sim: fold most accessors behind the meta method

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

@@ -2,6 +2,7 @@ pub mod mat;
 
 use crate::geom::{Coord, Index, Meters};
 use crate::cross::real::{R32, Real};
+use crate::cross::step::SimMeta;
 use crate::cross::vec::{Vec3, Vec3u};
 use crate::sim::{CellStateWithM, GenericSim, MaterialSim, Sample, SampleableSim, StaticSim};
 use crate::stim::AbstractStimulus;
@@ -343,22 +344,23 @@ impl<R: Real, M: Material<R> + Send + Sync> SampleableSim for SimState<R, M> {
         }
     }
 
-    fn size(&self) -> Index {
-        Index(Vec3u::new(
+    fn meta(&self) -> SimMeta<f32> {
+        let dim = Vec3u::new(
             self.cells.shape()[2] as _,
             self.cells.shape()[1] as _,
             self.cells.shape()[0] as _,
-        ))
-    }
-    fn feature_size(&self) -> f32 {
-        self.feature_size.to_f32()
-    }
-    fn timestep(&self) -> f32 {
-        self.timestep.to_f32()
+        );
+        let feature_size = self.feature_size.to_f32();
+        let inv_feature_size = 1.0/feature_size;
+        let time_step = self.timestep.to_f32();
+        SimMeta {
+            dim, feature_size, inv_feature_size, time_step
+        }
     }
     fn step_no(&self) -> u64 {
         self.step_no
     }
+
     fn to_static(&self) -> StaticSim {
         unimplemented!()
     }

crates/coremem/src/sim/mod.rs

@@ -1,6 +1,7 @@
 use crate::geom::{Coord, Cube, Index, InvertedRegion, Meters, Region};
 use crate::cross::mat::Vacuum;
 use crate::cross::real::Real;
+use crate::cross::step::SimMeta;
 use crate::cross::vec::{Vec3, Vec3u};
 use crate::stim::{AbstractStimulus, NoopStimulus};
 use rayon::prelude::*;
@@ -292,9 +293,18 @@ impl<'a> dyn SampleableSim + 'a {
 // TODO: the Send/Sync bounds here could be removed with some refactoring
 pub trait SampleableSim: Send + Sync {
     fn sample(&self, pos: Meters) -> Sample;
+    fn meta(&self) -> SimMeta<f32>;
+    fn step_no(&self) -> u64;
 
-    fn size(&self) -> Index;
-    fn feature_size(&self) -> f32;
+    /// Take a "snapshot" of the simulation, dropping all material-specific information.
+    fn to_static(&self) -> StaticSim;
+
+    fn size(&self) -> Index {
+        Index(self.meta().dim)
+    }
+    fn feature_size(&self) -> f32 {
+        self.meta().feature_size
+    }
     fn feature_volume(&self) -> f32 {
         let f = self.feature_size();
         f*f*f
@@ -303,9 +313,9 @@ pub trait SampleableSim: Send + Sync {
         let s = self.size().to_meters(self.feature_size());
         s.x() * s.y() * s.z()
     }
-    fn timestep(&self) -> f32;
-
-    fn step_no(&self) -> u64;
+    fn timestep(&self) -> f32 {
+        self.meta().time_step
+    }
 
     fn width(&self) -> u32 {
         self.size().x()
@@ -319,7 +329,4 @@ pub trait SampleableSim: Send + Sync {
     fn time(&self) -> f32 {
         self.timestep() * self.step_no() as f32
     }
-
-    /// Take a "snapshot" of the simulation, dropping all material-specific information.
-    fn to_static(&self) -> StaticSim;
 }

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

@@ -113,18 +113,13 @@ where
         }
     }
 
-    fn size(&self) -> Index {
-        Index(self.meta.dim)
-    }
-    fn feature_size(&self) -> f32 {
-        self.meta.feature_size.cast()
-    }
-    fn timestep(&self) -> f32 {
-        self.meta.time_step.cast()
+    fn meta(&self) -> SimMeta<f32> {
+        self.meta.cast()
     }
     fn step_no(&self) -> u64 {
         self.step_no
     }
+
     fn to_static(&self) -> StaticSim {
         let mut mat = Vec::new();
         mat.resize(self.e.len(), Default::default());