Move the components into their own module

This makes the module tree more reflective of module use patterns. In
particular, it restores the condition that every top-level module is
used in top-level code, which was broken by the addition of the
`test_assembly_chooser` module in commit 91e4e1f.

README.md

@@ -12,11 +12,11 @@ Note that currently this is just the barest beginnings of the project, more of a
 
 ### Implementation goals
 
-* Provide a comfortable, intuitive UI
+* Comfortable, intuitive UI
 
-* Allow execution in browser (so implemented in WASM-compatible language)
+* Able to run in browser (so implemented in WASM-compatible language)
 
-* Produce scalable graphics of 3D diagrams, and maybe STL files (or other fabricatable file format) as well
+* Produce scalable graphics of 3D diagrams, and maybe STL files (or other fabricatable file format) as well.
 
 ## Prototype
 
@@ -24,40 +24,33 @@ The latest prototype is in the folder `app-proto`. It includes both a user inter
 
 ### Install the prerequisites
 
-1. Install [`rustup`](https://rust-lang.github.io/rustup/): the officially recommended Rust toolchain manager.
-   - It's available on Ubuntu as a [Snap](https://snapcraft.io/rustup).
-2. Call `rustup default stable` to "download the latest stable release of Rust and set it as your default toolchain".
-   - If you forget, the `rustup` [help system](https://github.com/rust-lang/rustup/blob/d9b3601c3feb2e88cf3f8ca4f7ab4fdad71441fd/src/errors.rs#L109-L112) will remind you.
-3. Call `rustup target add wasm32-unknown-unknown` to add the [most generic 32-bit WebAssembly target](https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32-unknown-unknown.html).
-4. Call `cargo install wasm-pack` to install the [WebAssembly toolchain](https://rustwasm.github.io/docs/wasm-pack/).
-5. Call `cargo install trunk` to install the [Trunk](https://trunkrs.dev/) web-build tool.
-   - In the future, `trunk` can be updated with the same command. (You may need the `--locked` flag if your ambient version of `rustc` does not match that required by `trunk`.)
+1. Install [`rustup`](https://rust-lang.github.io/rustup/): the officially recommended Rust toolchain manager
+   * It's available on Ubuntu as a [Snap](https://snapcraft.io/rustup)
+2. Call `rustup default stable` to "download the latest stable release of Rust and set it as your default toolchain"
+   * If you forget, the `rustup` [help system](https://github.com/rust-lang/rustup/blob/d9b3601c3feb2e88cf3f8ca4f7ab4fdad71441fd/src/errors.rs#L109-L112) will remind you
+3. Call `rustup target add wasm32-unknown-unknown` to add the [most generic 32-bit WebAssembly target](https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32-unknown-unknown.html)
+4. Call `cargo install wasm-pack` to install the [WebAssembly toolchain](https://rustwasm.github.io/docs/wasm-pack/)
+5. Call `cargo install trunk` to install the [Trunk](https://trunkrs.dev/) web-build tool
 6. Add the `.cargo/bin` folder in your home directory to your executable search path
-   - This lets you call Trunk, and other tools installed by Cargo, without specifying their paths.
-   - On POSIX systems, the search path is stored in the `PATH` environment variable.
-   - Alternatively, if you don't want to adjust your `PATH`, you can install `trunk` in another directory `DIR` via `cargo install --root DIR trunk`.
+   * This lets you call Trunk, and other tools installed by Cargo, without specifying their paths
+   * On POSIX systems, the search path is stored in the `PATH` environment variable
 
 ### Play with the prototype
 
-1. From the `app-proto` folder, call `trunk serve --release` to build and serve the prototype.
-   - The crates the prototype depends on will be downloaded and served automatically.
-   - For a faster build, at the expense of a much slower prototype, you can call `trunk serve` without the `--release` flag.
-   - If you want to stay in the top-level folder, you can call `trunk serve --config app-proto [--release]` from there instead.
-3. In a web browser, visit one of the URLs listed under the message `INFO 📡 server listening at:`.
-   - Touching any file in the `app-proto` folder will make Trunk rebuild and live-reload the prototype.
-4. Press *ctrl+C* in the shell where Trunk is running to stop serving the prototype.
+1. From the `app-proto` folder, call `trunk serve --release` to build and serve the prototype
+   * *The crates the prototype depends on will be downloaded and served automatically*
+   * *For a faster build, at the expense of a much slower prototype, you can call `trunk serve` without the `--release` flag*
+   * *If you want to stay in the top-level folder, you can call `trunk serve --config app-proto [--release]`* from there instead.
+3. In a web browser, visit one of the URLs listed under the message `INFO 📡 server listening at:`
+   * *Touching any file in the `app-proto` folder will make Trunk rebuild and live-reload the prototype*
+4. Press *ctrl+C* in the shell where Trunk is running to stop serving the prototype
 
 ### Run the engine on some example problems
 
-1. Use `sh` to run the script `tools/run-examples.sh`.
-   - The script is location-independent, so you can do this from anywhere in the dyna3 repository.
-   - The call from the top level of the repository is:
-     
-     ```bash
-     sh tools/run-examples.sh
-     ```
-   - For each example problem, the engine will print the value of the loss function at each optimization step.
-   - The first example that prints is the same as the Irisawa hexlet example from the Julia version of the engine prototype. If you go into `engine-proto/gram-test`, launch Julia, and then execute
+1. Go into the `app-proto` folder
+2. Call `./run-examples`
+   * *For each example problem, the engine will print the value of the loss function at each optimization step*
+   * *The first example that prints is the same as the Irisawa hexlet example from the Julia version of the engine prototype. If you go into `engine-proto/gram-test`, launch Julia, and then*
      
      ```julia
      include("irisawa-hexlet.jl")
@@ -66,24 +59,9 @@ The latest prototype is in the folder `app-proto`. It includes both a user inter
      end
      ```
      
-     you should see that it prints basically the same loss history until the last few steps, when the lower default precision of the Rust engine really starts to show.
+     *you should see that it prints basically the same loss history until the last few steps, when the lower default precision of the Rust engine really starts to show*
 
 ### Run the automated tests
 
-1. Go into the `app-proto` folder.
-2. Call `cargo test`.
-
-### Deploy the prototype
-
-1. From the `app-proto` folder, call `trunk build --release`.
-   - Building in [release mode](https://doc.rust-lang.org/cargo/reference/profiles.html#release) produces an executable which is smaller and often much faster, but harder to debug and more time-consuming to build.
-   - If you want to stay in the top-level folder, you can call `trunk build --config app-proto --release` from there instead.
-2. Use `sh` to run the packaging script `tools/package-for-deployment.sh`.
-   - The script is location-independent, so you can do this from anywhere in the dyna3 repository.
-   - The call from the top level of the repository is:
-     ```bash
-     sh tools/package-for-deployment.sh
-     ```
-   - This will overwrite or replace the files in `deploy/dyna3`.
-3. Put the contents of `deploy/dyna3` in the folder on your server that the prototype will be served from.
-   - To simplify uploading, you might want to combine these files into an archive called `deploy/dyna3.zip`. Git has been set to ignore this path.
+1. Go into the `app-proto` folder
+2. Call `cargo test`

app-proto/Cargo.lock

@@ -255,7 +255,6 @@ dependencies = [
  "charming",
  "console_error_panic_hook",
  "dyna3",
- "enum-iterator",
  "itertools",
  "js-sys",
  "lazy_static",
@@ -272,26 +271,6 @@ version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
 
-[[package]]
-name = "enum-iterator"
-version = "2.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4549325971814bda7a44061bf3fe7e487d447cba01e4220a4b454d630d7a016"
-dependencies = [
- "enum-iterator-derive",
-]
-
-[[package]]
-name = "enum-iterator-derive"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "685adfa4d6f3d765a26bc5dbc936577de9abf756c1feeb3089b01dd395034842"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "equivalent"
 version = "1.0.1"

app-proto/Cargo.toml

@@ -10,7 +10,6 @@ default = ["console_error_panic_hook"]
 dev = []
 
 [dependencies]
-enum-iterator = "2.3.0"
 itertools = "0.13.0"
 js-sys = "0.3.70"
 lazy_static = "1.5.0"

app-proto/Trunk.toml

@@ -1,2 +0,0 @@
-[build]
-public_url = "./"

app-proto/examples/kaleidocycle.rs

@@ -23,7 +23,7 @@ fn main() {
         let twist_motion: DMatrix<_> = (0..N_POINTS).step_by(4).flat_map(
             |n| [
                 tangent.proj(&up.as_view(), n),
-                tangent.proj(&down.as_view(), n+1),
+                tangent.proj(&down.as_view(), n+1)
             ]
         ).sum();
         let normalization = 5.0 / twist_motion[(2, 0)];

app-proto/examples/point-on-sphere.rs

@@ -6,7 +6,7 @@ use dyna3::engine::{
     realize_gram,
     sphere,
     ConfigNeighborhood,
-    ConstraintProblem,
+    ConstraintProblem
 };
 
 fn main() {
@@ -25,7 +25,7 @@ fn main() {
     );
     print::title("Point on a sphere");
     print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, .. }) = realization.result {
+    if let Ok(ConfigNeighborhood{ config, .. }) = realization.result {
         print::gram_matrix(&config);
         print::config(&config);
     }

app-proto/examples/three-spheres.rs

@@ -5,7 +5,7 @@ use dyna3::engine::{
     realize_gram,
     sphere,
     ConfigNeighborhood,
-    ConstraintProblem,
+    ConstraintProblem
 };
 
 fn main() {
@@ -14,7 +14,7 @@ fn main() {
         &[
             sphere(1.0, 0.0, 0.0, 1.0),
             sphere(-0.5, a, 0.0, 1.0),
-            sphere(-0.5, -a, 0.0, 1.0),
+            sphere(-0.5, -a, 0.0, 1.0)
         ]
     });
     for j in 0..3 {
@@ -27,7 +27,7 @@ fn main() {
     );
     print::title("Three spheres");
     print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, .. }) = realization.result {
+    if let Ok(ConfigNeighborhood{ config, .. }) = realization.result {
         print::gram_matrix(&config);
     }
     print::loss_history(&realization.history);

app-proto/main.css

@@ -184,7 +184,6 @@ details[open]:has(li) .element-switch::after {
 
 #diagnostics-bar {
   display: flex;
-  gap: 8px;
 }
 
 #realization-status {
@@ -208,14 +207,6 @@ details[open]:has(li) .element-switch::after {
   content: '⚠';
 }
 
-#step-input > label {
-  padding-right: 4px;
-}
-
-#step-input > input {
-  width: 45px;
-}
-
 .diagnostics-panel {
   margin-top: 10px;
   min-height: 180px;

app-proto/run-examples.sh

@@ -8,7 +8,7 @@
 # the application prototype
 
 # find the manifest file for the application prototype
-MANIFEST="$(dirname -- $0)/../app-proto/Cargo.toml"
+MANIFEST="$(dirname -- $0)/Cargo.toml"
 
 # set up the command that runs each example
 RUN_EXAMPLE="cargo run --manifest-path $MANIFEST --example"

app-proto/src/assembly.rs

@@ -1,14 +1,13 @@
-use enum_iterator::{all, Sequence};
 use nalgebra::{DMatrix, DVector, DVectorView};
 use std::{
     cell::Cell,
-    cmp::Ordering,
     collections::{BTreeMap, BTreeSet},
+    cmp::Ordering,
     fmt,
-    fmt::{Debug, Display, Formatter},
+    fmt::{Debug, Formatter},
     hash::{Hash, Hasher},
     rc::Rc,
-    sync::{atomic, atomic::AtomicU64},
+    sync::{atomic, atomic::AtomicU64}
 };
 use sycamore::prelude::*;
 use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
@@ -17,6 +16,7 @@ use crate::{
     components::{display::DisplayItem, outline::OutlineItem},
     engine::{
         Q,
+        change_half_curvature,
         local_unif_to_std,
         point,
         project_point_to_normalized,
@@ -27,10 +27,9 @@ use crate::{
         ConfigSubspace,
         ConstraintProblem,
         DescentHistory,
-        MatrixEntry,
-        Realization,
+        Realization
     },
-    specified::SpecifiedValue,
+    specified::SpecifiedValue
 };
 
 pub type ElementColor = [f32; 3];
@@ -86,14 +85,6 @@ impl Ord for dyn Serial {
     }
 }
 
-// Small helper function to generate consistent errors when there
-// are indexing issues in a ProblemPoser
-fn indexing_error(item: &str, name: &str, actor: &str) -> String {
-    format!(
-        "{item} \"{name}\" must be indexed before {actor} writes problem data"
-    )
-}
-
 pub trait ProblemPoser {
     fn pose(&self, problem: &mut ConstraintProblem);
 }
@@ -135,8 +126,8 @@ pub trait Element: Serial + ProblemPoser + DisplayItem {
 }
 
 impl Debug for dyn Element {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        Debug::fmt(&self.id(), f)
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
+        self.id().fmt(f)
     }
 }
 
@@ -174,7 +165,7 @@ pub struct Sphere {
     pub ghost: Signal<bool>,
     pub regulators: Signal<BTreeSet<Rc<dyn Regulator>>>,
     serial: u64,
-    column_index: Cell<Option<usize>>,
+    column_index: Cell<Option<usize>>
 }
 
 impl Sphere {
@@ -184,17 +175,17 @@ impl Sphere {
         id: String,
         label: String,
         color: ElementColor,
-        representation: DVector<f64>,
-    ) -> Self {
-        Self {
-            id,
-            label,
-            color,
+        representation: DVector<f64>
+    ) -> Sphere {
+        Sphere {
+            id: id,
+            label: label,
+            color: color,
             representation: create_signal(representation),
             ghost: create_signal(false),
             regulators: create_signal(BTreeSet::new()),
             serial: Self::next_serial(),
-            column_index: None.into(),
+            column_index: None.into()
         }
     }
 }
@@ -204,12 +195,12 @@ impl Element for Sphere {
         "sphere".to_string()
     }
     
-    fn default(id: String, id_num: u64) -> Self {
-        Self::new(
+    fn default(id: String, id_num: u64) -> Sphere {
+        Sphere::new(
             id,
             format!("Sphere {id_num}"),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            sphere(0.0, 0.0, 0.0, 1.0),
+            sphere(0.0, 0.0, 0.0, 1.0)
         )
     }
     
