Choose save data location

src/app.rs

@@ -26,10 +26,10 @@ use crate::{
     config::{AppConfig, CliArgs},
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
+    filesystem::Persistence,
     images::ImageTextureLoader,
     input::{MappingProvider, ShortcutProvider},
     memory::MemoryClient,
-    persistence::Persistence,
     window::{AppWindow, ChildWindow, GameScreen, GameWindow, InitArgs},
 };
 

src/config.rs

@@ -1,9 +1,10 @@
 use anyhow::Result;
+use bytemuck::NoUninit;
 use clap::{Parser, ValueEnum};
 use egui::{Color32, Pos2, Vec2};
 use serde::{Deserialize, Serialize};
 
-use crate::{emulator::SimId, persistence::Persistence, window::DisplayMode};
+use crate::{emulator::SimId, filesystem::Persistence, window::DisplayMode};
 use std::path::PathBuf;
 
 #[derive(Parser)]
@@ -53,6 +54,9 @@ pub struct CliArgs {
     /// Set a preference for whether to use a low-power or high-performance GPU adapter
     #[arg(long)]
     pub wgpu_power_preference: Option<PowerPreferenceWrapper>,
+    /// Choose whether save files are kept in the rom or the data directory
+    #[arg(long)]
+    pub save_data_location: Option<SaveDataLocation>,
 }
 
 #[derive(ValueEnum, Clone, Copy)]
@@ -90,12 +94,27 @@ const fn default_power_preference() -> wgpu::PowerPreference {
     wgpu::PowerPreference::LowPower
 }
 
+#[derive(Serialize, Deserialize, Clone, Copy, PartialEq, Eq, ValueEnum, Debug, NoUninit)]
+#[repr(usize)]
+pub enum SaveDataLocation {
+    /// The same directory as the ROM
+    RomDirectory,
+    /// This application's data directory
+    DataDirectory,
+}
+
+const fn default_save_data_location() -> SaveDataLocation {
+    SaveDataLocation::RomDirectory
+}
+
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 pub struct AppConfig {
     #[serde(default = "default_power_preference")]
     pub power_preference: wgpu::PowerPreference,
     #[serde(default)]
     pub force_fallback: bool,
+    #[serde(default = "default_save_data_location")]
+    pub save_data_location: SaveDataLocation,
 }
 
 impl AppConfig {
@@ -106,6 +125,7 @@ impl AppConfig {
         Self {
             power_preference: default_power_preference(),
             force_fallback: false,
+            save_data_location: default_save_data_location(),
         }
     }
 
@@ -123,6 +143,10 @@ impl AppConfig {
             self.force_fallback = force_fallback;
             updated = true;
         }
+        if let Some(save_data_location) = args.save_data_location {
+            self.save_data_location = save_data_location;
+            updated = true;
+        }
         updated
     }
 }

src/emulator.rs

@@ -18,6 +18,7 @@ use tracing::{error, warn};
 
 use crate::{
     audio::Audio,
+    config::SaveDataLocation,
     graphics::TextureSink,
     memory::{MemoryRange, MemoryRegion},
 };
@@ -74,12 +75,13 @@ pub struct EmulatorBuilder {
     state: Arc<Atomic<EmulatorState>>,
     audio_on: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     start_paused: bool,
     watch_rom: Arc<[AtomicBool; 2]>,
 }
 
 impl EmulatorBuilder {
-    pub fn new() -> (Self, EmulatorClient) {
+    pub fn new(save_data_location: SaveDataLocation) -> (Self, EmulatorClient) {
         let (queue, commands) = mpsc::channel();
         let builder = Self {
             rom: None,
@@ -91,6 +93,7 @@ impl EmulatorBuilder {
             state: Arc::new(Atomic::new(EmulatorState::Paused)),
             audio_on: Arc::new([AtomicBool::new(true), AtomicBool::new(true)]),
             linked: Arc::new(AtomicBool::new(false)),
+            save_data_location: Arc::new(Atomic::new(save_data_location)),
             start_paused: false,
             watch_rom: Arc::new([AtomicBool::new(false), AtomicBool::new(false)]),
         };
@@ -98,8 +101,9 @@ impl EmulatorBuilder {
             queue,
             sim_state: builder.sim_state.clone(),
             state: builder.state.clone(),
-            watch_rom: builder.watch_rom.clone(),
             linked: builder.linked.clone(),
+            save_data_location: builder.save_data_location.clone(),
+            watch_rom: builder.watch_rom.clone(),
         };
         (builder, client)
     }
@@ -131,18 +135,42 @@ impl EmulatorBuilder {
     }
 
