Aggression System

                            #======================#
                            #  Z-Systems by: Zetu  #
#===========================#======================#===========================#
#                     *  *  *  Aggro System v1.01  *  *  *                     #
#=#==========================================================================#=#
  # OVERWRITES                                                               #
  #   Game_Enemy::make_action                                                #
  #   Game_Interpretor::command_339                                          #
  # SEMI-OVERWRITES                                                          #
  #   Game_BattleAction::decide_random_target                                #
  #--------------------------------------------------------------------------#
  # Introduction:  What is Aggro?                                            #
  #   Aggro (or Aggression) is a statistical value that helps determine the  #
  #   percent chance an enemy will attack a specific actor.                  #
  # What is this good for?                                                   #
  #   In many RPGs, there are strong characters that can take a hit, also    #
  #   called "Tanks", and weaker ones that cannot take much damage.  By      #
  #   manipulating these statistical values, you can control which actors    #
  #   will take damage, and which ones will not.                             #
  # How to increase Aggro?                                                   #
  #   In this system, Aggro can be gained/lost by Attacks, Skills, and by    #
  #   guarding.  The default values are defined by the module below.  Inside #
  #   note tags of skills, you may add tags to change its default amount.    #
  #                                                                          #
  # <aggro: X>                                                               #
  #   Increases aggro by a rating of X.  Keep this value between             #
  #   0.0 and 1 OR 0 and 100.  Does not perfectly increase aggro by the      #
  #   amount given.                                                          #
  # <pro aggro: X>                                                           #
  #   This sets aggro to an amount, reducing all other aggro to match.  Only #
  #   use in hard aggro skills, such as a provoke (gain all aggro) or fade   #
  #   (remove all aggro).  This tag is still in testing and not guarenteed   #
  #   to be bug free.                                                        #
  #--------------------------------------------------------------------------#
  # Version History:                                                         #
  #  v1.01 ALPHA (Please Report all bugs related to this script)             #
  #--------------------------------------------------------------------------#
  #           * * *  FOR SCRIPTERS WANTING TO CREATE A HUD!  * * *           #
  # The aggro values are stored in $scene.aggro and is a two dimensional     #
  # array.  @aggro[enemy.index][actor.index] returns the percent value of    #
  # aggro, and will be between 0.0 and 1.0.                                  #
  #==========================================================================#

module Z_Systems
  module Aggro
    NORMAL_ATTACK   =  0.06
    SKILL_DEFAULT   =  0.06
    GUARD           = -0.06
  end
end
#========#======================#====#================================#========#
#--------#                      #----# DO NOT EDIT PAST THIS POINT!!! #--------#
#--------# End of Customization #----# Editing will cause death by    #--------#
#--------#                      #----# brain asplosions.              #--------#
#========#======================#====#================================#========#

class Array; def sum; inject( nil ) { |sum,x| sum ? sum+x : x }; end; end

class Scene_Battle < Scene_Base

  alias zs_aggro_start start
  def start
    zs_aggro_start
    @aggro = []
    for e in 0...$game_troop.members.size
        array = []
        for actor in $game_party.members
          array.push(1.0/$game_party.members.size)
        end
        @aggro[e] = array
      end
  end

  def aggro
    return @aggro
  end

  def normalize_aggro
    for e in 0...$game_troop.members.size
        value = @aggro[e].sum
        for a in 0...$game_party.members.size
          @aggro[e][a] /= value
        end
      end
  end

  def inc_aggro(e, a, value)
    return if $game_party.members.size <= 1
    @aggro[e][a] += value
      @aggro[e][a] = [[@aggro[e][a], 0.0].max, 1.0].min
    return if @aggro[e][a] == 1.0
    div = (@aggro[e].sum - @aggro[e][a])/(1.0-@aggro[e][a])
    for aindex in 0...$game_party.members.size
      unless a == aindex
        @aggro[e][aindex] /= div
      end
    end
  end

  def set_aggro(e, a, value)
    return if $game_party.members.size <= 1
    @aggro[e][a] = value
      @aggro[e][a] = [[@aggro[e][a], 0.0].max, 1.0].min
    if @aggro[e][a] == 1.0
      for aindex in 0...$game_party.members.size
        unless a == aindex
          @aggro[e][aindex] = 0
        end
      end
    else
      div = (@aggro[e].sum - @aggro[e][a])/(1.0-@aggro[e][a])
      for aindex in 0...$game_party.members.size
        unless a == aindex
          @aggro[e][aindex] /= div
        end
      end
    end
  end

