------------------------------------- #