     pub fn build(self) -> Result<Emulator> {
-        let mut emulator = Emulator::new(
+        let Self {
-            self.commands,
+            rom,
-            self.sim_state,
+            commands,
-            self.state,
+            sim_state,
-            self.audio_on,
+            state,
-            self.watch_rom,
+            audio_on,
-            self.linked,
+            watch_rom,
-        );
+            linked,
-        if let Some(path) = self.rom {
+            save_data_location,
+            start_paused,
+        } = self;
+        let mut emulator = Emulator {
+            sims: vec![],
+            carts: [None, None],
+            audio: Audio::init(),
+            commands,
+            sim_state,
+            state,
+            audio_on,
+            watch_rom,
+            linked,
+            save_data_location,
+            profilers: [None, None],
+            renderers: HashMap::new(),
+            messages: HashMap::new(),
+            debuggers: HashMap::new(),
+            stdouts: HashMap::new(),
+            watched_regions: HashMap::new(),
+            eye_contents: [vec![0u8; 384 * 224 * 2], vec![0u8; 384 * 224 * 2]],
+            audio_samples: Vec::with_capacity(EXPECTED_FRAME_SIZE),
+            buffer: vec![],
+        };
+        if let Some(path) = rom {
             emulator.load_cart(SimId::Player1, &path)?;
         }
-        if self.start_paused {
+        if start_paused {
             emulator.pause_sims()?;
         }
         Ok(emulator)
@@ -159,6 +187,7 @@ pub struct Emulator {
     audio_on: Arc<[AtomicBool; 2]>,
     watch_rom: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     profilers: [Option<ProfileSender>; 2],
     renderers: HashMap<SimId, TextureSink>,
     messages: HashMap<SimId, mpsc::Sender<Toast>>,
@@ -171,36 +200,6 @@ pub struct Emulator {
 }
 
 impl Emulator {
-    fn new(
-        commands: mpsc::Receiver<EmulatorCommand>,
-        sim_state: Arc<[Atomic<SimState>; 2]>,
-        state: Arc<Atomic<EmulatorState>>,
-        audio_on: Arc<[AtomicBool; 2]>,
-        watch_rom: Arc<[AtomicBool; 2]>,
-        linked: Arc<AtomicBool>,
-    ) -> Self {
-        Self {
-            sims: vec![],
-            carts: [None, None],
-            audio: Audio::init(),
-            commands,
-            sim_state,
-            state,
-            audio_on,
-            watch_rom,
-            linked,
-            profilers: [None, None],
-            renderers: HashMap::new(),
-            messages: HashMap::new(),
-            debuggers: HashMap::new(),
-            stdouts: HashMap::new(),
-            watched_regions: HashMap::new(),
-            eye_contents: [vec![0u8; 384 * 224 * 2], vec![0u8; 384 * 224 * 2]],
-            audio_samples: Vec::with_capacity(EXPECTED_FRAME_SIZE),
-            buffer: vec![],
-        }
-    }
-
     pub fn reload_cart(&mut self, sim_id: SimId) -> Result<()> {
         let Some(cart) = &self.carts[sim_id.to_index()] else {
             return Ok(());
@@ -211,7 +210,12 @@ impl Emulator {
 