  alias zs_aggro_execute_action_attack execute_action_attack
  def execute_action_attack
    zs_aggro_execute_action_attack
    return if @active_battler.action.make_targets[0].actor?
    for target in @active_battler.action.make_targets
      inc_aggro(target.index, @active_battler.index, Z_Systems::Aggro::NORMAL_ATTACK)
    end
      normalize_aggro
  end

  alias zs_aggro_execute_action_skill execute_action_skill
  def execute_action_skill
    zs_aggro_execute_action_skill
    return if @active_battler.action.make_targets[0].actor?
    value = Z_Systems::Aggro::SKILL_DEFAULT
      for line in @active_battler.action.skill.note.split(//)
      case line
        when /<aggro:[ ](.*)>/i
        value = $1.to_f
        if value > 1.0
            value /= 100.0
          end
        for target in @active_battler.action.make_targets
          inc_aggro(target.index, @active_battler.index, value)
        end
        return
      when /<pro[ ][_]aggro:[ ](.*)>/i
        value = $1.to_f
        if value > 1.0
          value /= 100.0
        end
        for target in @active_battler.action.make_targets
          set_aggro(target.index, @active_battler.index, value)
        end
        return
      end
      end
    for target in @active_battler.action.make_targets
      inc_aggro(target.index, @active_battler.index, value)
    end
  end

  alias zs_aggro_execute_action_guard execute_action_guard
  def execute_action_guard
    zs_aggro_execute_action_guard
    for enemy in $game_troop.members
      inc_aggro(enemy.index, @active_battler.index, Z_Systems::Aggro::GUARD)
    end
    normalize_aggro
  end

end

class Game_Unit

  def random_target_aggro(enemy)
    $scene.normalize_aggro
    rref = rand(101).to_f/100.0
#~     print $scene.aggro[enemy.index].inspect
    for a in 0...$game_party.members.size
      if rref <= $scene.aggro[enemy.index][0..a].sum and !$game_party.members[a].dead?
#~         print $scene.aggro[enemy.index][0..a].inspect
        return $game_party.members[a]
      end
    end
    return random_target_aggro(enemy)
  end

end

class Game_BattleAction

  alias zs_aggro_decide_random_target decide_random_target
  def decide_random_target(attacker = nil)                       #SEMI-OVERWRITE
    if !friends_unit.members[0].actor? or attacker != nil
      if for_friend?
        target = friends_unit.random_target
      elsif for_dead_friend?
        target = friends_unit.random_dead_target
      else
        target = opponents_unit.random_target_aggro(attacker)
      end
      if target == nil
        clear
      else
        @target_index = target.index
      end
    else
      zs_aggro_decide_random_target
    end
  end

end

class Game_Enemy < Game_Battler

  def make_action
    @action.clear
    return unless movable?
    available_actions = []
    rating_max = 0
    for action in enemy.actions
      next unless conditions_met?(action)
      if action.kind == 1
        next unless skill_can_use?($data_skills[action.skill_id])
      end
      available_actions.push(action)
      rating_max = [rating_max, action.rating].max
    end
    ratings_total = 0
    rating_zero = rating_max - 3
    for action in available_actions
      next if action.rating <= rating_zero
      ratings_total += action.rating - rating_zero
    end
    return if ratings_total == 0
    value = rand(ratings_total)
    for action in available_actions
      next if action.rating <= rating_zero
      if value < action.rating - rating_zero
        @action.kind = action.kind
        @action.basic = action.basic
        @action.skill_id = action.skill_id
        @action.decide_random_target(self)
        return
      else
        value -= action.rating - rating_zero
      end
    end
  end

end

class Game_Interpretor

  def command_339
    iterate_battler(@params[0], @params[1]) do |battler|
      next unless battler.exist?
      battler.action.kind = @params[2]
      if battler.action.kind == 0
        battler.action.basic = @params[3]
      else
        battler.action.skill_id = @params[3]
      end
      if @params[4] == -2                   # Last target
        battler.action.decide_last_target
      elsif @params[4] == -1                # Random
        battler.action.decide_random_target(battler)
      elsif @params[4] >= 0                 # Index designation
        battler.action.target_index = @params[4]
      end
      battler.action.forcing = true
      $game_troop.forcing_battler = battler
      @index += 1
      return false
    end
    return true
  end

end