feat: run input_system less, rework profiling system to allow for conditional ticks, prepopulate and simplify locking mechanisms, drop RwLock

Bumps the dependencies group with 1 update: [actions/upload-pages-artifact](https://github.com/actions/upload-pages-artifact).


Updates `actions/upload-pages-artifact` from 3 to 4
- [Release notes](https://github.com/actions/upload-pages-artifact/releases)
- [Commits](https://github.com/actions/upload-pages-artifact/compare/v3...v4)

---
updated-dependencies:
- dependency-name: actions/upload-pages-artifact
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build.yaml

@@ -151,7 +151,7 @@ jobs:
           done
 
       - name: Upload Artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         if: github.ref == 'refs/heads/master' && github.event_name == 'push'
         with:
           path: "./dist/"

Cargo.lock

@@ -722,6 +722,15 @@ dependencies = [
  "portable-atomic",
 ]
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
 [[package]]
 name = "pretty_assertions"
 version = "1.4.1"
@@ -762,6 +771,17 @@ version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
 dependencies = [
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
+dependencies = [
+ "ppv-lite86",
  "rand_core",
 ]
 
@@ -1529,3 +1549,23 @@ name = "yansi"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1039dd0d3c310cf05de012d8a39ff557cb0d23087fd44cad61df08fc31907a2f"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ecf5b4cc5364572d7f4c329661bcc82724222973f2cab6f050a4e5c22f75181"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]

Cargo.toml

@@ -13,30 +13,51 @@ keywords = ["game", "pacman", "arcade", "sdl2"]
 categories = ["games", "emulators"]
 publish = false
 exclude = ["/assets/unpacked/**", "/assets/site/**", "/bacon.toml", "/Justfile"]
+default-run = "pacman"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+bevy_ecs = "0.16.1"
+glam = "0.30.5"
+pathfinding = "4.14"
 tracing = { version = "0.1.41", features = ["max_level_debug", "release_max_level_debug"]}
 tracing-error = "0.2.0"
 tracing-subscriber = {version = "0.3.20", features = ["env-filter"]}
 thiserror = "2.0.16"
 anyhow = "1.0"
-bevy_ecs = "0.16.1"
-glam = "0.30.5"
-rand = { version = "0.9.2", default-features = false, features = ["small_rng", "os_rng"] }
-pathfinding = "4.14"
 smallvec = "1.15.1"
 bitflags = "2.9.4"
 micromap = "0.1.0"
 circular-buffer = "1.1.0"
 parking_lot = "0.12.3"
-spin_sleep = "1.3.2"
 strum = "0.27.2"
 strum_macros = "0.27.2"
-phf = { version = "0.13.1", features = ["macros"] }
 thousands = "0.2.0"
 num-width = "0.1.0"
+# While not actively used in code, `build.rs` generates code that relies on this. Keep the versions synchronized.
+phf = { version = "0.13.1", features = ["macros"] }
+
+# Windows-specific dependencies
+[target.'cfg(target_os = "windows")'.dependencies]
+# Used for customizing console output on Windows; both are required due to the `windows` crate having poor Result handling with `GetStdHandle`.
+windows = { version = "0.61.3", features = ["Win32_Security", "Win32_Storage_FileSystem", "Win32_System_Console"] }
+windows-sys = { version = "0.60.2", features = ["Win32_System_Console"] }
+
+# Desktop-specific dependencies
+[target.'cfg(not(target_os = "emscripten"))'.dependencies]
+# On desktop platforms, build SDL2 with cargo-vcpkg
+sdl2 = { version = "0.38", default-features = false, features = ["image", "ttf", "gfx", "mixer", "unsafe_textures", "static-link", "use-vcpkg"] }
+rand = { version = "0.9.2", default-features = false, features = ["thread_rng"] }
+spin_sleep = "1.3.2"
+
+# Browser-specific dependencies
+[target.'cfg(target_os = "emscripten")'.dependencies]
+# On Emscripten, we don't use cargo-vcpkg
+sdl2 = { version = "0.38", default-features = false, features = ["image", "ttf", "gfx", "mixer", "unsafe_textures"] }
+# TODO: Document why Emscripten cannot use `os_rng`.
+rand = { version = "0.9.2", default-features = false, features = ["small_rng", "os_rng"] }
+libc = "0.2.175"  # TODO: Describe why this is required.
 
 [dev-dependencies]
 pretty_assertions = "1.4.1"
@@ -59,32 +80,16 @@ opt-level = 3
 lto = false
 panic = 'unwind'
 
-# LTO optimizations, no unwinding on panic, optimize for size
+# Optimized release profile for size
 [profile.release]
+opt-level = "z"
 lto = true
 panic = "abort"
-opt-level = "z"
-
-# Used for customizing console output on Windows; both are required due to the `windows` crate having poor Result handling with `GetStdHandle`.
-[target.'cfg(target_os = "windows")'.dependencies]
-windows = { version = "0.61.3", features = ["Win32_Security", "Win32_Storage_FileSystem", "Win32_System_Console"] }
-windows-sys = { version = "0.60.2", features = ["Win32_System_Console"] }
-
-# On desktop platforms, build SDL2 with cargo-vcpkg
-[target.'cfg(not(target_os = "emscripten"))'.dependencies.sdl2]
-version = "0.38"
-default-features = false
-features = ["image", "ttf", "gfx", "mixer", "unsafe_textures", "static-link", "use-vcpkg"]
-
-# On Emscripten, we don't use cargo-vcpkg
-[target.'cfg(target_os = "emscripten")'.dependencies]
-sdl2 = { version = "0.38", default-features = false, features = ["image", "ttf", "gfx", "mixer", "unsafe_textures"] }
-libc = "0.2.175"  # TODO: Describe why this is required.
 
 [package.metadata.vcpkg]
 dependencies = ["sdl2", "sdl2-image", "sdl2-ttf", "sdl2-gfx", "sdl2-mixer"]
 git = "https://github.com/microsoft/vcpkg"
-rev = "2024.05.24" # release 2024.05.24 # to check for a new one, check https://github.com/microsoft/vcpkg/releases
+rev = "2024.05.24" # to check for a new one, check https://github.com/microsoft/vcpkg/releases
 
 [package.metadata.vcpkg.target]
 x86_64-pc-windows-msvc = { triplet = "x64-windows-static-md" }

Justfile

@@ -38,3 +38,7 @@ coverage:
 samply:
     cargo build --profile profile
     samply record ./target/profile/pacman{{ binary_extension }}
+
+# Build the project for Emscripten
+web:
+    bun run web.build.ts

src/app.rs

@@ -4,7 +4,8 @@ use crate::error::{GameError, GameResult};
 
 use crate::constants::{CANVAS_SIZE, LOOP_TIME, SCALE};
 use crate::game::Game;
-use crate::platform::get_platform;
+use crate::platform;
+use sdl2::{AudioSubsystem, Sdl};
 
 /// Main application wrapper that manages SDL initialization, window lifecycle, and the game loop.
 ///
@@ -15,6 +16,9 @@ pub struct App {
     pub game: Game,
     last_tick: Instant,
     focused: bool,
+    // Keep SDL alive for the app lifetime so subsystems (audio) are not shut down
+    _sdl_context: Sdl,
+    _audio_subsystem: AudioSubsystem,
 }
 
 impl App {
@@ -31,8 +35,8 @@ impl App {
     pub fn new() -> GameResult<Self> {
         let sdl_context = sdl2::init().map_err(|e| GameError::Sdl(e.to_string()))?;
         let video_subsystem = sdl_context.video().map_err(|e| GameError::Sdl(e.to_string()))?;
-        let _audio_subsystem = sdl_context.audio().map_err(|e| GameError::Sdl(e.to_string()))?;
-        let _ttf_context = sdl2::ttf::init().map_err(|e| GameError::Sdl(e.to_string()))?;
+        let audio_subsystem = sdl_context.audio().map_err(|e| GameError::Sdl(e.to_string()))?;
+        // TTF context is initialized within Game::new where it is leaked for font usage
         let event_pump = sdl_context.event_pump().map_err(|e| GameError::Sdl(e.to_string()))?;
 
         let window = video_subsystem
@@ -65,6 +69,8 @@ impl App {
             game,
             focused: true,
             last_tick: Instant::now(),
+            _sdl_context: sdl_context,
+            _audio_subsystem: audio_subsystem,
         })
     }
 
@@ -83,7 +89,7 @@ impl App {
             let start = Instant::now();
 
             let dt = self.last_tick.elapsed().as_secs_f32();
-            self.last_tick = Instant::now();
+            self.last_tick = start;
 
             let exit = self.game.tick(dt);
 
@@ -95,7 +101,7 @@ impl App {
             if start.elapsed() < LOOP_TIME {
                 let time = LOOP_TIME.saturating_sub(start.elapsed());
                 if time != Duration::ZERO {
-                    get_platform().sleep(time, self.focused);
+                    platform::sleep(time, self.focused);
                 }
             }
 

src/asset.rs

@@ -44,7 +44,7 @@ impl Asset {
 mod imp {
     use super::*;
     use crate::error::AssetError;
-    use crate::platform::get_platform;
+    use crate::platform;
 