     pub fn load_cart(&mut self, sim_id: SimId, path: &Path) -> Result<()> {
         let watch = self.watch_rom[sim_id.to_index()].load(Ordering::Acquire);
-        let cart = Cart::load(path, sim_id, watch)?;
+        let cart = Cart::load(
+            path,
+            sim_id,
+            self.save_data_location.load(Ordering::Acquire),
+            watch,
+        )?;
         self.try_reset_sim(sim_id, Some(cart))?;
         Ok(())
     }
@@ -224,7 +228,12 @@ impl Emulator {
         };
         let watch = self.watch_rom[SimId::Player2.to_index()].load(Ordering::Acquire);
         let cart = match file_path {
-            Some(rom_path) => Some(Cart::load(&rom_path, SimId::Player2, watch)?),
+            Some(rom_path) => Some(Cart::load(
+                &rom_path,
+                SimId::Player2,
+                self.save_data_location.load(Ordering::Acquire),
+                watch,
+            )?),
             None => None,
         };
         self.try_reset_sim(SimId::Player2, cart)?;
@@ -687,6 +696,20 @@ impl Emulator {
                     cart.stop_watching();
                 }
             }
+            EmulatorCommand::SetSaveDataLocation(save_data_location) => {
+                self.save_data_location
+                    .store(save_data_location, Ordering::Release);
+                for sim_id in SimId::values() {
+                    if let Some(cart) = self.carts[sim_id.to_index()].as_mut()
+                        && let Err(error) = cart.change_save_data_location(save_data_location)
+                    {
+                        self.report_error(
+                            sim_id,
+                            format!("Error changing save data location: {error}"),
+                        );
+                    }
+                }
+            }
             EmulatorCommand::StartSecondSim(path) => {
                 if let Err(error) = self.start_second_sim(path) {
                     self.report_error(
@@ -854,6 +877,7 @@ pub enum EmulatorCommand {
     LoadGame(SimId, PathBuf),
     ReloadRom(SimId),
     WatchRom(SimId, bool),
+    SetSaveDataLocation(SaveDataLocation),
     StartSecondSim(Option<PathBuf>),
     StopSecondSim,
     Pause,
@@ -943,6 +967,7 @@ pub struct EmulatorClient {
     sim_state: Arc<[Atomic<SimState>; 2]>,
     state: Arc<Atomic<EmulatorState>>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     watch_rom: Arc<[AtomicBool; 2]>,
 }
 
@@ -959,6 +984,9 @@ impl EmulatorClient {
     pub fn are_sims_linked(&self) -> bool {
         self.linked.load(Ordering::Acquire)
     }
+    pub fn save_data_location(&self) -> SaveDataLocation {
+        self.save_data_location.load(Ordering::Acquire)
+    }
     pub fn is_rom_watched(&self, sim_id: SimId) -> bool {
         self.watch_rom[sim_id.to_index()].load(Ordering::Acquire)
     }

src/emulator/cart.rs

@@ -8,10 +8,15 @@ use std::{
     sync::{Arc, atomic::AtomicBool},
 };
 
-use crate::emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx};
+use crate::{
+    config::SaveDataLocation,
+    emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx},
+    filesystem,
+};
 
 pub struct Cart {
     pub file_path: PathBuf,
+    sim_id: SimId,
     pub rom: Vec<u8>,
     sram_file: File,
     pub sram: Vec<u8>,
@@ -21,7 +26,12 @@ pub struct Cart {
 }
 
 impl Cart {
-    pub fn load(file_path: &Path, sim_id: SimId, watch: bool) -> Result<Self> {
+    pub fn load(
+        file_path: &Path,
+        sim_id: SimId,
+        save_data_location: SaveDataLocation,
+        watch: bool,
+    ) -> Result<Self> {
         let (rom, info) = Self::read_rom(file_path)?;
 
         let mut sram_file = File::options()
@@ -29,7 +39,7 @@ impl Cart {
             .write(true)
             .create(true)
             .truncate(false)
-            .open(sram_path(file_path, sim_id))?;
+            .open(sram_path(file_path, sim_id, save_data_location))?;
 
         let sram = if sram_file.metadata()?.len() == 0 {
             // new SRAM file, randomize the contents
@@ -54,6 +64,7 @@ impl Cart {
 
         Ok(Cart {
             file_path: file_path.to_path_buf(),
+            sim_id,
             rom,
             sram_file,
             sram,
@@ -73,6 +84,19 @@ impl Cart {
         Ok(())
     }
 
+    pub fn change_save_data_location(
+        &mut self,
+        save_data_location: SaveDataLocation,
+    ) -> Result<()> {
+        self.sram_file = File::options()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(sram_path(&self.file_path, self.sim_id, save_data_location))?;
+        self.save_sram()
+    }
+
     pub fn save_sram(&mut self) -> Result<()> {
         self.sram_file.seek(SeekFrom::Start(0))?;
         self.sram_file.write_all(&self.sram)?;
@@ -177,9 +201,17 @@ fn parse_elf_program<Elf: object::read::elf::FileHeader<Endian = object::Endiann
     Some(bytes)
 }
 