@@ -259,7 +250,8 @@ impl Serial for Sphere {
 impl ProblemPoser for Sphere {
     fn pose(&self, problem: &mut ConstraintProblem) {
         let index = self.column_index().expect(
-            indexing_error("Sphere", &self.id, "it").as_str());
+            format!("Sphere \"{}\" should be indexed before writing problem data", self.id).as_str()
+        );
         problem.gram.push_sym(index, index, 1.0);
         problem.guess.set_column(index, &self.representation.get_clone_untracked());
     }
@@ -273,20 +265,19 @@ pub struct Point {
     pub ghost: Signal<bool>,
     pub regulators: Signal<BTreeSet<Rc<dyn Regulator>>>,
     serial: u64,
-    column_index: Cell<Option<usize>>,
+    column_index: Cell<Option<usize>>
 }
 
 impl Point {
     const WEIGHT_COMPONENT: usize = 3;
-    const NORM_COMPONENT: usize = 4;
     
     pub fn new(
         id: String,
         label: String,
         color: ElementColor,
-        representation: DVector<f64>,
-    ) -> Self {
-        Self {
+        representation: DVector<f64>
+    ) -> Point {
+        Point {
             id,
             label,
             color,
@@ -294,7 +285,7 @@ impl Point {
             ghost: create_signal(false),
             regulators: create_signal(BTreeSet::new()),
             serial: Self::next_serial(),
-            column_index: None.into(),
+            column_index: None.into()
         }
     }
 }
@@ -304,23 +295,14 @@ impl Element for Point {
         "point".to_string()
     }
     
-    fn default(id: String, id_num: u64) -> Self {
-        Self::new(
+    fn default(id: String, id_num: u64) -> Point {
+        Point::new(
             id,
             format!("Point {id_num}"),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            point(0.0, 0.0, 0.0),
+            point(0.0, 0.0, 0.0)
         )
     }
-
-    fn default_regulators(self: Rc<Self>) -> Vec<Rc<dyn Regulator>> {
-        all::<Axis>()
-            .map(|axis| {
-                Rc::new(PointCoordinateRegulator::new(self.clone(), axis))
-                    as Rc::<dyn Regulator>
-            })
-            .collect()
-    }
     
     fn id(&self) -> &String {
         &self.id
@@ -364,9 +346,10 @@ impl Serial for Point {
 impl ProblemPoser for Point {
     fn pose(&self, problem: &mut ConstraintProblem) {
         let index = self.column_index().expect(
-            indexing_error("Point", &self.id, "it").as_str());
+            format!("Point \"{}\" should be indexed before writing problem data", self.id).as_str()
+        );
         problem.gram.push_sym(index, index, 0.0);
-        problem.frozen.push(Self::WEIGHT_COMPONENT, index, 0.5);
+        problem.frozen.push(Point::WEIGHT_COMPONENT, index, 0.5);
         problem.guess.set_column(index, &self.representation.get_clone_untracked());
     }
 }
@@ -375,6 +358,16 @@ pub trait Regulator: Serial + ProblemPoser + OutlineItem {
     fn subjects(&self) -> Vec<Rc<dyn Element>>;
     fn measurement(&self) -> ReadSignal<f64>;
     fn set_point(&self) -> Signal<SpecifiedValue>;
+    
+    // this method is used to responsively precondition the assembly for
+    // realization when the regulator becomes a constraint, or is edited while
+    // acting as a constraint. it should track the set point, do any desired
+    // preconditioning when the set point is present, and use its return value
+    // to report whether the set is present. the default implementation does no
+    // preconditioning
+    fn try_activate(&self) -> bool {
+        self.set_point().with(|set_pt| set_pt.is_present())
+    }
 }
 
 impl Hash for dyn Regulator {
@@ -407,11 +400,11 @@ pub struct InversiveDistanceRegulator {
     pub subjects: [Rc<dyn Element>; 2],
     pub measurement: ReadSignal<f64>,
     pub set_point: Signal<SpecifiedValue>,
-    serial: u64,
+    serial: u64
 }
 
 impl InversiveDistanceRegulator {
-    pub fn new(subjects: [Rc<dyn Element>; 2]) -> Self {
+    pub fn new(subjects: [Rc<dyn Element>; 2]) -> InversiveDistanceRegulator {
         let representations = subjects.each_ref().map(|subj| subj.representation());
         let measurement = create_memo(move || {
             representations[0].with(|rep_0|
@@ -424,7 +417,7 @@ impl InversiveDistanceRegulator {
         let set_point = create_signal(SpecifiedValue::from_empty_spec());
         let serial = Self::next_serial();
         
-        Self { subjects, measurement, set_point, serial }
+        InversiveDistanceRegulator { subjects, measurement, set_point, serial }
     }
 }
 
@@ -454,8 +447,8 @@ impl ProblemPoser for InversiveDistanceRegulator {
             if let Some(val) = set_pt.value {
                 let [row, col] = self.subjects.each_ref().map(
                     |subj| subj.column_index().expect(
-                        indexing_error("Subject", subj.id(),
-                            "inversive distance regulator").as_str())
+                        "Subjects should be indexed before inversive distance regulator writes problem data"
+                    )
                 );
                 problem.gram.push_sym(row, col, val);
             }
@@ -464,14 +457,14 @@ impl ProblemPoser for InversiveDistanceRegulator {
 }
 
 pub struct HalfCurvatureRegulator {
-    pub subject: Rc<Sphere>,
+    pub subject: Rc<dyn Element>,
     pub measurement: ReadSignal<f64>,
     pub set_point: Signal<SpecifiedValue>,
-    serial: u64,
+    serial: u64
 }
 
 impl HalfCurvatureRegulator {
-    pub fn new(subject: Rc<Sphere>) -> Self {
+    pub fn new(subject: Rc<dyn Element>) -> HalfCurvatureRegulator {
         let measurement = subject.representation().map(
             |rep| rep[Sphere::CURVATURE_COMPONENT]
         );
@@ -479,7 +472,7 @@ impl HalfCurvatureRegulator {
         let set_point = create_signal(SpecifiedValue::from_empty_spec());
         let serial = Self::next_serial();
         
-        Self { subject, measurement, set_point, serial }
+        HalfCurvatureRegulator { subject, measurement, set_point, serial }
     }
 }
 
@@ -495,6 +488,18 @@ impl Regulator for HalfCurvatureRegulator {
     fn set_point(&self) -> Signal<SpecifiedValue> {
         self.set_point
     }
+    
+    fn try_activate(&self) -> bool {
+        match self.set_point.with(|set_pt| set_pt.value) {
+            Some(half_curv) => {
+                self.subject.representation().update(
+                    |rep| change_half_curvature(rep, half_curv)
+                );
+                true
+            }
+            None => false
+        }
+    }
 }
 
 impl Serial for HalfCurvatureRegulator {
@@ -508,89 +513,18 @@ impl ProblemPoser for HalfCurvatureRegulator {
         self.set_point.with_untracked(|set_pt| {
             if let Some(val) = set_pt.value {
                 let col = self.subject.column_index().expect(
-                    indexing_error("Subject", &self.subject.id,
-                        "half-curvature regulator").as_str());
+                    "Subject should be indexed before half-curvature regulator writes problem data"
+                );
                 problem.frozen.push(Sphere::CURVATURE_COMPONENT, col, val);
             }
         });
     }
 }
 
-#[derive(Clone, Copy, Sequence)]
-pub enum Axis { X = 0, Y = 1, Z = 2 }
-
-impl Axis {
-    fn name(&self) -> &'static str {
-        match self { Axis::X => "X", Axis::Y => "Y", Axis::Z => "Z" }
-    }
-}
-
-impl Display for Axis {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(self.name())
-    }
-}
-
-pub struct PointCoordinateRegulator {
-    pub subject: Rc<Point>,
-    pub axis: Axis,
-    pub measurement: ReadSignal<f64>,
-    pub set_point: Signal<SpecifiedValue>,
-    serial: u64
-}
-
-impl PointCoordinateRegulator {
-    pub fn new(subject: Rc<Point>, axis: Axis) -> Self {
-        let measurement = subject.representation().map(
-            move |rep| rep[axis as usize]
-        );
-        let set_point = create_signal(SpecifiedValue::from_empty_spec());
-        Self { subject, axis, measurement, set_point, serial: Self::next_serial() }
-    }
-}
-
-impl Serial for PointCoordinateRegulator {
-    fn serial(&self) -> u64 { self.serial }
-}
-
-impl Regulator for PointCoordinateRegulator {
-    fn subjects(&self) -> Vec<Rc<dyn Element>> { vec![self.subject.clone()] }
-    fn measurement(&self) -> ReadSignal<f64> { self.measurement }
-    fn set_point(&self) -> Signal<SpecifiedValue> { self.set_point }
-}
-
-impl ProblemPoser for PointCoordinateRegulator {
-    fn pose(&self, problem: &mut ConstraintProblem) {
-        self.set_point.with_untracked(|set_pt| {
-            if let Some(val) = set_pt.value {
-                let col = self.subject.column_index().expect(
-                    indexing_error("Subject", &self.subject.id,
-                        "point-coordinate regulator").as_str());
-                problem.frozen.push(self.axis as usize, col, val);
-                // If all three of the subject's spatial coordinates have been
-                // frozen, then freeze its norm component:
-                let mut coords = [0.0; Axis::CARDINALITY];
-                let mut nset: usize = 0;
-                for &MatrixEntry {index, value} in &(problem.frozen) {
-                    if index.1 == col && index.0 < Axis::CARDINALITY {
-                        nset += 1;
-                        coords[index.0] = value
-                    }
-                }
-                if nset == Axis::CARDINALITY {
-                    let [x, y, z] = coords;
-                    problem.frozen.push(
-                        Point::NORM_COMPONENT, col, point(x,y,z)[Point::NORM_COMPONENT]);
-                }
-            }
-        });
-    }
-}
-
 // the velocity is expressed in uniform coordinates
 pub struct ElementMotion<'a> {
     pub element: Rc<dyn Element>,
-    pub velocity: DVectorView<'a, f64>,
+    pub velocity: DVectorView<'a, f64>
 }
 
 type AssemblyMotion<'a> = Vec<ElementMotion<'a>>;
@@ -618,12 +552,12 @@ pub struct Assembly {
     pub elements_by_id: Signal<BTreeMap<String, Rc<dyn Element>>>,
     
     // realization control
-    pub realization_trigger: Signal<()>,
+    pub keep_realized: Signal<bool>,
+    pub needs_realization: Signal<bool>,
     
     // realization diagnostics
     pub realization_status: Signal<Result<(), String>>,
-    pub descent_history: Signal<DescentHistory>,
-    pub step: Signal<SpecifiedValue>,
+    pub descent_history: Signal<DescentHistory>
 }
 
 impl Assembly {
@@ -634,35 +568,20 @@ impl Assembly {
             regulators: create_signal(BTreeSet::new()),
             tangent: create_signal(ConfigSubspace::zero(0)),
             elements_by_id: create_signal(BTreeMap::default()),
-            realization_trigger: create_signal(()),
+            keep_realized: create_signal(true),
+            needs_realization: create_signal(false),
             realization_status: create_signal(Ok(())),
-            descent_history: create_signal(DescentHistory::new()),
-            step: create_signal(SpecifiedValue::from_empty_spec()),
+            descent_history: create_signal(DescentHistory::new())
         };
         
-        // realize the assembly whenever the element list, the regulator list,
-        // a regulator's set point, or the realization trigger is updated
-        let assembly_for_realization = assembly.clone();
+        // realize the assembly whenever it becomes simultaneously true that
+        // we're trying to keep it realized and it needs realization
+        let assembly_for_effect = assembly.clone();
         create_effect(move || {
-            assembly_for_realization.elements.track();
-            assembly_for_realization.regulators.with(
-                |regs| for reg in regs {
-                    reg.set_point().track();
-                }
-            );
-            assembly_for_realization.realization_trigger.track();
-            assembly_for_realization.realize();
-        });
-        
-        // load a configuration from the descent history whenever the active
-        // step is updated
-        let assembly_for_step_selection = assembly.clone();
-        create_effect(move || {
-            if let Some(step) = assembly.step.with(|n| n.value) {
-                let config = assembly.descent_history.with_untracked(
-                    |history| history.config[step as usize].clone()
-                );
-                assembly_for_step_selection.load_config(&config)
+            let should_realize = assembly_for_effect.keep_realized.get()
+                && assembly_for_effect.needs_realization.get();
+            if should_realize {
+                assembly_for_effect.realize();
             }
         });
         
@@ -727,6 +646,19 @@ impl Assembly {
             regulators.update(|regs| regs.insert(regulator.clone()));
         }
         
+        // request a realization when the regulator becomes a constraint, or is
+        // edited while acting as a constraint
+        let self_for_effect = self.clone();
+        create_effect(move || {
+            /* DEBUG */
+            // log the regulator update
+            console_log!("Updated regulator with subjects {:?}", regulator.subjects());
+            
+            if regulator.try_activate() {
+                self_for_effect.needs_realization.set(true);
+            }
+        });
+        
         /* DEBUG */
         // print an updated list of regulators
         console_log!("Regulators:");
@@ -750,16 +682,6 @@ impl Assembly {
         });
     }
     
-    // --- updating the configuration ---
-    
-    pub fn load_config(&self, config: &DMatrix<f64>) {
-        for elt in self.elements.get_clone_untracked() {
-            elt.representation().update(
-                |rep| rep.set_column(0, &config.column(elt.column_index().unwrap()))
-            );
-        }
-    }
-    
     // --- realization ---
     
     pub fn realize(&self) {
@@ -787,7 +709,6 @@ impl Assembly {
         /* DEBUG */
         // log the Gram matrix
         console_log!("Gram matrix:\n{}", problem.gram);
-        console_log!("Frozen entries:\n{}", problem.frozen);
         
         /* DEBUG */
         // log the initial configuration matrix
@@ -805,17 +726,14 @@ impl Assembly {
         } else {
             console_log!("✅️ Target accuracy achieved!");
         }
-        if history.scaled_loss.len() > 0 {
-            console_log!("Steps: {}", history.scaled_loss.len() - 1);
-            console_log!("Loss: {}", history.scaled_loss.last().unwrap());
-        }
+        console_log!("Steps: {}", history.scaled_loss.len() - 1);
+        console_log!("Loss: {}", history.scaled_loss.last().unwrap());
         
