A small and unoptimized script to clean Rime and Frost traps from Pillars of Eternity MobileObjects.save files

trap_cleaner.rb

#!/usr/bin/env ruby

file = File.open(ARGV.last, 'rb')

chunks = Array.new
buffer = Array.new(10+4+1)

# Header is different, read until "b77a5c561934e089"
head_limiter = Array.new
"b77a5c561934e089".each_char do |c| 
	head_limiter << c.ord
end
head_limiter << 6

# Chunks after the header
# We will read until we encounter the Root string in the next chunk. Then we will roll back that root and 10 bytes
# before it.
chunk_limiter = Array.new
"Root".each_char do |c|
	chunk_limiter << c.ord
end

read = Array.new
got_header = false

$stdout.sync = true

file.each_byte do |b|
	read << b
	if (!got_header) && (read[-head_limiter.size, head_limiter.size] == head_limiter)
		# Header
		chunks[0] = read
		got_header = true
		read = Array.new
		puts "Found the header: #{chunks[0].size} bytes."
		puts "Now reading chunks:"
	elsif (got_header) && (read.size > 20) && (read.last == chunk_limiter.last) && (read[-4,4] == chunk_limiter) 
		# Other chunks
		next_chunk = read.pop(8)
		chunks << read
		read = next_chunk
		print "."
	end
end

chunk_total = chunks.size

puts "\nDeleting traps:"
chunks.delete_if do |chunk|
	str = String.new
	chunk.each do |b|
		str << b.chr
	end
	if str.include? "Rime_and_Frost_Trap.prefab"
		print "X"
		true
	else
		print "."
		false
	end
end

puts "\nDeleted #{chunk_total - chunks.size} traps."

new_file = "#{ARGV.last}.cleaned"
puts "Writing altered save to file: #{new_file}"

File.open(new_file, 'wb') do |f|
	chunks.each do |chunk|
		chunk.each do |b|
			f.putc b 
		end
		print "."
	end
end

puts "\nDone, may you have good luck loading it!"