V.M. Enemy HP Bars + critical hp level

    #--# Basic Enemy HP Bars v 2.2.01
    #
    # Adds customizable hp bars to enemies in battle. See configuration
    #  below for more detail. Also allows for the option of using a nice
    #  graphical hp bar from a image file.
    #
    # Usage: Plug and play, customize as needed.
    #
    #------#
    #-- Script by: V.M of D.T
    #
    #- Questions or comments can be left:
    #    on the thread for the script
    #    given by email: sumptuaryspade@live.ca
    #    or by facebook: http://www.facebook.com/DaimoniousTailsGames
    #
    #- Free to use in any project with credit given, though donations are always
    #   welcome via paypal (same as email)

    #Customization starts here:
    module DTP_HP
      #Whether to place the hp bar above or below the enemy
      ABOVE_MONSTER = true
      #Whether to use a custome image or not:
      #Image would be placed in Graphics/System and named Custom_HP.png
      CUSTOM_BAR = false

      #The width of the hp bar
      BAR_WIDTH = 66
      #The height of the hp bar
      BAR_HEIGHT = 5
      #The width of the border around the hp bar
      BORDER_WIDTH = 1
      #The height of the border around the hp bar
      BORDER_HEIGHT = 1
      #Offset the hp bar along the x-axis(left,right)
      BAR_OFFSET_X = 0
      #Offset the hp bar along the y-axis(up,down)
      BAR_OFFSET_Y = 0

      #Color for the back of the hp bar
      COLOR_BAR_BACK = Color.new(0,0,0,200)

      #Outside border color
      COLOR_BORDER_1 = Color.new(0,0,0,185)
      #Inside border color
      COLOR_BORDER_2 = Color.new(255,255,255,185)

      #Set critical hp (bar changes color at said hp %)
      #Set between 0-1, set to 0 to disable critical hp display)
      CRITICAL_HP = 0.5
      #Colors for normal hp (gradient, left-right)
      COLOR_BAR_1 = Color.new(255,0,0)
      COLOR_BAR_2 = Color.new(200,100,100)
      #Colors for critical hp (gradient, left-right)
      COLOR_BAR_3 = Color.new(50,205,50)
      COLOR_BAR_4 = Color.new(188,238,104)

      #Whether to display text or not
      USE_TEXT = false
      #Text to be displayed, chp = current hp, mhp = max hp, php = percentage hp
      #Examples: "php%" or "chp/mhp" or "chp - php%"
      TEXT_DISPLAY = "chp"
      #Offset for the text along the x-axis(left,right)
      TEXT_OFFSET_X = 5
      #Offset for the text along the y-axis(up,down)
      TEXT_OFFSET_Y = -24
      #Size of the displayed text
      TEXT_SIZE = Font.default_size
      #Font of the displayed text
      TEXT_FONT = Font.default_name

      #Show bars only when specific actor in party. Array format. Example: [8,7]
      #Set to [] to not use actor only
      SPECIFIC_ACTOR = []
      #Show enemy hp bar only if certain state is applied (like a scan state)
      #Set to 0 to not use state only
      SCAN_STATE = 0
    end
    #Customization ends here