-        // report the descent history
-        let step_cnt = history.config.len();
+        // report the loss history
         self.descent_history.set(history);
         
         match result {
-            Ok(ConfigNeighborhood { nbhd: tangent, .. }) => {
+            Ok(ConfigNeighborhood { config, nbhd: tangent }) => {
                 /* DEBUG */
                 // report the tangent dimension
                 console_log!("Tangent dimension: {}", tangent.dim());
@@ -823,29 +741,26 @@ impl Assembly {
                 // report the realization status
                 self.realization_status.set(Ok(()));
                 
-                // display the last realization step
-                self.step.set(
-                    if step_cnt > 0 {
-                        let last_step = step_cnt - 1;
-                        SpecifiedValue::try_from(last_step.to_string()).unwrap()
-                    } else {
-                        SpecifiedValue::from_empty_spec()
-                    }
-                );
+                // read out the solution
+                for elt in self.elements.get_clone_untracked() {
+                    elt.representation().update(
+                        |rep| rep.set_column(0, &config.column(elt.column_index().unwrap()))
+                    );
+                }
                 
                 // save the tangent space
                 self.tangent.set_silent(tangent);
+                
+                // clear the realization request flag
+                self.needs_realization.set(false);
             },
             Err(message) => {
                 // report the realization status. the `Err(message)` we're
                 // setting the status to has a different type than the
                 // `Err(message)` we received from the match: we're changing the
                 // `Ok` type from `Realization` to `()`
-                self.realization_status.set(Err(message));
-                
-                // display the initial guess
-                self.step.set(SpecifiedValue::from(Some(0.0)));
-            },
+                self.realization_status.set(Err(message))
+            }
         }
     }
     
@@ -928,15 +843,15 @@ impl Assembly {
                     },
                     None => {
                         console_log!("No velocity to unpack for fresh element \"{}\"", elt.id())
-                    },
+                    }
                 };
             });
         }
         
-        // trigger a realization to bring the configuration back onto the
+        // request a realization to bring the configuration back onto the
         // solution variety. this also gets the elements' column indices and the
         // saved tangent space back in sync
-        self.realization_trigger.set(());
+        self.needs_realization.set(true);
     }
 }
 
@@ -947,8 +862,7 @@ mod tests {
     use crate::engine;
     
     #[test]
-    #[should_panic(expected =
-        "Sphere \"sphere\" must be indexed before it writes problem data")]
+    #[should_panic(expected = "Sphere \"sphere\" should be indexed before writing problem data")]
     fn unindexed_element_test() {
         let _ = create_root(|| {
             let elt = Sphere::default("sphere".to_string(), 0);
@@ -957,8 +871,7 @@ mod tests {
     }
     
     #[test]
-    #[should_panic(expected = "Subject \"sphere1\" must be indexed before \
-        inversive distance regulator writes problem data")]
+    #[should_panic(expected = "Subjects should be indexed before inversive distance regulator writes problem data")]
     fn unindexed_subject_test_inversive_distance() {
         let _ = create_root(|| {
             let subjects = [0, 1].map(
@@ -990,7 +903,7 @@ mod tests {
                     String::from(sphere_id),
                     String::from("Sphere 0"),
                     [0.75_f32, 0.75_f32, 0.75_f32],
-                    engine::sphere(0.0, 0.0, 0.0, INITIAL_RADIUS),
+                    engine::sphere(0.0, 0.0, 0.0, INITIAL_RADIUS)
                 )
             );
             
@@ -1004,7 +917,7 @@ mod tests {
                     vec![
                         ElementMotion {
                             element: sphere.clone(),
-                            velocity: velocity.as_view(),
+                            velocity: velocity.as_view()
                         }
                     ]
                 );
@@ -1019,4 +932,4 @@ mod tests {
             assert!((final_half_curv / INITIAL_HALF_CURV - 1.0).abs() < DRIFT_TOL);
         });
     }
-}
+}

app-proto/src/components/add_remove.rs

@@ -4,47 +4,32 @@ use sycamore::prelude::*;
 use super::test_assembly_chooser::TestAssemblyChooser;
 use crate::{
     AppState,
-    assembly::{InversiveDistanceRegulator, Point, Sphere},
+    assembly::{InversiveDistanceRegulator, Point, Sphere}
 };
 
 #[component]
 pub fn AddRemove() -> View {
     view! {
-        div(id = "add-remove") {
+        div(id="add-remove") {
             button(
-                on:click = |_| {
+                on:click=|_| {
                     let state = use_context::<AppState>();
-                    batch(|| {
-                        // this call is batched to avoid redundant realizations.
-                        // it updates the element list and the regulator list,
-                        // which are both tracked by the realization effect
-                        /* TO DO */
-                        // it would make more to do the batching inside
-                        // `insert_element_default`, but that will have to wait
-                        // until Sycamore handles nested batches correctly.
-                        //
-                        //   https://github.com/sycamore-rs/sycamore/issues/802
-                        //
-                        // the nested batch issue is relevant here because the
-                        // assembly loaders in the test assembly chooser use
-                        // `insert_element_default` within larger batches
-                        state.assembly.insert_element_default::<Sphere>();
-                    });
+                    state.assembly.insert_element_default::<Sphere>();
                 }
             ) { "Add sphere" }
             button(
-                on:click = |_| {
+                on:click=|_| {
                     let state = use_context::<AppState>();
                     state.assembly.insert_element_default::<Point>();
                 }
             ) { "Add point" }
             button(
-                class = "emoji", /* KLUDGE */ // for convenience, we're using an emoji as a temporary icon for this button
-                disabled = {
+                class="emoji", /* KLUDGE */ // for convenience, we're using an emoji as a temporary icon for this button
+                disabled={
                     let state = use_context::<AppState>();
                     state.selection.with(|sel| sel.len() != 2)
                 },
-                on:click = |_| {
+                on:click=|_| {
                     let state = use_context::<AppState>();
                     let subjects: [_; 2] = state.selection.with(
                         // the button is only enabled when two elements are

app-proto/src/components/diagnostics.rs

@@ -7,16 +7,18 @@ use charming::{
 };
 use sycamore::prelude::*;
 
-use crate::{AppState, specified::SpecifiedValue};
+use crate::AppState;
 
 #[derive(Clone)]
 struct DiagnosticsState {
-    active_tab: Signal<String>,
+    active_tab: Signal<String>
 }
 
 impl DiagnosticsState {
-    fn new(initial_tab: String) -> Self {
-        Self { active_tab: create_signal(initial_tab) }
+    fn new(initial_tab: String) -> DiagnosticsState {
+        DiagnosticsState {
+            active_tab: create_signal(initial_tab)
+        }
     }
 }
 
@@ -27,20 +29,20 @@ fn RealizationStatus() -> View {
     let realization_status = state.assembly.realization_status;
     view! {
         div(
-            id = "realization-status",
-            class = realization_status.with(
+            id="realization-status",
+            class=realization_status.with(
                 |status| match status {
                     Ok(_) => "",
-                    Err(_) => "invalid",
+                    Err(_) => "invalid"
                 }
             )
         ) {
-            div(class = "status")
+            div(class="status")
             div {
                 (realization_status.with(
                     |status| match status {
                         Ok(_) => "Target accuracy achieved".to_string(),
-                        Err(message) => message.clone(),
+                        Err(message) => message.clone()
                     }
                 ))
             }
@@ -48,73 +50,10 @@ fn RealizationStatus() -> View {
     }
 }
 
-// history step input
-#[component]
-fn StepInput() -> View {
-    // get the assembly
-    let state = use_context::<AppState>();
-    let assembly = state.assembly;
-    
-    // the `last_step` signal holds the index of the last step
-    let last_step = assembly.descent_history.map(
-        |history| match history.config.len() {
-            0 => None,
-            n => Some(n - 1),
-        }
-    );
-    let input_max = last_step.map(|last| last.unwrap_or(0));
-    
-    // these signals hold the entered step number
-    let value = create_signal(String::new());
-    let value_as_number = create_signal(0.0);
-    
-    create_effect(move || {
-        value.set(assembly.step.with(|n| n.spec.clone()));
-    });
-    
-    view! {
-        div(id = "step-input") {
-            label { "Step" }
-            input(
-                r#type = "number",
-                min = "0",
-                max = input_max.with(|max| max.to_string()),
-                bind:value = value,
-                bind:valueAsNumber = value_as_number,
-                on:change = move |_| {
-                    if last_step.with(|last| last.is_some()) {
-                        // clamp the step within its allowed range. the lower
-                        // bound is redundant on browsers that make it
-                        // impossible to type negative values into a number
-                        // input with a non-negative `min`, but there's no harm
-                        // in being careful
-                        let step_raw = value.with(
-                            |val| SpecifiedValue::try_from(val.clone())
-                                .unwrap_or(SpecifiedValue::from_empty_spec()
-                            )
-                        );
-                        let step = SpecifiedValue::from(
-                            step_raw.value.map(
-                                |val| val.clamp(0.0, input_max.get() as f64)
-                            )
-                        );
-                        
-                        // set the input string and the assembly's active step
-                        value.set(step.spec.clone());
-                        assembly.step.set(step);
-                    } else {
-                        value.set(String::new());
-                    }
-                },
-            )
-        }
-    }
-}
-
 fn into_log10_time_point((step, value): (usize, f64)) -> Vec<Option<f64>> {
     vec![
         Some(step as f64),
-        if value == 0.0 { None } else { Some(value.abs().log10()) },
+        if value == 0.0 { None } else { Some(value.abs().log10()) }
     ]
 }
 
@@ -166,7 +105,7 @@ fn LossHistory() -> View {
     });
     
     view! {
-        div(id = CONTAINER_ID, class = "diagnostics-chart")
+        div(id=CONTAINER_ID, class="diagnostics-chart")
     }
 }
 
@@ -183,7 +122,7 @@ fn SpectrumHistory() -> View {
             // positive, negative, and strictly-zero parts
             let (
                 hess_eigvals_zero,
-                hess_eigvals_nonzero,
+                hess_eigvals_nonzero
             ): (Vec<_>, Vec<_>) = state.assembly.descent_history.with(
                 |history| history.hess_eigvals
                     .iter()
@@ -204,7 +143,7 @@ fn SpectrumHistory() -> View {
                 .unwrap_or(1.0);
             let (
                 hess_eigvals_pos,
-                hess_eigvals_neg,
+                hess_eigvals_neg
             ): (Vec<_>, Vec<_>) = hess_eigvals_nonzero
                 .into_iter()
                 .partition(|&(_, val)| val > 0.0);
@@ -272,7 +211,7 @@ fn SpectrumHistory() -> View {
     });
     
     view! {
-        div(id = CONTAINER_ID, class = "diagnostics-chart")
+        div(id=CONTAINER_ID, class="diagnostics-chart")
     }
 }
 
@@ -281,8 +220,8 @@ fn DiagnosticsPanel(name: &'static str, children: Children) -> View {
     let diagnostics_state = use_context::<DiagnosticsState>();
     view! {
         div(
-            class = "diagnostics-panel",
-            "hidden" = diagnostics_state.active_tab.with(
+            class="diagnostics-panel",
+            "hidden"=diagnostics_state.active_tab.with(
                 |active_tab| {
                     if active_tab == name {
                         None
@@ -304,17 +243,16 @@ pub fn Diagnostics() -> View {
     provide_context(diagnostics_state);
     
     view! {
-        div(id = "diagnostics") {
-            div(id = "diagnostics-bar") {
+        div(id="diagnostics") {
+            div(id="diagnostics-bar") {
                 RealizationStatus {}
-                select(bind:value = active_tab) {
-                    option(value = "loss") { "Loss" }
-                    option(value = "spectrum") { "Spectrum" }
+                select(bind:value=active_tab) {
+                    option(value="loss") { "Loss" }
+                    option(value="spectrum") { "Spectrum" }
                 }
-                StepInput {}
             }
-            DiagnosticsPanel(name = "loss") { LossHistory {} }
-            DiagnosticsPanel(name = "spectrum") { SpectrumHistory {} }
+            DiagnosticsPanel(name="loss") { LossHistory {} }
+            DiagnosticsPanel(name="spectrum") { SpectrumHistory {} }
         }
     }
 }

app-proto/src/components/display.rs

@@ -12,12 +12,12 @@ use web_sys::{
     WebGlProgram,
     WebGlShader,
     WebGlUniformLocation,
-    wasm_bindgen::{JsCast, JsValue},
+    wasm_bindgen::{JsCast, JsValue}
 };
 
 use crate::{
     AppState,
-    assembly::{Element, ElementColor, ElementMotion, Point, Sphere},
+    assembly::{Element, ElementColor, ElementMotion, Point, Sphere}
 };
 
 // --- color ---
@@ -37,15 +37,15 @@ fn combine_channels(color: ElementColor, opacity: f32) -> ColorWithOpacity {
 struct SceneSpheres {
     representations: Vec<DVector<f64>>,
     colors_with_opacity: Vec<ColorWithOpacity>,
-    highlights: Vec<f32>,
+    highlights: Vec<f32>
 }
 
 impl SceneSpheres {
-    fn new() -> Self {
-        Self {
+    fn new() -> SceneSpheres{
+        SceneSpheres {
             representations: Vec::new(),
             colors_with_opacity: Vec::new(),
-            highlights: Vec::new(),
+            highlights: Vec::new()
         }
     }
     
@@ -53,10 +53,7 @@ impl SceneSpheres {
         self.representations.len().try_into().expect("Number of spheres must fit in a 32-bit integer")
     }
     