     /// Loads asset bytes using the appropriate platform-specific method.
     ///
@@ -58,7 +58,7 @@ mod imp {
     /// Returns `AssetError::NotFound` if the asset file cannot be located (Emscripten only),
     /// or `AssetError::Io` for filesystem I/O failures.
     pub fn get_asset_bytes(asset: Asset) -> Result<Cow<'static, [u8]>, AssetError> {
-        get_platform().get_asset_bytes(asset)
+        platform::get_asset_bytes(asset)
     }
 }
 

src/bin/timing_demo.rs

@@ -0,0 +1,91 @@
+use circular_buffer::CircularBuffer;
+use pacman::constants::CANVAS_SIZE;
+use sdl2::event::Event;
+use sdl2::keyboard::Keycode;
+use sdl2::pixels::Color;
+use std::time::{Duration, Instant};
+
+fn main() -> Result<(), String> {
+    let sdl_context = sdl2::init()?;
+    let video_subsystem = sdl_context.video()?;
+
+    let window = video_subsystem
+        .window("SDL2 Timing Demo", CANVAS_SIZE.x, CANVAS_SIZE.y)
+        .opengl()
+        .position_centered()
+        .build()
+        .map_err(|e| e.to_string())?;
+
+    let mut canvas = window.into_canvas().accelerated().build().map_err(|e| e.to_string())?;
+    canvas
+        .set_logical_size(CANVAS_SIZE.x, CANVAS_SIZE.y)
+        .map_err(|e| e.to_string())?;
+
+    let mut event_pump = sdl_context.event_pump()?;
+
+    // Store frame timings in milliseconds
+    let mut frame_timings = CircularBuffer::<20_000, f64>::new();
+    let mut last_report_time = Instant::now();
+    let report_interval = Duration::from_millis(500);
+
+    'running: loop {
+        let frame_start_time = Instant::now();
+
+        for event in event_pump.poll_iter() {
+            match event {
+                Event::Quit { .. }
+                | Event::KeyDown {
+                    keycode: Some(Keycode::Escape),
+                    ..
+                } => {
+                    break 'running;
+                }
+                _ => {}
+            }
+        }
+
+        // Clear the screen
+        canvas.set_draw_color(Color::RGB(0, 0, 0));
+        canvas.clear();
+        canvas.present();
+
+        // Record timing
+        let frame_duration = frame_start_time.elapsed();
+        frame_timings.push_back(frame_duration.as_secs_f64());
+
+        // Report stats every `report_interval`
+        let elapsed = last_report_time.elapsed();
+        if elapsed >= report_interval {
+            if !frame_timings.is_empty() {
+                let count = frame_timings.len() as f64;
+                let sum: f64 = frame_timings.iter().sum();
+                let mean = sum / count;
+
+                let variance = frame_timings
+                    .iter()
+                    .map(|value| {
+                        let diff = mean - value;
+                        diff * diff
+                    })
+                    .sum::<f64>()
+                    / count;
+                let std_dev = variance.sqrt();
+
+                println!(
+                    "Rendered {count} frames at {fps:.1} fps (last {elapsed:.2?}): mean={mean:.3?}, std_dev={std_dev:.3?}",
+                    count = frame_timings.len(),
+                    fps = count / elapsed.as_secs_f64(),
+                    elapsed = elapsed,
+                    mean = Duration::from_secs_f64(mean),
+                    std_dev = Duration::from_secs_f64(std_dev),
+                );
+            }
+
+            // Reset for next interval
+            frame_timings.clear();
+            last_report_time = Instant::now();
+        }
+    }
+
+    Ok(())
+}

src/constants.rs

@@ -8,8 +8,8 @@ use glam::UVec2;
 ///
 /// Calculated as 1/60th of a second (≈16.67ms).
 ///
-/// Written out explicitly to satisfy const-eval constraints.
-pub const LOOP_TIME: Duration = Duration::from_nanos((1_000_000_000.0 / 60.0) as u64);
+/// Uses integer arithmetic to avoid floating-point precision loss.
+pub const LOOP_TIME: Duration = Duration::from_nanos(1_000_000_000 / 60);
 
 /// The size of each cell, in pixels.
 pub const CELL_SIZE: u32 = 8;

src/game.rs

@@ -18,10 +18,10 @@ use crate::systems::{self, ghost_collision_system, present_system, Hidden, Linea
 use crate::systems::{
     audio_system, blinking_system, collision_system, debug_render_system, directional_render_system, dirty_render_system,
     eaten_ghost_system, ghost_movement_system, ghost_state_system, hud_render_system, item_system, linear_render_system, profile,
-    render_system, AudioEvent, AudioResource, AudioState, BackbufferResource, Collider, DebugFontResource, DebugState,
-    DebugTextureResource, DeltaTime, DirectionalAnimation, EntityType, Frozen, Ghost, GhostAnimations, GhostBundle,
-    GhostCollider, GlobalState, ItemBundle, ItemCollider, MapTextureResource, PacmanCollider, PlayerBundle, PlayerControlled,
-    Renderable, ScoreResource, StartupSequence, SystemTimings,
+    render_system, AudioEvent, AudioResource, AudioState, BackbufferResource, Collider, DebugState, DebugTextureResource,
+    DeltaTime, DirectionalAnimation, EntityType, Frozen, Ghost, GhostAnimations, GhostBundle, GhostCollider, GlobalState,
+    ItemBundle, ItemCollider, MapTextureResource, PacmanCollider, PlayerBundle, PlayerControlled, Renderable, ScoreResource,
+    StartupSequence, SystemTimings,
 };
 use crate::texture::animated::{DirectionalTiles, TileSequence};
 use crate::texture::sprite::AtlasTile;
@@ -29,8 +29,9 @@ use bevy_ecs::event::EventRegistry;
 use bevy_ecs::observer::Trigger;
 use bevy_ecs::schedule::common_conditions::resource_changed;
 use bevy_ecs::schedule::{Condition, IntoScheduleConfigs, Schedule, SystemSet};
-use bevy_ecs::system::ResMut;
+use bevy_ecs::system::{Local, ResMut};
 use bevy_ecs::world::World;
+use glam::UVec2;
 use sdl2::event::EventType;
 use sdl2::image::LoadTexture;
 use sdl2::render::{BlendMode, Canvas, ScaleMode, TextureCreator};
@@ -42,6 +43,7 @@ use crate::{
     asset::{get_asset_bytes, Asset},
     events::GameCommand,
     map::render::MapRenderer,
+    systems::debug::{BatchedLinesResource, TtfAtlasResource},
     systems::input::{Bindings, CursorPosition},
     texture::sprite::{AtlasMapper, SpriteAtlas},
 };
@@ -125,7 +127,7 @@ impl Game {
             EventType::Display,
             EventType::Window,
             EventType::MouseWheel,
-            EventType::MouseMotion,
+            // EventType::MouseMotion,
             EventType::MouseButtonDown,
             EventType::MouseButtonUp,
             EventType::MouseButtonDown,
@@ -162,12 +164,17 @@ impl Game {
         debug_texture.set_blend_mode(BlendMode::Blend);
         debug_texture.set_scale_mode(ScaleMode::Nearest);
 
+        // Create debug text atlas for efficient debug rendering
         let font_data: &'static [u8] = get_asset_bytes(Asset::Font)?.to_vec().leak();
         let font_asset = RWops::from_bytes(font_data).map_err(|_| GameError::Sdl("Failed to load font".to_string()))?;
         let debug_font = ttf_context
             .load_font_from_rwops(font_asset, constants::ui::DEBUG_FONT_SIZE)
             .map_err(|e| GameError::Sdl(e.to_string()))?;
 
+        let mut ttf_atlas = crate::texture::ttf::TtfAtlas::new(&texture_creator, &debug_font)?;
+        // Populate the atlas with actual character data
+        ttf_atlas.populate_atlas(&mut canvas, &texture_creator, &debug_font)?;
+
         // Initialize audio system
         let audio = crate::audio::Audio::new();
 
@@ -293,6 +300,10 @@ impl Game {
         EventRegistry::register_event::<GameEvent>(&mut world);
         EventRegistry::register_event::<AudioEvent>(&mut world);
 
+        let scale =
+            (UVec2::from(canvas.output_size().unwrap()).as_vec2() / UVec2::from(canvas.logical_size()).as_vec2()).min_element();
+
+        world.insert_resource(BatchedLinesResource::new(&map, scale));
         world.insert_resource(Self::create_ghost_animations(&atlas)?);
         world.insert_resource(map);
         world.insert_resource(GlobalState { exit: false });
@@ -315,7 +326,7 @@ impl Game {
         world.insert_non_send_resource(BackbufferResource(backbuffer));
         world.insert_non_send_resource(MapTextureResource(map_texture));
         world.insert_non_send_resource(DebugTextureResource(debug_texture));
-        world.insert_non_send_resource(DebugFontResource(debug_font));
+        world.insert_non_send_resource(TtfAtlasResource(ttf_atlas));
         world.insert_non_send_resource(AudioResource(audio));
 
         world.add_observer(
@@ -354,7 +365,11 @@ impl Game {
         schedule.add_systems((
             forced_dirty_system.run_if(resource_changed::<ScoreResource>.or(resource_changed::<StartupSequence>)),
             (
-                input_system,
+                input_system.run_if(|mut local: Local<u8>| {
+                    *local = local.wrapping_add(1u8);
+                    // run every nth frame
+                    *local % 2 == 0
+                }),
                 player_control_system,
                 player_movement_system,
                 startup_stage_system,

src/main.rs

@@ -22,13 +22,12 @@ mod texture;
 /// This function initializes SDL, the window, the game state, and then enters
 /// the main game loop.
 pub fn main() {
-    let platform = platform::get_platform();
-    if platform.requires_console() {
+    if platform::requires_console() {
         // Setup buffered tracing subscriber that will buffer logs until console is ready
         let switchable_writer = platform::tracing_buffer::setup_switchable_subscriber();
 
         // Initialize platform-specific console
-        platform.init_console().expect("Could not initialize console");
+        platform::init_console().expect("Could not initialize console");
 
