add frame count

crates/bevy_pbr/src/render/mesh_view_types.wgsl

@@ -91,4 +91,6 @@ struct Globals {
     time: f32,
     // The delta time of the previous frame in seconds
     delta_time: f32,
+    // Frame count since the start of the app.
+    frame_count: u32,
 }

crates/bevy_render/src/globals.rs

@@ -6,9 +6,13 @@ use crate::{
 };
 use bevy_app::{App, Plugin};
 use bevy_ecs::prelude::*;
+use bevy_log::info;
 use bevy_reflect::Reflect;
 use bevy_time::Time;
 
+#[derive(Default, Resource)]
+struct FrameCount(u32);
+
 pub struct GlobalsPlugin;
 
 impl Plugin for GlobalsPlugin {
@@ -17,6 +21,7 @@ impl Plugin for GlobalsPlugin {
             render_app
                 .init_resource::<GlobalsBuffer>()
                 .init_resource::<Time>()
+                .init_resource::<FrameCount>()
                 .add_system_to_stage(RenderStage::Extract, extract_time)
                 .add_system_to_stage(RenderStage::Prepare, prepare_globals_buffer);
         }
@@ -36,6 +41,8 @@ pub struct GlobalsUniform {
     time: f32,
     /// The duration of the last frame in seconds
     delta_time: f32,
+    /// Frame count since the start of the app.
+    frame_count: u32,
 }
 
 /// The buffer containing the [`GlobalsUniform`]
@@ -49,10 +56,17 @@ fn prepare_globals_buffer(
     render_queue: Res<RenderQueue>,
     mut globals_buffer: ResMut<GlobalsBuffer>,
     time: Res<Time>,
+    mut frame_count: Local<u32>,
 ) {
+    // We can't rely on the FrameTimeDiagnosticsPlugin to be present since it is not part of DefaultPlugins
+    *frame_count = frame_count.wrapping_add(1);
+
     let buffer = globals_buffer.buffer.get_mut();
     buffer.time = time.seconds_since_startup() as f32;
     buffer.delta_time = time.delta_seconds();
+    buffer.frame_count = *frame_count;
+
+    info!("{frame_count:?}");
 
     globals_buffer
         .buffer