Byte Map Font
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A Byte Map Font, or BMF, contains an arbitrary amount of paletted characters.
It is of this form:
| Offset | Length | Name | Content |
|---|---|---|---|
| 0x0000 | 4 | Identifier | 0x1AD5E6E1 |
| 0x0004 | 1 | Version | Normally 0x11 |
| 0x0005 | 1 | Line height | Unsigned value |
| 0x0006 | 1 | Size over the base line | Signed value |
| 0x0007 | 1 | Size under the base line | Signed value |
| 0x0008 | 1 | Space after each character, in addition to each character's own shift | Signed value |
| 0x0009 | 1 | Inner size (?) | Signed value |
| 0x000A | 1 | Count of used colors (not the same as palette size) | Unsigned value |
| 0x000B | 1 | Highest used color index | Unsigned value |
| 0x000C | 4 | Reserved values | Should be 0x00000000 |
| 0x0010 | 1 | Number of RGB entries in the palette | Unsigned value |
| 0x0011 | x*3 | Palette | A series of 6-bit RGB values, starting from palette index 1 (index 0 is transparent and not described). |
After the palette comes an information string about the font:
| Offset | Length | Name | Content |
|---|---|---|---|
| 0x0000 | 1 | Size | Unsigned value |
| 0x0001 | x | Info | ASCII characters |
After the string comes a two-byte, little-endian unsigned value for the amount of characters. Then comes the character data:
| Offset | Length | Name | Content |
|---|---|---|---|
| 0x0000 | 1 | Which character | ASCII character |
| 0x0001 | 1 | Width | Unsigned value, size of the character image |
| 0x0002 | 1 | Height | Unsigned value, size of the character image |
| 0x0003 | 1 | X-offset | Signed value, offset of the character image relative to the cursor |
| 0x0004 | 1 | Y-offset | Signed value, offset of the character image relative to the cursor |
| 0x0005 | 1 | Shift | Horizontal cursor shift after drawing the character (used instead of width) in addition to the global font value of space added after each character |
| 0x0001 | x | Info | Character image as raw pixels in row-major format |
Characters are listed one after the other until the end of the file. Note that some characters may have a null image (0 width and/or 0 height); spaces are likely to have no image and instead be defined only by the shift value.
External link
- BMF Homepage - contains a couple of utilities and a large collection of fonts