Diagnostics / Custom Diagnostic

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Support for WebGPU in Bevy hasn't been released yet, this example has been compiled using the main branch.

//! This example illustrates how to create a custom diagnostic.

use bevy::{
    diagnostic::{Diagnostic, DiagnosticId, Diagnostics, LogDiagnosticsPlugin},

fn main() {
        // The "print diagnostics" plugin is optional.
        // It just visualizes our diagnostics in the console.
        .add_systems(Startup, setup_diagnostic_system)
        .add_systems(Update, my_system)

// All diagnostics should have a unique DiagnosticId.
// For each new diagnostic, generate a new random number.
pub const SYSTEM_ITERATION_COUNT: DiagnosticId =

fn setup_diagnostic_system(mut diagnostics: ResMut<Diagnostics>) {
    // Diagnostics must be initialized before measurements can be added.
    // In general it's a good idea to set them up in a "startup system".

fn my_system(mut diagnostics: ResMut<Diagnostics>) {
    // Add a measurement of 10.0 for our diagnostic each time this system runs.
    diagnostics.add_measurement(SYSTEM_ITERATION_COUNT, || 10.0);