         // Now that console is initialized, flush buffered logs and switch to direct output
         debug!("Switching to direct logging mode and flushing buffer...");

src/platform/desktop.rs

@@ -3,171 +3,167 @@
 use std::borrow::Cow;
 use std::time::Duration;
 
+use rand::rngs::ThreadRng;
+
 use crate::asset::Asset;
 use crate::error::{AssetError, PlatformError};
-use crate::platform::CommonPlatform;
 
 /// Desktop platform implementation.
-pub struct Platform;
+pub fn sleep(duration: Duration, focused: bool) {
+    if focused {
+        spin_sleep::sleep(duration);
+    } else {
+        std::thread::sleep(duration);
+    }
+}
 
-impl CommonPlatform for Platform {
-    fn sleep(&self, duration: Duration, focused: bool) {
-        if focused {
-            spin_sleep::sleep(duration);
+pub fn init_console() -> Result<(), PlatformError> {
+    #[cfg(windows)]
+    {
+        use tracing::{debug, info};
+        use windows::Win32::System::Console::GetConsoleWindow;
+
+        // Check if we already have a console window
+        if unsafe { !GetConsoleWindow().0.is_null() } {
+            debug!("Already have a console window");
+            return Ok(());
         } else {
-            std::thread::sleep(duration);
+            debug!("No existing console window found");
+        }
+
+        if let Some(file_type) = is_output_setup()? {
+            debug!(r#type = file_type, "Existing output detected");
+        } else {
+            debug!("No existing output detected");
+
+            // Try to attach to parent console for direct cargo run
+            attach_to_parent_console()?;
+            info!("Successfully attached to parent console");
         }
     }
 
-    fn get_time(&self) -> f64 {
-        std::time::Instant::now().elapsed().as_secs_f64()
-    }
+    Ok(())
+}
 
-    fn init_console(&self) -> Result<(), PlatformError> {
-        #[cfg(windows)]
-        {
-            use tracing::{debug, info};
-            use windows::Win32::System::Console::GetConsoleWindow;
+pub fn requires_console() -> bool {
+    cfg!(windows)
+}
 
-            // Check if we already have a console window
-            if unsafe { !GetConsoleWindow().0.is_null() } {
-                debug!("Already have a console window");
-                return Ok(());
-            } else {
-                debug!("No existing console window found");
-            }
-
-            if let Some(file_type) = Self::is_output_setup()? {
-                debug!(r#type = file_type, "Existing output detected");
-            } else {
-                debug!("No existing output detected");
-
-                // Try to attach to parent console for direct cargo run
-                Self::attach_to_parent_console()?;
-                info!("Successfully attached to parent console");
-            }
-        }
-
-        Ok(())
-    }
-
-    fn requires_console(&self) -> bool {
-        cfg!(windows)
-    }
-
-    fn get_canvas_size(&self) -> Option<(u32, u32)> {
-        None // Desktop doesn't need this
-    }
-
-    fn get_asset_bytes(&self, asset: Asset) -> Result<Cow<'static, [u8]>, AssetError> {
-        match asset {
-            Asset::Wav1 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/1.ogg"))),
-            Asset::Wav2 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/2.ogg"))),
-            Asset::Wav3 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/3.ogg"))),
-            Asset::Wav4 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/4.ogg"))),
-            Asset::AtlasImage => Ok(Cow::Borrowed(include_bytes!("../../assets/game/atlas.png"))),
-            Asset::Font => Ok(Cow::Borrowed(include_bytes!("../../assets/game/TerminalVector.ttf"))),
-        }
+pub fn get_asset_bytes(asset: Asset) -> Result<Cow<'static, [u8]>, AssetError> {
+    match asset {
+        Asset::Wav1 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/1.ogg"))),
+        Asset::Wav2 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/2.ogg"))),
+        Asset::Wav3 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/3.ogg"))),
+        Asset::Wav4 => Ok(Cow::Borrowed(include_bytes!("../../assets/game/sound/waka/4.ogg"))),
+        Asset::AtlasImage => Ok(Cow::Borrowed(include_bytes!("../../assets/game/atlas.png"))),
+        Asset::Font => Ok(Cow::Borrowed(include_bytes!("../../assets/game/TerminalVector.ttf"))),
     }
 }
 
+pub fn rng() -> ThreadRng {
+    rand::rng()
+}
+
+/* Internal functions */
+
+/// Check if the output stream has been setup by a parent process
+/// Windows-only
 #[cfg(windows)]
-impl Platform {
-    /// Check if the output stream has been setup by a parent process
-    fn is_output_setup() -> Result<Option<&'static str>, PlatformError> {
-        use tracing::{debug, warn};
+fn is_output_setup() -> Result<Option<&'static str>, PlatformError> {
+    use tracing::{debug, warn};
 
-        use windows::Win32::Storage::FileSystem::{
-            GetFileType, FILE_TYPE_CHAR, FILE_TYPE_DISK, FILE_TYPE_PIPE, FILE_TYPE_REMOTE, FILE_TYPE_UNKNOWN,
-        };
+    use windows::Win32::Storage::FileSystem::{
+        GetFileType, FILE_TYPE_CHAR, FILE_TYPE_DISK, FILE_TYPE_PIPE, FILE_TYPE_REMOTE, FILE_TYPE_UNKNOWN,
+    };
 
-        use windows_sys::Win32::{
-            Foundation::INVALID_HANDLE_VALUE,
-            System::Console::{GetStdHandle, STD_OUTPUT_HANDLE},
-        };
+    use windows_sys::Win32::{
+        Foundation::INVALID_HANDLE_VALUE,
+        System::Console::{GetStdHandle, STD_OUTPUT_HANDLE},
+    };
 
-        // Get the process's standard output handle, check if it's invalid
-        let handle = match unsafe { GetStdHandle(STD_OUTPUT_HANDLE) } {
-            INVALID_HANDLE_VALUE => {
-                return Err(PlatformError::ConsoleInit("Invalid handle".to_string()));
-            }
-            handle => handle,
-        };
-
-        // Identify the file type of the handle and whether it's 'well known' (i.e. we trust it to be a reasonable output destination)
-        let (well_known, file_type) = match unsafe {
-            use windows::Win32::Foundation::HANDLE;
-            GetFileType(HANDLE(handle))
-        } {
-            FILE_TYPE_PIPE => (true, "pipe"),
-            FILE_TYPE_CHAR => (true, "char"),
-            FILE_TYPE_DISK => (true, "disk"),
-            FILE_TYPE_UNKNOWN => (false, "unknown"),
-            FILE_TYPE_REMOTE => (false, "remote"),
-            unexpected => {
-                warn!("Unexpected file type: {unexpected:?}");
-                (false, "unknown")
-            }
-        };
-
-        debug!("File type: {file_type:?}, well known: {well_known}");
-
-        // If it's anything recognizable and valid, assume that a parent process has setup an output stream
-        Ok(well_known.then_some(file_type))
-    }
-
-    /// Try to attach to parent console
-    fn attach_to_parent_console() -> Result<(), PlatformError> {
-        use windows::{
-            core::PCSTR,
-            Win32::{
-                Foundation::{GENERIC_READ, GENERIC_WRITE},
-                Storage::FileSystem::{CreateFileA, FILE_FLAGS_AND_ATTRIBUTES, FILE_SHARE_READ, FILE_SHARE_WRITE, OPEN_EXISTING},
-                System::Console::{
-                    AttachConsole, FreeConsole, SetStdHandle, ATTACH_PARENT_PROCESS, STD_ERROR_HANDLE, STD_OUTPUT_HANDLE,
-                },
-            },
-        };
-
-        // Attach the process to the parent's console
-        unsafe { AttachConsole(ATTACH_PARENT_PROCESS) }
-            .map_err(|e| PlatformError::ConsoleInit(format!("Failed to attach to parent console: {:?}", e)))?;
-
-        let handle = unsafe {
-            let pcstr = PCSTR::from_raw(c"CONOUT$".as_ptr() as *const u8);
-            CreateFileA::<PCSTR>(
-                pcstr,
-                (GENERIC_READ | GENERIC_WRITE).0,
-                FILE_SHARE_READ | FILE_SHARE_WRITE,
-                None,
-                OPEN_EXISTING,
-                FILE_FLAGS_AND_ATTRIBUTES(0),
-                None,
-            )
+    // Get the process's standard output handle, check if it's invalid
+    let handle = match unsafe { GetStdHandle(STD_OUTPUT_HANDLE) } {
+        INVALID_HANDLE_VALUE => {
+            return Err(PlatformError::ConsoleInit("Invalid handle".to_string()));
         }
-        .map_err(|e| PlatformError::ConsoleInit(format!("Failed to create console handle: {:?}", e)))?;
+        handle => handle,
+    };
 
-        // Set the console's output and then error handles
-        if let Some(handle_error) = unsafe { SetStdHandle(STD_OUTPUT_HANDLE, handle) }
-            .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console output handle: {:?}", e)))
-            .and_then(|_| {
-                unsafe { SetStdHandle(STD_ERROR_HANDLE, handle) }
-                    .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console error handle: {:?}", e)))
-            })
-            .err()
-        {
-            // If either set handle call fails, free the console
-            unsafe { FreeConsole() }
-                // Free the console if the SetStdHandle calls fail
-                .map_err(|free_error| {
-                    PlatformError::ConsoleInit(format!(
-                        "Failed to free console after SetStdHandle failed: {free_error:?} ({handle_error:?})"
-                    ))
-                })
-                // And then return the original error if the FreeConsole call succeeds
-                .and(Err(handle_error))?;
+    // Identify the file type of the handle and whether it's 'well known' (i.e. we trust it to be a reasonable output destination)
+    let (well_known, file_type) = match unsafe {
+        use windows::Win32::Foundation::HANDLE;
+        GetFileType(HANDLE(handle))
+    } {
+        FILE_TYPE_PIPE => (true, "pipe"),
+        FILE_TYPE_CHAR => (true, "char"),
+        FILE_TYPE_DISK => (true, "disk"),
+        FILE_TYPE_UNKNOWN => (false, "unknown"),
+        FILE_TYPE_REMOTE => (false, "remote"),
+        unexpected => {
+            warn!("Unexpected file type: {unexpected:?}");
+            (false, "unknown")
         }
+    };
 
