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Diffstat (limited to 'doc/devel/fontres')
| -rw-r--r-- | doc/devel/fontres | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/doc/devel/fontres b/doc/devel/fontres new file mode 100644 index 0000000..c70cb6c --- /dev/null +++ b/doc/devel/fontres @@ -0,0 +1,75 @@ +This is the format for resources of type GFXRES (font variantion -- these +have the extension .fon in the original source). + +All fonts have exactly 96 character descriptors starting with ASCII +code 32 (space). + +Everything is stored MSB first unless otherwise specified. + +position length meaning + 4 0xffffffff if the file is uncompressed. + Otherwise, the file is compressed. When uncompressed, the + file complies with the rest of the format as described + below. + 4 Unused in file, always 0x00000000 + 1 Font leading: the vertical distance between lines of text + in pixels. + 1 Max ascender: the maximum extent of the font upwards from + the baseline in pixels. + 1 Max descender: the maximum extent of the font downwards + from the baseline in pixels. + 1 Char spacing: the number of pixels in between the + successive characters. + 1 Kern amount: the number of pixels (out of char spacing) + that are used for kerning (explained later). Cannot be + more than char spacing. + 96 Kerning table: each byte corresponds to a character: + bits 0-1: right-hand side kerning mask + bits 2-3: left-hand side kerning mask + For each pair of chars printed the code figures out whether + the kerning should be used by taking the right mask of a + preceeding char and ANDing it with the left mask of a + succeeding char. If the result is 0, the Kern amount is + subtracted from Char spacing. + 3 alignment padding: aligns the following char descriptors + on 8-byte boundary. + + +Then for all 96 chars: +Char descriptors (these are frame descriptors from .ani format and some +bits are most likely never used): + 4 Type index and flags (TypeIndexAndFlags) + Low 2 bytes: + bits 0-11 is the index of this frame + bits 12-15 are the type flags: + - bit 12-13: + - 0: (ROM_DRAWABLE) + - 1: Direct drawable (RAM_DRAWABLE) + - 2: (SCREEN_DRAWABLE) + - 3: (OVERLAY_DRAWABLE) + High 2 bytes (frame flags): + - bits 0-7: global PLUT to use (probably unused) + - bit 12: Frame is in cel format (DATA_HARDWARE) + - bit 13: (DATA_COPY aka DATA_SCREEN) + - bit 14: (DATA_PACKED) + - bit 15: (X_FLIP) + 4 Hot spot information (definition of (0, 0) in the image): + - low 2 bytes: x location of hot spot + (probably never used) + - high 2 bytes: y location of hot spot + This is the baseline of a character. The hotspot Y aligns + with the baseline of the text. + 4 Image bounds: + - low 2 bytes: Image width + - low 2 bytes: Image height + 4 Offset from beginning of the char descriptor for this + char to the beginning of the frame data. + +Frames: +Then for all frames: + See "Frames" in gfxres. + + +Initial version 2003-09-02, by Alex Volkov +Frame descriptors and data from gfxres by Serge van den Boom + |