add some perf notes

src/render/render_graph_2/shader.rs

@@ -348,6 +348,7 @@ where
             for (i, (entity, _uniforms)) in query.iter_entities(world).enumerate() {
                 // TODO: check if index has changed. if it has, then entity should be updated
                 // TODO: only mem-map entities if their data has changed
+                // PERF: These hashmap inserts are pretty expensive (10 fps for 10000 entities)
                 info.offsets.insert(entity, offset as u64);
                 info.indices.insert(i, entity);
                 // TODO: try getting ref first

src/render/render_graph_2/wgpu_renderer.rs

@@ -667,7 +667,8 @@ impl<'a, 'b, 'c, 'd> RenderPass for WgpuRenderPass<'a, 'b, 'c, 'd> {
                     if !dynamic {
                         continue;
                     }
-
+                    
+                    // PERF: This hashmap get is pretty expensive (10 fps per 10000 entities)
                     if let Some(dynamic_uniform_buffer_info) =
                         self.renderer.dynamic_uniform_buffer_info.get(&binding.name)
                     {