-    fn push(
-        &mut self, representation: DVector<f64>,
-        color: ElementColor, opacity: f32, highlight: f32,
-    ) {
+    fn push(&mut self, representation: DVector<f64>, color: ElementColor, opacity: f32, highlight: f32) {
         self.representations.push(representation);
         self.colors_with_opacity.push(combine_channels(color, opacity));
         self.highlights.push(highlight);
@@ -67,23 +64,20 @@ struct ScenePoints {
     representations: Vec<DVector<f64>>,
     colors_with_opacity: Vec<ColorWithOpacity>,
     highlights: Vec<f32>,
-    selections: Vec<f32>,
+    selections: Vec<f32>
 }
 
 impl ScenePoints {
-    fn new() -> Self {
-        Self {
+    fn new() -> ScenePoints {
+        ScenePoints {
             representations: Vec::new(),
             colors_with_opacity: Vec::new(),
             highlights: Vec::new(),
-            selections: Vec::new(),
+            selections: Vec::new()
         }
     }
     
-    fn push(
-        &mut self, representation: DVector<f64>,
-        color: ElementColor, opacity: f32, highlight: f32, selected: bool,
-    ) {
+    fn push(&mut self, representation: DVector<f64>, color: ElementColor, opacity: f32, highlight: f32, selected: bool) {
         self.representations.push(representation);
         self.colors_with_opacity.push(combine_channels(color, opacity));
         self.highlights.push(highlight);
@@ -93,14 +87,14 @@ impl ScenePoints {
 
 pub struct Scene {
     spheres: SceneSpheres,
-    points: ScenePoints,
+    points: ScenePoints
 }
 
 impl Scene {
-    fn new() -> Self {
-        Self {
+    fn new() -> Scene {
+        Scene {
             spheres: SceneSpheres::new(),
-            points: ScenePoints::new(),
+            points: ScenePoints::new()
         }
     }
 }
@@ -111,12 +105,7 @@ pub trait DisplayItem {
     // the smallest positive depth, represented as a multiple of `dir`, where
     // the line generated by `dir` hits the element. returns `None` if the line
     // misses the element
-    fn cast(
-        &self,
-        dir: Vector3<f64>,
-        assembly_to_world: &DMatrix<f64>,
-        pixel_size: f64,
-    ) -> Option<f64>;
+    fn cast(&self, dir: Vector3<f64>, assembly_to_world: &DMatrix<f64>, pixel_size: f64) -> Option<f64>;
 }
 
 impl DisplayItem for Sphere {
@@ -135,12 +124,7 @@ impl DisplayItem for Sphere {
     
     // this method should be kept synchronized with `sphere_cast` in
     // `spheres.frag`, which does essentially the same thing on the GPU side
-    fn cast(
-        &self,
-        dir: Vector3<f64>,
-        assembly_to_world: &DMatrix<f64>,
-        _pixel_size: f64,
-    ) -> Option<f64> {
+    fn cast(&self, dir: Vector3<f64>, assembly_to_world: &DMatrix<f64>, _pixel_size: f64) -> Option<f64> {
         // if `a/b` is less than this threshold, we approximate
         // `a*u^2 + b*u + c` by the linear function `b*u + c`
         const DEG_THRESHOLD: f64 = 1e-9;
@@ -193,12 +177,7 @@ impl DisplayItem for Point {
     }
     
     /* SCAFFOLDING */
-    fn cast(
-        &self,
-        dir: Vector3<f64>,
-        assembly_to_world: &DMatrix<f64>,
-        pixel_size: f64,
-    ) -> Option<f64> {
+    fn cast(&self, dir: Vector3<f64>, assembly_to_world: &DMatrix<f64>, pixel_size: f64) -> Option<f64> {
         let rep = self.representation.with_untracked(|rep| assembly_to_world * rep);
         if rep[2] < 0.0 {
             // this constant should be kept synchronized with `point.frag`
@@ -241,7 +220,7 @@ fn compile_shader(
 fn set_up_program(
     context: &WebGl2RenderingContext,
     vertex_shader_source: &str,
-    fragment_shader_source: &str,
+    fragment_shader_source: &str
 ) -> WebGlProgram {
     // compile the shaders
     let vertex_shader = compile_shader(
@@ -281,12 +260,12 @@ fn get_uniform_array_locations<const N: usize>(
     context: &WebGl2RenderingContext,
     program: &WebGlProgram,
     var_name: &str,
-    member_name_opt: Option<&str>,
+    member_name_opt: Option<&str>
 ) -> [Option<WebGlUniformLocation>; N] {
     array::from_fn(|n| {
         let name = match member_name_opt {
             Some(member_name) => format!("{var_name}[{n}].{member_name}"),
-            None => format!("{var_name}[{n}]"),
+            None => format!("{var_name}[{n}]")
         };
         context.get_uniform_location(&program, name.as_str())
     })
@@ -297,7 +276,7 @@ fn bind_to_attribute(
     context: &WebGl2RenderingContext,
     attr_index: u32,
     attr_size: i32,
-    buffer: &Option<WebGlBuffer>,
+    buffer: &Option<WebGlBuffer>
 ) {
     context.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, buffer.as_ref());
     context.vertex_attrib_pointer_with_i32(
@@ -313,7 +292,7 @@ fn bind_to_attribute(
 // load the given data into a new vertex buffer object
 fn load_new_buffer(
     context: &WebGl2RenderingContext,
-    data: &[f32],
+    data: &[f32]
 ) -> Option<WebGlBuffer> {
     // create a buffer and bind it to ARRAY_BUFFER
     let buffer = context.create_buffer();
@@ -340,7 +319,7 @@ fn bind_new_buffer_to_attribute(
     context: &WebGl2RenderingContext,
     attr_index: u32,
     attr_size: i32,
-    data: &[f32],
+    data: &[f32]
 ) {
     let buffer = load_new_buffer(context, data);
     bind_to_attribute(context, attr_index, attr_size, &buffer);
@@ -362,9 +341,9 @@ fn event_dir(event: &MouseEvent) -> (Vector3<f64>, f64) {
         Vector3::new(
             FOCAL_SLOPE * (2.0*(f64::from(event.client_x()) - rect.left()) - width) / shortdim,
             FOCAL_SLOPE * (2.0*(rect.bottom() - f64::from(event.client_y())) - height) / shortdim,
-            -1.0,
+            -1.0
         ),
-        FOCAL_SLOPE * 2.0 / shortdim,
+        FOCAL_SLOPE * 2.0 / shortdim
     )
 }
 
@@ -464,14 +443,14 @@ pub fn Display() -> View {
         let sphere_program = set_up_program(
             &ctx,
             include_str!("identity.vert"),
-            include_str!("spheres.frag"),
+            include_str!("spheres.frag")
         );
         
         // set up the point rendering program
         let point_program = set_up_program(
             &ctx,
             include_str!("point.vert"),
-            include_str!("point.frag"),
+            include_str!("point.frag")
         );
         
         /* DEBUG */
@@ -488,7 +467,7 @@ pub fn Display() -> View {
         // capped at 1024 elements
         console::log_2(
             &ctx.get_parameter(WebGl2RenderingContext::MAX_FRAGMENT_UNIFORM_VECTORS).unwrap(),
-            &JsValue::from("uniform vectors available"),
+            &JsValue::from("uniform vectors available")
         );
         
         // find the sphere program's vertex attribute
@@ -524,7 +503,7 @@ pub fn Display() -> View {
             // southeast triangle
             -1.0, -1.0, 0.0,
              1.0,  1.0, 0.0,
-             1.0, -1.0, 0.0,
+             1.0, -1.0, 0.0
         ];
         let viewport_position_buffer = load_new_buffer(&ctx, &viewport_positions);
         
@@ -588,25 +567,7 @@ pub fn Display() -> View {
             location_z *= (time_step * ZOOM_SPEED * zoom).exp();
             
             // manipulate the assembly
-            /* KLUDGE */
-            // to avoid the complexity of making tangent space projection
-            // conditional and dealing with unnormalized representation vectors,
-            // we only allow manipulation when we're looking at the last step of
-            // a successful realization
-            let realization_successful = state.assembly.realization_status.with(
-                |status| status.is_ok()
-            );
-            let step_val = state.assembly.step.with_untracked(|step| step.value);
-            let on_init_step = step_val.is_some_and(|n| n == 0.0);
-            let on_last_step = step_val.is_some_and(
-                |n| state.assembly.descent_history.with_untracked(
-                    |history| n as usize + 1 == history.config.len().max(1)
-                )
-            );
-            let on_manipulable_step =
-                !realization_successful && on_init_step
-                || realization_successful && on_last_step;
-            if on_manipulable_step && state.selection.with(|sel| sel.len() == 1) {
+            if state.selection.with(|sel| sel.len() == 1) {
                 let sel = state.selection.with(
                     |sel| sel.into_iter().next().unwrap().clone()
                 );
@@ -635,7 +596,7 @@ pub fn Display() -> View {
                         vec![
                             ElementMotion {
                                 element: sel,
-                                velocity: elt_motion.as_view(),
+                                velocity: elt_motion.as_view()
                             }
                         ]
                     );
@@ -668,7 +629,7 @@ pub fn Display() -> View {
                         0.0, 1.0,   0.0, 0.0, 0.0,
                         0.0, 0.0,   1.0, 0.0,   u,
                         0.0, 0.0, 2.0*u, 1.0, u*u,
-                        0.0, 0.0,   0.0, 0.0, 1.0,
+                        0.0, 0.0,   0.0, 0.0, 1.0
                     ])
                 };
                 let asm_to_world = &location * &orientation;
@@ -707,19 +668,19 @@ pub fn Display() -> View {
                     let v = &sphere_reps_world[n];
                     ctx.uniform3fv_with_f32_array(
                         sphere_sp_locs[n].as_ref(),
-                        v.rows(0, 3).as_slice(),
+                        v.rows(0, 3).as_slice()
                     );
                     ctx.uniform2fv_with_f32_array(
                         sphere_lt_locs[n].as_ref(),
-                        v.rows(3, 2).as_slice(),
+                        v.rows(3, 2).as_slice()
                     );
                     ctx.uniform4fv_with_f32_array(
                         sphere_color_locs[n].as_ref(),
-                        &scene.spheres.colors_with_opacity[n],
+                        &scene.spheres.colors_with_opacity[n]
                     );
                     ctx.uniform1f(
                         sphere_highlight_locs[n].as_ref(),
-                        scene.spheres.highlights[n],
+                        scene.spheres.highlights[n]
                     );
                 }
                 
@@ -812,7 +773,7 @@ pub fn Display() -> View {
             "ArrowLeft" if shift => roll_ccw.set(value),
             "ArrowRight" => yaw_right.set(value),
             "ArrowLeft" => yaw_left.set(value),
-            _ => navigating = false,
+            _ => navigating = false
         };
         if navigating {
             scene_changed.set(true);
@@ -832,7 +793,7 @@ pub fn Display() -> View {
             "s" | "S" => translate_neg_y.set(value),
             "]" | "}" => shrink_neg.set(value),
             "[" | "{" => shrink_pos.set(value),
-            _ => manipulating = false,
+            _ => manipulating = false
         };
         if manipulating {
             event.prevent_default();
@@ -844,12 +805,12 @@ pub fn Display() -> View {
         // switch back to integer-valued parameters when that becomes possible
         // again
         canvas(
-            ref = display,
-            id = "display",
-            width = "600",
-            height = "600",
-            tabindex = "0",
-            on:keydown = move |event: KeyboardEvent| {
+            ref=display,
+            id="display",
+            width="600",
+            height="600",
+            tabindex="0",
+            on:keydown=move |event: KeyboardEvent| {
                 if event.key() == "Shift" {
                     // swap navigation inputs
                     roll_cw.set(yaw_right.get());
@@ -875,7 +836,7 @@ pub fn Display() -> View {
                     set_manip_signal(&event, 1.0);
                 }
             },
-            on:keyup = move |event: KeyboardEvent| {
+            on:keyup=move |event: KeyboardEvent| {
                 if event.key() == "Shift" {
                     // swap navigation inputs
                     yaw_right.set(roll_cw.get());
@@ -897,7 +858,7 @@ pub fn Display() -> View {
                     set_manip_signal(&event, 0.0);
                 }
             },
-            on:blur = move |_| {
+            on:blur=move |_| {
                 pitch_up.set(0.0);
                 pitch_down.set(0.0);
                 yaw_right.set(0.0);
@@ -905,7 +866,7 @@ pub fn Display() -> View {
                 roll_ccw.set(0.0);
                 roll_cw.set(0.0);
             },
-            on:click = move |event: MouseEvent| {
+            on:click=move |event: MouseEvent| {
                 // find the nearest element along the pointer direction
                 let (dir, pixel_size) = event_dir(&event);
                 console::log_1(&JsValue::from(dir.to_string()));
@@ -922,18 +883,18 @@ pub fn Display() -> View {
                                     clicked = Some((elt, depth))
                                 }
                             },
-                            None => clicked = Some((elt, depth)),
-                        },
-                        None => (),
+                            None => clicked = Some((elt, depth))
+                        }
+                        None => ()
                     };
                 }
                 
