Stealth/Field of Vision Script

[Yawgmothsbud]

I'm looking for a script on which to base my stealth system; basically it makes it so that if certain NPC's "see" you, an event triggers. I tried to do it with eventing, but that quickly became insanely complicated. I'd heard that such a script might exist, but I have been unable to find one here, or on hbgames.org or creationasylum...anyone got one and feel like sharing, or know where I can find one?

[tSwitch]

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the switch to be activated when the event see the hero. false if none
SWITCH = 35

class Game_Character
  attr_reader :cone
  attr_reader :prev_x
  attr_reader :prev_y
  attr_reader :prev_dir
  attr_accessor :sight

  alias conesys_gamecharacter_initialize initialize
 
  def initialize
    @cone = []
    @sight = 0
    conesys_gamecharacter_initialize
  end
 
  def get_cone(sight = 7)
    cone = []
    @sight = sight
    #This algorithim makes the cone using a 2d array
    case self.direction
    when 2 #down
      #adds the first square
      line = 1
      cone.push([self.x,self.y + 1])
      factor = 1
      #now comes the routine to make the cone
      while line < sight
        line += 1
        cone.push([self.x,self.y + line])
        1.upto(factor) do |a|
          cone.push([self.x - a,self.y + line])
          cone.push([self.x + a,self.y + line])
        end
        factor += 1
      end
    when 4 #left
      line = 1
      cone.push([self.x - 1,self.y])
      factor = 1
      #now comes the routine to make the cone
      while line < sight
        line += 1
        cone.push([self.x - line,self.y])
        1.upto(factor) do |a|
          cone.push([self.x - line,self.y - a])
          cone.push([self.x - line,self.y + a])
        end
        factor += 1
      end
      when 6 #right
      line = 1
      cone.push([self.x + 1,self.y])
      factor = 1
      #now comes the routine to make the cone
      while line < sight
        line += 1
        cone.push([self.x + line,self.y])
        1.upto(factor) do |a|
          cone.push([self.x + line,self.y - a])
          cone.push([self.x + line,self.y + a])
        end
        factor += 1
      end
    when 8 #up
      #adds the first square
      line = 1
      cone.push([self.x,self.y + 1])
      factor = 1
      #now comes the routine to make the cone
      while line < sight
        line += 1
        cone.push([self.x,self.y - line])
        1.upto(factor) do |a|
          cone.push([self.x - a,self.y - line])
          cone.push([self.x + a,self.y - line])
        end
        factor += 1
      end
    end

    cone_obstacles(cone)
  end
  #here any tile that is covered by an obstacle is removed
  #from the cone
  def cone_obstacles(cone)
    for i in 0..cone.length
      if cone[i] != nil
        if !$game_map.passable?(cone[i][0], cone[i][1], 0)
          case self.direction
          when 2 #down
            #the diference between the sight and the obstacle position
            limit = self.sight - (cone[i][1] - self.y)
            position = 1
            #to make the read easier
            index = cone.index([cone[i][0],cone[i][1] + 1])
            cone[index] = nil if index != nil
            factor = 1
            #now comes the routine to remove the bloked tiles
              while position < limit
              position += 1
              index = cone.index([cone[i][0],cone[i][1] + position])
              cone[index] = nil if index != nil
                1.upto(factor) do |a|
                  index = cone.index([cone[i][0] - a,cone[i][1] + position])
                  cone[index] = nil if index != nil
                  index = cone.index([cone[i][0] + a,cone[i][1] + position])
                  cone[index] = nil if index != nil
                end
              factor += 1
            end
          when 4 #left
            #the diference between the sight and the obstacle position
            limit = self.sight - (self.x - cone[i][0])
            position = 1
            #to make the read easier
            index = cone.index([cone[i][0] - 1,cone[i][1]])
            cone[index] = nil if index != nil
            factor = 1
            #now comes the routine to remove the bloked tiles
            while position < limit
              position += 1
              index = cone.index([cone[i][0] - position,cone[i][1]])
              cone[index] = nil if index != nil
                1.upto(factor) do |a|
                  index = cone.index([cone[i][0] - position,cone[i][1] - a])
                  cone[index] = nil if index != nil
                  index = cone.index([cone[i][0] - position,cone[i][1] + a])
                  cone[index] = nil if index != nil
                end
              factor += 1
            end
          when 6 #right
            #the diference between the sight and the obstacle position
            limit = self.sight - (cone[i][0] - self.x)
            position = 1
            #to make the read easier
            index = cone.index([cone[i][0] + 1,cone[i][1]])
            cone[index] = nil if index != nil
            factor = 1
            #now comes the routine to remove the bloked tiles
              while position < limit
              position += 1
              index = cone.index([cone[i][0] + position,cone[i][1]])
              cone[index] = nil if index != nil
                1.upto(factor) do |a|
                  index = cone.index([cone[i][0] + position,cone[i][1] - a])
                  cone[index] = nil if index != nil
                  index = cone.index([cone[i][0] + position,cone[i][1] + a])
                  cone[index] = nil if index != nil
                end
            factor += 1
            end
          when 8 #up
            #the diference between the sight and the obstacle position
            limit = self.sight - (self.y - cone[i][1])
            position = 1
            #to make the read easier
            index = cone.index([cone[i][0],cone[i][1] - 1])
            cone[index] = nil if index != nil
            factor = 1
            #now comes the routine to remove the bloked tiles
              while position < limit
              position += 1
              index = cone.index([cone[i][0],cone[i][1] - position])
              cone[index] = nil if index != nil
                1.upto(factor) do |a|
                  index = cone.index([cone[i][0] - a,cone[i][1] - position])
                  cone[index] = nil if index != nil
                  index = cone.index([cone[i][0] + a,cone[i][1] - position])
                  cone[index] = nil if index != nil
                end
              factor += 1
            end
          end
        end
      end
    end
    #update the variables used to check the need of a refresh
    @prev_x = self.x
    @prev_y = self.y
    @prev_dir = self.direction
    @cone = cone
  end

