diff options
Diffstat (limited to 'docs/AJF')
-rw-r--r-- | docs/AJF | 29 |
1 files changed, 21 insertions, 8 deletions
@@ -1,4 +1,4 @@ | |||
1 | Description of the binary AJF font file format | 1 | Description of the binary AJF font file format (version 2) |
2 | 2 | ||
3 | Index Descripton | 3 | Index Descripton |
4 | 4 | ||
@@ -9,14 +9,27 @@ Index Descripton | |||
9 | 23 - 24 "bound width" (high 8 bits, low 8 bits) | 9 | 23 - 24 "bound width" (high 8 bits, low 8 bits) |
10 | 25 - 26 "bound height" (high 8 bits, low 8 bits) | 10 | 25 - 26 "bound height" (high 8 bits, low 8 bits) |
11 | 26 - 28 first character in the font | 11 | 26 - 28 first character in the font |
12 | 29 - 2a 0x00ff (supposed number of characters in the font?) | 12 | 29 - 2a number of characters in the font (alwasys 0x00ff now) |
13 | 2b - map offset table starts here. Each offset entry is supposed to be | 13 | 2b - map offset table starts here. Each offset entry is two bytes: |
14 | three bytes: width, offset highbyte, offset lowbyte | 14 | offset highbyte, offset lowbyte |
15 | The offset is a relative offset, counted in bytes, to where in the | ||
16 | font data this particular char's bitmap image starts. | ||
17 | 15 | ||
18 | font data, in Rockbox-internal image-format. That means column-wise | 16 | The offset is number of bytes from the start of this file, to where |
17 | in the font data this particular char's font data starts. | ||
18 | |||
19 | There is one offset entry for each character in this font, starting | ||
20 | with 'first character' (set above) and ending when all the 'number | ||
21 | of characters' have been stored. | ||
22 | |||
23 | ?? - Font data. First four bytes width, height, dispx and dispy and then | ||
24 | the glyph in Rockbox-internal image-format. That means column-wise | ||
19 | left-to-right for the full width, the first 8 pixels of height. Then | 25 | left-to-right for the full width, the first 8 pixels of height. Then |
20 | follows the next 8 pixels of height left-to-right. | 26 | follows the next 8 pixels of height left-to-right. |
21 | 27 | ||
22 | We don't currently support fonts larger than 16 pixels. | 28 | We don't currently support fonts larger than 16 pixels. (This font |
29 | file format would have no problem with bigger sizes, but the internal | ||
30 | bitmap function has.) | ||
31 | |||
32 | References | ||
33 | |||
34 | The BDF file format | ||
35 | http://partners.adobe.com/asn/developer/pdfs/tn/5005.BDF_Spec.pdf \ No newline at end of file | ||