$:.unshift(File.dirname(__FILE__)) unless
	$:.include?(File.dirname(__FILE__)) || $:.include?(File.expand_path(File.dirname(__FILE__)))

$:.unshift(File.dirname(__FILE__+"\\..")) unless
	$:.include?(File.dirname(__FILE__+"\\..")) || $:.include?(File.expand_path(File.dirname(__FILE__+"\\..")))

require 'ImageFormat'

#Atari ATR format - http://pages.suddenlink.net/wa5bdu/readme.txt
class Atr < ImageFormat

ATR_HEADER_LENGTH=0x10
ATR_SECTORS_PER_TRACK=18

def self.possible_extensions
    ['.atr']
end  

is_valid_image_if lambda {
  file_system_image.file_bytes[0,2]==[0x96,0x02]
}

def self.host_system
    Atari800
end  

#Atari disks actually don't use tracks, just a single flat list of sectors
#however for ease of use with utilities that assume there are tracks & sectors
#we will assign 18 sectors per track
def sectors_in_track(track_no)
  first_sector=track_no*ATR_SECTORS_PER_TRACK
  (first_sector..first_sector+ATR_SECTORS_PER_TRACK-1).collect
end

# how many tracks could be interpreted by this image format?
def track_count
  (@file_bytes.length-ATR_HEADER_LENGTH)/(@sector_size*ATR_SECTORS_PER_TRACK)
end


# how many sectors could be interpreted by this image format?
def sector_count
  (@file_bytes.length-ATR_HEADER_LENGTH)/(@sector_size)
end

#we ignore the track no, but keep the paramater for compatability with other image formats
def get_sector(track_no,sector_no)   
	offset_of_sector=(sector_no-1)*@sector_size+ATR_HEADER_LENGTH
	return @file_bytes[offset_of_sector,@sector_size]
end

def initialize(file_bytes)
  @file_bytes=file_bytes
  @sector_size=file_bytes[4,2].unpack("v")[0]
end


end

# == Author
# Jonno Downes (jonno@jamtronix.com)
#
# == Copyright
# Copyright (c) 2007 Jonno Downes (jonno@jamtronix.com)
#
#Permission is hereby granted, free of charge, to any person obtaining
#a copy of this software and associated documentation files (the
#"Software"), to deal in the Software without restriction, including
#without limitation the rights to use, copy, modify, merge, publish,
#distribute, sublicense, and/or sell copies of the Software, and to
#permit persons to whom the Software is furnished to do so, subject to
#the following conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.