-        Ok(())
-    }
+    debug!("File type: {file_type:?}, well known: {well_known}");
+
+    // If it's anything recognizable and valid, assume that a parent process has setup an output stream
+    Ok(well_known.then_some(file_type))
+}
+
+/// Try to attach to parent console
+/// Windows-only
+#[cfg(windows)]
+fn attach_to_parent_console() -> Result<(), PlatformError> {
+    use windows::{
+        core::PCSTR,
+        Win32::{
+            Foundation::{GENERIC_READ, GENERIC_WRITE},
+            Storage::FileSystem::{CreateFileA, FILE_FLAGS_AND_ATTRIBUTES, FILE_SHARE_READ, FILE_SHARE_WRITE, OPEN_EXISTING},
+            System::Console::{
+                AttachConsole, FreeConsole, SetStdHandle, ATTACH_PARENT_PROCESS, STD_ERROR_HANDLE, STD_OUTPUT_HANDLE,
+            },
+        },
+    };
+
+    // Attach the process to the parent's console
+    unsafe { AttachConsole(ATTACH_PARENT_PROCESS) }
+        .map_err(|e| PlatformError::ConsoleInit(format!("Failed to attach to parent console: {:?}", e)))?;
+
+    let handle = unsafe {
+        let pcstr = PCSTR::from_raw(c"CONOUT$".as_ptr() as *const u8);
+        CreateFileA::<PCSTR>(
+            pcstr,
+            (GENERIC_READ | GENERIC_WRITE).0,
+            FILE_SHARE_READ | FILE_SHARE_WRITE,
+            None,
+            OPEN_EXISTING,
+            FILE_FLAGS_AND_ATTRIBUTES(0),
+            None,
+        )
+    }
+    .map_err(|e| PlatformError::ConsoleInit(format!("Failed to create console handle: {:?}", e)))?;
+
+    // Set the console's output and then error handles
+    if let Some(handle_error) = unsafe { SetStdHandle(STD_OUTPUT_HANDLE, handle) }
+        .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console output handle: {:?}", e)))
+        .and_then(|_| {
+            unsafe { SetStdHandle(STD_ERROR_HANDLE, handle) }
+                .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set console error handle: {:?}", e)))
+        })
+        .err()
+    {
+        // If either set handle call fails, free the console
+        unsafe { FreeConsole() }
+            // Free the console if the SetStdHandle calls fail
+            .map_err(|free_error| {
+                PlatformError::ConsoleInit(format!(
+                    "Failed to free console after SetStdHandle failed: {free_error:?} ({handle_error:?})"
+                ))
+            })
+            // And then return the original error if the FreeConsole call succeeds
+            .and(Err(handle_error))?;
+    }
+
+    Ok(())
 }

src/platform/emscripten.rs

@@ -5,62 +5,60 @@ use std::time::Duration;
 
 use crate::asset::Asset;
 use crate::error::{AssetError, PlatformError};
-use crate::platform::CommonPlatform;
-
-/// Emscripten platform implementation.
-pub struct Platform;
-
-impl CommonPlatform for Platform {
-    fn sleep(&self, duration: Duration, _focused: bool) {
-        unsafe {
-            emscripten_sleep(duration.as_millis() as u32);
-        }
-    }
-
-    fn get_time(&self) -> f64 {
-        unsafe { emscripten_get_now() }
-    }
-
-    fn init_console(&self) -> Result<(), PlatformError> {
-        Ok(()) // No-op for Emscripten
-    }
-
-    fn requires_console(&self) -> bool {
-        false
-    }
-
-    fn get_canvas_size(&self) -> Option<(u32, u32)> {
-        Some(unsafe { get_canvas_size() })
-    }
-
-    fn get_asset_bytes(&self, asset: Asset) -> Result<Cow<'static, [u8]>, AssetError> {
-        use sdl2::rwops::RWops;
-        use std::io::Read;
-
-        let path = format!("assets/game/{}", asset.path());
-        let mut rwops = RWops::from_file(&path, "rb").map_err(|_| AssetError::NotFound(asset.path().to_string()))?;
-
-        let len = rwops.len().ok_or_else(|| AssetError::NotFound(asset.path().to_string()))?;
-
-        let mut buf = vec![0u8; len];
-        rwops
-            .read_exact(&mut buf)
-            .map_err(|e| AssetError::Io(std::io::Error::other(e)))?;
-
-        Ok(Cow::Owned(buf))
-    }
-}
+use rand::{rngs::SmallRng, SeedableRng};
 
 // Emscripten FFI functions
+#[allow(dead_code)]
 extern "C" {
     fn emscripten_get_now() -> f64;
     fn emscripten_sleep(ms: u32);
     fn emscripten_get_element_css_size(target: *const u8, width: *mut f64, height: *mut f64) -> i32;
 }
 
-unsafe fn get_canvas_size() -> (u32, u32) {
+pub fn sleep(duration: Duration, _focused: bool) {
+    unsafe {
+        emscripten_sleep(duration.as_millis() as u32);
+    }
+}
+
+pub fn init_console() -> Result<(), PlatformError> {
+    Ok(()) // No-op for Emscripten
+}
+
+pub fn requires_console() -> bool {
+    false
+}
+
+pub fn get_canvas_size() -> Option<(u32, u32)> {
     let mut width = 0.0;
     let mut height = 0.0;
-    emscripten_get_element_css_size(c"canvas".as_ptr().cast(), &mut width, &mut height);
-    (width as u32, height as u32)
+
+    unsafe {
+        emscripten_get_element_css_size(c"canvas".as_ptr().cast(), &mut width, &mut height);
+        if width == 0.0 || height == 0.0 {
+            return None;
+        }
+    }
+    Some((width as u32, height as u32))
+}
+
+pub fn get_asset_bytes(asset: Asset) -> Result<Cow<'static, [u8]>, AssetError> {
+    use sdl2::rwops::RWops;
+    use std::io::Read;
+
+    let path = format!("assets/game/{}", asset.path());
+    let mut rwops = RWops::from_file(&path, "rb").map_err(|_| AssetError::NotFound(asset.path().to_string()))?;
+
+    let len = rwops.len().ok_or_else(|| AssetError::NotFound(asset.path().to_string()))?;
+
+    let mut buf = vec![0u8; len];
+    rwops
+        .read_exact(&mut buf)
+        .map_err(|e| AssetError::Io(std::io::Error::other(e)))?;
+
+    Ok(Cow::Owned(buf))
+}
+
+pub fn rng() -> SmallRng {
+    SmallRng::from_os_rng()
 }

src/platform/mod.rs

@@ -1,52 +1,13 @@
 //! Platform abstraction layer for cross-platform functionality.
-
-use crate::asset::Asset;
-use crate::error::{AssetError, PlatformError};
-use std::borrow::Cow;
-use std::time::Duration;
-
-#[cfg(not(target_os = "emscripten"))]
-mod desktop;
-#[cfg(target_os = "emscripten")]
-mod emscripten;
-
 pub mod buffered_writer;
 pub mod tracing_buffer;
 
-/// Cross-platform abstraction layer providing unified APIs for platform-specific operations.
-pub trait CommonPlatform {
-    /// Platform-specific sleep function (required due to Emscripten's non-standard sleep requirements).
-    ///
-    /// Provides access to current window focus state, useful for changing sleep algorithm conditionally.
-    fn sleep(&self, duration: Duration, focused: bool);
+#[cfg(not(target_os = "emscripten"))]
+mod desktop;
+#[cfg(not(target_os = "emscripten"))]
+pub use desktop::*;
 
-    #[allow(dead_code)]
-    fn get_time(&self) -> f64;
-
-    /// Configures platform-specific console and debugging output capabilities.
-    fn init_console(&self) -> Result<(), PlatformError>;
-
-    /// Retrieves the actual display canvas dimensions.
-    #[allow(dead_code)]
-    fn get_canvas_size(&self) -> Option<(u32, u32)>;
-
-    /// Loads raw asset data using the appropriate platform-specific method.
-    fn get_asset_bytes(&self, asset: Asset) -> Result<Cow<'static, [u8]>, AssetError>;
-
-    /// Whether the platform requires a console to be initialized.
-    fn requires_console(&self) -> bool;
-}
-
-/// Returns the appropriate platform implementation based on compile-time target.
-#[allow(dead_code)]
-pub fn get_platform() -> &'static dyn CommonPlatform {
-    #[cfg(not(target_os = "emscripten"))]
-    {
-        &desktop::Platform
-    }
-
-    #[cfg(target_os = "emscripten")]
-    {
-        &emscripten::Platform
-    }
-}
+#[cfg(target_os = "emscripten")]
+pub use emscripten::*;
+#[cfg(target_os = "emscripten")]
+mod emscripten;

src/systems/debug.rs

@@ -4,14 +4,17 @@ use std::cmp::Ordering;
 use crate::constants::BOARD_PIXEL_OFFSET;
 use crate::map::builder::Map;
 use crate::systems::{Collider, CursorPosition, NodeId, Position, SystemTimings};
+use crate::texture::ttf::{TtfAtlas, TtfRenderer};
 use bevy_ecs::resource::Resource;
 use bevy_ecs::system::{NonSendMut, Query, Res};
 use glam::{IVec2, UVec2, Vec2};
 use sdl2::pixels::Color;
 use sdl2::rect::{Point, Rect};
-use sdl2::render::{Canvas, Texture, TextureCreator};
-use sdl2::ttf::Font;
-use sdl2::video::{Window, WindowContext};
+use sdl2::render::{Canvas, Texture};
+use sdl2::video::Window;
+use smallvec::SmallVec;
+use std::collections::{HashMap, HashSet};
+use tracing::warn;
 