-fn sram_path(file_path: &Path, sim_id: SimId) -> PathBuf {
+fn sram_path(file_path: &Path, sim_id: SimId, save_data_location: SaveDataLocation) -> PathBuf {
-    match sim_id {
+    let extension = match sim_id {
-        SimId::Player1 => file_path.with_extension("p1.sram"),
+        SimId::Player1 => "p1.sram",
-        SimId::Player2 => file_path.with_extension("p2.sram"),
+        SimId::Player2 => "p2.sram",
+    };
+    if let SaveDataLocation::DataDirectory = save_data_location
+        && let Some(data_dir) = filesystem::init_data_dir()
+        && let Some(rom_name) = file_path.file_name()
+    {
+        data_dir.join(rom_name).with_extension(extension)
+    } else {
+        file_path.with_extension(extension)
     }
 }

src/filesystem.rs

@@ -0,0 +1,52 @@
+use std::{fs, path::PathBuf};
+
+use anyhow::{Result, bail};
+use directories::ProjectDirs;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone)]
+pub struct Persistence {
+    config_dir: Option<PathBuf>,
+}
+
+impl Persistence {
+    pub fn new() -> Self {
+        Self {
+            config_dir: init_config_dir(),
+        }
+    }
+
+    pub fn save_config<T: Serialize>(&self, file: &str, data: &T) -> Result<()> {
+        if let Some(config_dir) = self.config_dir.as_ref() {
+            let bytes = serde_json::to_vec_pretty(data)?;
+            let filename = config_dir.join(file).with_extension("json");
+            fs::write(&filename, bytes)?;
+        }
+        Ok(())
+    }
+
+    pub fn load_config<T: for<'a> Deserialize<'a>>(&self, file: &str) -> Result<T> {
+        let Some(config_dir) = self.config_dir.as_ref() else {
+            bail!("config directory not found");
+        };
+        let filename = config_dir.join(file).with_extension("json");
+        let bytes = fs::read(filename)?;
+        Ok(serde_json::from_slice(&bytes)?)
+    }
+}
+
+fn init_config_dir() -> Option<PathBuf> {
+    let config_dir = project_dirs()?.config_dir().to_path_buf();
+    fs::create_dir_all(&config_dir).ok()?;
+    Some(config_dir)
+}
+
+pub fn init_data_dir() -> Option<PathBuf> {
+    let data_dir = project_dirs()?.data_dir().to_path_buf();
+    fs::create_dir_all(&data_dir).ok()?;
+    Some(data_dir)
+}
+
+fn project_dirs() -> Option<ProjectDirs> {
+    ProjectDirs::from("com", "virtual-boy", "Lemur")
+}

src/input.rs

@@ -14,7 +14,7 @@ use winit::keyboard::{KeyCode, PhysicalKey};
 
 use crate::{
     emulator::{SimId, VBKey},
-    persistence::Persistence,
+    filesystem::Persistence,
 };
 
 #[derive(Clone, PartialEq, Eq, Hash)]

src/main.rs

@@ -15,7 +15,7 @@ use winit::event_loop::{ControlFlow, EventLoop};
 use crate::{
     config::{AppConfig, CliArgs, SimConfig},
     emulator::SimId,
-    persistence::Persistence,
+    filesystem::Persistence,
 };
 
 mod app;
@@ -24,12 +24,12 @@ mod config;
 mod controller;
 mod emulator;
 mod filepicker;
+mod filesystem;
 mod gdbserver;
 mod graphics;
 mod images;
 mod input;
 mod memory;
-mod persistence;
 mod profiler;
 mod window;
 
@@ -60,14 +60,9 @@ fn set_panic_handler() {
 
         eprint!("{message}");
 
-        let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
+        let Some(data_dir) = filesystem::init_data_dir() else {
-        else {
             return;
         };
-        let data_dir = project_dirs.data_dir();
-        if std::fs::create_dir_all(data_dir).is_err() {
-            return;
-        }
         let timestamp = SystemTime::now()
             .duration_since(SystemTime::UNIX_EPOCH)
             .unwrap()
@@ -98,7 +93,14 @@ fn main() -> Result<()> {
 
     let persistence = Persistence::new();
 