                 // if we clicked something, select it
                 match clicked {
                     Some((elt, _)) => state.select(&elt, event.shift_key()),
-                    None => state.selection.update(|sel| sel.clear()),
+                    None => state.selection.update(|sel| sel.clear())
                 };
-            },
+            }
         )
     }
 }

app-proto/src/components/outline.rs

@@ -1,7 +1,11 @@
 use itertools::Itertools;
 use std::rc::Rc;
 use sycamore::prelude::*;
-use web_sys::{KeyboardEvent, MouseEvent, wasm_bindgen::JsCast};
+use web_sys::{
+    KeyboardEvent,
+    MouseEvent,
+    wasm_bindgen::JsCast
+};
 
 use crate::{
     AppState,
@@ -9,8 +13,7 @@ use crate::{
         Element,
         HalfCurvatureRegulator,
         InversiveDistanceRegulator,
-        PointCoordinateRegulator,
-        Regulator,
+        Regulator
     },
     specified::SpecifiedValue
 };
@@ -46,8 +49,8 @@ fn RegulatorInput(regulator: Rc<dyn Regulator>) -> View {
     
     view! {
         input(
-            r#type = "text",
-            class = move || {
+            r#type="text",
+            class=move || {
                 if valid.get() {
                     set_point.with(|set_pt| {
                         if set_pt.is_present() {
@@ -60,27 +63,27 @@ fn RegulatorInput(regulator: Rc<dyn Regulator>) -> View {
                     "regulator-input invalid"
                 }
             },
-            placeholder = measurement.with(|result| result.to_string()),
-            bind:value = value,
-            on:change = move |_| {
+            placeholder=measurement.with(|result| result.to_string()),
+            bind:value=value,
+            on:change=move |_| {
                 valid.set(
                     match SpecifiedValue::try_from(value.get_clone_untracked()) {
                         Ok(set_pt) => {
                             set_point.set(set_pt);
                             true
-                        },
-                        Err(_) => false,
+                        }
+                        Err(_) => false
                     }
                 )
             },
-            on:keydown = {
+            on:keydown={
                 move |event: KeyboardEvent| {
                     match event.key().as_str() {
                         "Escape" => reset_value(),
-                        _ => (),
+                        _ => ()
                     }
                 }
-            },
+            }
         )
     }
 }
@@ -97,11 +100,11 @@ impl OutlineItem for InversiveDistanceRegulator {
             self.subjects[0].label()
         }.clone();
         view! {
-            li(class = "regulator") {
-                div(class = "regulator-label") { (other_subject_label) }
-                div(class = "regulator-type") { "Inversive distance" }
-                RegulatorInput(regulator = self)
-                div(class = "status")
+            li(class="regulator") {
+                div(class="regulator-label") { (other_subject_label) }
+                div(class="regulator-type") { "Inversive distance" }
+                RegulatorInput(regulator=self)
+                div(class="status")
             }
         }
     }
@@ -110,25 +113,11 @@ impl OutlineItem for InversiveDistanceRegulator {
 impl OutlineItem for HalfCurvatureRegulator {
     fn outline_item(self: Rc<Self>, _element: &Rc<dyn Element>) -> View {
         view! {
-            li(class = "regulator") {
-                div(class = "regulator-label") // for spacing
-                div(class = "regulator-type") { "Half-curvature" }
-                RegulatorInput(regulator = self)
-                div(class = "status")
-            }
-        }
-    }
-}
-
-impl OutlineItem for PointCoordinateRegulator {
-    fn outline_item(self: Rc<Self>, _element: &Rc<dyn Element>) -> View {
-        let name = format!("{} coordinate", self.axis);
-        view! {
-            li(class = "regulator") {
-                div(class = "regulator-label") // for spacing
-                div(class = "regulator-type") { (name) }
-                RegulatorInput(regulator = self)
-                div(class = "status")
+            li(class="regulator") {
+                div(class="regulator-label") // for spacing
+                div(class="regulator-type") { "Half-curvature" }
+                RegulatorInput(regulator=self)
+                div(class="status")
             }
         }
     }
@@ -167,10 +156,10 @@ fn ElementOutlineItem(element: Rc<dyn Element>) -> View {
     let details_node = create_node_ref();
     view! {
         li {
-            details(ref = details_node) {
+            details(ref=details_node) {
                 summary(
-                    class = class.get(),
-                    on:keydown = {
+                    class=class.get(),
+                    on:keydown={
                         let element_for_handler = element.clone();
                         move |event: KeyboardEvent| {
                             match event.key().as_str() {
@@ -190,18 +179,18 @@ fn ElementOutlineItem(element: Rc<dyn Element>) -> View {
                                         .unchecked_into::<web_sys::Element>()
                                         .remove_attribute("open");
                                 },
-                                _ => (),
+                                _ => ()
                             }
                         }
                     }
                 ) {
                     div(
-                        class = "element-switch",
-                        on:click = |event: MouseEvent| event.stop_propagation()
+                        class="element-switch",
+                        on:click=|event: MouseEvent| event.stop_propagation()
                     )
                     div(
-                        class = "element",
-                        on:click = {
+                        class="element",
+                        on:click={
                             let state_for_handler = state.clone();
                             let element_for_handler = element.clone();
                             move |event: MouseEvent| {
@@ -211,20 +200,20 @@ fn ElementOutlineItem(element: Rc<dyn Element>) -> View {
                             }
                         }
                     ) {
-                        div(class = "element-label") { (label) }
-                        div(class = "element-representation") { (rep_components) }
+                        div(class="element-label") { (label) }
+                        div(class="element-representation") { (rep_components) }
                         input(
-                            r#type = "checkbox",
-                            bind:checked = element.ghost(),
-                            on:click = |event: MouseEvent| event.stop_propagation()
+                            r#type="checkbox",
+                            bind:checked=element.ghost(),
+                            on:click=|event: MouseEvent| event.stop_propagation()
                         )
                     }
                 }
-                ul(class = "regulators") {
+                ul(class="regulators") {
                     Keyed(
-                        list = regulator_list,
-                        view = move |reg| reg.outline_item(&element),
-                        key = |reg| reg.serial()
+                        list=regulator_list,
+                        view=move |reg| reg.outline_item(&element),
+                        key=|reg| reg.serial()
                     )
                 }
             }
@@ -257,18 +246,18 @@ pub fn Outline() -> View {
     
     view! {
         ul(
-            id = "outline",
-            on:click = {
+            id="outline",
+            on:click={
                 let state = use_context::<AppState>();
                 move |_| state.selection.update(|sel| sel.clear())
             }
         ) {
             Keyed(
-                list = element_list,
-                view = |elt| view! {
-                    ElementOutlineItem(element = elt)
+                list=element_list,
+                view=|elt| view! {
+                    ElementOutlineItem(element=elt)
                 },
-                key = |elt| elt.serial()
+                key=|elt| elt.serial()
             )
         }
     }

app-proto/src/components/test_assembly_chooser.rs

@@ -6,17 +6,17 @@ use web_sys::{console, wasm_bindgen::JsValue};
 
 use crate::{
     AppState,
+    engine,
+    engine::DescentHistory,
     assembly::{
         Assembly,
         Element,
         ElementColor,
         InversiveDistanceRegulator,
         Point,
-        Sphere,
+        Sphere
     },
-    engine,
-    engine::DescentHistory,
-    specified::SpecifiedValue,
+    specified::SpecifiedValue
 };
 
 // --- loaders ---
@@ -26,13 +26,13 @@ use crate::{
 // done more work on saving and loading assemblies, we should come back to this
 // code to see if it can be simplified
 
-fn load_general(assembly: &Assembly) {
+fn load_gen_assemb(assembly: &Assembly) {
     let _ = assembly.try_insert_element(
         Sphere::new(
             String::from("gemini_a"),
             String::from("Castor"),
             [1.00_f32, 0.25_f32, 0.00_f32],
-            engine::sphere(0.5, 0.5, 0.0, 1.0),
+            engine::sphere(0.5, 0.5, 0.0, 1.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -40,7 +40,7 @@ fn load_general(assembly: &Assembly) {
             String::from("gemini_b"),
             String::from("Pollux"),
             [0.00_f32, 0.25_f32, 1.00_f32],
-            engine::sphere(-0.5, -0.5, 0.0, 1.0),
+            engine::sphere(-0.5, -0.5, 0.0, 1.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -48,7 +48,7 @@ fn load_general(assembly: &Assembly) {
             String::from("ursa_major"),
             String::from("Ursa major"),
             [0.25_f32, 0.00_f32, 1.00_f32],
-            engine::sphere(-0.5, 0.5, 0.0, 0.75),
+            engine::sphere(-0.5, 0.5, 0.0, 0.75)
         )
     );
     let _ = assembly.try_insert_element(
@@ -56,7 +56,7 @@ fn load_general(assembly: &Assembly) {
             String::from("ursa_minor"),
             String::from("Ursa minor"),
             [0.25_f32, 1.00_f32, 0.00_f32],
-            engine::sphere(0.5, -0.5, 0.0, 0.5),
+            engine::sphere(0.5, -0.5, 0.0, 0.5)
         )
     );
     let _ = assembly.try_insert_element(
@@ -64,7 +64,7 @@ fn load_general(assembly: &Assembly) {
             String::from("moon_deimos"),
             String::from("Deimos"),
             [0.75_f32, 0.75_f32, 0.00_f32],
-            engine::sphere(0.0, 0.15, 1.0, 0.25),
+            engine::sphere(0.0, 0.15, 1.0, 0.25)
         )
     );
     let _ = assembly.try_insert_element(
@@ -72,12 +72,12 @@ fn load_general(assembly: &Assembly) {
             String::from("moon_phobos"),
             String::from("Phobos"),
             [0.00_f32, 0.75_f32, 0.50_f32],
-            engine::sphere(0.0, -0.15, -1.0, 0.25),
+            engine::sphere(0.0, -0.15, -1.0, 0.25)
         )
     );
 }
 
-fn load_low_curvature(assembly: &Assembly) {
+fn load_low_curv_assemb(assembly: &Assembly) {
     // create the spheres
     let a = 0.75_f64.sqrt();
     let _ = assembly.try_insert_element(
@@ -85,7 +85,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "central".to_string(),
             "Central".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(0.0, 0.0, 0.0, 1.0),
+            engine::sphere(0.0, 0.0, 0.0, 1.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -93,7 +93,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "assemb_plane".to_string(),
             "Assembly plane".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere_with_offset(0.0, 0.0, 1.0, 0.0, 0.0),
+            engine::sphere_with_offset(0.0, 0.0, 1.0, 0.0, 0.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -101,7 +101,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "side1".to_string(),
             "Side 1".to_string(),
             [1.00_f32, 0.00_f32, 0.25_f32],
-            engine::sphere_with_offset(1.0, 0.0, 0.0, 1.0, 0.0),
+            engine::sphere_with_offset(1.0, 0.0, 0.0, 1.0, 0.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -109,7 +109,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "side2".to_string(),
             "Side 2".to_string(),
             [0.25_f32, 1.00_f32, 0.00_f32],
-            engine::sphere_with_offset(-0.5, a, 0.0, 1.0, 0.0),
+            engine::sphere_with_offset(-0.5, a, 0.0, 1.0, 0.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -117,7 +117,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "side3".to_string(),
             "Side 3".to_string(),
             [0.00_f32, 0.25_f32, 1.00_f32],
-            engine::sphere_with_offset(-0.5, -a, 0.0, 1.0, 0.0),
+            engine::sphere_with_offset(-0.5, -a, 0.0, 1.0, 0.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -125,7 +125,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "corner1".to_string(),
             "Corner 1".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(-4.0/3.0, 0.0, 0.0, 1.0/3.0),
+            engine::sphere(-4.0/3.0, 0.0, 0.0, 1.0/3.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -133,7 +133,7 @@ fn load_low_curvature(assembly: &Assembly) {
             "corner2".to_string(),
             "Corner 2".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(2.0/3.0, -4.0/3.0 * a, 0.0, 1.0/3.0),
+            engine::sphere(2.0/3.0, -4.0/3.0 * a, 0.0, 1.0/3.0)
         )
     );
     let _ = assembly.try_insert_element(
@@ -141,7 +141,7 @@ fn load_low_curvature(assembly: &Assembly) {
             String::from("corner3"),
             String::from("Corner 3"),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(2.0/3.0, 4.0/3.0 * a, 0.0, 1.0/3.0),
+            engine::sphere(2.0/3.0, 4.0/3.0 * a, 0.0, 1.0/3.0)
         )
     );
     
@@ -196,13 +196,13 @@ fn load_low_curvature(assembly: &Assembly) {
     }
 }
 
-fn load_pointed(assembly: &Assembly) {
+fn load_pointed_assemb(assembly: &Assembly) {
     let _ = assembly.try_insert_element(
         Point::new(
             format!("point_front"),
             format!("Front point"),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::point(0.0, 0.0, FRAC_1_SQRT_2),
+            engine::point(0.0, 0.0, FRAC_1_SQRT_2)
         )
     );
     let _ = assembly.try_insert_element(
@@ -210,7 +210,7 @@ fn load_pointed(assembly: &Assembly) {
             format!("point_back"),
             format!("Back point"),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::point(0.0, 0.0, -FRAC_1_SQRT_2),
+            engine::point(0.0, 0.0, -FRAC_1_SQRT_2)
         )
     );
     for index_x in 0..=1 {
@@ -223,7 +223,7 @@ fn load_pointed(assembly: &Assembly) {
                     format!("sphere{index_x}{index_y}"),
                     format!("Sphere {index_x}{index_y}"),
                     [0.5*(1.0 + x) as f32, 0.5*(1.0 + y) as f32, 0.5*(1.0 - x*y) as f32],
-                    engine::sphere(x, y, 0.0, 1.0),
+                    engine::sphere(x, y, 0.0, 1.0)
                 )
             );
             