 #[derive(Resource, Default, Debug, Copy, Clone)]
 pub struct DebugState {
@@ -25,31 +28,143 @@ fn f32_to_u8(value: f32) -> u8 {
 /// Resource to hold the debug texture for persistent rendering
 pub struct DebugTextureResource(pub Texture);
 
-/// Resource to hold the debug font
-pub struct DebugFontResource(pub Font<'static, 'static>);
+/// Resource to hold the TTF text atlas
+pub struct TtfAtlasResource(pub TtfAtlas);
+
+/// Resource to hold pre-computed batched line segments
+#[derive(Resource, Default, Debug, Clone)]
+pub struct BatchedLinesResource {
+    horizontal_lines: Vec<(i32, i32, i32)>, // (y, x_start, x_end)
+    vertical_lines: Vec<(i32, i32, i32)>,   // (x, y_start, y_end)
+}
+
+impl BatchedLinesResource {
+    /// Computes and caches batched line segments for the map graph
+    pub fn new(map: &Map, scale: f32) -> Self {
+        let mut horizontal_segments: HashMap<i32, Vec<(i32, i32)>> = HashMap::new();
+        let mut vertical_segments: HashMap<i32, Vec<(i32, i32)>> = HashMap::new();
+        let mut processed_edges: HashSet<(u16, u16)> = HashSet::new();
+
+        // Process all edges and group them by axis
+        for (start_node_id, edge) in map.graph.edges() {
+            // Acquire a stable key for the edge (from < to)
+            let edge_key = (start_node_id.min(edge.target), start_node_id.max(edge.target));
+
+            // Skip if we've already processed this edge in the reverse direction
+            if processed_edges.contains(&edge_key) {
+                continue;
+            }
+            processed_edges.insert(edge_key);
+
+            let start_pos = map.graph.get_node(start_node_id).unwrap().position;
+            let end_pos = map.graph.get_node(edge.target).unwrap().position;
+
+            let start = transform_position_with_offset(start_pos, scale);
+            let end = transform_position_with_offset(end_pos, scale);
+
+            // Determine if this is a horizontal or vertical line
+            if (start.y - end.y).abs() < 2 {
+                // Horizontal line (allowing for slight vertical variance)
+                let y = start.y;
+                let x_min = start.x.min(end.x);
+                let x_max = start.x.max(end.x);
+                horizontal_segments.entry(y).or_default().push((x_min, x_max));
+            } else if (start.x - end.x).abs() < 2 {
+                // Vertical line (allowing for slight horizontal variance)
+                let x = start.x;
+                let y_min = start.y.min(end.y);
+                let y_max = start.y.max(end.y);
+                vertical_segments.entry(x).or_default().push((y_min, y_max));
+            }
+        }
+
+        /// Merges overlapping or adjacent segments into continuous lines
+        fn merge_segments(segments: Vec<(i32, i32)>) -> Vec<(i32, i32)> {
+            if segments.is_empty() {
+                return Vec::new();
+            }
+
+            let mut merged = Vec::new();
+            let mut current_start = segments[0].0;
+            let mut current_end = segments[0].1;
+
+            for &(start, end) in segments.iter().skip(1) {
+                if start <= current_end + 1 {
+                    // Adjacent or overlapping
+                    current_end = current_end.max(end);
+                } else {
+                    merged.push((current_start, current_end));
+                    current_start = start;
+                    current_end = end;
+                }
+            }
+
+            merged.push((current_start, current_end));
+            merged
+        }
+
+        // Convert to flat vectors for fast iteration during rendering
+        let horizontal_lines = horizontal_segments
+            .into_iter()
+            .flat_map(|(y, mut segments)| {
+                segments.sort_unstable_by_key(|(start, _)| *start);
+                let merged = merge_segments(segments);
+                merged.into_iter().map(move |(x_start, x_end)| (y, x_start, x_end))
+            })
+            .collect::<Vec<_>>();
+
+        let vertical_lines = vertical_segments
+            .into_iter()
+            .flat_map(|(x, mut segments)| {
+                segments.sort_unstable_by_key(|(start, _)| *start);
+                let merged = merge_segments(segments);
+                merged.into_iter().map(move |(y_start, y_end)| (x, y_start, y_end))
+            })
+            .collect::<Vec<_>>();
+
+        Self {
+            horizontal_lines,
+            vertical_lines,
+        }
+    }
+
+    pub fn render(&self, canvas: &mut Canvas<Window>) {
+        // Render horizontal lines
+        for &(y, x_start, x_end) in &self.horizontal_lines {
+            let points = [Point::new(x_start, y), Point::new(x_end, y)];
+            let _ = canvas.draw_lines(&points[..]);
+        }
+
+        // Render vertical lines
+        for &(x, y_start, y_end) in &self.vertical_lines {
+            let points = [Point::new(x, y_start), Point::new(x, y_end)];
+            let _ = canvas.draw_lines(&points[..]);
+        }
+    }
+}
 
 /// Transforms a position from logical canvas coordinates to output canvas coordinates (with board offset)
 fn transform_position_with_offset(pos: Vec2, scale: f32) -> IVec2 {
     ((pos + BOARD_PIXEL_OFFSET.as_vec2()) * scale).as_ivec2()
 }
 
-/// Renders timing information in the top-left corner of the screen
+/// Renders timing information in the top-left corner of the screen using the debug text atlas
 fn render_timing_display(
     canvas: &mut Canvas<Window>,
-    texture_creator: &mut TextureCreator<WindowContext>,
     timings: &SystemTimings,
-    font: &Font,
+    text_renderer: &TtfRenderer,
+    atlas: &mut TtfAtlas,
 ) {
     // Format timing information using the formatting module
     let lines = timings.format_timing_display();
-    let line_height = 14; // Approximate line height for 12pt font
+    let line_height = text_renderer.text_height(atlas) as i32 + 2; // Add 2px line spacing
     let padding = 10;
 
     // Calculate background dimensions
     let max_width = lines
         .iter()
         .filter(|l| !l.is_empty()) // Don't consider empty lines for width
-        .map(|line| font.size_of(line).unwrap().0)
+        .map(|line| text_renderer.text_width(atlas, line))
         .max()
         .unwrap_or(0);
 
@@ -75,14 +190,14 @@ fn render_timing_display(
             continue;
         }
 
-        // Render each line
-        let surface = font.render(line).blended(Color::RGBA(255, 255, 255, 200)).unwrap();
-        let texture = texture_creator.create_texture_from_surface(&surface).unwrap();
-
         // Position each line below the previous one
-        let y_pos = padding + (i * line_height) as i32;
-        let dest = Rect::new(padding, y_pos, texture.query().width, texture.query().height);
-        canvas.copy(&texture, None, dest).unwrap();
+        let y_pos = padding + (i as i32 * line_height);
+        let position = Vec2::new(padding as f32, y_pos as f32);
+
+        // Render the line using the debug text renderer
+        text_renderer
+            .render_text(canvas, atlas, line, position, Color::RGBA(255, 255, 255, 200))
+            .unwrap();
     }
 }
 
@@ -90,7 +205,8 @@ fn render_timing_display(
 pub fn debug_render_system(
     mut canvas: NonSendMut<&mut Canvas<Window>>,
     mut debug_texture: NonSendMut<DebugTextureResource>,
-    debug_font: NonSendMut<DebugFontResource>,
+    mut ttf_atlas: NonSendMut<TtfAtlasResource>,
+    batched_lines: Res<BatchedLinesResource>,
     debug_state: Res<DebugState>,
     timings: Res<SystemTimings>,
     map: Res<Map>,
@@ -103,9 +219,8 @@ pub fn debug_render_system(
     let scale =
         (UVec2::from(canvas.output_size().unwrap()).as_vec2() / UVec2::from(canvas.logical_size()).as_vec2()).min_element();
 
-    // Get texture creator before entering the closure to avoid borrowing conflicts
-    let mut texture_creator = canvas.texture_creator();
-    let font = &debug_font.0;
+    // Create debug text renderer
+    let text_renderer = TtfRenderer::new(1.0);
 
     let cursor_world_pos = match *cursor {
         CursorPosition::None => None,
@@ -132,55 +247,70 @@ pub fn debug_render_system(
             };
 
             debug_canvas.set_draw_color(Color::GREEN);
-            for (collider, position) in colliders.iter() {
-                let pos = position.get_pixel_position(&map.graph).unwrap();
+            {
+                let rects = colliders
+                    .iter()
+                    .map(|(collider, position)| {
+                        let pos = position.get_pixel_position(&map.graph).unwrap();
 
-                // Transform position and size using common methods
-                let pos = (pos * scale).as_ivec2();
-                let size = (collider.size * scale) as u32;
+                        // Transform position and size using common methods
+                        let pos = (pos * scale).as_ivec2();
+                        let size = (collider.size * scale) as u32;
 
