scavenge_trackers.rb

require 'strscan'

class SloppyParser < StringScanner
  def skip_until(pattern)
    pattern.is_a?(String) ? super(/#{Regexp.escape(pattern)}/m) : super(pattern)
  end
  
  def scan_until(pattern)
    pattern.is_a?(String) ? super(/#{Regexp.escape(pattern)}/m) : super(pattern)
  end
end

class ValueAt
  attr_accessor :value, :frame
  def self.from_string(str)
    v = new
    v.value, v.frame = str.scan(/(.+)@(\d+)/).to_a.flatten
    v
  end
  
  def reverse_float
    1 - @value.to_f
  end
end

class CurveParser < SloppyParser
  BLOCK_ENDS = /\d,|\)/
  
  attr_reader :values
  def initialize(with_curve_arg)
    @values = []
    
    super(with_curve_arg.to_s)
    
    # Skip the interpolation
    skip_until '('
    
    # Skip the first defining parameter whatever that might be
    skip_until ','
    
    loop do
      break unless (value_at = scan_until(BLOCK_ENDS))
      @values << ValueAt.from_string(value_at)
    end
  end
end

class TrackerParser < SloppyParser
  attr_reader :x_curve, :y_curve, :c_curve, :name
  
  def initialize(with_tracker_args)
    super(with_tracker_args)
    
    # Name me!
    @name = scan_until(/(\w+) /)
    
    # All the tracker arguments
    17.times { skip_until ',' } # input data
    
    # Grab the curves
    @x_curve, @y_curve, @c_curve = (0..2).map{ CurveParser.new(scan_until('),')).values }
  end
  
  def curves
    [@x_curve, @y_curve, @c_curve]
  end
end

class TrackParser < SloppyParser
  def initialize(with_tracker_block)
    # scan until the first " - name of the track
    # scan values
    # discard the 8 box determinators
    8.times { skip_until  ',' }
    # discard the box animation
    2.times { skip_until  ',' }
  end
end  

# Read the Shake file
script_file = File.read("E036_tracks.shk")
out_to = File.open("dumped_tracks.2dt", 'w')

# Grab all tracker blocks
TRACKER_PATTERN = /((\w+) = Tracker\(([^;]+))/m

script_file.scan(TRACKER_PATTERN).each_with_index do | tracker_text_block, idx |
  
  parser = TrackerParser.new(tracker_text_block.to_s)
  
  tracker_name = parser.name
  x, y, c = TrackerParser.new(tracker_text_block.to_s).curves
  
  out_to.puts "\n"
  out_to.puts tracker_name.inspect # "autoquotes"
  out_to.puts x.length
  
  x.each_with_index do | value_at, k |
    begin
      out_to.puts "%s %.3f %.3f %.3f" % [value_at.frame.to_i - 1, value_at.value, y[k].value, c[k].reverse_float]
    rescue NoMethodError
    end
  end
end