  def in_cone
    #return false if the event do not have a cone
    if cone != []
      #now it checks if the actual position of the hero is inside the cone
      for i in 0...cone.length
        if cone[i] != nil
          if $game_player.x == cone[i][0] && $game_player.y == cone[i][1]
            $game_switches[SWITCH] = true if SWITCH
            $game_map.need_refresh = true
            move_toward_player
          end
        end
      end
    end
  end
 
  def move_toward_player
    # Get difference in player coordinates
    sx = @x - $game_player.x
    sy = @y - $game_player.y
    # If coordinates are equal
    if sx == 0 and sy == 0
      return
    end
    #Now the 8-direction following
      #diagonal movements
    if sx > 0 && sy > 0;  move_upper_left
    elsif sx > 0 && sy < 0;  move_lower_left
    elsif sx < 0 && sy > 0;  move_upper_right
    elsif sx < 0 && sy < 0;  move_lower_right
      #normal movement
    elsif sx < 0 && sy == 0; move_right
    elsif sx > 0 && sy == 0; move_left
    elsif sx == 0 && sy < 0; move_down
    elsif sx == 0 && sy > 0; move_up
    end
  end
 
  #these modifications make the "hero touch" work better
  #thanks Linkin_T for the help
  def check_event_trigger_touch(x, y)
    return if not @stop_count > (40 - @move_frequency * 2) * (6 - @move_frequency)
    old_touch(x, y)
  end
  def check_event_trigger_auto
    return if not @stop_count > (40 - @move_frequency * 2) * (6 - @move_frequency)
    old_auto
  end
end

class Game_Event < Game_Character

  attr_reader :has_cone
  alias conesys_gameevent_initialize initialize
  alias old_touch check_event_trigger_touch
  alias old_auto check_event_trigger_auto
     
  def initialize(map_id, event)
    #a flag that tells if the event is cone-following-enabled or not
    @has_cone = false
    conesys_gameevent_initialize(map_id, event)
  end
 
    #start the cone routine.
  def add_cone(sight = 7)
    @has_cone = true
    get_cone(sight)
  end
    #stop the "cone following"
  def stop_cone
    @has_cone = false
  end
end

class Game_Player < Game_Character
 
  alias conesys_gameplayer_update update
 
  def update
    check_cone
    conesys_gameplayer_update
  end
 
  def check_cone
    #check if the event has a cone
    for i in $game_map.events.keys
      event = $game_map.events[i]
      if event.has_cone && $scene.is_a?(Scene_Map)
        #check if the player is inside the cone of vision and make the
        #event follow him
        event.in_cone
        #update the cone if the event moved or the direction is different
        if event.x != event.prev_x || event.y != event.prev_y || event.direction != event.prev_dir
          event.get_cone(event.sight)
        end
      end
    end
  end
end
Credit to Lobosque if used.

To set up a cone, you need to add
$game_map.events[EVENT NUMBER].add_cone(VIEW RANGE)
in a script command, put the event number and the range (in tiles) in the appropriate spots.

http://www.hbgames.org/forums/showthread.php?t=19301

[Yawgmothsbud]

Woot, thanks a ton! I've been searching for quite awhile now...I can finally finish my assassin quests xD

[ChaosSpartan28]

Solved? Add [Resolved] to the topic title.

[Yawgmothsbud]

 Nope, need some troubleshooting: When I run the game, I get

?? NOMethodError ??

undefined method 'add_cone' for nil:NilClass

I added

$game_map.events[35].add_cone(4)

To an event and that caused it...obviously something isnt matching up...

I think I fixed it, but Im gonna keep this open for a bit in case I get into any more trouble...

[tSwitch]

Nope, need some troubleshooting: When I run the game, I get

?? NOMethodError ??

undefined method 'add_cone' for nil:NilClass

I added

$game_map.events[35].add_cone(4)

To an event and that caused it...obviously something isnt matching up...

I think I fixed it, but Im gonna keep this open for a bit in case I get into any more trouble...

see that's weird, I never got that error at all.
did you try 035 instead of 35?