Preemptive-Surprise Event Battle

#==============================================================================
# ** Preemptive-Surprise Event Battle
# by: Jeneeus Guruman
#------------------------------------------------------------------------------
#     This script allows to make evented encounters have preemptive and
#   surprise encounters.
#
#   How to use:
#
#     * Plug-n-play
#     * Place this below default and most non-aliased scripts.
#     * Not compatible and has problems with the following:
#       - Any 8-directional movement scripts
#       - Any pixel movement scripts
#     * Not recommended if followers are shown.
#     * "Encounter Half" and "Encounter None" party abilities do not work for
#     evented encounters but "Raise Preemptive" and "Cancel Surprise" does work.
#
#==============================================================================

module Jene
  #--------------------------------------------------------------------------
  # * PREEMPTIVE_SIDE_CHANCE
  #     The percent chance of having a preemtive encounter occured when
  #   going to the evented enemy's side. Putting any negative number will use
  #   the default formula for preemptive attack.
  #--------------------------------------------------------------------------
  PREEMPTIVE_SIDE_CHANCE = -1
  #--------------------------------------------------------------------------
  # * SURPRISE_SIDE_CHANCE
  #     The percent chance of having a surprised encounter occured when enemies
  #   are going to the character's side. Putting any negative number will use
  #   the default formula for surprise attack.
  #--------------------------------------------------------------------------
  SURPRISE_SIDE_CHANCE = -1
  #--------------------------------------------------------------------------
  # * PREEMPTIVE_SURPRISE_SWITCH
  #     The switch that will enable to use the preemptive-surprise function.
  #   Making the value 0 will make it always enabled. Making the value negative
  #   will disable it instead when turning on.
  #--------------------------------------------------------------------------
  PREEMPTIVE_SURPRISE_SWITCH = 0
  #--------------------------------------------------------------------------
  # * PREEMPTIVE_SURPRISE_AFFIX
  #     The affix name of the event that will enable to use the
  #   preemptive-surprise function.
  #--------------------------------------------------------------------------
  PREEMPTIVE_SURPRISE_AFFIX = "[enemy]"
  #--------------------------------------------------------------------------
  # * PREEMPTIVE_SURPRISE_TANKENTAI
  #     Always enable this if you are using the Tankentai Ace script and
  #   always disable this if otherwise. Not doing so will cause problems.
  #--------------------------------------------------------------------------
  PREEMPTIVE_SURPRISE_TANKENTAI = false
end

#----------------------------------------------------------------------------
# * Do not edit anything below here. Or else, evil errors will be released
# from the other dimension of evil.
#----------------------------------------------------------------------------

#==============================================================================
# ** BattleManager
#------------------------------------------------------------------------------
#  This module manages battle progress.
#==============================================================================

module BattleManager
  class <<self
    alias jene_pseb_on_encounter on_encounter
    alias jene_pseb_battle_end battle_end
  end
  #--------------------------------------------------------------------------
  # * Processing at Encounter Time
  #--------------------------------------------------------------------------
  def self.on_encounter
    if Jene::PREEMPTIVE_SURPRISE_SWITCH > 0
      psbe_enable = $game_switches[Jene::PREEMPTIVE_SURPRISE_SWITCH]
    elsif Jene::PREEMPTIVE_SURPRISE_SWITCH < 0
      psbe_enable = !$game_switches[-Jene::PREEMPTIVE_SURPRISE_SWITCH]
    else
      psbe_enable = true
    end
    if psbe_enable
      @preemptive = $game_temp.ps_num > 0
      @surprise = $game_temp.ps_num < 0
    else
      jene_pseb_on_encounter
    end
    if Jene::PREEMPTIVE_SURPRISE_TANKENTAI
      $sv_camera.mirror = @surprise if N03::BACK_ATTACK
    end
  end
  #--------------------------------------------------------------------------
  # * End Battle
  #     result : Result (0: Win 1: Escape 2: Lose)
  #--------------------------------------------------------------------------
  def self.battle_end(result)
    $game_temp.ps_num = 0
    jene_pseb_battle_end(result)
  end
end

#==============================================================================
# ** Game_Temp
#------------------------------------------------------------------------------
#  This class handles temporary data that is not included with save data.
# The instance of this class is referenced by $game_temp.
#==============================================================================

class Game_Temp
  #--------------------------------------------------------------------------
  # * Public Instance Variables
  #--------------------------------------------------------------------------
  attr_accessor :ps_num                 # Number indicator for encounters
  #--------------------------------------------------------------------------
  # * Object Initialization
  #--------------------------------------------------------------------------
  alias jene_pseb_temp_initialize initialize
  def initialize
    jene_pseb_temp_initialize
    @ps_num = 0
  end
end

#==============================================================================
# ** Game_CharacterBase
#------------------------------------------------------------------------------
#  This base class handles characters. It retains basic information, such as
# coordinates and graphics, shared by all characters.
#==============================================================================

class Game_CharacterBase
  #--------------------------------------------------------------------------
  # * Public Instance Variables
  #--------------------------------------------------------------------------
  attr_reader   :prev_direction           # Previous Direction
  #--------------------------------------------------------------------------
  # * Initialize Public Member Variables
  #--------------------------------------------------------------------------
  alias jene_pseb_init_public_members init_public_members
  def init_public_members
    jene_pseb_init_public_members
    @prev_direction = 2
  end
  #--------------------------------------------------------------------------
  # * Change Direction to Designated Direction
  #     d : Direction (2,4,6,8)
  #--------------------------------------------------------------------------
  def set_direction(d)
    @prev_direction = @direction if !@direction_fix && @direction != 0
    @direction = d if !@direction_fix && d != 0
    @stop_count = 0
  end
end

