Add a half-curvature regulator

In the process, add the `OutlineItem` trait so that each regulator can implement its own outline item view.
Specify the values of the frozen entries
2025-04-01 22:23:08 -07:00 · 2025-03-27 13:57:46 -07:00 · 2025-03-27 02:56:46 -07:00 · 2025-03-27 00:29:27 -07:00 · 2025-03-26 23:50:40 -07:00 · 2025-03-25 02:15:03 -07:00
35 changed files with 1601 additions and 4062 deletions
--- a/.forgejo/setup-trunk/action.yaml
+++ b/.forgejo/setup-trunk/action.yaml
@ -1,22 +0,0 @@
-# set up the Trunk web build system
-#
-#   https://trunkrs.dev
-#
-# the `curl` call is based on David Tolnay's `rust-toolchain` action
-#
-#   https://github.com/dtolnay/rust-toolchain
-#
-runs:
-  using: "composite"
-  steps:
-    - run: rustup target add wasm32-unknown-unknown
-    
-    # install the Trunk binary to `ci-bin` within the workspace directory, which
-    # is determined by the `github.workspace` label and reflected in the
-    # `GITHUB_WORKSPACE` environment variable. then, make the `trunk` command
-    # available by placing the fully qualified path to `ci-bin` on the
-    # workflow's search path
-    - run: mkdir -p ci-bin
-    - run: curl --output - --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused --location --silent --show-error --fail 'https://github.com/trunk-rs/trunk/releases/download/v0.21.12/trunk-x86_64-unknown-linux-gnu.tar.gz' | tar --gunzip --extract --file -
-      working-directory: ci-bin
-    - run: echo "${{ github.workspace }}/ci-bin" >> $GITHUB_PATH
--- a/.forgejo/workflows/continuous-integration.yaml
+++ b/.forgejo/workflows/continuous-integration.yaml
@ -1,29 +0,0 @@
-on:
-  pull_request:
-  push:
-    branches: [main]
-jobs:
-  # run the automated tests, reporting success if the tests pass and were built
-  # without warnings. the examples are run as tests, because we've configured
-  # each example target with `test = true` and `harness = false` in Cargo.toml.
-  # Trunk build failures caused by problems outside the Rust source code, like
-  # missing assets, should be caught by `trunk_build_test`
-  test:
-    runs-on: docker
-    container:
-      image: cimg/rust:1.86-node
-    defaults:
-      run:
-        # set the default working directory for each `run` step, relative to the
-        # workspace directory. this default only affects `run` steps (and if we
-        # tried to set the `working-directory` label for any other kind of step,
-        # it wouldn't be recognized anyway)
-        working-directory: app-proto
-    steps:
-      # Check out the repository so that its top-level directory is the
-      # workspace directory (action variable `github.workspace`, environment
-      # variable `$GITHUB_WORKSPACE`):
-      - uses: https://code.forgejo.org/actions/checkout@v4
-      
-      - uses: ./.forgejo/setup-trunk
-      - run: RUSTFLAGS='-D warnings' cargo test
--- a/.gitignore
+++ b/.gitignore
@ -1,2 +1,8 @@
-ci-bin
+node_modules
+site
+docbuild
+__tests__
+coverage
+dyna3.zip
+tmpproj
 *~
--- a/README.md
+++ b/README.md
@ -25,37 +25,32 @@ 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)
+   * 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
+   * 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
+   * 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.
+1. Go into the `app-proto` folder
+2. 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*
 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
+   * *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
+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")
@ -64,24 +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
--- a/app-proto/Cargo.lock
+++ b/app-proto/Cargo.lock
@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 4
+version = 3

 [[package]]
 name = "ahash"
@ -20,21 +20,6 @@ version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c6cb57a04249c6480766f7f7cef5467412af1490f8d1e243141daddada3264f"

-[[package]]
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e999941b234f3131b00bc13c22d06e8c5ff726d1b6318ac7eb276997bbb4fef0"
-
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-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "approx"
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@ -50,21 +35,6 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"

-[[package]]
-name = "base64"
-version = "0.22.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
-
-[[package]]
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-dependencies = [
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-
 [[package]]
 name = "bumpalo"
 version = "3.16.0"
@ -98,35 +68,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

