instrument the stimulus evaluation in our sim

... stimulus evaluation accounts for like 80% of the execution time 🤦

crates/coremem/src/diagnostics.rs

@@ -50,7 +50,7 @@ impl Diagnostics {
             render_time,
             block_time,
             render_prep_time,
-            overall_time - step_time - stim_time - block_time - render_prep_time,
+            overall_time - step_time /*- stim_time*/ - block_time - render_prep_time,
         )
     }
 }

crates/coremem/src/driver.rs

@@ -31,7 +31,9 @@ pub struct Driver<S> {
 }
 
 impl<S: AbstractSim> Driver<S> {
-    pub fn new(state: S) -> Self {
+    pub fn new(mut state: S) -> Self {
+        let diag = SyncDiagnostics::new();
+        state.use_diagnostics(diag.clone());
         Self {
             state,
             renderer: Arc::new(MultiRenderer::new()),
@@ -45,7 +47,7 @@ impl<S: AbstractSim> Driver<S> {
             ],
             stimuli: StimuliAdapter::new(),
             sim_end_time: None,
-            diag: SyncDiagnostics::new(),
+            diag,
             last_diag_time: Instant::now(),
         }
     }
@@ -125,6 +127,7 @@ impl<S: AbstractSim + Send + Sync + Serialize + for<'a> Deserialize<'a> + 'stati
         let ser = render::SerializerRenderer::new(state_file);
         let loaded = ser.try_load().map(|s| {
             self.state = s.state;
+            self.state.use_diagnostics(self.diag.clone());
         }).is_some();
         self.add_renderer(ser, state_file, snapshot_frequency, None);
         loaded

crates/coremem/src/sim/mod.rs

@@ -1,3 +1,4 @@
+use crate::diagnostics::SyncDiagnostics;
 use crate::geom::{Coord, Cube, Index, InvertedRegion, Region};
 use crate::cross::mat::{FullyGenericMaterial, Material, Vacuum};
 use crate::cross::real::Real;
@@ -209,6 +210,9 @@ pub trait AbstractSim: Sync {
     /// Take a "snapshot" of the simulation, dropping all material-specific information.
     fn to_static(&self) -> StaticSim;
     fn to_generic(&self) -> GenericSim<Self::Real>;
+    fn use_diagnostics(&mut self, _diag: SyncDiagnostics) {
+        // optional
+    }
 
 
     //--- HELPER METHODS below (derived) ---//

crates/coremem/src/sim/spirv/mod.rs

@@ -152,6 +152,10 @@ where
             diag: self.diag.clone(),
         }
     }
+
+    fn use_diagnostics(&mut self, diag: SyncDiagnostics) {
+        self.diag = diag;
+    }
 }
 
 impl<R: Real, M: Default, B> SpirvSim<R, M, B>