Remember power preerence and force fallback

src/app.rs

@@ -23,7 +23,7 @@ use winit::{
 };
 
 use crate::{
-    config::CliArgs,
+    config::{AppConfig, CliArgs},
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
     images::ImageTextureLoader,
@@ -94,8 +94,9 @@ impl Application {
         handle: OwnedDisplayHandle,
         persistence: Persistence,
         args: CliArgs,
+        config: AppConfig,
     ) -> Self {
-        let wgpu = WgpuState::new(handle);
+        let wgpu = WgpuState::new(handle, config);
         let icon = load_icon().ok().map(Arc::new);
         let mappings = MappingProvider::new(persistence.clone(), args.player2_controller);
         let shortcuts = ShortcutProvider::new(persistence.clone());
@@ -496,10 +497,11 @@ impl ApplicationHandler<UserEvent> for Application {
 struct WgpuState {
     instance: wgpu::Instance,
     device_descriptor: Arc<dyn Fn(&wgpu::Adapter) -> wgpu::DeviceDescriptor<'static> + Send + Sync>,
+    config: AppConfig,
 }
 
 impl WgpuState {
-    fn new(handle: OwnedDisplayHandle) -> Self {
+    fn new(handle: OwnedDisplayHandle, config: AppConfig) -> Self {
         #[allow(unused_variables)]
         let egui_wgpu::WgpuSetupCreateNew {
             instance_descriptor: wgpu::InstanceDescriptor { backends, .. },
@@ -517,16 +519,19 @@ impl WgpuState {
         Self {
             instance,
             device_descriptor,
+            config,
         }
     }
 
     fn init(&mut self, window: &Window) -> egui_wgpu::WgpuSetupExisting {
         let power_preference =
-            wgpu::PowerPreference::from_env().unwrap_or(wgpu::PowerPreference::LowPower);
+            wgpu::PowerPreference::from_env().unwrap_or(self.config.power_preference);
         debug!("power preference: {power_preference:?}");
 
         let force_fallback_adapter = std::env::var("WGPU_FORCE_FALLBACK")
-            .is_ok_and(|f| f.eq_ignore_ascii_case("true") || f.eq_ignore_ascii_case("1"));
+            .map_or(self.config.force_fallback, |f| {
+                f.eq_ignore_ascii_case("true") || f.eq_ignore_ascii_case("1")
+            });
         debug!("force fallback: {force_fallback_adapter}");
 
         let surface = self

src/config.rs

@@ -1,5 +1,5 @@
 use anyhow::Result;
-use clap::Parser;
+use clap::{Parser, ValueEnum};
 use egui::{Color32, Pos2, Vec2};
 use serde::{Deserialize, Serialize};
 
@@ -47,6 +47,28 @@ pub struct CliArgs {
     /// Map the first connected controller to Player 2
     #[arg(long)]
     pub player2_controller: bool,
+    /// Force the application to render with CPU, rather than GPU.
+    #[arg(long)]
+    pub wgpu_force_fallback: Option<bool>,
+    /// Set a preference for whether to use a low-power or high-performance GPU adapter
+    #[arg(long)]
+    pub wgpu_power_preference: Option<PowerPreferenceWrapper>,
+}
+
+#[derive(ValueEnum, Clone, Copy)]
+pub enum PowerPreferenceWrapper {
+    Low,
+    High,
+    None,
+}
+impl From<PowerPreferenceWrapper> for wgpu::PowerPreference {
+    fn from(value: PowerPreferenceWrapper) -> Self {
+        match value {
+            PowerPreferenceWrapper::Low => wgpu::PowerPreference::LowPower,
+            PowerPreferenceWrapper::High => wgpu::PowerPreference::HighPerformance,
+            PowerPreferenceWrapper::None => wgpu::PowerPreference::None,
+        }
+    }
 }
 
 pub const COLOR_PRESETS: [[Color32; 2]; 3] = [
@@ -64,6 +86,49 @@ pub const COLOR_PRESETS: [[Color32; 2]; 3] = [
     ],
 ];
 
+const fn default_power_preference() -> wgpu::PowerPreference {
+    wgpu::PowerPreference::LowPower
+}
+
+#[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,
+}
+
+impl AppConfig {
+    pub fn load(persistence: &Persistence) -> Self {
+        if let Ok(config) = persistence.load_config(APP_CONFIG_FILENAME) {
+            return config;
+        }
+        Self {
+            power_preference: default_power_preference(),
+            force_fallback: false,
+        }
+    }
+
+    pub fn save(&self, persistence: &Persistence) -> Result<()> {
+        persistence.save_config(APP_CONFIG_FILENAME, &self)
+    }
+
+    pub fn update(&mut self, args: &CliArgs) -> bool {
+        let mut updated = false;
+        if let Some(pref) = args.wgpu_power_preference {
+            self.power_preference = pref.into();
+            updated = true;
+        }
+        if let Some(force_fallback) = args.wgpu_force_fallback {
+            self.force_fallback = force_fallback;
+            updated = true;
+        }
+        updated
+    }
+}
+
+const APP_CONFIG_FILENAME: &str = "config";
+
 const fn default_audio_enabled() -> bool {
     true
 }
@@ -81,7 +146,7 @@ pub struct SimConfig {
 
 impl SimConfig {
     pub fn load(persistence: &Persistence, sim_id: SimId) -> Self {
-        if let Ok(config) = persistence.load_config(config_filename(sim_id)) {
+        if let Ok(config) = persistence.load_config(sim_config_filename(sim_id)) {
             return config;
         }
         Self {
@@ -94,11 +159,11 @@ impl SimConfig {
     }
 
     pub fn save(&self, persistence: &Persistence, sim_id: SimId) -> Result<()> {
-        persistence.save_config(config_filename(sim_id), self)
+        persistence.save_config(sim_config_filename(sim_id), self)
     }
 }
 
-fn config_filename(sim_id: SimId) -> &'static str {
+fn sim_config_filename(sim_id: SimId) -> &'static str {
     match sim_id {
         SimId::Player1 => "config_p1",
         SimId::Player2 => "config_p2",

src/main.rs

@@ -13,7 +13,7 @@ use tracing_subscriber::{EnvFilter, Layer, layer::SubscriberExt, util::Subscribe
 use winit::event_loop::{ControlFlow, EventLoop};
 
 use crate::{
-    config::{CliArgs, SimConfig},
+    config::{AppConfig, CliArgs, SimConfig},
     emulator::SimId,
     persistence::Persistence,
 };
@@ -110,6 +110,10 @@ 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);
 
@@ -143,6 +147,7 @@ fn main() -> Result<()> {
         handle,
         persistence,
         args,
+        config,
     ))?;
     Ok(())
 }