feat: fix emscripten browser logging, streamline console initialization and logging

src/main.rs

@@ -2,7 +2,7 @@
 #![windows_subsystem = "windows"]
 
 use crate::{app::App, constants::LOOP_TIME};
-use tracing::{debug, info, warn};
+use tracing::info;
 
 mod app;
 mod asset;
@@ -22,19 +22,9 @@ mod texture;
 /// This function initializes SDL, the window, the game state, and then enters
 /// the main game loop.
 pub fn main() {
-    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");
-
-        // Now that console is initialized, flush buffered logs and switch to direct output
-        debug!("Switching to direct logging mode and flushing buffer...");
-        if let Err(error) = switchable_writer.switch_to_direct_mode() {
-            warn!("Failed to flush buffered logs to console: {error:?}");
-        }
-    }
+    // On Windows, this connects output streams to the console dynamically
+    // On Emscripten, this connects the subscriber to the browser console
+    platform::init_console().expect("Could not initialize console");
 
     let mut app = App::new().expect("Could not create app");
 

src/platform/desktop.rs

@@ -20,9 +20,13 @@ pub fn sleep(duration: Duration, focused: bool) {
 pub fn init_console() -> Result<(), PlatformError> {
     #[cfg(windows)]
     {
+        use crate::platform::tracing_buffer::setup_switchable_subscriber;
         use tracing::{debug, info};
         use windows::Win32::System::Console::GetConsoleWindow;
 
+        // Setup buffered tracing subscriber that will buffer logs until console is ready
+        let switchable_writer = setup_switchable_subscriber();
+
         // Check if we already have a console window
         if unsafe { !GetConsoleWindow().0.is_null() } {
             debug!("Already have a console window");
@@ -40,15 +44,19 @@ pub fn init_console() -> Result<(), PlatformError> {
             attach_to_parent_console()?;
             info!("Successfully attached to parent console");
         }
+
+        // Now that console is initialized, flush buffered logs and switch to direct output
+        debug!("Switching to direct logging mode and flushing buffer...");
+        if let Err(error) = switchable_writer.switch_to_direct_mode() {
+            use tracing::warn;
+
+            warn!("Failed to flush buffered logs to console: {error:?}");
+        }
     }
 
     Ok(())
 }
 
-pub fn requires_console() -> bool {
-    cfg!(windows)
-}
-
 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"))),

src/platform/emscripten.rs

@@ -1,18 +1,21 @@
 //! Emscripten platform implementation.
 
-use std::borrow::Cow;
-use std::time::Duration;
-
 use crate::asset::Asset;
 use crate::error::{AssetError, PlatformError};
 use rand::{rngs::SmallRng, SeedableRng};
+use sdl2::rwops::RWops;
+use std::borrow::Cow;
+use std::ffi::CString;
+use std::io::{self, Read, Write};
+use std::time::Duration;
 
 // 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;
+    // Standard C functions that Emscripten redirects to console
+    fn printf(format: *const u8, ...) -> i32;
 }
 
 pub fn sleep(duration: Duration, _focused: bool) {
@@ -22,11 +25,44 @@ pub fn sleep(duration: Duration, _focused: bool) {
 }
 
 pub fn init_console() -> Result<(), PlatformError> {
-    Ok(()) // No-op for Emscripten
+    use tracing_subscriber::{fmt, layer::SubscriberExt, EnvFilter};
+
+    // Set up a custom tracing subscriber that writes directly to emscripten console
+    let subscriber = tracing_subscriber::registry()
+        .with(
+            fmt::layer()
+                .with_writer(|| EmscriptenConsoleWriter)
+                .with_ansi(false)
+                .without_time()
+                .with_target(false),
+        )
+        .with(EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("debug")));
+
+    tracing::subscriber::set_global_default(subscriber)
+        .map_err(|e| PlatformError::ConsoleInit(format!("Failed to set tracing subscriber: {}", e)))?;
+
+    Ok(())
 }
 
-pub fn requires_console() -> bool {
-    false
+/// A writer that outputs to the browser console via printf (redirected by emscripten)
+struct EmscriptenConsoleWriter;
+
+impl Write for EmscriptenConsoleWriter {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        if let Ok(s) = std::str::from_utf8(buf) {
+            if let Ok(cstr) = CString::new(s.trim_end_matches('\n')) {
+                let format_str = CString::new("%s\n").unwrap();
+                unsafe {
+                    printf(format_str.as_ptr().cast(), cstr.as_ptr());
+                }
+            }
+        }
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
 }
 
 #[allow(dead_code)]
@@ -44,18 +80,13 @@ pub fn get_canvas_size() -> Option<(u32, 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)))?;
+    rwops.read_exact(&mut buf).map_err(|e| AssetError::Io(io::Error::other(e)))?;
 
     Ok(Cow::Owned(buf))
 }

src/platform/mod.rs

@@ -1,10 +1,12 @@
 //! Platform abstraction layer for cross-platform functionality.
-pub mod buffered_writer;
-pub mod tracing_buffer;
 
+#[cfg(not(target_os = "emscripten"))]
+pub mod buffered_writer;
 #[cfg(not(target_os = "emscripten"))]
 mod desktop;
 #[cfg(not(target_os = "emscripten"))]
+pub mod tracing_buffer;
+#[cfg(not(target_os = "emscripten"))]
 pub use desktop::*;
 
 #[cfg(target_os = "emscripten")]

src/systems/input.rs

@@ -293,6 +293,9 @@ pub fn input_system(
                     simple_key_events.push(SimpleKeyEvent::KeyUp(key));
                 }
             }
+            Event::RenderTargetsReset { .. } | Event::Window { .. } => {
+                // No-op
+            }
             _ => {
                 tracing::warn!("Unhandled event, consider disabling: {:?}", event);
             }