@@ -232,7 +232,7 @@ fn load_pointed(assembly: &Assembly) {
                     format!("point{index_x}{index_y}"),
                     format!("Point {index_x}{index_y}"),
                     [0.5*(1.0 + x) as f32, 0.5*(1.0 + y) as f32, 0.5*(1.0 - x*y) as f32],
-                    engine::point(x, y, 0.0),
+                    engine::point(x, y, 0.0)
                 )
             );
         }
@@ -246,7 +246,7 @@ fn load_pointed(assembly: &Assembly) {
 //   B-C     "
 //   C-C     "
 //   A-C   -0.25 * φ^2 = -0.6545084971874737
-fn load_tridiminished_icosahedron(assembly: &Assembly) {
+fn load_tridim_icosahedron_assemb(assembly: &Assembly) {
     // create the vertices
     const COLOR_A: ElementColor = [1.00_f32, 0.25_f32, 0.25_f32];
     const COLOR_B: ElementColor = [0.75_f32, 0.75_f32, 0.75_f32];
@@ -256,56 +256,56 @@ fn load_tridiminished_icosahedron(assembly: &Assembly) {
             "a1".to_string(),
             "A₁".to_string(),
             COLOR_A,
-            engine::point(0.25, 0.75, 0.75),
+            engine::point(0.25, 0.75, 0.75)
         ),
         Point::new(
             "a2".to_string(),
             "A₂".to_string(),
             COLOR_A,
-            engine::point(0.75, 0.25, 0.75),
+            engine::point(0.75, 0.25, 0.75)
         ),
         Point::new(
             "a3".to_string(),
             "A₃".to_string(),
             COLOR_A,
-            engine::point(0.75, 0.75, 0.25),
+            engine::point(0.75, 0.75, 0.25)
         ),
         Point::new(
             "b1".to_string(),
             "B₁".to_string(),
             COLOR_B,
-            engine::point(0.75, -0.25, -0.25),
+            engine::point(0.75, -0.25, -0.25)
         ),
         Point::new(
             "b2".to_string(),
             "B₂".to_string(),
             COLOR_B,
-            engine::point(-0.25, 0.75, -0.25),
+            engine::point(-0.25, 0.75, -0.25)
         ),
         Point::new(
             "b3".to_string(),
             "B₃".to_string(),
             COLOR_B,
-            engine::point(-0.25, -0.25, 0.75),
+            engine::point(-0.25, -0.25, 0.75)
         ),
         Point::new(
             "c1".to_string(),
             "C₁".to_string(),
             COLOR_C,
-            engine::point(0.0, -1.0, -1.0),
+            engine::point(0.0, -1.0, -1.0)
         ),
         Point::new(
             "c2".to_string(),
             "C₂".to_string(),
             COLOR_C,
-            engine::point(-1.0, 0.0, -1.0),
+            engine::point(-1.0, 0.0, -1.0)
         ),
         Point::new(
             "c3".to_string(),
             "C₃".to_string(),
             COLOR_C,
-            engine::point(-1.0, -1.0, 0.0),
-        ),
+            engine::point(-1.0, -1.0, 0.0)
+        )
     ];
     for vertex in vertices {
         let _ = assembly.try_insert_element(vertex);
@@ -320,20 +320,20 @@ fn load_tridiminished_icosahedron(assembly: &Assembly) {
             "face1".to_string(),
             "Face 1".to_string(),
             COLOR_FACE,
-            engine::sphere_with_offset(frac_2_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, 0.0),
+            engine::sphere_with_offset(frac_2_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, 0.0)
         ),
         Sphere::new(
             "face2".to_string(),
             "Face 2".to_string(),
             COLOR_FACE,
-            engine::sphere_with_offset(-frac_1_sqrt_6, frac_2_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, 0.0),
+            engine::sphere_with_offset(-frac_1_sqrt_6, frac_2_sqrt_6, -frac_1_sqrt_6, -frac_1_sqrt_6, 0.0)
         ),
         Sphere::new(
             "face3".to_string(),
             "Face 3".to_string(),
             COLOR_FACE,
-            engine::sphere_with_offset(-frac_1_sqrt_6, -frac_1_sqrt_6, frac_2_sqrt_6, -frac_1_sqrt_6, 0.0),
-        ),
+            engine::sphere_with_offset(-frac_1_sqrt_6, -frac_1_sqrt_6, frac_2_sqrt_6, -frac_1_sqrt_6, 0.0)
+        )
     ];
     for face in faces {
         face.ghost().set(true);
@@ -409,14 +409,14 @@ fn load_tridiminished_icosahedron(assembly: &Assembly) {
 
 // to finish describing the dodecahedral circle packing, set the inversive
 // distance regulators to -1. some of the regulators have already been set
-fn load_dodecahedral_packing(assembly: &Assembly) {
+fn load_dodeca_packing_assemb(assembly: &Assembly) {
     // add the substrate
     let _ = assembly.try_insert_element(
         Sphere::new(
             "substrate".to_string(),
             "Substrate".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(0.0, 0.0, 0.0, 1.0),
+            engine::sphere(0.0, 0.0, 0.0, 1.0)
         )
     );
     let substrate = assembly.elements_by_id.with_untracked(
@@ -456,7 +456,7 @@ fn load_dodecahedral_packing(assembly: &Assembly) {
                     id_a.clone(),
                     format!("A{label_sub}"),
                     COLOR_A,
-                    engine::sphere(0.0, small_coord, big_coord, face_radii[k]),
+                    engine::sphere(0.0, small_coord, big_coord, face_radii[k])
                 )
             );
             faces.push(
@@ -472,7 +472,7 @@ fn load_dodecahedral_packing(assembly: &Assembly) {
                     id_b.clone(),
                     format!("B{label_sub}"),
                     COLOR_B,
-                    engine::sphere(small_coord, big_coord, 0.0, face_radii[k]),
+                    engine::sphere(small_coord, big_coord, 0.0, face_radii[k])
                 )
             );
             faces.push(
@@ -488,7 +488,7 @@ fn load_dodecahedral_packing(assembly: &Assembly) {
                     id_c.clone(),
                     format!("C{label_sub}"),
                     COLOR_C,
-                    engine::sphere(big_coord, 0.0, small_coord, face_radii[k]),
+                    engine::sphere(big_coord, 0.0, small_coord, face_radii[k])
                 )
             );
             faces.push(
@@ -550,7 +550,7 @@ fn load_dodecahedral_packing(assembly: &Assembly) {
 
 // the initial configuration of this test assembly deliberately violates the
 // constraints, so loading the assembly will trigger a non-trivial realization
-fn load_balanced(assembly: &Assembly) {
+fn load_balanced_assemb(assembly: &Assembly) {
     // create the spheres
     const R_OUTER: f64 = 10.0;
     const R_INNER: f64 = 4.0;
@@ -559,19 +559,19 @@ fn load_balanced(assembly: &Assembly) {
             "outer".to_string(),
             "Outer".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(0.0, 0.0, 0.0, R_OUTER),
+            engine::sphere(0.0, 0.0, 0.0, R_OUTER)
         ),
         Sphere::new(
             "a".to_string(),
             "A".to_string(),
             [1.00_f32, 0.00_f32, 0.25_f32],
-            engine::sphere(0.0, 4.0, 0.0, R_INNER),
+            engine::sphere(0.0, 4.0, 0.0, R_INNER)
         ),
         Sphere::new(
             "b".to_string(),
             "B".to_string(),
             [0.00_f32, 0.25_f32, 1.00_f32],
-            engine::sphere(0.0, -4.0, 0.0, R_INNER),
+            engine::sphere(0.0, -4.0, 0.0, R_INNER)
         ),
     ];
     for sphere in spheres {
@@ -589,7 +589,7 @@ fn load_balanced(assembly: &Assembly) {
     for (sphere, radius) in [
         (outer.clone(), R_OUTER),
         (a.clone(), R_INNER),
-        (b.clone(), R_INNER),
+        (b.clone(), R_INNER)
     ] {
         let curvature_regulator = sphere.regulators().with_untracked(
             |regs| regs.first().unwrap().clone()
@@ -611,14 +611,14 @@ fn load_balanced(assembly: &Assembly) {
 
 // the initial configuration of this test assembly deliberately violates the
 // constraints, so loading the assembly will trigger a non-trivial realization
-fn load_off_center(assembly: &Assembly) {
+fn load_off_center_assemb(assembly: &Assembly) {
     // create a point almost at the origin and a sphere centered on the origin
     let _ = assembly.try_insert_element(
         Point::new(
             "point".to_string(),
             "Point".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::point(1e-9, 0.0, 0.0),
+            engine::point(1e-9, 0.0, 0.0)
         ),
     );
     let _ = assembly.try_insert_element(
@@ -626,7 +626,7 @@ fn load_off_center(assembly: &Assembly) {
             "sphere".to_string(),
             "Sphere".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(0.0, 0.0, 0.0, 1.0),
+            engine::sphere(0.0, 0.0, 0.0, 1.0)
         ),
     );
     
@@ -648,7 +648,7 @@ fn load_off_center(assembly: &Assembly) {
 // sqrt(1/6) and sqrt(3/2), respectively. to measure those radii, set an
 // inversive distance of -1 between the insphere and each face, and then set an
 // inversive distance of 0 between the circumsphere and each vertex
-fn load_radius_ratio(assembly: &Assembly) {
+fn load_radius_ratio_assemb(assembly: &Assembly) {
     let index_range = 1..=4;
     
     // create the spheres
@@ -658,14 +658,14 @@ fn load_radius_ratio(assembly: &Assembly) {
             "sphere_faces".to_string(),
             "Insphere".to_string(),
             GRAY,
-            engine::sphere(0.0, 0.0, 0.0, 0.5),
+            engine::sphere(0.0, 0.0, 0.0, 0.5)
         ),
         Sphere::new(
             "sphere_vertices".to_string(),
             "Circumsphere".to_string(),
             GRAY,
-            engine::sphere(0.0, 0.0, 0.0, 0.25),
-        ),
+            engine::sphere(0.0, 0.0, 0.0, 0.25)
+        )
     ];
     for sphere in spheres {
         let _ = assembly.try_insert_element(sphere);
@@ -678,13 +678,13 @@ fn load_radius_ratio(assembly: &Assembly) {
             [1.00_f32, 0.50_f32, 0.75_f32],
             [1.00_f32, 0.75_f32, 0.50_f32],
             [1.00_f32, 1.00_f32, 0.50_f32],
-            [0.75_f32, 0.50_f32, 1.00_f32],
+            [0.75_f32, 0.50_f32, 1.00_f32]
         ].into_iter(),
         [
             engine::point(-0.6, -0.8, -0.6),
             engine::point(-0.6, 0.8, 0.6),
             engine::point(0.6, -0.8, 0.6),
-            engine::point(0.6, 0.8, -0.6),
+            engine::point(0.6, 0.8, -0.6)
         ].into_iter()
     ).map(
         |(k, color, representation)| {
@@ -692,7 +692,7 @@ fn load_radius_ratio(assembly: &Assembly) {
                 format!("v{k}"),
                 format!("Vertex {k}"),
                 color,
-                representation,
+                representation
             )
         }
     );
@@ -709,13 +709,13 @@ fn load_radius_ratio(assembly: &Assembly) {
             [1.00_f32, 0.00_f32, 0.25_f32],
             [1.00_f32, 0.25_f32, 0.00_f32],
             [0.75_f32, 0.75_f32, 0.00_f32],
-            [0.25_f32, 0.00_f32, 1.00_f32],
+            [0.25_f32, 0.00_f32, 1.00_f32]
         ].into_iter(),
         [
             engine::sphere_with_offset(base_dir[0], base_dir[1], base_dir[2], offset, 0.0),
             engine::sphere_with_offset(base_dir[0], -base_dir[1], -base_dir[2], offset, 0.0),
             engine::sphere_with_offset(-base_dir[0], base_dir[1], -base_dir[2], offset, 0.0),
-            engine::sphere_with_offset(-base_dir[0], -base_dir[1], base_dir[2], offset, 0.0),
+            engine::sphere_with_offset(-base_dir[0], -base_dir[1], base_dir[2], offset, 0.0)
         ].into_iter()
     ).map(
         |(k, color, representation)| {
@@ -723,7 +723,7 @@ fn load_radius_ratio(assembly: &Assembly) {
                 format!("f{k}"),
                 format!("Face {k}"),
                 color,
-                representation,
+                representation
             )
         }
     );
@@ -736,7 +736,7 @@ fn load_radius_ratio(assembly: &Assembly) {
     for j in index_range.clone() {
         let [face_j, vertex_j] = [
             format!("f{j}"),
-            format!("v{j}"),
+            format!("v{j}")
         ].map(
             |id| assembly.elements_by_id.with_untracked(
                 |elts_by_id| elts_by_id[&id].clone()
@@ -789,7 +789,7 @@ fn load_radius_ratio(assembly: &Assembly) {
 // conditions are exactly representable as floats, unlike the analogous numbers
 // in the scaled-up problem. the inexact representations might break the
 // symmetry that's getting the engine stuck
-fn load_irisawa_hexlet(assembly: &Assembly) {
+fn load_irisawa_hexlet_assemb(assembly: &Assembly) {
     let index_range = 1..=6;
     let colors = [
         [1.00_f32, 0.00_f32, 0.25_f32],
@@ -797,7 +797,7 @@ fn load_irisawa_hexlet(assembly: &Assembly) {
         [0.75_f32, 0.75_f32, 0.00_f32],
         [0.25_f32, 1.00_f32, 0.00_f32],
         [0.00_f32, 0.25_f32, 1.00_f32],
-        [0.25_f32, 0.00_f32, 1.00_f32],
+        [0.25_f32, 0.00_f32, 1.00_f32]
     ].into_iter();
     
     // create the spheres
@@ -806,19 +806,19 @@ fn load_irisawa_hexlet(assembly: &Assembly) {
             "outer".to_string(),
             "Outer".to_string(),
             [0.5_f32, 0.5_f32, 0.5_f32],
-            engine::sphere(0.0, 0.0, 0.0, 1.5),
+            engine::sphere(0.0, 0.0, 0.0, 1.5)
         ),
         Sphere::new(
             "sun".to_string(),
             "Sun".to_string(),
             [0.75_f32, 0.75_f32, 0.75_f32],
-            engine::sphere(0.0, -0.75, 0.0, 0.75),
+            engine::sphere(0.0, -0.75, 0.0, 0.75)
         ),
         Sphere::new(
             "moon".to_string(),
             "Moon".to_string(),
             [0.25_f32, 0.25_f32, 0.25_f32],
-            engine::sphere(0.0, 0.75, 0.0, 0.75),
+            engine::sphere(0.0, 0.75, 0.0, 0.75)
         ),
     ].into_iter().chain(
         index_range.clone().zip(colors).map(
@@ -828,7 +828,7 @@ fn load_irisawa_hexlet(assembly: &Assembly) {
                     format!("chain{k}"),
                     format!("Chain {k}"),
                     color,
-                    engine::sphere(1.0 * ang.sin(), 0.0, 1.0 * ang.cos(), 0.5),
+                    engine::sphere(1.0 * ang.sin(), 0.0, 1.0 * ang.cos(), 0.5)
                 )
             }
         )
@@ -865,7 +865,7 @@ fn load_irisawa_hexlet(assembly: &Assembly) {
             (outer.clone(), "1"),
             (sun.clone(), "-1"),
             (moon.clone(), "-1"),
-            (chain_sphere_next.clone(), "-1"),
+            (chain_sphere_next.clone(), "-1")
         ] {
             let tangency = InversiveDistanceRegulator::new([chain_sphere.clone(), other_sphere]);
             tangency.set_point.set(SpecifiedValue::try_from(inversive_distance.to_string()).unwrap());
@@ -900,6 +900,9 @@ pub fn TestAssemblyChooser() -> View {
             let state = use_context::<AppState>();
             let assembly = &state.assembly;
             
+            // pause realization
+            assembly.keep_realized.set(false);
+            
             // clear state
             assembly.regulators.update(|regs| regs.clear());
             assembly.elements.update(|elts| elts.clear());
@@ -909,33 +912,36 @@ pub fn TestAssemblyChooser() -> View {
             
