$:.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'

class D64 < ImageFormat
	
#
# For manipulating D64 files, as used by many C64 emulators.
#
# References: 
#     http://www.unusedino.de/ec64/technical/formats/d64.html
#     http://www.baltissen.org/newhtm/1541c.htm
#     http://www.scribd.com/doc/40438/The-Commodore-1541-Disk-Drive-Users-Guide
#

D64_BYTES_PER_SECTOR=256
  
@@sectors_in_track=[]
@@offset_of_track=[]
1.upto(17) {|t| @@sectors_in_track[t]=21}
18.upto(24) {|t| @@sectors_in_track[t]=19}
25.upto(30) {|t| @@sectors_in_track[t]=18}
31.upto(40) {|t| @@sectors_in_track[t]=17}
@@offset_of_track[1]=0
1.upto(39) {|t| @@offset_of_track[t+1]=@@offset_of_track[t]+(@@sectors_in_track[t]*D64_BYTES_PER_SECTOR)}

def self.possible_extensions
    ['.d64']
end  

def self.host_system
    C64
end  

def sectors_in_track(track_no)
 (0..@@sectors_in_track[track_no]-1).collect
end

#for a given byte stream, how many tracks could be interpreted by this image format?
def track_count
  track_count=0
  1.upto(@@offset_of_track.length-1) do |t|
     track_count=t if file_bytes.length>@@offset_of_track[t]
  end
  track_count
end

def end_track
  return   track_count
end

def get_sector(track_no,sector_no)
    return nil if @@sectors_in_track[track_no].nil?
		return nil unless sector_no.between?(0,@@sectors_in_track[track_no]-1)
		start_byte=@@offset_of_track[track_no]+(D64_BYTES_PER_SECTOR*(sector_no))    
		file_bytes[start_byte,D64_BYTES_PER_SECTOR]
end

end
# == Author
# Jonno Downes (jonno@jamtronix.com)
#
# == Copyright
# Copyright (c) 2008 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.