Parses scenery data of the 1987 game Sublogic Flight Simulator 2. Those data files contain a bytecode that is parsed by an interpreter embedded in FS2.
This is an exploratory attempt at reverse engineering the file format and uncovering the secrets of the FS2 scenery.
As a personal project, this is work in progress, very incomplete and certainly contains errors.
Usage:
ghc Fs2
./Fs2 F8
Output:
(0,Op_0x0a_toc [TOCEntry {tocKey = 52, offset = 1, blocks = 8}, ...])
(226,Op_0x20_jump_if_outside1 {ofs = 130, var = 22, lwb = -9700, upb = 10000})
(236,Op_0x20_jump_if_outside1 {ofs = 76, var = 22, lwb = -9700, upb = 2000})
(246,Op_0x34_jump_if_outside3 {ofs = 22, z = 1066, x = 0, delta = 500})
(256,Op_0x0d_load {loadKey = 68, readOfs = 346, d5 = 0})
...
(5100,Op_0x37_coord_frame {scale = 4, x = 64, y = -11263, z = 0})
(5110,Op_0x00_xyz (-18652) 1016 31)
(5118,OpOther 242)
Every line contains a relative offset (in bytes, decimal) and a decoded bytecode instruction.
Properties named var refer to state variables maintained by the Flight Simulator.
At runtime, they are mapped to RAM address $50000 + x (at least on the Atari ST version),
where x is the value of a var property, such as:
| Decimal offset | Size (bytes) | Description |
|---|---|---|
| 22 | 4 | Aircraft position longitude (x coordinate) |
| 30 | 4 | Aircraft position latitude (z coordinate) |