             // load assembly
             match name.as_str() {
-                "general" => load_general(assembly),
-                "low-curvature" => load_low_curvature(assembly),
-                "pointed" => load_pointed(assembly),
-                "tridiminished-icosahedron" => load_tridiminished_icosahedron(assembly),
-                "dodecahedral-packing" => load_dodecahedral_packing(assembly),
-                "balanced" => load_balanced(assembly),
-                "off-center" => load_off_center(assembly),
-                "radius-ratio" => load_radius_ratio(assembly),
-                "irisawa-hexlet" => load_irisawa_hexlet(assembly),
-                _ => (),
+                "general" => load_gen_assemb(assembly),
+                "low-curv" => load_low_curv_assemb(assembly),
+                "pointed" => load_pointed_assemb(assembly),
+                "tridim-icosahedron" => load_tridim_icosahedron_assemb(assembly),
+                "dodeca-packing" => load_dodeca_packing_assemb(assembly),
+                "balanced" => load_balanced_assemb(assembly),
+                "off-center" => load_off_center_assemb(assembly),
+                "radius-ratio" => load_radius_ratio_assemb(assembly),
+                "irisawa-hexlet" => load_irisawa_hexlet_assemb(assembly),
+                _ => ()
             };
+            
+            // resume realization
+            assembly.keep_realized.set(true);
         });
     });
     
     // build the chooser
     view! {
-        select(bind:value = assembly_name) {
-            option(value = "general") { "General" }
-            option(value = "low-curvature") { "Low-curvature" }
-            option(value = "pointed") { "Pointed" }
-            option(value = "tridiminished-icosahedron") { "Tridiminished icosahedron" }
-            option(value = "dodecahedral-packing") { "Dodecahedral packing" }
-            option(value = "balanced") { "Balanced" }
-            option(value = "off-center") { "Off-center" }
-            option(value = "radius-ratio") { "Radius ratio" }
-            option(value = "irisawa-hexlet") { "Irisawa hexlet" }
-            option(value = "empty") { "Empty" }
+        select(bind:value=assembly_name) {
+            option(value="general") { "General" }
+            option(value="low-curv") { "Low-curvature" }
+            option(value="pointed") { "Pointed" }
+            option(value="tridim-icosahedron") { "Tridiminished icosahedron" }
+            option(value="dodeca-packing") { "Dodecahedral packing" }
+            option(value="balanced") { "Balanced" }
+            option(value="off-center") { "Off-center" }
+            option(value="radius-ratio") { "Radius ratio" }
+            option(value="irisawa-hexlet") { "Irisawa hexlet" }
+            option(value="empty") { "Empty" }
         }
     }
 }

app-proto/src/engine.rs

@@ -1,6 +1,7 @@
 use lazy_static::lazy_static;
 use nalgebra::{Const, DMatrix, DVector, DVectorView, Dyn, SymmetricEigen};
 use std::fmt::{Display, Error, Formatter};
+use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
 
 // --- elements ---
 
@@ -16,7 +17,7 @@ pub fn sphere(center_x: f64, center_y: f64, center_z: f64, radius: f64) -> DVect
         center_y / radius,
         center_z / radius,
         0.5 / radius,
-        0.5 * (center_norm_sq / radius - radius),
+        0.5 * (center_norm_sq / radius - radius)
     ])
 }
 
@@ -30,7 +31,7 @@ pub fn sphere_with_offset(dir_x: f64, dir_y: f64, dir_z: f64, off: f64, curv: f6
         norm_sp * dir_y,
         norm_sp * dir_z,
         0.5 * curv,
-        off * (1.0 + 0.5 * off * curv),
+        off * (1.0 + 0.5 * off * curv)
     ])
 }
 
@@ -49,23 +50,57 @@ pub fn project_point_to_normalized(rep: &mut DVector<f64>) {
     rep.scale_mut(0.5 / rep[3]);
 }
 
+// given a sphere's representation vector, change the sphere's half-curvature to
+// `half-curv` and then restore normalization by contracting the representation
+// vector toward the curvature axis
+pub fn change_half_curvature(rep: &mut DVector<f64>, half_curv: f64) {
+    // set the sphere's half-curvature to the desired value
+    rep[3] = half_curv;
+    
+    // restore normalization by contracting toward the curvature axis
+    const SIZE_THRESHOLD: f64 = 1e-9;
+    let half_q_lt = -2.0 * half_curv * rep[4];
+    let half_q_lt_sq = half_q_lt * half_q_lt;
+    let mut spatial = rep.fixed_rows_mut::<3>(0);
+    let q_sp = spatial.norm_squared();
+    if q_sp < SIZE_THRESHOLD && half_q_lt_sq < SIZE_THRESHOLD {
+        spatial.copy_from_slice(
+            &[0.0, 0.0, (1.0 - 2.0 * half_q_lt).sqrt()]
+        );
+    } else {
+        let scaling = half_q_lt + (q_sp + half_q_lt_sq).sqrt();
+        spatial.scale_mut(1.0 / scaling);
+        rep[4] /= scaling;
+    }
+    
+    /* DEBUG */
+    // verify normalization
+    let rep_for_debug = rep.clone();
+    console::log_1(&JsValue::from(
+        format!(
+            "Sphere self-product after curvature change: {}",
+            rep_for_debug.dot(&(&*Q * &rep_for_debug))
+        )
+    ));
+}
+
 // --- partial matrices ---
 
 pub struct MatrixEntry {
-    pub index: (usize, usize),
-    pub value: f64,
+    index: (usize, usize),
+    value: f64
 }
 
 pub struct PartialMatrix(Vec<MatrixEntry>);
 
 impl PartialMatrix {
-    pub fn new() -> Self {
-        Self(Vec::<MatrixEntry>::new())
+    pub fn new() -> PartialMatrix {
+        PartialMatrix(Vec::<MatrixEntry>::new())
     }
     
     pub fn push(&mut self, row: usize, col: usize, value: f64) {
-        let Self(entries) = self;
-        entries.push(MatrixEntry { index: (row, col), value });
+        let PartialMatrix(entries) = self;
+        entries.push(MatrixEntry { index: (row, col), value: value });
     }
     
     pub fn push_sym(&mut self, row: usize, col: usize, value: f64) {
@@ -114,7 +149,7 @@ impl IntoIterator for PartialMatrix {
     type IntoIter = std::vec::IntoIter<Self::Item>;
     
     fn into_iter(self) -> Self::IntoIter {
-        let Self(entries) = self;
+        let PartialMatrix(entries) = self;
         entries.into_iter()
     }
 }
@@ -135,26 +170,22 @@ impl<'a> IntoIterator for &'a PartialMatrix {
 pub struct ConfigSubspace {
     assembly_dim: usize,
     basis_std: Vec<DMatrix<f64>>,
-    basis_proj: Vec<DMatrix<f64>>,
+    basis_proj: Vec<DMatrix<f64>>
 }
 
 impl ConfigSubspace {
-    pub fn zero(assembly_dim: usize) -> Self {
-        Self {
-            assembly_dim,
+    pub fn zero(assembly_dim: usize) -> ConfigSubspace {
+        ConfigSubspace {
+            assembly_dim: assembly_dim,
             basis_proj: Vec::new(),
-            basis_std: Vec::new(),
+            basis_std: Vec::new()
         }
     }
     
     // approximate the kernel of a symmetric endomorphism of the configuration
     // space for `assembly_dim` elements. we consider an eigenvector to be part
     // of the kernel if its eigenvalue is smaller than the constant `THRESHOLD`
-    fn symmetric_kernel(
-        a: DMatrix<f64>,
-        proj_to_std: DMatrix<f64>,
-        assembly_dim: usize,
-    ) -> Self {
+    fn symmetric_kernel(a: DMatrix<f64>, proj_to_std: DMatrix<f64>, assembly_dim: usize) -> ConfigSubspace {
         // find a basis for the kernel. the basis is expressed in the projection
         // coordinates, and it's orthonormal with respect to the projection
         // inner product
@@ -168,13 +199,20 @@ impl ConfigSubspace {
             ).collect::<Vec<_>>().as_slice()
         );
         
+        /* DEBUG */
+        // print the eigenvalues
+        #[cfg(all(target_family = "wasm", target_os = "unknown"))]
+        console::log_1(&JsValue::from(
+            format!("Eigenvalues used to find kernel:{}", eig.eigenvalues)
+        ));
+        
         // express the basis in the standard coordinates
         let basis_std = proj_to_std * &basis_proj;
         
         const ELEMENT_DIM: usize = 5;
         const UNIFORM_DIM: usize = 4;
-        Self {
-            assembly_dim,
+        ConfigSubspace {
+            assembly_dim: assembly_dim,
             basis_std: basis_std.column_iter().map(
                 |v| Into::<DMatrix<f64>>::into(
                     v.reshape_generic(Dyn(ELEMENT_DIM), Dyn(assembly_dim))
@@ -184,7 +222,7 @@ impl ConfigSubspace {
                 |v| Into::<DMatrix<f64>>::into(
                     v.reshape_generic(Dyn(UNIFORM_DIM), Dyn(assembly_dim))
                 )
-            ).collect(),
+            ).collect()
         }
     }
     
@@ -218,14 +256,14 @@ pub struct DescentHistory {
     pub config: Vec<DMatrix<f64>>,
     pub scaled_loss: Vec<f64>,
     pub neg_grad: Vec<DMatrix<f64>>,
-    pub hess_eigvals: Vec<DVector<f64>>,
+    pub hess_eigvals: Vec::<DVector<f64>>,
     pub base_step: Vec<DMatrix<f64>>,
-    pub backoff_steps: Vec<i32>,
+    pub backoff_steps: Vec<i32>
 }
 
 impl DescentHistory {
-    pub fn new() -> Self {
-        Self {
+    pub fn new() -> DescentHistory {
+        DescentHistory {
             config: Vec::<DMatrix<f64>>::new(),
             scaled_loss: Vec::<f64>::new(),
             neg_grad: Vec::<DMatrix<f64>>::new(),
@@ -245,21 +283,21 @@ pub struct ConstraintProblem {
 }
 
 impl ConstraintProblem {
-    pub fn new(element_count: usize) -> Self {
+    pub fn new(element_count: usize) -> ConstraintProblem {
         const ELEMENT_DIM: usize = 5;
-        Self {
+        ConstraintProblem {
             gram: PartialMatrix::new(),
             frozen: PartialMatrix::new(),
-            guess: DMatrix::<f64>::zeros(ELEMENT_DIM, element_count),
+            guess: DMatrix::<f64>::zeros(ELEMENT_DIM, element_count)
         }
     }
     
     #[cfg(feature = "dev")]
-    pub fn from_guess(guess_columns: &[DVector<f64>]) -> Self {
-        Self {
+    pub fn from_guess(guess_columns: &[DVector<f64>]) -> ConstraintProblem {
+        ConstraintProblem {
             gram: PartialMatrix::new(),
             frozen: PartialMatrix::new(),
-            guess: DMatrix::from_columns(guess_columns),
+            guess: DMatrix::from_columns(guess_columns)
         }
     }
 }
@@ -273,21 +311,25 @@ lazy_static! {
         0.0, 1.0, 0.0,  0.0,  0.0,
         0.0, 0.0, 1.0,  0.0,  0.0,
         0.0, 0.0, 0.0,  0.0, -2.0,
-        0.0, 0.0, 0.0, -2.0,  0.0,
+        0.0, 0.0, 0.0, -2.0,  0.0
     ]);
 }
 
 struct SearchState {
     config: DMatrix<f64>,
     err_proj: DMatrix<f64>,
-    loss: f64,
+    loss: f64
 }
 
 impl SearchState {
-    fn from_config(gram: &PartialMatrix, config: DMatrix<f64>) -> Self {
+    fn from_config(gram: &PartialMatrix, config: DMatrix<f64>) -> SearchState {
         let err_proj = gram.sub_proj(&(config.tr_mul(&*Q) * &config));
         let loss = err_proj.norm_squared();
-        Self { config, err_proj, loss }
+        SearchState {
+            config: config,
+            err_proj: err_proj,
+            loss: loss
+        }
     }
 }
 
@@ -314,7 +356,7 @@ pub fn local_unif_to_std(v: DVectorView<f64>) -> DMatrix<f64> {
             curv,  0.0,  0.0,  0.0, v[0],
              0.0, curv,  0.0,  0.0, v[1],
              0.0,  0.0, curv,  0.0, v[2],
-             0.0,  0.0,  0.0,  0.0,  1.0,
+             0.0,  0.0,  0.0,  0.0,  1.0
         ])
     } else {
         // `v` represents a sphere. the normalization condition says that the
@@ -323,7 +365,7 @@ pub fn local_unif_to_std(v: DVectorView<f64>) -> DMatrix<f64> {
                  curv,       0.0,       0.0,       0.0,            v[0],
                   0.0,      curv,       0.0,       0.0,            v[1],
                   0.0,       0.0,      curv,       0.0,            v[2],
-            curv*v[0], curv*v[1], curv*v[2], curv*v[3], curv*v[4] + 1.0,
+            curv*v[0], curv*v[1], curv*v[2], curv*v[3], curv*v[4] + 1.0
         ])
     }
 }
@@ -336,7 +378,7 @@ fn seek_better_config(
     base_target_improvement: f64,
     min_efficiency: f64,
     backoff: f64,
-    max_backoff_steps: i32,
+    max_backoff_steps: i32
 ) -> Option<(SearchState, i32)> {
     let mut rate = 1.0;
     for backoff_steps in 0..max_backoff_steps {
@@ -353,13 +395,13 @@ fn seek_better_config(
 
 // a first-order neighborhood of a configuration
 pub struct ConfigNeighborhood {
-    #[cfg(feature = "dev")] pub config: DMatrix<f64>,
-    pub nbhd: ConfigSubspace,
+    pub config: DMatrix<f64>,
+    pub nbhd: ConfigSubspace
 }
 
 pub struct Realization {
     pub result: Result<ConfigNeighborhood, String>,
-    pub history: DescentHistory,
+    pub history: DescentHistory
 }
 