-                let rect = Rect::from_center(Point::from((pos.x, pos.y)), size, size);
-                debug_canvas.draw_rect(rect).unwrap();
+                        Rect::from_center(Point::from((pos.x, pos.y)), size, size)
+                    })
+                    .collect::<SmallVec<[Rect; 100]>>();
+                if rects.len() > rects.capacity() {
+                    warn!(
+                        capacity = rects.capacity(),
+                        count = rects.len(),
+                        "Collider rects capacity exceeded"
+                    );
+                }
+                debug_canvas.draw_rects(&rects).unwrap();
             }
 
             debug_canvas.set_draw_color(Color {
-                a: f32_to_u8(0.4),
+                a: f32_to_u8(0.6),
                 ..Color::RED
             });
             debug_canvas.set_blend_mode(sdl2::render::BlendMode::Blend);
-            for (start_node, end_node) in map.graph.edges() {
-                let start_node_model = map.graph.get_node(start_node).unwrap();
-                let end_node = map.graph.get_node(end_node.target).unwrap().position;
 
-                // Transform positions using common method
-                let start = transform_position_with_offset(start_node_model.position, scale);
-                let end = transform_position_with_offset(end_node, scale);
+            // Use cached batched line segments
+            batched_lines.render(debug_canvas);
 
-                debug_canvas
-                    .draw_line(Point::from((start.x, start.y)), Point::from((end.x, end.y)))
-                    .unwrap();
-            }
+            {
+                let rects: Vec<_> = map
+                    .graph
+                    .nodes()
+                    .enumerate()
+                    .filter_map(|(id, node)| {
+                        let pos = transform_position_with_offset(node.position, scale);
+                        let size = (2.0 * scale) as u32;
+                        let rect = Rect::new(pos.x - (size as i32 / 2), pos.y - (size as i32 / 2), size, size);
 
-            for (id, node) in map.graph.nodes().enumerate() {
-                let pos = node.position;
+                        // If the node is the one closest to the cursor, draw it immediately
+                        if closest_node == Some(id) {
+                            debug_canvas.set_draw_color(Color::YELLOW);
+                            debug_canvas.fill_rect(rect).unwrap();
+                            return None;
+                        }
 
-                // Set color based on whether the node is the closest to the cursor
-                debug_canvas.set_draw_color(Color {
-                    a: f32_to_u8(if Some(id) == closest_node { 0.75 } else { 0.6 }),
-                    ..(if Some(id) == closest_node {
-                        Color::YELLOW
-                    } else {
-                        Color::BLUE
+                        Some(rect)
                     })
-                });
+                    .collect();
 
-                // Transform position using common method
-                let pos = transform_position_with_offset(pos, scale);
-                let size = (2.0 * scale) as u32;
+                if rects.len() > rects.capacity() {
+                    warn!(
+                        capacity = rects.capacity(),
+                        count = rects.len(),
+                        "Node rects capacity exceeded"
+                    );
+                }
 
-                debug_canvas
-                    .fill_rect(Rect::new(pos.x - (size as i32 / 2), pos.y - (size as i32 / 2), size, size))
-                    .unwrap();
+                // Draw the non-closest nodes all at once in blue
+                debug_canvas.set_draw_color(Color::BLUE);
+                debug_canvas.fill_rects(&rects).unwrap();
             }
 
             // Render node ID if a node is highlighted
@@ -188,20 +318,25 @@ pub fn debug_render_system(
                 let node = map.graph.get_node(closest_node_id as NodeId).unwrap();
                 let pos = transform_position_with_offset(node.position, scale);
 
-                let surface = font
-                    .render(&closest_node_id.to_string())
-                    .blended(Color {
-                        a: f32_to_u8(0.4),
-                        ..Color::WHITE
-                    })
+                let node_id_text = closest_node_id.to_string();
+                let text_pos = Vec2::new((pos.x + 10) as f32, (pos.y - 5) as f32);
+
+                text_renderer
+                    .render_text(
+                        debug_canvas,
+                        &mut ttf_atlas.0,
+                        &node_id_text,
+                        text_pos,
+                        Color {
+                            a: f32_to_u8(0.4),
+                            ..Color::WHITE
+                        },
+                    )
                     .unwrap();
-                let texture = texture_creator.create_texture_from_surface(&surface).unwrap();
-                let dest = Rect::new(pos.x + 10, pos.y - 5, texture.query().width, texture.query().height);
-                debug_canvas.copy(&texture, None, dest).unwrap();
             }
 
             // Render timing information in the top-left corner
-            render_timing_display(debug_canvas, &mut texture_creator, &timings, font);
+            render_timing_display(debug_canvas, &timings, &text_renderer, &mut ttf_atlas.0);
         })
         .unwrap();
 }

src/systems/ghost.rs

@@ -1,3 +1,4 @@
+use crate::platform;
 use crate::systems::components::{DirectionalAnimation, Frozen, GhostAnimation, GhostState, LastAnimationState, LinearAnimation};
 use crate::{
     map::{
@@ -14,9 +15,7 @@ use crate::{
 use crate::systems::GhostAnimations;
 use bevy_ecs::query::Without;
 use bevy_ecs::system::{Commands, Query, Res};
-use rand::rngs::SmallRng;
 use rand::seq::IndexedRandom;
-use rand::SeedableRng;
 use smallvec::SmallVec;
 
 /// Autonomous ghost AI system implementing randomized movement with backtracking avoidance.
@@ -49,7 +48,7 @@ pub fn ghost_movement_system(
                             break;
                         }
                     } else {
-                        *non_opposite_options.choose(&mut SmallRng::from_os_rng()).unwrap()
+                        *non_opposite_options.choose(&mut platform::rng()).unwrap()
                     };
 
                     velocity.direction = new_edge.direction;

src/systems/input.rs

@@ -138,14 +138,12 @@ pub fn input_system(
 
     // Warn if the smallvec was heap allocated due to exceeding stack capacity
     #[cfg(debug_assertions)]
-    {
-        if frame_events.len() > frame_events.capacity() {
-            tracing::warn!(
-                "More than {} events in a frame, consider adjusting stack capacity: {:?}",
-                frame_events.capacity(),
-                frame_events
-            );
-        }
+    if frame_events.len() > frame_events.capacity() {
+        tracing::warn!(
+            "More than {} events in a frame, consider adjusting stack capacity: {:?}",
+            frame_events.capacity(),
+            frame_events
+        );
     }
 
     // Handle non-keyboard events inline and build a simplified keyboard event stream.

src/systems/profiling.rs

@@ -3,12 +3,12 @@ use bevy_ecs::{resource::Resource, system::System};
 use circular_buffer::CircularBuffer;
 use micromap::Map;
 use num_width::NumberWidth;
-use parking_lot::{Mutex, RwLock};
+use parking_lot::Mutex;
 use smallvec::SmallVec;
 use std::fmt::Display;
 use std::time::Duration;
-use strum::EnumCount;
-use strum_macros::{EnumCount, IntoStaticStr};
+use strum::{EnumCount, IntoEnumIterator};
+use strum_macros::{EnumCount, EnumIter, IntoStaticStr};
 use thousands::Separable;
 
 /// The maximum number of systems that can be profiled. Must not be exceeded, or it will panic.
@@ -16,7 +16,7 @@ const MAX_SYSTEMS: usize = SystemId::COUNT;
 /// The number of durations to keep in the circular buffer.
 const TIMING_WINDOW_SIZE: usize = 30;
 
-#[derive(EnumCount, IntoStaticStr, Debug, PartialEq, Eq, Hash, Copy, Clone)]
+#[derive(EnumCount, EnumIter, IntoStaticStr, Debug, PartialEq, Eq, Hash, Copy, Clone)]
 pub enum SystemId {
     Input,
     PlayerControls,
@@ -46,7 +46,7 @@ impl Display for SystemId {
     }
 }
 
-#[derive(Resource, Default, Debug)]
+#[derive(Resource, Debug)]
 pub struct SystemTimings {
     /// Map of system names to a queue of durations, using a circular buffer.
     ///
@@ -55,52 +55,64 @@ pub struct SystemTimings {
     ///
     /// Also, we use a micromap::Map as the number of systems is generally quite small.
     /// Just make sure to set the capacity appropriately, or it will panic.
-    pub timings: RwLock<Map<SystemId, Mutex<CircularBuffer<TIMING_WINDOW_SIZE, Duration>>, MAX_SYSTEMS>>,
+    ///
+    /// Pre-populated with all SystemId variants during initialization to avoid runtime allocations
+    /// and allow systems to have default zero timings when they don't submit data.
+    pub timings: Map<SystemId, Mutex<CircularBuffer<TIMING_WINDOW_SIZE, Duration>>, MAX_SYSTEMS>,
+}
+
+impl Default for SystemTimings {
+    fn default() -> Self {
+        let mut timings = Map::new();
+
+        // Pre-populate with all SystemId variants to avoid runtime allocations
+        // and provide default zero timings for systems that don't submit data
+        for id in SystemId::iter() {
+            timings.insert(id, Mutex::new(CircularBuffer::new()));
+        }
+
+        Self { timings }
+    }
 }
 
 impl SystemTimings {
     pub fn add_timing(&self, id: SystemId, duration: Duration) {
-        // acquire a upgradable read lock
-        let mut timings = self.timings.upgradable_read();
-
-        // happy path, the name is already in the map (no need to mutate the hashmap)
-        if timings.contains_key(&id) {
-            let queue = timings
-                .get(&id)
-                .expect("System name not found in map after contains_key check");
-            let mut queue = queue.lock();
-
-            queue.push_back(duration);
-            return;
-        }
-
-        // otherwise, acquire a write lock and insert a new queue
-        timings.with_upgraded(|timings| {
-            let queue = timings.entry(id).or_insert_with(|| Mutex::new(CircularBuffer::new()));
-            queue.lock().push_back(duration);
-        });
+        // Since all SystemId variants are pre-populated, we can use a simple read lock
+        let queue = self
+            .timings
+            .get(&id)
+            .expect("SystemId not found in pre-populated map - this is a bug");
+        queue.lock().push_back(duration);
     }
 
     pub fn get_stats(&self) -> Map<SystemId, (Duration, Duration), MAX_SYSTEMS> {
-        let timings = self.timings.read();
         let mut stats = Map::new();
 
