[RMXP] Event Range Conditions 1.1

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# Event Range Conditions
# Author: ForeverZer0
# Date: 5.1.2011
# Version: 1.1
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#
# Explanation:
#
#   Allows you to set up conditional branches in events that will be based off
#   the event's coordinates in relation to the player's coordinates without
#   having to create any variables for the X and Y of each.
#
#   Here are the new features you can use a conditional branch. Just type these
#   into the script box for the branch.
#
#   range?(RANGE, EVENT_ID) - Will be true if player is anywhere in the radius
#                             defined by RANGE from the event with EVENT_ID
#
#   on_screen?(EVENT_ID)    - Will be true if the event with EVENT_ID is within
#                             the visible screen
#
#   x_dist?(DIST, EVENT_ID) - Returns true if the player's x/y is within DIST
#            OR               of event's x/y with EVENT_ID. These are absolute
#   y_dist?(DIST, EVENT_ID)   values, meaning it doesn't matter which direction,
#                             it just uses the total distance in tiles for that
#                             axis. Use a DIST of 0 to check if that axis is
#                             equal.
#
#   player_above?(EVENT_ID) - Returns true when player is above event.
#   player_below?(EVENT_ID) - Returns true when player is below event.
#   player_right?(EVENT_ID) - Returns true when player is right of the event.
#   player_left?(EVENT_ID)  - Returns true when player is left of the event.
#
#   For all of these, if the conditional branch that is using them is within
#   the event that it applies to, you do not have to include the EVENT_ID, it
#   is assumed to be that event's ID unless otherwise defined.
#
#   You can use these as a condition for just about anything, such as having
#   an event say something, run away, or run toward the player if it is within a
#   specific distance, and it's much easier than using multiple branches and
#   game variables to set it up.
#
#   Remember that if you use a range condition with a parallel trigger, it will
#   continue to execute as long as the condition is met and if the player cannot
#   move during the event's code, the game will effectively be stuck.
#
# Compatability:
#
#   - You may encounter issues if using a Pixel Movement script, though it
#     should still work fine with an 8-Way Movement script. (Not tested)
#
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class Interpreter

  def range?(range = 4, id = @event_id)
    e = $game_map.events[id]
    radius = (Math.hypot((e.x - $game_player.x), (e.y - $game_player.y))).abs
    return (radius <= range)
  end

  def on_screen?(id = @event_id)
    x, y = $game_map.events[id].real_x, $game_map.events[id].real_y
    return ((x - $game_map.display_x + 64) / 4).between?(0, 640) &&
      ((y - $game_map.display_y) / 4).between?(0, 480)
  end

  def x_dist?(distance = 0, id = @event_id)
    x_dif = ($game_map.events[id].x - $game_player.x).abs
    return (x_dif <= distance)
  end

  def y_dist?(distance = 0, id = @event_id)
    y_dif = ($game_map.events[id].y - $game_player.y).abs
    return (y_dif <= distance)
  end

  def player_above?(id = @event_id)
    return ($game_map.events[id].y > $game_player.y)
  end

  def player_below?(id = @event_id)
    return ($game_map.events[id].y < $game_player.y)
  end

  def player_right?(id = @event_id)
    return ($game_map.events[id].x < $game_player.x)
  end

  def player_left?(id = @event_id)
    return ($game_map.events[id].x > $game_player.x)
  end
end