GUI: add --load-save-state arg to load a specific save state slot at …

…launch (when used in combination with -f)

frontend/jgenesis-gui/src/app.rs

@@ -245,26 +245,32 @@ impl<'a, T: Copy + FromStr> Widget for NumericTextEdit<'a, T> {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct LoadAtStartup {
+    pub file_path: String,
+    pub load_state_slot: Option<usize>,
+}
+
 pub struct App {
     config: AppConfig,
     state: AppState,
     config_path: PathBuf,
     emu_thread: EmuThreadHandle,
     rom_list_thread: RomListThreadHandle,
-    startup_file_path: Option<String>,
+    load_at_startup: Option<LoadAtStartup>,
 }
 
 impl App {
     #[must_use]
-    pub fn new(config_path: PathBuf, startup_file_path: Option<String>, ctx: Context) -> Self {
+    pub fn new(config_path: PathBuf, load_at_startup: Option<LoadAtStartup>, ctx: Context) -> Self {
         let config = AppConfig::from_file(&config_path);
         let state = AppState::from_config(&config);
         let emu_thread = emuthread::spawn(ctx);
 
         let rom_list_thread = RomListThreadHandle::spawn(Arc::clone(&state.rom_list));
         rom_list_thread.request_scan(config.rom_search_dirs.clone());
 
-        Self { config, state, config_path, emu_thread, rom_list_thread, startup_file_path }
+        Self { config, state, config_path, emu_thread, rom_list_thread, load_at_startup }
     }
 
     fn open_file(&mut self, console: Option<Console>) {
@@ -1101,8 +1107,13 @@ impl eframe::App for App {
         }
 
         if self.state.rendered_first_frame {
-            if let Some(startup_file_path) = self.startup_file_path.take() {
-                self.launch_emulator(startup_file_path, None);
+            if let Some(load_at_startup) = self.load_at_startup.take() {
+                self.launch_emulator(load_at_startup.file_path, None);
+
+                if let Some(load_state_slot) = load_at_startup.load_state_slot {
+                    self.emu_thread.send(EmuThreadCommand::LoadState { slot: load_state_slot });
+                }
+
                 self.state.close_on_emulator_exit = true;
             }
         }

frontend/jgenesis-gui/src/main.rs

@@ -2,7 +2,7 @@ use clap::Parser;
 use eframe::NativeOptions;
 use egui::{Vec2, ViewportBuilder};
 use env_logger::Env;
-use jgenesis_gui::app::App;
+use jgenesis_gui::app::{App, LoadAtStartup};
 use std::path::PathBuf;
 
 #[derive(Debug, Parser)]
@@ -15,6 +15,20 @@ struct Args {
     /// when the emulator window is closed
     #[arg(long = "file-path", short = 'f')]
     startup_file_path: Option<String>,
+
+    /// In combination with -f, attempt to load the specified save state when launching the game.
+    /// This arg has no effect if -f/--file-path is not set
+    #[arg(long, value_name = "SLOT")]
+    load_save_state: Option<usize>,
+}
+
+impl Args {
+    fn load_at_startup(&self) -> Option<LoadAtStartup> {
+        self.startup_file_path.as_ref().map(|file_path| LoadAtStartup {
+            file_path: file_path.clone(),
+            load_state_slot: self.load_save_state,
+        })
+    }
 }
 
 // Attempt to detect if the application is running on a Steam Deck, and if it is then override
@@ -68,8 +82,10 @@ fn main() -> eframe::Result<()> {
     #[cfg(all(unix, not(target_os = "macos")))]
     steam_deck_dpi_hack();
 
-    let config_path =
-        args.config_path.map_or_else(jgenesis_native_config::default_config_path, PathBuf::from);
+    let config_path = args
+        .config_path
+        .as_ref()
+        .map_or_else(jgenesis_native_config::default_config_path, Into::<PathBuf>::into);
     log::info!("Using config path '{}'", config_path.display());
 
     if let Some(file_path) = &args.startup_file_path {
@@ -81,11 +97,10 @@ fn main() -> eframe::Result<()> {
         ..NativeOptions::default()
     };
 
+    let load_at_startup = args.load_at_startup();
     eframe::run_native(
         "jgenesis",
         options,
-        Box::new(|cc| {
-            Ok(Box::new(App::new(config_path, args.startup_file_path, cc.egui_ctx.clone())))
-        }),
+        Box::new(|cc| Ok(Box::new(App::new(config_path, load_at_startup, cc.egui_ctx.clone())))),
     )
 }