=begin
#===============================================================================
 Title: Negate Conditional Branch
 Author: Hime
 Date: Oct 22, 2013
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 ** Change log
 Oct 22, 2013
   - Initial release
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 ** Terms of Use
 * Free to use in non-commercial projects
 * Contact me for commercial use
 * No real support. The script is provided as-is
 * Will do bug fixes, but no compatibility patches
 * Features may be requested but no guarantees, especially if it is non-trivial
 * Credits to Hime Works in your project
 * Preserve this header
--------------------------------------------------------------------------------
 ** Description
 
 This script allows you to create negated conditional branches in your events.
 For example, if your conditional branch tests "if actor exists", then the
 negated conditional branch tests "if actor does not exist".
 
 The purpose is to provide negation logic without having to figure out how
 to write the condition as a script call.

--------------------------------------------------------------------------------
 ** Installation
 
 In the script editor, place this script below Materials and above Main

--------------------------------------------------------------------------------
 ** Usage 
  
 To negate a conditional branch, create a comment before a conditional branch
 and write
 
   <negate condition>
    
#===============================================================================
=end
$imported = {} if $imported.nil?
$imported["TH_NegateConditionalBranch"] = true
#===============================================================================
# ** Configuration
#===============================================================================
module TH
  module Negate_Conditional_Branch
    Regex = /<negate[-_ ]condition>/i
    
    def parse_negate_conditional_branch
      @negate_condition_parsed = true
      @list.size.times do |i|
        cmd = @list[i]
        if cmd.code == 108 && cmd.parameters[0] =~ TH::Negate_Conditional_Branch::Regex
          next_cmd = @list[i+1]
          next_cmd.negate_condition = true if next_cmd.code == 111
        end
      end
    end
  end
end
#===============================================================================
# ** Rest of script
#===============================================================================
module RPG
  class EventCommand
    attr_accessor :negate_condition
  end
  
  class Event::Page
    include TH::Negate_Conditional_Branch
    
    alias :th_negate_conditional_branch_list :list
    def list
      parse_negate_conditional_branch unless @negate_condition_parsed
      th_negate_conditional_branch_list
    end
  end
  
  class Troop::Page
    include TH::Negate_Conditional_Branch
    
    alias :th_negate_conditional_branch_list :list
    def list
      parse_negate_conditional_branch unless @negate_condition_parsed
      th_negate_conditional_branch_list
    end
  end
end

class Game_Interpreter
  
  alias :th_negate_conditional_branch_command_111 :command_111
  def command_111
    if @list[@index].negate_condition
      old_index = @index
      th_negate_conditional_branch_command_111
      
      # revert the command skipping and negate the result, then check again
      @index = old_index
      @branch[@indent] = !@branch[@indent]
      command_skip if !@branch[@indent]
    else
      th_negate_conditional_branch_command_111
    end
  end
end