-    let (mut builder, client) = EmulatorBuilder::new();
+    let mut config = AppConfig::load(&persistence);
+    if config.update(&args) {
+        let _ = config.save(&persistence);
+    }
+    let p1 = SimConfig::load(&persistence, SimId::Player1);
+    let p2 = SimConfig::load(&persistence, SimId::Player2);
+
+    let (mut builder, client) = EmulatorBuilder::new(config.save_data_location);
     if let Some(path) = &args.rom {
         builder = builder.with_rom(path);
     }
@@ -111,12 +113,6 @@ fn main() -> Result<()> {
     if args.profile {
         builder = builder.start_paused(true)
     }
-    let mut config = AppConfig::load(&persistence);
-    if config.update(&args) {
-        let _ = config.save(&persistence);
-    }
-    let p1 = SimConfig::load(&persistence, SimId::Player1);
-    let p2 = SimConfig::load(&persistence, SimId::Player2);
 
     let watch = args.watch;
 

src/persistence.rs

@@ -1,46 +0,0 @@
-use std::{fs, path::PathBuf};
-
-use anyhow::{Result, bail};
-use directories::ProjectDirs;
-use serde::{Deserialize, Serialize};
-
-#[derive(Clone)]
-pub struct Persistence {
-    dirs: Option<Dirs>,
-}
-
-impl Persistence {
-    pub fn new() -> Self {
-        Self { dirs: init_dirs() }
-    }
-
-    pub fn save_config<T: Serialize>(&self, file: &str, data: &T) -> Result<()> {
-        if let Some(dirs) = self.dirs.as_ref() {
-            let bytes = serde_json::to_vec_pretty(data)?;
-            let filename = dirs.config_dir.join(file).with_extension("json");
-            fs::write(&filename, bytes)?;
-        }
-        Ok(())
-    }
-
-    pub fn load_config<T: for<'a> Deserialize<'a>>(&self, file: &str) -> Result<T> {
-        let Some(dirs) = self.dirs.as_ref() else {
-            bail!("config directory not found");
-        };
-        let filename = dirs.config_dir.join(file).with_extension("json");
-        let bytes = fs::read(filename)?;
-        Ok(serde_json::from_slice(&bytes)?)
-    }
-}
-
-#[derive(Clone)]
-struct Dirs {
-    config_dir: PathBuf,
-}
-
-fn init_dirs() -> Option<Dirs> {
-    let dirs = ProjectDirs::from("com", "virtual-boy", "Lemur")?;
-    let config_dir = dirs.config_dir().to_path_buf();
-    fs::create_dir_all(&config_dir).ok()?;
-    Some(Dirs { config_dir })
-}

src/window/game.rs

@@ -7,13 +7,13 @@ use std::{
 
 use crate::{
     app::UserEvent,
-    config::{COLOR_PRESETS, SimConfig},
+    config::{AppConfig, COLOR_PRESETS, SaveDataLocation, SimConfig},
     emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId, SimState},
     filepicker::FilePicker,
+    filesystem::Persistence,
     images::ImageTextureLoader,
     input::{Command, MappingProvider, ShortcutProvider},
     memory::MemoryClient,
-    persistence::Persistence,
     window::{
         AboutWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GdbServerWindow,
         HotkeysWindow, InitArgs, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
@@ -604,6 +604,37 @@ impl GameWindow {
         if ui.button("Hotkeys").clicked() {
             self.open(ChildWindow::Hotkeys);
         }
+        ui.menu_button("Save Data Location", |ui| {
+            let save_data_location = self.client.save_data_location();
+            let update_save_data_location = |new_location: SaveDataLocation| {
+                if new_location == save_data_location {
+                    return;
+                };
+                let mut app_config = AppConfig::load(&self.persistence);
+                app_config.save_data_location = new_location;
+                let _ = app_config.save(&self.persistence);
+                self.client
+                    .send_command(EmulatorCommand::SetSaveDataLocation(new_location));
+            };
+            if ui
+                .selectable_button(
+                    save_data_location == SaveDataLocation::RomDirectory,
+                    "Same Directory as ROM",
+                )
+                .clicked()
+            {
+                update_save_data_location(SaveDataLocation::RomDirectory);
+            }
+            if ui
+                .selectable_button(
+                    save_data_location == SaveDataLocation::DataDirectory,
+                    "App Data Directory",
+                )
+                .clicked()
+            {
+                update_save_data_location(SaveDataLocation::DataDirectory);
+            }
+        });
     }
 
     fn show_color_picker(&mut self, ui: &mut Ui) {