#==============================================================================
# ** Game_Event
#------------------------------------------------------------------------------
#  This class handles events. Functions include event page switching via
# condition determinants and running parallel process events. Used within the
# Game_Map class.
#==============================================================================

class Game_Event < Game_Character
  #--------------------------------------------------------------------------
  # * Public Instance Variables
  #--------------------------------------------------------------------------
  attr_reader   :event                    # Event

  #--------------------------------------------------------------------------
  # alias method: update_self_movement
  #--------------------------------------------------------------------------
  alias jene_pseb_update_self_movement update_self_movement
  def update_self_movement
    return if $game_map.interpreter.running? && @event.name.include?(Jene::PREEMPTIVE_SURPRISE_AFFIX)
    jene_pseb_update_self_movement
  end
end

#==============================================================================
# ** Game_Follower
#------------------------------------------------------------------------------
#  This class handles followers. A follower is an allied character, other than
# the front character, displayed in the party. It is referenced within the
# Game_Followers class.
#==============================================================================

class Game_Follower < Game_Character
  #--------------------------------------------------------------------------
  # * Object Initialization
  #--------------------------------------------------------------------------
  alias jene_pseb_follower_initialize initialize
  def initialize(member_index, preceding_character)
    jene_pseb_follower_initialize(member_index, preceding_character)
    #@priority_type = 0
  end
end

#==============================================================================
# ** Game_Interpreter
#------------------------------------------------------------------------------
#  An interpreter for executing event commands. This class is used within the
# Game_Map, Game_Troop, and Game_Event classes.
#==============================================================================

class Game_Interpreter
  #--------------------------------------------------------------------------
  # * Battle Processing
  #--------------------------------------------------------------------------
  alias jene_pseb_command_301 command_301
  def command_301
    if Jene::PREEMPTIVE_SURPRISE_SWITCH > 0
      psbe_enable = $game_switches[Jene::PREEMPTIVE_SURPRISE_SWITCH]
    elsif Jene::PREEMPTIVE_SURPRISE_SWITCH < 0
      psbe_enable = !$game_switches[-Jene::PREEMPTIVE_SURPRISE_SWITCH]
    else
      psbe_enable = true
    end
    if psbe_enable
      return if $game_party.in_battle
      if @params[0] == 0                      # Direct designation
        troop_id = @params[1]
      elsif @params[0] == 1                   # Designation with variables
        troop_id = $game_variables[@params[1]]
      else                                    # Map-designated troop
        troop_id = $game_player.make_encounter_troop_id
      end
      if $data_troops[troop_id]
        preemptive_or_surprise
        BattleManager.setup(troop_id, @params[2], @params[3])
        BattleManager.event_proc = Proc.new {|n| @branch[@indent] = n }
        BattleManager.on_encounter
        $game_player.make_encounter_count
        SceneManager.call(Scene_Battle)
      end
      Fiber.yield
    else
      jene_pseb_command_301
    end
  end
  #--------------------------------------------------------------------------
  # * Battle Processing
  #--------------------------------------------------------------------------
  def preemptive_or_surprise
    enemy = get_character(0)
    player = get_character(-1)
    return unless enemy.event.name.include?(Jene::PREEMPTIVE_SURPRISE_AFFIX)
    if player.direction == enemy.prev_direction
      case player.direction
      when 2
        if player.y < enemy.y; $game_temp.ps_num = 1; end
      when 4
        if player.x > enemy.x; $game_temp.ps_num = 1; end
      when 6
        if player.x < enemy.x; $game_temp.ps_num = 1; end
      when 8
        if player.y > enemy.y; $game_temp.ps_num = 1; end
      end
    end
    if player.direction == enemy.direction && !$game_party.cancel_surprise?
      case enemy.direction
      when 2
        if enemy.y < player.y; $game_temp.ps_num = -1; end
      when 4
        if enemy.x > player.x; $game_temp.ps_num = -1; end
      when 6
        if enemy.x < player.x; $game_temp.ps_num = -1; end
      when 8
        if enemy.y > player.y; $game_temp.ps_num = -1; end
      end
    end
    if 10 - player.direction != enemy.prev_direction
      if Jene::PREEMPTIVE_SIDE_CHANCE < 0
        chance = rand < $game_party.rate_preemptive($game_troop.agi)
      else
        chance = rand < Jene::PREEMPTIVE_SIDE_CHANCE / 100.to_f
        chance *= 4 if $game_party.raise_preemptive?
      end
      case player.direction
      when 2
        if player.y < enemy.y && chance; $game_temp.ps_num = 1; end
      when 4
        if player.x > enemy.x && chance; $game_temp.ps_num = 1; end
      when 6
        if player.x < enemy.x && chance; $game_temp.ps_num = 1; end
      when 8
        if player.y > enemy.y && chance; $game_temp.ps_num = 1; end
      end
    end
    if 10 - enemy.direction != player.direction && !$game_party.cancel_surprise?
      if Jene::SURPRISE_SIDE_CHANCE < 0
        chance = rand < $game_party.rate_surprise($game_troop.agi)
      else
        chance = rand < Jene::SURPRISE_SIDE_CHANCE / 100.to_f
      end
      case enemy.direction
      when 2
        if player.y > enemy.y && chance; $game_temp.ps_num = -1; end
        return
      when 4
        if player.x < enemy.x && chance; $game_temp.ps_num = -1; end
        return
      when 6
        if player.x > enemy.x && chance; $game_temp.ps_num = -1; end
        return
      when 8
        if player.y < enemy.y && chance; $game_temp.ps_num = -1; end
        return
      end
    end
  end
end