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       aewan - File format documentation


       Starting with version 0.9.0, Aewan features an all-new, easier to parse
       file format. Prior versions used a binary (largely  undocumented)  file
       format,  and  relied  on a program (ae2aes) to convert it to a readable
       format. With the new format, the ae2aes utility became unnecessary  and
       was deprecated.

       An  aewan  document is a gzipped file. Therefore, you must first gunzip
       it in order to be able to parse its contents. On the command line,  you
       could  use  zcat  or  something  of  the  sort.  On a program, you will
       probably want to use the zlib library.

       In the future it might be better for Aewan to supply a  shared  library
       to  enable  parsing  of aewan files with minimal effort. Such a library
       would have to be integrated with the editor in order  not  to  have  to
       duplicate  code  (i.e.  the editor itself would be just a client of the
       library).  But for the time being, you  have  to  read  and  parse  the
       format on your own.


       In  the  description  below,  the  items  in  between  brackets are NOT
       literal, they are placeholders. [S] is a placeholder for a  string  and
       [N]  is  a  placeholder for a decimal integer, and [B] is a placeholder
       for a boolean value (’true’ or ’false’).  A  line  with  "..."  is  not
       literal  either,  it  just  means that the lines above repeat a certain
       number of times.

       <Aewan Document v1
          layer-count: int: [N]
          meta-info: str: [S]
               name: str: [S]
               width: int: [N]
               height: int: [N]
               visible: bool: [B]
               transparent: bool: [B]
               layer-line: str: [S]
               layer-line: str: [S]
               layer-line: str: [S]
               (...there are <height> such lines...)
          (...there are <layer-count> such blocks...)
       >Aewan Document v1

       Indentation is ignored, but all other whitespace is significant.
       In particular, you can’t omit the space that immediately follows
       the ’:’ field delimiters, or supply more than one space there.
       Notice that the file format does not use any quotation marks
       for the values, not even strings.


       Strings are represented almost literally in the  file  (where  the  [S]
       placeholders  are  in  the blueprint above), and are not put in between
       quotes or anything. However, special characters (ASCII codes 1  to  31)
       are  escaped: the escape code is a backslash, followed by the character
       ’0’ + ch, where ch is the special character. Thus, a newline  character
       would be represented by "\:", since ":" is ’0’ + 10.


       Integers  use  just  the plain old decimal representation. The booleans
       are represented as strings: either "true" or "false" (without  quotes).


       Each  layer-line is a string, but it is specially formatted in order to
       convey  the  characters  and  attibutes  in  that  line.  In  order  to
       understand  the format of a layer-line string, it is first necessary to
       introduce the concept of cells. A cell in an aewan layer is each of the
       spaces that can contain a character. A cell has two pieces of data: the
       character that is in it, and a color attribute.  The character is  just
       that:  an  8-bit  value  represing the character drawn there. The color
       attribute is an 8-bit unsigned value  that  packs  the  foreground  and
       background  color  of  a  given  cell,  as  well  as standout and blink

       The following color codes are used: 0=black, 1=red, 2=green,  3=yellow,
       4=blue, 5=magenta, 6=cyan, 7=white.

       The  8  bits  of  the  attribute have the following meanings: SFFFLBBB.
       Where S is the standout bit, FFF  is  the  3-bit  color  code  for  the
       foreground  color,  L is the blink bit, and BBB is the 3-bit color code
       for the background color.

       The layer-line string is composed of the hexadecimal representation  of
       layer_width*2  bytes.  Each  2 bytes is the information for one cell of
       the line: the first byte is  the  character,  and  the  second  is  the
       attribute.  For  example,  the hex representation for ’A’ is 0x41, so a
       line with five ’A’s each of them in a different foreground  color  (but
       all    with    black    background)    would    be    represented    as


       Copyright (c) 2004-2005 Bruno Takahashi  C.  de  Oliveira.  All  rights

       This  program is licensed under the GNU General Public License, version
       2 or, at your option, any later version. For full license  information,
       please refer to the COPYING file that accompanies the program.


       aecat(1), aewan(1)