 // seek a matrix `config` that matches the partial matrix `problem.frozen` and
@@ -373,30 +415,19 @@ pub fn realize_gram(
     backoff: f64,
     reg_scale: f64,
     max_descent_steps: i32,
-    max_backoff_steps: i32,
+    max_backoff_steps: i32
 ) -> Realization {
     // destructure the problem data
-    let ConstraintProblem { gram, guess, frozen } = problem;
+    let ConstraintProblem {
+        gram, guess, frozen
+    } = problem;
     
     // start the descent history
     let mut history = DescentHistory::new();
     
-    // handle the case where the assembly is empty. our general realization
-    // routine can't handle this case because it builds the Hessian using
-    // `DMatrix::from_columns`, which panics when the list of columns is empty
-    let assembly_dim = guess.ncols();
-    if assembly_dim == 0 {
-        let result = Ok(
-            ConfigNeighborhood {
-                #[cfg(feature = "dev")] config: guess.clone(),
-                nbhd: ConfigSubspace::zero(0),
-            }
-        );
-        return Realization { result, history };
-    }
-    
     // find the dimension of the search space
     let element_dim = guess.nrows();
+    let assembly_dim = guess.ncols();
     let total_dim = element_dim * assembly_dim;
     
     // scale the tolerance
@@ -473,8 +504,8 @@ pub fn realize_gram(
             Some(cholesky) => cholesky,
             None => return Realization {
                 result: Err("Cholesky decomposition failed".to_string()),
-                history,
-            },
+                history
+            }
         };
         let base_step_stacked = hess_cholesky.solve(&neg_grad_stacked);
         let base_step = base_step_stacked.reshape_generic(Dyn(element_dim), Dyn(assembly_dim));
@@ -483,16 +514,16 @@ pub fn realize_gram(
         // use backtracking line search to find a better configuration
         if let Some((better_state, backoff_steps)) = seek_better_config(
             gram, &state, &base_step, neg_grad.dot(&base_step),
-            min_efficiency, backoff, max_backoff_steps,
+            min_efficiency, backoff, max_backoff_steps
         ) {
             state = better_state;
             history.backoff_steps.push(backoff_steps);
         } else {
             return Realization {
                 result: Err("Line search failed".to_string()),
-                history,
-            };
-        }
+                history
+            }
+        };
     }
     let result = if state.loss < tol {
         // express the uniform basis in the standard basis
@@ -509,7 +540,7 @@ pub fn realize_gram(
         // find the kernel of the Hessian. give it the uniform inner product
         let tangent = ConfigSubspace::symmetric_kernel(hess, unif_to_std, assembly_dim);
         
-        Ok(ConfigNeighborhood { #[cfg(feature = "dev")] config: state.config, nbhd: tangent })
+        Ok(ConfigNeighborhood { config: state.config, nbhd: tangent })
     } else {
         Err("Failed to reach target accuracy".to_string())
     };
@@ -537,7 +568,7 @@ pub mod examples {
             [
                 sphere(0.0, 0.0, 0.0, 15.0),
                 sphere(0.0, 0.0, -9.0, 5.0),
-                sphere(0.0, 0.0, 11.0, 3.0),
+                sphere(0.0, 0.0, 11.0, 3.0)
             ].into_iter().chain(
                 (1..=6).map(
                     |k| {
@@ -596,7 +627,7 @@ pub mod examples {
                         point(0.0, 0.0, 0.0),
                         point(ang_hor.cos(), ang_hor.sin(), 0.0),
                         point(x_vert, y_vert, -0.5),
-                        point(x_vert, y_vert, 0.5),
+                        point(x_vert, y_vert, 0.5)
                     ]
                 }
             ).collect::<Vec<_>>().as_slice()
@@ -639,15 +670,15 @@ mod tests {
             MatrixEntry { index: (0, 0), value: 14.0 },
             MatrixEntry { index: (0, 2), value: 28.0 },
             MatrixEntry { index: (1, 1), value: 42.0 },
-            MatrixEntry { index: (1, 2), value: 49.0 },
+            MatrixEntry { index: (1, 2), value: 49.0 }
         ]);
         let config = DMatrix::<f64>::from_row_slice(2, 3, &[
             1.0, 2.0, 3.0,
-            4.0, 5.0, 6.0,
+            4.0, 5.0, 6.0
         ]);
         let expected_result = DMatrix::<f64>::from_row_slice(2, 3, &[
             14.0, 2.0, 28.0,
-            4.0, 42.0, 49.0,
+            4.0, 42.0, 49.0
         ]);
         assert_eq!(frozen.freeze(&config), expected_result);
     }
@@ -658,15 +689,15 @@ mod tests {
             MatrixEntry { index: (0, 0), value: 19.0 },
             MatrixEntry { index: (0, 2), value: 39.0 },
             MatrixEntry { index: (1, 1), value: 59.0 },
-            MatrixEntry { index: (1, 2), value: 69.0 },
+            MatrixEntry { index: (1, 2), value: 69.0 }
         ]);
         let attempt = DMatrix::<f64>::from_row_slice(2, 3, &[
             1.0, 2.0, 3.0,
-            4.0, 5.0, 6.0,
+            4.0, 5.0, 6.0
         ]);
         let expected_result = DMatrix::<f64>::from_row_slice(2, 3, &[
             18.0, 0.0, 36.0,
-            0.0, 54.0, 63.0,
+            0.0, 54.0, 63.0
         ]);
         assert_eq!(target.sub_proj(&attempt), expected_result);
     }
@@ -684,7 +715,7 @@ mod tests {
             DMatrix::from_columns(&[
                 sphere(1.0, 0.0, 0.0, a),
                 sphere(-0.5, a, 0.0, a),
-                sphere(-0.5, -a, 0.0, a),
+                sphere(-0.5, -a, 0.0, a)
             ])
         };
         let state = SearchState::from_config(&gram, config);
@@ -698,7 +729,7 @@ mod tests {
     fn frozen_entry_test() {
         let mut problem = ConstraintProblem::from_guess(&[
             point(0.0, 0.0, 2.0),
-            sphere(0.0, 0.0, 0.0, 0.95),
+            sphere(0.0, 0.0, 0.0, 0.95)
         ]);
         for j in 0..2 {
             for k in j..2 {
@@ -742,7 +773,7 @@ mod tests {
         let mut problem = ConstraintProblem::from_guess(&[
             sphere(0.0, 0.0, 0.0, -2.0),
             sphere(0.0, 0.0, 1.0, 1.0),
-            sphere(0.0, 0.0, -1.0, 1.0),
+            sphere(0.0, 0.0, -1.0, 1.0)
         ]);
         for j in 0..3 {
             for k in j..3 {
@@ -772,8 +803,8 @@ mod tests {
             DMatrix::<f64>::from_column_slice(UNIFORM_DIM, assembly_dim, &[
                 0.0, 0.0,  0.0,  0.0,
                 0.0, 0.0, -0.5, -0.5,
-                0.0, 0.0, -0.5,  0.5,
-            ]),
+                0.0, 0.0, -0.5,  0.5
+            ])
         ];
         let tangent_motions_std = vec![
             basis_matrix((0, 1), element_dim, assembly_dim),
@@ -783,8 +814,8 @@ mod tests {
             DMatrix::<f64>::from_column_slice(element_dim, assembly_dim, &[
                 0.0, 0.0,  0.0,  0.00,  0.0,
                 0.0, 0.0, -1.0, -0.25, -1.0,
-                0.0, 0.0, -1.0,  0.25,  1.0,
-            ]),
+                0.0, 0.0, -1.0,  0.25,  1.0
+            ])
         ];
         
         // confirm that the dimension of the tangent space is no greater than
@@ -860,10 +891,10 @@ mod tests {
                         DVector::from_column_slice(&[0.0, 0.0, 5.0, 0.0]),
                         DVector::from_column_slice(&[0.0, 0.0, 1.0, 0.0]),
                         DVector::from_column_slice(&[-vel_vert_x, -vel_vert_y, -3.0, 0.0]),
-                        DVector::from_column_slice(&[vel_vert_x, vel_vert_y, -3.0, 0.0]),
+                        DVector::from_column_slice(&[vel_vert_x, vel_vert_y, -3.0, 0.0])
                     ]
                 }
-            ).collect::<Vec<_>>(),
+            ).collect::<Vec<_>>()
         ];
         let tangent_motions_std = tangent_motions_unif.iter().map(
             |motion| DMatrix::from_columns(
@@ -896,7 +927,7 @@ mod tests {
                    0.0,        1.0,        0.0, 0.0,             dis[1],
                    0.0,        0.0,        1.0, 0.0,             dis[2],
             2.0*dis[0], 2.0*dis[1], 2.0*dis[2], 1.0, dis.norm_squared(),
-                   0.0,        0.0,        0.0, 0.0,                1.0,
+                   0.0,        0.0,        0.0, 0.0,                1.0
         ])
     }
     
@@ -908,7 +939,7 @@ mod tests {
         const SCALED_TOL: f64 = 1.0e-12;
         let mut problem_orig = ConstraintProblem::from_guess(&[
             sphere(0.0, 0.0, 0.5, 1.0),
-            sphere(0.0, 0.0, -0.5, 1.0),
+            sphere(0.0, 0.0, -0.5, 1.0)
         ]);
         problem_orig.gram.push_sym(0, 0, 1.0);
         problem_orig.gram.push_sym(1, 1, 1.0);
@@ -926,13 +957,13 @@ mod tests {
             let a = 0.5 * FRAC_1_SQRT_2;
             DMatrix::from_columns(&[
                 sphere(a, 0.0, 7.0 + a, 1.0),
-                sphere(-a, 0.0, 7.0 - a, 1.0),
+                sphere(-a, 0.0, 7.0 - a, 1.0)
             ])
         };
         let problem_tfm = ConstraintProblem {
             gram: problem_orig.gram,
-            frozen: problem_orig.frozen,
             guess: guess_tfm,
+            frozen: problem_orig.frozen
         };
         let Realization { result: result_tfm, history: history_tfm } = realize_gram(
             &problem_tfm, SCALED_TOL, 0.5, 0.9, 1.1, 200, 110
@@ -960,7 +991,7 @@ mod tests {
                       0.0, 1.0,            0.0, 0.0, 0.0,
             FRAC_1_SQRT_2, 0.0,  FRAC_1_SQRT_2, 0.0, 0.0,
                       0.0, 0.0,            0.0, 1.0, 0.0,
-                      0.0, 0.0,            0.0, 0.0, 1.0,
+                      0.0, 0.0,            0.0, 0.0, 1.0
         ]);
         let transl = translation(Vector3::new(0.0, 0.0, 7.0));
         let motion_proj_tfm = transl * rot * motion_orig_proj;

app-proto/src/main.rs

@@ -14,20 +14,20 @@ use components::{
     add_remove::AddRemove,
     diagnostics::Diagnostics,
     display::Display,
-    outline::Outline,
+    outline::Outline
 };
 
 #[derive(Clone)]
 struct AppState {
     assembly: Assembly,
-    selection: Signal<BTreeSet<Rc<dyn Element>>>,
+    selection: Signal<BTreeSet<Rc<dyn Element>>>
 }
 
 impl AppState {
-    fn new() -> Self {
-        Self {
+    fn new() -> AppState {
+        AppState {
             assembly: Assembly::new(),
-            selection: create_signal(BTreeSet::default()),
+            selection: create_signal(BTreeSet::default())
         }
     }
     
@@ -58,7 +58,7 @@ fn main() {
         provide_context(AppState::new());
         
         view! {
-            div(id = "sidebar") {
+            div(id="sidebar") {
                 AddRemove {}
                 Outline {}
                 Diagnostics {}

app-proto/src/specified.rs

@@ -13,12 +13,12 @@ use std::num::ParseFloatError;
 #[readonly::make]
 pub struct SpecifiedValue {
     pub spec: String,
-    pub value: Option<f64>,
+    pub value: Option<f64>
 }
 
 impl SpecifiedValue {
-    pub fn from_empty_spec() -> Self {
-        Self { spec: String::new(), value: None }
+    pub fn from_empty_spec() -> SpecifiedValue {
+        SpecifiedValue { spec: String::new(), value: None }
     }
     
     pub fn is_present(&self) -> bool {
@@ -26,17 +26,6 @@ impl SpecifiedValue {
     }
 }
 
-// a `SpecifiedValue` can be constructed from a floating-point option, which is
-// given a canonical specification
-impl From<Option<f64>> for SpecifiedValue {
-    fn from(value: Option<f64>) -> Self {
-        match value {
-            Some(x) => SpecifiedValue{ spec: x.to_string(), value },
-            None => SpecifiedValue::from_empty_spec(),
-        }
-    }
-}
-
 // a `SpecifiedValue` can be constructed from a specification string, formatted
 // as described in the comment on the structure definition. the result is `Ok`
 // if the specification is properly formatted, and `Error` if not
@@ -45,10 +34,10 @@ impl TryFrom<String> for SpecifiedValue {
     
     fn try_from(spec: String) -> Result<Self, Self::Error> {
         if spec.is_empty() {
-            Ok(Self::from_empty_spec())
+            Ok(SpecifiedValue::from_empty_spec())
         } else {
             spec.parse::<f64>().map(
-                |value| Self { spec, value: Some(value) }
+                |value| SpecifiedValue { spec: spec, value: Some(value) }
             )
         }
     }

deploy/.gitignore

@@ -1,5 +0,0 @@
-/dyna3.zip
-/dyna3/index.html
-/dyna3/dyna3-*.js
-/dyna3/dyna3-*.wasm
-/dyna3/main-*.css

tools/package-for-deployment.sh

@@ -1,16 +0,0 @@
-# set paths. this technique for getting the script location comes from
-# `mklement0` on Stack Overflow
-#
-#   https://stackoverflow.com/a/24114056
-#
-TOOLS=$(dirname -- $0)
-SRC="$TOOLS/../app-proto/dist"
-DEST="$TOOLS/../deploy/dyna3"
-
-# remove the old hash-named files
-[ -e "$DEST"/dyna3-*.js ] && rm "$DEST"/dyna3-*.js
-[ -e "$DEST"/dyna3-*.wasm ] && rm "$DEST"/dyna3-*.wasm
-[ -e "$DEST"/main-*.css ] && rm "$DEST"/main-*.css
-
-# copy the distribution
-cp -r "$SRC/." "$DEST"