-[[package]]
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- "serde",
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- "web-sys",
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-
-[[package]]
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- "num-traits",
- "serde",
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-
 [[package]]
 name = "console_error_panic_hook"
 version = "0.1.7"
@ -137,122 +78,10 @@ dependencies = [
 "wasm-bindgen",
 ]

-[[package]]
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-
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-
 [[package]]
 name = "dyna3"
 version = "0.1.0"
 dependencies = [
- "charming",
 "console_error_panic_hook",
 "dyna3",
 "itertools",
@ -260,6 +89,8 @@ dependencies = [
 "lazy_static",
 "nalgebra",
 "readonly",
+ "rustc-hash",
+ "slab",
 "sycamore",
 "wasm-bindgen-test",
 "web-sys",
@ -277,22 +108,6 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
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-
 [[package]]
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@ -304,28 +119,6 @@ dependencies = [
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-[[package]]
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@ -336,12 +129,6 @@ dependencies = [
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@ -351,47 +138,6 @@ dependencies = [
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@ -399,8 +145,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
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- "hashbrown 0.14.5",
- "serde",
+ "hashbrown",
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 [[package]]
@ -412,12 +157,6 @@ dependencies = [
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@ -455,12 +194,6 @@ dependencies = [
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@ -517,12 +250,6 @@ dependencies = [
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@ -532,21 +259,6 @@ dependencies = [
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db7d01726be8ab66ab32f9df467ae8b1148906685bbe75c82d1e65d7f5b3f841"
-dependencies = [
- "pest",
- "pest_meta",
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "pest_meta"
-version = "2.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f9f832470494906d1fca5329f8ab5791cc60beb230c74815dff541cbd2b5ca0"
-dependencies = [
- "once_cell",
- "pest",
- "sha2",
-]
-
-[[package]]
-name = "powerfmt"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
-
 [[package]]
 name = "ppv-lite86"
 version = "0.2.20"
@ -705,10 +366,10 @@ dependencies = [
 ]

 [[package]]
-name = "ryu"
-version = "1.0.20"
+name = "rustc-hash"
+version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"

 [[package]]
 name = "safe_arch"
@ -734,90 +395,6 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1cf6437eb19a8f4a6cc0f7dca544973b0b78843adbfeb3683d1a94a0024a294"

-[[package]]
-name = "serde"
-version = "1.0.219"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
-dependencies = [
- "serde_derive",
-]
-
-[[package]]
-name = "serde-wasm-bindgen"
-version = "0.6.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8302e169f0eddcc139c70f139d19d6467353af16f9fce27e8c30158036a1e16b"
-dependencies = [
- "js-sys",
- "serde",
- "wasm-bindgen",
-]
-
-[[package]]
-name = "serde_derive"
-version = "1.0.219"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "serde_json"
-version = "1.0.140"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
-dependencies = [
- "itoa",
- "memchr",
- "ryu",
- "serde",
-]
-
-[[package]]
-name = "serde_with"
-version = "3.12.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6b6f7f2fcb69f747921f79f3926bd1e203fce4fef62c268dd3abfb6d86029aa"
-dependencies = [
- "base64",
- "chrono",
- "hex",
- "indexmap 1.9.3",
- "indexmap 2.5.0",
- "serde",
- "serde_derive",
- "serde_json",
- "serde_with_macros",
- "time",
-]
-
-[[package]]
-name = "serde_with_macros"
-version = "3.12.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d00caa5193a3c8362ac2b73be6b9e768aa5a4b2f721d8f4b339600c3cb51f8e"
-dependencies = [
- "darling",
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "sha2"
-version = "0.10.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
-dependencies = [
- "cfg-if",
- "cpufeatures",
- "digest",
-]
-
 [[package]]
 name = "shlex"
 version = "1.3.0"
@ -837,6 +414,15 @@ dependencies = [
 "wide",
 ]

+[[package]]
+name = "slab"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f92a496fb766b417c996b9c5e57daf2f7ad3b0bebe1ccfca4856390e3d3bb67"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "slotmap"
 version = "1.0.7"
@ -852,20 +438,14 @@ version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"

-[[package]]
-name = "strsim"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
-
 [[package]]
 name = "sycamore"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f38201dcb10aa609e81ca6f7547758a7eb602240a5ff682e668909fd0f7b2cc"
+checksum = "dedaf7237c05913604a5b0b2536b613f6c8510c6b213d2583b1294869755cabd"
 dependencies = [
- "hashbrown 0.14.5",
- "indexmap 2.5.0",
+ "hashbrown",
+ "indexmap",
 "paste",
 "sycamore-core",
 "sycamore-macro",
@ -877,20 +457,20 @@ dependencies = [

