Here comes description of the sprites format:

<anything> ... really anything up to the end of line
<num:> ....... decimal number
<str:images> . list of images to follow, one per character, in that order:
               't' - text              'a' - attr
               'b' - background (TODO)
               Default is "ta" if unspecified.
<img:text> ... text to be displayed, verbatim (missing chars = ' ')
<img:attr> ... attributes corresponding to the given position
               (missing chars = '|'):
               '.' - transparent       ':' - translucent (darkening)
               '|' - current color normal
               '#' - current color standout (opposite intensity)
               TODO: '@' as an "alternative color"; now equiv. to '#'
               Dark colors:
               'r' - red               'c' - cyan
               'g' - green             'm' - magenta
               'b' - blue              'y' - yellow
               'h' - grey              'k' - black
               Equivalent bright colors:
               'RGBHCMYK'

Blank lines are permitted except inside of images.


The file:

<num:directions> <anything>
Nx<direction>

<direction>:

<num:frames> <anything>
Nx<frame>

<frame>:

<num:width> <num:height> <num:center_x> <num:center_y> [<str:images>]
<img:text>
<img:attr>
