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diff --git a/doc/devel/sc1 b/doc/devel/sc1 new file mode 100644 index 0000000..373ac16 --- /dev/null +++ b/doc/devel/sc1 @@ -0,0 +1,186 @@ +This file documents the file formats used in Star Control 1. + +The .pkg files are in the format described in the file "pkgformat". +The extracted files are described in this document. + +The following describes the format used in the DOS version of SC1. + +Resource types used in starcon.pkg: + 1 - key config + 2 - some graphics type (flags = 7) + 3 - some graphics type (flags = 1) + 4 - some graphics type (flags = 2) 5 - some graphics type (flags = 3) + 6 - font + 7 - scenario + 8 - palette + 9 - strtab +10 - ? (sound?) + + +Files of types 2, 3, 4, 5, 9, and 10 may be compressed; they have +a header of the following format: have the following format: + +Uncompressed files: + off len + 0x00 1 0 (means: not compressed) + 0x01 1 flags, 0 in practice + 0x04 2 Number of bytes that follow (MSB first) + 0x06 start of data + +Compressed files: + off len + 0x00 1 6 (means: compressed) + 0x01 1 flags + bit 0: unused + bit 1: (table2CodeLen) + if not set: table2 results are shifted by 6 bits. + if set: table2 results are shifted by 7 bits. + (never set in PC SC1 files) + bit 2: (litencoded) set if literal bytes are Huffman encoded + (never set in PC SC1 files) + rest: unused + 0x02 4 uncompressed size (MSB first) + 0x06 Huffman table 0 (8-bit codes) (only present if litencoded set) + used for encoding literal bytes + Huffman table 1 (6-bit codes) + used for encoding lengths + Huffman table 2 (6-bit codes) + used for the most significant table2CodeLen bits of an offset + + + +Huffman table: +(numbers are in bits) + 8 one less than the number of lengths of codes + in the table (lenCnt) + 8 * lenCnt LONIBBLE: one less than one of the code lengths + HINIBBLE: one less than the number of codes with + this length +This is enough to construct the huffman table. + +TODO: document the rest of the compression format; for now, look at the + code of sc1-decomp. + + +Resource type 1 (key config): + off len + 0x00 1 bottom player special key ('n') + 0x01 1 top player special key ('1') + 0x02 1 bottom player left key ('m') + 0x03 1 top player left key ('2') + 0x04 1 bottom player right key (',') + 0x05 1 top player right key ('3') + 0x06 1 bottom player thrust key ('.') + 0x07 1 top player thrust key ('4') + 0x08 1 bottom player fire key ('/') + 0x09 1 top player fire key ('5') + 0x0a 1 ? + 0x0b 1 ? + 0x0c 1 ? + 0x0d 1 ? + 0x0e 1 ? + 0x0f 1 ? + 0x10 1 ? + 0x11 1 ? + 0x12 1 ? + 0x13 1 ? + + +Resource types 2, 3, 4, and 5 (graphics): +The difference between those types is the flags parameter that is passed +to the load functions (see above in the table of resource types). +bit 0: ? +bit 1: probably indicates whether a palette is used +bit 2: ? +rest: unused + +(after decompression/removing packing header) + off len + 0x00 4 "IANM" + 0x04 2 frame count (MSB first) + 0x06 2 MSB first + LOBYTE: bits per pixel. All SC1 files are either 1 bpp or 4 bpp. +For every frame: + 2 width (MSB first) + 2 height (MSB first) +For every frame: + 2 x hotspot + 2 y hotspot + 1 if not zero, the file includes palettes + 1 transparant color + 16 (optional) (CGA?) palette (16 entries of 1 byte) + 16 (optional) (EGA/Tandy?) palette (16 entries of 1 byte) + 16 (optional) (MCGA/VGA?) palette (16 entries of 1 byte) + ? pixel data (indicees in palette) + + + +Resource type 6 (font): + off len + 0x00 1 ? + 0x01 1 ? + 0x02 1 LONIBBLE: + HINIBBLE: + 0x03 48 + +The letters are actually readable if you do 'xxd -b'; it shouldn't be too +hard to RE this one. + + +Resource type 7 (scenario): + off len + 0x00 16 Title (\0 terminated) + 0x10 ? Short description (\0 terminated) + ? ? Unknown (probably description of star systems, Space Spines, + fleets and bases (maybe random seeds?)) + 0x80 840(?) Long description (\0 terminated) + + +Resource type 8 (palette): + off len + 0 768 palette data: +for each of the 256 entries (with index 0 through 255): + 1 red value + 1 green value + 1 blue value + + +Resource type 9 (string): + off len + 0x00 2 Number of strings (MSB first) + 0x02 2 unknown (always 0x0000) +for each string s: + 2 len[s]: length of the string (MSB first) +for each string s: + len[s] String data (not '\0'-terminated) + + +starcon.exe: +compressed using lzexe +(http://fabrice.bellard.free.fr/lzexe.html) +Using PLINK86 to load starcon.ovl as an overlay. + + + +The Amiga version of SC1: + +Resource types used in starcon.pkg: + 1 - key config (presumed; different from the DOS version) + 2 - graphics + 3 - graphics + 4 - graphics + 5 - graphics + 6 - font + 7 - scenario (as with the DOS version) + 8 - strings as on DOS, but also other data in the same format + (presumably including sound) + +Files of types 2, 3, 4, 5, 8 may be compressed as in the DOS version. + +Graphics files are in a different file format as on DOS. I haven't worked +on these files yet. + + +Initial version created on 2007-06-01 by Serge van den Boom. + + |