Performance Profiling

Understanding the performance of your plugins is crucial for maintaining a smooth user experience, especially in a real-time 3D environment like the Foresight SDK.

Using Spans for Profiling

The primary way to profile code in the Foresight SDK is by instrumenting it with tracing spans. By wrapping a block of code in a span, you record how long it takes to execute.

use tracing::info_span;

pub fn heavy_computation() {
    let _span = info_span!("heavy_computation").entered();
    // Your complex logic here...
}

Or using the #[instrument] attribute:

use tracing::instrument;

#[instrument(skip_all)]
pub fn complex_system() {
    // This entire function is now a span.
}

Built-in Profiler

The Foresight SDK includes a built-in profiler that can visualize these spans in real-time. This is often the quickest way to identify which systems or tools are consuming the most frame time.

Opening Developer Tools

You can open the built-in developer tools and profiler using the following keyboard shortcut:

macOS: ⌘ + Shift + I
Windows/Linux: Ctrl + Shift + I

The developer tools panel provides access to real-time performance metrics, span timelines, and other diagnostic utilities.

Third-Party Tools: Tracy

For more in-depth analysis, the SDK supports Tracy, a powerful graphical profiler. Tracy provides a detailed timeline of all spans across different threads, along with memory allocation tracking and more.

How to use Tracy:

Build with Tracy support: Enable the trace_tracy feature when building the client.
```
cargo run --features trace_tracy
```
Run Tracy: Download and run the Tracy profiler application on your machine.
Connect: The client will automatically attempt to connect to the Tracy application when it starts.

Best Practices

Instrument key systems: Add spans to your main Bevy systems and any long-running asynchronous tasks.
Keep spans meaningful: Use descriptive names for your spans.
Avoid excessive overhead: While tracing is efficient, adding thousands of very short spans in a tight loop can impact performance.

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