    class Sprite_Battler
      alias hpbar_update update
      alias hpbar_dispose dispose
      def update
        hpbar_update
        return unless @battler.is_a?(Game_Enemy)
        if @battler
          update_hp_bar
        end
      end
      def update_hp_bar
        if @hp_bar.nil?
          @hp_bar = Sprite_Base.new(self.viewport)
          width = DTP_HP::BAR_WIDTH + DTP_HP::BORDER_WIDTH * 4
          height = DTP_HP::BAR_HEIGHT + DTP_HP::BORDER_HEIGHT * 4
          @hp_bar.bitmap = Bitmap.new(width,height)
          @hp_bar.x = self.x - @hp_bar.width / 2 + DTP_HP::BAR_OFFSET_X
          @hp_bar.y = self.y + DTP_HP::BAR_OFFSET_Y - self.bitmap.height - @hp_bar.height
          @hp_bar.y = self.y + DTP_HP::BAR_OFFSET_Y unless DTP_HP::ABOVE_MONSTER
          @hp_bar.x = 0 if @hp_bar.x < 0
          @hp_bar.y = 0 if @hp_bar.y < 0
          @hp_bar.z = 98
        end
        if @text_display.nil?
          @text_display = Sprite_Base.new(self.viewport)
          @text_display.bitmap = Bitmap.new(100,DTP_HP::TEXT_SIZE)
          @text_display.bitmap.font.size = DTP_HP::TEXT_SIZE
          @text_display.bitmap.font.name = DTP_HP::TEXT_FONT
          @text_display.x = @hp_bar.x + DTP_HP::TEXT_OFFSET_X
          @text_display.y = @hp_bar.y + DTP_HP::TEXT_OFFSET_Y
          @text_display.z = 99
        end
        determine_visible
        return unless @hp_bar.visible
        @hp_bar.bitmap.clear
        width = DTP_HP::BAR_WIDTH
        height = DTP_HP::BAR_HEIGHT
        bwidth = DTP_HP::BORDER_WIDTH
        bheight = DTP_HP::BORDER_HEIGHT
        btotal = (bwidth + bheight) * 2
        rwidth = @hp_bar.bitmap.width
        rheight = @hp_bar.bitmap.height
        if !DTP_HP::CUSTOM_BAR
          @hp_bar.bitmap.fill_rect(0,0,rwidth,rheight,DTP_HP::COLOR_BAR_BACK)
          @hp_bar.bitmap.fill_rect(bwidth,bheight,rwidth-bwidth*2,rheight-bheight*2,DTP_HP::COLOR_BORDER_2)
          @hp_bar.bitmap.fill_rect(bwidth*2,bheight*2,width,height,DTP_HP::COLOR_BORDER_1)
        end
        hp_width = @battler.hp_rate * width
        if @battler.hp_rate < DTP_HP::CRITICAL_HP
        @hp_bar.bitmap.gradient_fill_rect(bwidth*2,bheight*2,hp_width,height,DTP_HP::COLOR_BAR_1,DTP_HP::COLOR_BAR_2)
        else
        @hp_bar.bitmap.gradient_fill_rect(bwidth*2,bheight*2,hp_width,height,DTP_HP::COLOR_BAR_3,DTP_HP::COLOR_BAR_4)
        end
        if DTP_HP::CUSTOM_BAR
          border_bitmap = Bitmap.new("Graphics/System/Custom_HP.png")
          rect = Rect.new(0,0,border_bitmap.width,border_bitmap.height)
          @hp_bar.bitmap.blt(0,0,border_bitmap,rect)
        end
        return unless DTP_HP::USE_TEXT
        @text_display.bitmap.clear
        text = DTP_HP::TEXT_DISPLAY.clone
        text.gsub!(/chp/) {@battler.hp}
        text.gsub!(/mhp/) {@battler.mhp}
        text.gsub!(/php/) {(@battler.hp_rate * 100).to_i}
        @text_display.bitmap.draw_text(0,0,100,@text_display.height,text)
      end
      def determine_visible
        if !@battler.alive?
          @hp_bar.visible = false
          @text_display.visible = false
          return if !@battler.alive?
        end
        @hp_bar.visible = true
        if DTP_HP::SCAN_STATE != 0
          @hp_bar.visible = false
          @hp_bar.visible = true if @battler.state?(DTP_HP::SCAN_STATE)
        end
        if !DTP_HP::SPECIFIC_ACTOR.empty?
          @hp_bar.visible = false unless DTP_HP::SCAN_STATE != 0
          DTP_HP::SPECIFIC_ACTOR.each do |i|
            next unless $game_party.battle_members.include?($game_actors[i])
            @hp_bar.visible = true
          end
        end
        @text_display.visible = false if !@hp_bar.visible
        @text_display.visible = true if @hp_bar.visible
      end
      def dispose
        @hp_bar.dispose if @hpbar
        @text_display.dispose if @text_display
        hpbar_dispose
      end
    end