-        for (id, queue) in timings.iter() {
-            if queue.lock().is_empty() {
+        // Iterate over all SystemId variants to ensure every system has an entry
+        for id in SystemId::iter() {
+            let queue = self
+                .timings
+                .get(&id)
+                .expect("SystemId not found in pre-populated map - this is a bug");
+
+            let queue_guard = queue.lock();
+            if queue_guard.is_empty() {
+                // Return zero timing for systems that haven't submitted any data
+                stats.insert(id, (Duration::ZERO, Duration::ZERO));
                 continue;
             }
 
-            let durations: Vec<f64> = queue.lock().iter().map(|d| d.as_secs_f64() * 1000.0).collect();
+            let durations: Vec<f64> = queue_guard.iter().map(|d| d.as_secs_f64() * 1000.0).collect();
             let count = durations.len() as f64;
 
             let sum: f64 = durations.iter().sum();
             let mean = sum / count;
 
-            let variance = durations.iter().map(|x| (x - mean).powi(2)).sum::<f64>() / count;
+            let variance = durations.iter().map(|x| (x - mean).powi(2)).sum::<f64>() / (count - 1.0).max(1.0);
             let std_dev = variance.sqrt();
 
             stats.insert(
-                *id,
+                id,
                 (
                     Duration::from_secs_f64(mean / 1000.0),
                     Duration::from_secs_f64(std_dev / 1000.0),
@@ -113,8 +125,7 @@ impl SystemTimings {
 
     pub fn get_total_stats(&self) -> (Duration, Duration) {
         let duration_sums = {
-            let timings = self.timings.read();
-            timings
+            self.timings
                 .iter()
                 .map(|(_, queue)| queue.lock().iter().sum::<Duration>())
                 .collect::<Vec<_>>()
@@ -128,7 +139,7 @@ impl SystemTimings {
                 diff_secs * diff_secs
             })
             .sum::<f64>()
-            / duration_sums.len() as f64;
+            / (duration_sums.len() - 1).max(1) as f64;
         let std_dev_secs = variance.sqrt();
 
         (mean, Duration::from_secs_f64(std_dev_secs))
@@ -250,17 +261,22 @@ pub fn format_timing_display(
         })
         .collect::<SmallVec<[Entry; 12]>>();
 
-    let (max_name_width, max_avg_int_width, max_avg_decimal_width, max_std_int_width, max_std_decimal_width) = entries
-        .iter()
-        .fold((0, 0, 3, 0, 3), |(name_w, avg_int_w, avg_dec_w, std_int_w, std_dec_w), e| {
-            (
-                name_w.max(e.name.len()),
-                avg_int_w.max(e.avg_int.width() as usize),
-                avg_dec_w.max(e.avg_decimal.width() as usize),
-                std_int_w.max(e.std_int.width() as usize),
-                std_dec_w.max(e.std_decimal.width() as usize),
-            )
-        });
+    let (max_avg_int_width, max_avg_decimal_width, max_std_int_width, max_std_decimal_width) =
+        entries
+            .iter()
+            .fold((0, 3, 0, 3), |(avg_int_w, avg_dec_w, std_int_w, std_dec_w), e| {
+                (
+                    avg_int_w.max(e.avg_int.width() as usize),
+                    avg_dec_w.max(e.avg_decimal.width() as usize),
+                    std_int_w.max(e.std_int.width() as usize),
+                    std_dec_w.max(e.std_decimal.width() as usize),
+                )
+            });
+
+    let max_name_width = SystemId::iter()
+        .map(|id| id.to_string().len())
+        .max()
+        .expect("SystemId::iter() returned an empty iterator");
 
     entries.iter().map(|e| {
             format!(

src/systems/render.rs

@@ -225,8 +225,6 @@ pub fn render_system(
         })
         .err()
         .map(|e| errors.write(TextureError::RenderFailed(e.to_string()).into()));
-
-    canvas.copy(&backbuffer.0, None, None).unwrap();
 }
 
 pub fn present_system(

src/texture/mod.rs

@@ -2,3 +2,4 @@ pub mod animated;
 pub mod blinking;
 pub mod sprite;
 pub mod text;
+pub mod ttf;

src/texture/ttf.rs

@@ -0,0 +1,272 @@
+//! TTF font rendering using pre-rendered character atlas.
+//!
+//! This module provides efficient TTF font rendering by pre-rendering all needed
+//! characters into a texture atlas at startup, avoiding expensive SDL2 font
+//! surface-to-texture conversions every frame.
+
+use glam::{UVec2, Vec2};
+use sdl2::pixels::Color;
+use sdl2::rect::Rect;
+use sdl2::render::{Canvas, RenderTarget, Texture, TextureCreator};
+
+use sdl2::ttf::Font;
+use sdl2::video::WindowContext;
+use std::collections::HashMap;
+
+use crate::error::{GameError, TextureError};
+
+/// Character atlas tile representing a single rendered character
+#[derive(Clone, Copy, Debug)]
+pub struct TtfCharTile {
+    pub pos: UVec2,
+    pub size: UVec2,
+    pub advance: u32, // Character advance width for proportional fonts
+}
+
+/// TTF text atlas containing pre-rendered characters for efficient rendering
+pub struct TtfAtlas {
+    /// The texture containing all rendered characters
+    texture: Texture,
+    /// Mapping from character to its position and size in the atlas
+    char_tiles: HashMap<char, TtfCharTile>,
+    /// Cached color modulation state to avoid redundant SDL2 calls
+    last_modulation: Option<Color>,
+}
+
+const TTF_CHARS: &str = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.,:-/()ms μµ%± ";
+
+impl TtfAtlas {
+    /// Creates a new TTF text atlas by pre-rendering all needed characters.
+    ///
+    /// This should be called once at startup. It renders all characters that might
+    /// be used in text rendering into a single texture atlas for efficient GPU rendering.
+    pub fn new(texture_creator: &TextureCreator<WindowContext>, font: &Font) -> Result<Self, GameError> {
+        // Calculate character dimensions and advance widths for proportional fonts
+        let mut char_tiles = HashMap::new();
+        let mut max_height = 0u32;
+        let mut total_width = 0u32;
+        let mut char_metrics = Vec::new();
+
+        // First pass: measure all characters
+        for c in TTF_CHARS.chars() {
+            if c == ' ' {
+                // Handle space character specially - measure a non-space character for height
+                let space_height = font.size_of("0").map_err(|e| GameError::Sdl(e.to_string()))?.1;
+                let space_advance = font.size_of(" ").map_err(|e| GameError::Sdl(e.to_string()))?.0;
+                char_tiles.insert(
+                    c,
+                    TtfCharTile {
+                        pos: UVec2::ZERO,                  // Will be set during population
+                        size: UVec2::new(0, space_height), // Space has no visual content
+                        advance: space_advance,
+                    },
+                );
+                max_height = max_height.max(space_height);
+                char_metrics.push((c, 0, space_height, space_advance));
+            } else {
+                let (advance, height) = font.size_of(&c.to_string()).map_err(|e| GameError::Sdl(e.to_string()))?;
+                char_tiles.insert(
+                    c,
+                    TtfCharTile {
+                        pos: UVec2::ZERO, // Will be set during population
+                        size: UVec2::new(advance, height),
+                        advance,
+                    },
+                );
+                max_height = max_height.max(height);
+                total_width += advance;
+                char_metrics.push((c, advance, height, advance));
+            }
+        }
+
+        // Calculate atlas dimensions (pack characters horizontally for better space utilization)
+        let atlas_size = UVec2::new(total_width, max_height);
+
+        // Create atlas texture as a render target
+        let mut atlas_texture = texture_creator
+            .create_texture_target(None, atlas_size.x, atlas_size.y)
+            .map_err(|e| GameError::Sdl(e.to_string()))?;
+        atlas_texture.set_blend_mode(sdl2::render::BlendMode::Blend);
+
+        // Second pass: calculate positions
+        let mut current_x = 0u32;
+        for (c, width, _height, _advance) in char_metrics {
+            if let Some(tile) = char_tiles.get_mut(&c) {
+                tile.pos = UVec2::new(current_x, 0);
+                current_x += width;
+            }
+        }
+
+        Ok(Self {
+            texture: atlas_texture,
+            char_tiles,
+            last_modulation: None,
+        })
+    }
+
+    /// Renders all characters to the atlas texture using a canvas.
+    /// This must be called after creation to populate the atlas.
+    pub fn populate_atlas<C: RenderTarget>(
+        &mut self,
+        canvas: &mut Canvas<C>,
+        texture_creator: &TextureCreator<WindowContext>,
+        font: &Font,
+    ) -> Result<(), GameError> {
+        let mut render_error: Option<GameError> = None;
+
+        let result = canvas.with_texture_canvas(&mut self.texture, |atlas_canvas| {
+            // Clear with transparent background
+            atlas_canvas.set_draw_color(Color::RGBA(0, 0, 0, 0));
+            atlas_canvas.clear();
+
+            for c in TTF_CHARS.chars() {
+                if c == ' ' {
+                    // Skip rendering space character - it has no visual content
+                    continue;
+                }
+
+                // Render character to surface
+                let surface = match font.render(&c.to_string()).blended(Color::WHITE) {
+                    Ok(s) => s,
+                    Err(e) => {
+                        render_error = Some(GameError::Sdl(e.to_string()));
+                        return;
+                    }
+                };
+
+                // Create texture from surface
+                let char_texture = match texture_creator.create_texture_from_surface(&surface) {
+                    Ok(t) => t,
+                    Err(e) => {
+                        render_error = Some(GameError::Sdl(e.to_string()));
+                        return;
+                    }
+                };
+
+                // Get character tile info
+                let tile = match self.char_tiles.get(&c) {
+                    Some(t) => t,
+                    None => {
+                        render_error = Some(GameError::Sdl(format!("Character '{}' not found in atlas tiles", c)));
+                        return;
+                    }
+                };
+
+                // Copy character to atlas
+                let dest = Rect::new(tile.pos.x as i32, tile.pos.y as i32, tile.size.x, tile.size.y);
+                if let Err(e) = atlas_canvas.copy(&char_texture, None, dest) {
+                    render_error = Some(GameError::Sdl(e.to_string()));
+                    return;
+                }
+            }
+        });
+
+        // Check the result of with_texture_canvas and any render error
+        if let Err(e) = result {
+            return Err(GameError::Sdl(e.to_string()));
+        }
+
+        if let Some(error) = render_error {
+            return Err(error);
+        }
+
+        Ok(())
+    }
+
+    /// Gets a character tile from the atlas
+    pub fn get_char_tile(&self, c: char) -> Option<&TtfCharTile> {
+        self.char_tiles.get(&c)
+    }
+}
+
+/// TTF text renderer that uses the pre-rendered character atlas
+pub struct TtfRenderer {
+    scale: f32,
+}
+
+impl TtfRenderer {
+    pub fn new(scale: f32) -> Self {
+        Self { scale }
+    }
+
+    /// Renders a string of text at the given position with the specified color
+    pub fn render_text<C: RenderTarget>(
+        &self,
+        canvas: &mut Canvas<C>,
+        atlas: &mut TtfAtlas,
+        text: &str,
+        position: Vec2,
+        color: Color,
+    ) -> Result<(), TextureError> {
+        let mut x_offset = 0.0;
+
+        // Apply color modulation once at the beginning if needed
+        if atlas.last_modulation != Some(color) {
+            atlas.texture.set_color_mod(color.r, color.g, color.b);
+            atlas.texture.set_alpha_mod(color.a);
+            atlas.last_modulation = Some(color);
+        }
+
+        for c in text.chars() {
+            // Get character tile info first to avoid borrowing conflicts
+            let char_tile = atlas.get_char_tile(c);
+
+            if let Some(char_tile) = char_tile {
+                if char_tile.size.x > 0 && char_tile.size.y > 0 {
+                    // Only render non-space characters
+                    let dest = Rect::new(
+                        (position.x + x_offset) as i32,
+                        position.y as i32,
+                        (char_tile.size.x as f32 * self.scale) as u32,
+                        (char_tile.size.y as f32 * self.scale) as u32,
+                    );
+
+                    // Render the character directly
+                    let src = Rect::new(
+                        char_tile.pos.x as i32,
+                        char_tile.pos.y as i32,
+                        char_tile.size.x,
+                        char_tile.size.y,
+                    );
+                    canvas.copy(&atlas.texture, src, dest).map_err(TextureError::RenderFailed)?;
+                }
+
+                // Advance by character advance width (proportional spacing)
+                x_offset += char_tile.advance as f32 * self.scale;
+            } else {
+                // Fallback for unsupported characters - use a reasonable default
+                x_offset += 8.0 * self.scale;
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Calculate the width of a text string in pixels
+    pub fn text_width(&self, atlas: &TtfAtlas, text: &str) -> u32 {
+        let mut total_width = 0u32;
+
+        for c in text.chars() {
+            if let Some(char_tile) = atlas.get_char_tile(c) {
+                total_width += (char_tile.advance as f32 * self.scale) as u32;
+            } else {
+                // Fallback for unsupported characters
+                total_width += (8.0 * self.scale) as u32;
+            }
+        }
+
+        total_width
+    }
+
+    /// Calculate the height of text in pixels
+    pub fn text_height(&self, atlas: &TtfAtlas) -> u32 {
+        // Find the maximum height among all characters
+        atlas
+            .char_tiles
+            .values()
+            .map(|tile| tile.size.y)
+            .max()
+            .unwrap_or(0)
+            .saturating_mul(self.scale as u32)
+    }
+}

