rockbox/docs/AJF
Daniel Stenberg 52ef78b1b0 The undocumented .ajf format is now slightly less undocumented.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2233 a1c6a512-1295-4272-9138-f99709370657
2002-09-09 12:26:24 +00:00

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Description of the binary AJF font file format
Index Descripton
00 MAGIC1 (0xBD)
01 MAGIC2 (0xFC) used to make sure this is an ajf font
02 Unused, planned use: "code page"
03 - 22 ASCII text holding the font name
23 - 24 "bound width" (high 8 bits, low 8 bits)
25 - 26 "bound height" (high 8 bits, low 8 bits)
26 - 28 first character in the font
29 - 2a 0x00ff (supposed number of characters in the font?)
2b - map offset table starts here. Each offset entry is supposed to be
three bytes: width, offset highbyte, offset lowbyte
The offset is a relative offset, counted in bytes, to where in the
font data this particular char's bitmap image starts.
font data, in Rockbox-internal image-format. That means column-wise
left-to-right for the full width, the first 8 pixels of height. Then
follows the next 8 pixels of height left-to-right.
We don't currently support fonts larger than 16 pixels.