#===============================================================================
#
# Yanfly Engine RD - Event Chase Player
# Last Date Updated: 2009.06.19
# Level: Easy, Normal
#
# This is a relatively simplistic script. For those who would like their events
# to chase after the player is within a specific distance of it, it can happen
# now. All you would need to do is add a few commands to the event's move route
# and it will function as it should.
#
#===============================================================================
# Updates:
# ----------------------------------------------------------------------------
# o 2009.06.19 - Efficiency update.
# o 2009.06.18 - Started script and finished.
#===============================================================================
# Instructions
#===============================================================================
#
# Open up the event's move route settings. Under the menu, there is an option
# you can select called "Script..." Input either of the following:
#
# @chase_range = x     Event will chase the player after reaching x range.
# @flee_range = x      Event will flee from player after reaching x range.
#
# To change the movement speed of the event when chasing or fleeing, input the
# following tags:
#
# @chase_speed = x     Event will move at x speed when chasing.
# @flee_speed = x      Event will move at x speed when fleeing.
#
# -----------------------------------------------------------------------------
#
# For events that require them to see the player first, use the following tags
# inside the movement boxes. This does not follow line of sight rules, which
# means if there's a rock blocking you and the event, it will still see you.
#
# @see_player = true   Event needs to see player before chasing/fleeing.
# @sight_lock = x      Event will chase/flee from player for x frames.
#
# -----------------------------------------------------------------------------
#
# The next couple of options are a few extras.
# @alert_balloon = x   Event will show ballon ID x when chasing or fleeing.
#
#===============================================================================
#
# Compatibility
# - Alias: Game_Character: update_self_movement
#
#===============================================================================

$imported = {} if $imported == nil
$imported["EventChasePlayer"] = true

module YE
  module EVENT

    # The number of frames before a balloon can show up again on the same
    # event. This is to prevent a massive balloon spamming. 60 frames = 1 sec.
    ALERT_TIMER = 900

    # This is the default number of frames for how long the event will chase or
    # flee from the player if used with @see_player = true. To change the amount
    # individually for each event, use @sight_lock = x where x is a number.
    # By default, 300 frames is 5 seconds.
    SIGHT_LOCK = 300

  end # EVENT
end # YE

#===============================================================================
# Editting anything past this point may potentially result in causing computer
# damage, incontinence, explosion of user's head, coma, death, and/or halitosis.
# Therefore, edit at your own risk.
#===============================================================================

#===============================================================================
# Game_Character
#===============================================================================

class Game_Character

  #--------------------------------------------------------------------------
  # alias update_self_movement
  #--------------------------------------------------------------------------
  alias update_self_movement_ecp update_self_movement unless $@
  def update_self_movement
    update_alert_balloon
    update_chase_distance
    update_flee_distance
    if (@stop_count > 0) and @chase_player
      move_type_toward_player
    elsif (@stop_count > 0) and @flee_player
      move_type_away_player
    else
      update_self_movement_ecp
    end
  end

  #--------------------------------------------------------------------------
  # update_chase_distance
  #--------------------------------------------------------------------------
  def update_chase_distance
    return if @erased
    @chase_range = false if @chase_range == nil
    @chase_player = false if @chase_range == false
    return if @chase_range == false
    dis = (distance_x_from_player.abs + distance_y_from_player.abs)
    if chase_conditions
      @chase_player = true
      @move_speed = @chase_speed if @chase_speed != nil
    else
      @chase_player = false
      @move_speed = @page.move_speed
      @alert_player = false if @alert_timer <= 0
    end
  end

  #--------------------------------------------------------------------------
  # chase_conditions
  #--------------------------------------------------------------------------
  def chase_conditions
    dis = (distance_x_from_player.abs + distance_y_from_player.abs)
    return true if @alert_lock > 0
    return true if dis <= @chase_range and see_player?
    if dis <= @chase_range and @see_player != true
      if @sight_lock != nil and @sight_lock > 0
        @alert_lock = @sight_lock
      end
      return true
    end
    return false
  end

  #--------------------------------------------------------------------------
  # update_flee_distance
  #--------------------------------------------------------------------------
  def update_flee_distance
    return if @erased
    @flee_range = false if @flee_range == nil
    @flee_player = false if @flee_range == false
    return if @flee_range == false
    dis = (distance_x_from_player.abs + distance_y_from_player.abs)
    if flee_conditions
      @flee_player = true
      @move_speed = @flee_speed if @flee_speed != nil
    else
      @flee_player = false
      @move_speed = @page.move_speed
      @alert_player = false if @alert_timer <= 0
    end
  end

  #--------------------------------------------------------------------------
  # flee_conditions
  #--------------------------------------------------------------------------
  def flee_conditions
    dis = (distance_x_from_player.abs + distance_y_from_player.abs)
    return true if @alert_lock > 0
    return true if dis <= @flee_range and see_player?
    if dis <= @flee_range and @see_player != true
      if @sight_lock != nil and @sight_lock > 0
        @alert_lock = @sight_lock
      end
      return true
    end
    return false
  end

  #--------------------------------------------------------------------------
  # update_alert_balloon
  #--------------------------------------------------------------------------
  def update_alert_balloon
    return if @erased
    @alert_timer = 0 if @alert_timer == nil
    @alert_lock = 0 if @alert_lock == nil
    @alert_lock -= 1 if @alert_lock >= 0
    return if @alert_balloon == nil or @alert_balloon == 0
    if (@chase_player or @flee_player) and !@alert_player
      @balloon_id = @alert_balloon
      @alert_player = true
      @alert_timer = YE::EVENT::ALERT_TIMER
    end
    return unless @alert_player
    @alert_timer -= 1
  end

  #--------------------------------------------------------------------------
  # see_player?
  #--------------------------------------------------------------------------
  def see_player?
    return false if @see_player != true
    sx = distance_x_from_player
    sy = distance_y_from_player
    if sx.abs > sy.abs
      direction = sx > 0 ? 4 : 6
    else
      direction = sy > 0 ? 8 : 2
    end
    if direction == @direction
      if @sight_lock == nil or @sight_lock <= 0
        @sight_lock = YE::EVENT::SIGHT_LOCK
      end
      @alert_lock = @sight_lock
      return true
    end
    return false
  end

  #--------------------------------------------------------------------------
  # move_type_away_player
  #--------------------------------------------------------------------------
  def move_type_away_player
    sx = @x - $game_player.x
    sy = @y - $game_player.y
    if sx.abs + sy.abs >= 20
      move_random
    else
      case rand(5)
      when 0..3;  move_away_from_player
      when 4;     move_random
      end
    end
  end

end # Game_Character

#===============================================================================
#
# END OF FILE
#
#=======================================================================