feat: special formatting with game tick counter, remove date from tracing formatter

src/formatter.rs

@@ -0,0 +1,94 @@
+//! Custom tracing formatter with tick counter integration
+
+use std::fmt;
+use std::sync::atomic::{AtomicU64, Ordering};
+use time::macros::format_description;
+use time::{format_description::FormatItem, OffsetDateTime};
+use tracing::{Event, Subscriber};
+use tracing_subscriber::fmt::format::Writer;
+use tracing_subscriber::fmt::{FmtContext, FormatEvent, FormatFields};
+use tracing_subscriber::registry::LookupSpan;
+
+/// Global atomic counter for tracking game ticks
+static TICK_COUNTER: AtomicU64 = AtomicU64::new(0);
+
+/// Maximum value for tick counter display (16-bit hex)
+const TICK_DISPLAY_MASK: u64 = 0xFFFF;
+
+/// Cached format description for timestamps
+/// Uses 3 subsecond digits on Emscripten, 5 otherwise for better performance
+#[cfg(target_os = "emscripten")]
+const TIMESTAMP_FORMAT: &[FormatItem<'static>] = format_description!("[hour]:[minute]:[second].[subsecond digits:3]");
+
+#[cfg(not(target_os = "emscripten"))]
+const TIMESTAMP_FORMAT: &[FormatItem<'static>] = format_description!("[hour]:[minute]:[second].[subsecond digits:5]");
+
+/// A custom formatter that includes both timestamp and tick counter in hexadecimal
+///
+/// This formatter provides:
+/// - High-precision timestamps (HH:MM:SS.mmm on Emscripten, HH:MM:SS.mmmmm otherwise)
+/// - Hexadecimal tick counter for frame correlation
+/// - Standard log level and target information
+///
+/// Performance considerations:
+/// - Timestamp format is cached at compile time
+/// - Tick counter access is atomic and very fast
+/// - Combined formatting operations for efficiency
+pub struct CustomFormatter;
+
+impl<S, N> FormatEvent<S, N> for CustomFormatter
+where
+    S: Subscriber + for<'a> LookupSpan<'a>,
+    N: for<'a> FormatFields<'a> + 'static,
+{
+    fn format_event(&self, ctx: &FmtContext<'_, S, N>, mut writer: Writer<'_>, event: &Event<'_>) -> fmt::Result {
+        // Format timestamp using cached format description
+        let now = OffsetDateTime::now_utc();
+        let formatted_time = now.format(&TIMESTAMP_FORMAT).map_err(|e| {
+            // Preserve the original error information for debugging
+            eprintln!("Failed to format timestamp: {}", e);
+            fmt::Error
+        })?;
+
+        // Get tick count and format everything together
+        let tick_count = get_tick_count();
+        let metadata = event.metadata();
+
+        // Combined formatting: timestamp, tick counter, level, and target in one write
+        write!(
+            writer,
+            "{} 0x{:04X} {:5} {}: ",
+            formatted_time,
+            tick_count & TICK_DISPLAY_MASK,
+            metadata.level(),
+            metadata.target()
+        )?;
+
+        // Format the fields (the actual log message)
+        ctx.field_format().format_fields(writer.by_ref(), event)?;
+
+        writeln!(writer)
+    }
+}
+
+/// Increment the global tick counter by 1
+///
+/// This should be called once per game tick/frame from the main game loop
+pub fn increment_tick() {
+    TICK_COUNTER.fetch_add(1, Ordering::Relaxed);
+}
+
+/// Get the current tick count
+///
+/// Returns the current value of the global tick counter
+pub fn get_tick_count() -> u64 {
+    TICK_COUNTER.load(Ordering::Relaxed)
+}
+
+/// Reset the tick counter to 0
+///
+/// This can be used for testing or when restarting the game
+#[allow(dead_code)]
+pub fn reset_tick_counter() {
+    TICK_COUNTER.store(0, Ordering::Relaxed);
+}