sm64_binds/
sm64.rs

1use wasmtime::*;
2
3use std::convert::TryInto;
4
5mod game_pad;
6mod game_state;
7mod rng_config;
8mod util;
9
10pub use game_pad::GamePad;
11pub use game_state::GameState;
12pub use rng_config::RandomConfig;
13use util::unzip_bytes;
14
15pub struct SM64GameGenerator {
16    wasm_bytes: Vec<u8>,
17}
18
19impl SM64GameGenerator {
20    #[cfg(feature = "fs")]
21    pub fn new(rom_path: &str) -> Result<Self, Error> {
22        match util::check_hash(rom_path) {
23            Ok(_) => {},
24            Err(_) => {return Err(Error::msg("Invalid ROM. Should be a US copy, in z64 format (8.00MB)"));}
25        };
26        let rom_bytes = std::fs::read(rom_path)?;
27        Self::from_rom_bytes(rom_bytes)
28    }
29
30    pub fn from_rom_bytes(rom_bytes: Vec<u8>) -> Result<Self, Error> {
31        let wasm_bytes = Self::rom_to_wasm_bytes(rom_bytes);
32        Ok(SM64GameGenerator { wasm_bytes })
33    }
34
35    pub fn create_game(&self) -> Result<SM64Game, Error>  {
36        SM64Game::new(self.wasm_bytes.clone())
37    }
38
39    pub fn rom_to_wasm_bytes(rom_bytes: Vec<u8>) -> Vec<u8> {
40        let rom_len = rom_bytes.len();
41        let xor_bytes = include_bytes!("../pkg/sm64_headless.us.wasm.zip.xor");
42        let mut wasm_zip_bytes: Vec<u8> = Vec::new();
43        for i in 0..xor_bytes.len() {
44            wasm_zip_bytes.push(xor_bytes[i] ^ rom_bytes[i % rom_len]);
45        }
46
47        unzip_bytes(&wasm_zip_bytes)
48    }
49}
50
51
52pub struct SM64Game {
53    store: Store<u32>,
54    instance: Instance,
55    memory: Memory,
56    using_rng: bool
57}
58
59impl SM64Game {
60    pub fn new(wasm_bytes: Vec<u8>) -> Result<Self> {
61        let engine = Engine::default();
62        let mut store: Store<u32> = Store::new(&engine, 4);
63        let module = Module::new(&engine, wasm_bytes)?;
64        
65        let mut linker = Linker::new(&engine);
66        linker.define_unknown_imports_as_traps(&module)?;
67        
68        let instance = linker.instantiate(&mut store, &module)?;
69        let memory = instance.get_memory(&mut store, "memory").unwrap();
70
71        let using_rng = false;
72
73        let main_func = instance.get_typed_func::<(), ()>(&mut store, "main_func")?;
74        main_func.call(&mut store, ())?;
75
76        Ok(SM64Game {
77            store,
78            instance,
79            memory,
80            using_rng,
81        })
82    }
83
84    pub fn rng_init(&mut self, seed: u32, cfg: RandomConfig) -> Result<()> {
85        self.using_rng = true;
86        let rng_init = self.instance.get_typed_func::<(u32, u32, u32, f32, f32, f32), ()>(&mut self.store, "rng_init")?;
87        rng_init.call(&mut self.store, (
88            seed, cfg.max_random_action, cfg.max_window_length, 
89            cfg.a_prob, cfg.b_prob, cfg.z_prob)
90        )?;
91        Ok(())
92    }
93
94
95    pub fn step_game(&mut self, pad: GamePad) -> Result<()> {
96        let step_game = self.instance.get_typed_func::<(u32, i32, i32), ()>(&mut self.store, "step_game")?;
97        step_game.call(&mut self.store, (pad.button.into(), pad.stick_x.into(), pad.stick_y.into()))?;
98        Ok(())
99    }
100
101    pub fn get_game_state(&mut self) -> Result<GameState, Error> {
102        let get_game_state = self.instance.get_typed_func::<(), i32>(&mut self.store, "get_game_state")?;
103        let pointer = get_game_state.call(&mut self.store, ())?;
104        let mut buffer: [u8; 60] = [0; 60];
105        self.memory.read(&mut self.store, pointer.try_into()?, &mut buffer)?;
106        let state = GameState::new(&buffer);
107        Ok(state)
108    }
109
110    pub fn rng_pad(&mut self, pad: GamePad) -> Result<GamePad, Error> {
111        let rng_pad = self.instance.get_typed_func::<(u32, i32, i32), i32>(&mut self.store, "rng_pad")?;
112        let pointer = rng_pad.call(&mut self.store, (pad.button.into(), pad.stick_x.into(), pad.stick_y.into()))?;
113        let mut buffer: [u8; 4] = [0; 4];
114        self.memory.read(&mut self.store, pointer.try_into()?, &mut buffer)?;
115        let pad = GamePad::from_bytes(&buffer);
116        Ok(pad)
117    }
118    pub fn using_rng(&self) -> bool {
119        self.using_rng
120    }
121}
122