tests/profiling.rs

@@ -1,5 +1,22 @@
 use pacman::systems::profiling::{SystemId, SystemTimings};
 use std::time::Duration;
+use strum::IntoEnumIterator;
+
+macro_rules! assert_close {
+    ($actual:expr, $expected:expr, $concern:expr) => {
+        let tolerance = Duration::from_micros(500);
+        let diff = $actual.abs_diff($expected);
+        assert!(
+            diff < tolerance,
+            "Expected {expected:?} ± {tolerance:.0?}, got {actual:?}, off by {diff:?} ({concern})",
+            concern = $concern,
+            expected = $expected,
+            actual = $actual,
+            tolerance = tolerance,
+            diff = diff
+        );
+    };
+}
 
 #[test]
 fn test_timing_statistics() {
@@ -14,47 +31,80 @@ fn test_timing_statistics() {
     timings.add_timing(SystemId::Blinking, Duration::from_millis(3));
     timings.add_timing(SystemId::Blinking, Duration::from_millis(2));
     timings.add_timing(SystemId::Blinking, Duration::from_millis(1));
-    fn close_enough(a: Duration, b: Duration) -> bool {
-        if a > b {
-            a - b < Duration::from_micros(500) // 0.1ms
-        } else {
-            b - a < Duration::from_micros(500)
-        }
+
+    {
+        let stats = timings.get_stats();
+        let (avg, std_dev) = stats.get(&SystemId::PlayerControls).unwrap();
+
+        assert_close!(*avg, Duration::from_millis(10), "PlayerControls average timing");
+        assert_close!(*std_dev, Duration::from_millis(2), "PlayerControls standard deviation timing");
     }
 
-    let stats = timings.get_stats();
-    let (avg, std_dev) = stats.get(&SystemId::PlayerControls).unwrap();
-
-    // Average should be 10ms, standard deviation should be small
-    assert!(close_enough(*avg, Duration::from_millis(10)), "avg: {:?}", avg);
-    assert!(close_enough(*std_dev, Duration::from_millis(2)), "std_dev: {:?}", std_dev);
-
-    let (total_avg, total_std) = timings.get_total_stats();
-    assert!(
-        close_enough(total_avg, Duration::from_millis(18)),
-        "total_avg: {:?}",
-        total_avg
-    );
-    assert!(
-        close_enough(total_std, Duration::from_millis(12)),
-        "total_std: {:?}",
-        total_std
-    );
+    {
+        let (total_avg, total_std) = timings.get_total_stats();
+        assert_close!(total_avg, Duration::from_millis(2), "Total average timing across all systems");
+        assert_close!(
+            total_std,
+            Duration::from_millis(7),
+            "Total standard deviation timing across all systems"
+        );
+    }
 }
 
-// #[test]
-// fn test_window_size_limit() {
-//     let timings = SystemTimings::default();
+#[test]
+fn test_default_zero_timing_for_unused_systems() {
+    let timings = SystemTimings::default();
 
-//     // Add more than 90 timings to test window size limit
-//     for i in 0..100 {
-//         timings.add_timing("test_system", Duration::from_millis(i));
-//     }
+    // Add timing data for only one system
+    timings.add_timing(SystemId::PlayerControls, Duration::from_millis(5));
 
-//     let stats = timings.get_stats();
-//     let (avg, _) = stats.get("test_system").unwrap();
+    let stats = timings.get_stats();
 
-//     // Should only keep the last 90 values, so average should be around 55ms
-//     // (average of 10-99)
-//     assert!((avg.as_millis() as f64 - 55.0).abs() < 5.0);
-// }
+    // Verify all SystemId variants are present in the stats
+    let expected_count = SystemId::iter().count();
+    assert_eq!(stats.len(), expected_count, "All SystemId variants should be in stats");
+
+    // Verify that the system with data has non-zero timing
+    let (avg, std_dev) = stats.get(&SystemId::PlayerControls).unwrap();
+    assert_close!(*avg, Duration::from_millis(5), "System with data should have correct timing");
+    assert_close!(*std_dev, Duration::ZERO, "Single measurement should have zero std dev");
+
+    // Verify that all other systems have zero timing
+    for id in SystemId::iter() {
+        if id != SystemId::PlayerControls {
+            let (avg, std_dev) = stats.get(&id).unwrap();
+            assert_close!(
+                *avg,
+                Duration::ZERO,
+                format!("Unused system {:?} should have zero avg timing", id)
+            );
+            assert_close!(
+                *std_dev,
+                Duration::ZERO,
+                format!("Unused system {:?} should have zero std dev", id)
+            );
+        }
+    }
+}
+
+#[test]
+fn test_pre_populated_timing_entries() {
+    let timings = SystemTimings::default();
+
+    // Verify that we can add timing to any SystemId without panicking
+    // (this would fail with the old implementation if the entry didn't exist)
+    for id in SystemId::iter() {
+        timings.add_timing(id, Duration::from_nanos(1));
+    }
+
+    // Verify all systems now have non-zero timing
+    let stats = timings.get_stats();
+    for id in SystemId::iter() {
+        let (avg, _) = stats.get(&id).unwrap();
+        assert!(
+            *avg > Duration::ZERO,
+            "System {:?} should have non-zero timing after add_timing",
+            id
+        );
+    }
+}