 [[package]]
 name = "sycamore-core"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41dc04bf0de321c6486356b2be751fac82fabb06c992d25b6748587561bba187"
+checksum = "e5ddddc3d1bcb38c04ad55d2d1ab4f6a358e4daaeae0a0436892f1fade9fb31a"
 dependencies = [
- "hashbrown 0.14.5",
+ "hashbrown",
 "paste",
 "sycamore-reactive",
 ]

 [[package]]
 name = "sycamore-macro"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0c1d2eddc94db6d03e67eb832df5512b967e81053a573cd01bf3e1c3db00137"
+checksum = "77181c27cb753e86065308901871ccc7456fb19527b6a4ffacad3b63175ed014"
 dependencies = [
 "once_cell",
 "proc-macro2",
@ -902,21 +482,20 @@ dependencies = [

 [[package]]
 name = "sycamore-reactive"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2bacf810535efc2701187a716a5652197ad241d620d5b00fb12caa6dfa23add"
+checksum = "7aa6870203507c07e850687c0ccf528eb0f04240e3596bac9137007ffb6c50b1"
 dependencies = [
 "paste",
 "slotmap",
 "smallvec",
- "wasm-bindgen",
 ]

 [[package]]
 name = "sycamore-view-parser"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c22875843db83cd4d49c0123a195e433bdc74e13ed0fff4ace0e77bb0a67033"
+checksum = "a6144640af2eafffc68a92f3aacbbfaa21f7fd31906e2336fe304fd100fe226b"
 dependencies = [
 "proc-macro2",
 "quote",
@ -925,9 +504,9 @@ dependencies = [

 [[package]]
 name = "sycamore-web"
-version = "0.9.1"
+version = "0.9.0-beta.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b17aa5875f59f541cdf6fb58751ec702a6ed9801f30dd2b4d5f2279025b98bd"
+checksum = "bca93dcf1b1830bf1aac93508ed51babcda92c1d32d96067ab416d94e4b7c475"
 dependencies = [
 "html-escape",
 "js-sys",
@ -943,78 +522,21 @@ dependencies = [

 [[package]]
 name = "syn"
-version = "2.0.87"
+version = "2.0.77"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25aa4ce346d03a6dcd68dd8b4010bcb74e54e62c90c573f394c46eae99aba32d"
+checksum = "9f35bcdf61fd8e7be6caf75f429fdca8beb3ed76584befb503b1569faee373ed"
 dependencies = [
 "proc-macro2",
 "quote",
 "unicode-ident",
 ]

-[[package]]
-name = "thiserror"
-version = "2.0.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567b8a2dae586314f7be2a752ec7474332959c6460e02bde30d702a66d488708"
-dependencies = [
- "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "2.0.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f7cf42b4507d8ea322120659672cf1b9dbb93f8f2d4ecfd6e51350ff5b17a1d"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "time"
-version = "0.3.41"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a7619e19bc266e0f9c5e6686659d394bc57973859340060a69221e57dbc0c40"
-dependencies = [
- "deranged",
- "itoa",
- "num-conv",
- "powerfmt",
- "serde",
- "time-core",
- "time-macros",
-]
-
-[[package]]
-name = "time-core"
-version = "0.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9e9a38711f559d9e3ce1cdb06dd7c5b8ea546bc90052da6d06bb76da74bb07c"
-
-[[package]]
-name = "time-macros"
-version = "0.2.22"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3526739392ec93fd8b359c8e98514cb3e8e021beb4e5f597b00a0221f8ed8a49"
-dependencies = [
- "num-conv",
- "time-core",
-]
-
 [[package]]
 name = "typenum"
 version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"

-[[package]]
-name = "ucd-trie"
-version = "0.1.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2896d95c02a80c6d6a5d6e953d479f5ddf2dfdb6a244441010e373ac0fb88971"
-
 [[package]]
 name = "unicode-ident"
 version = "1.0.13"
@ -1171,65 +693,6 @@ dependencies = [
 "windows-sys",
 ]

-[[package]]
-name = "windows-core"
-version = "0.61.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0fdd3ddb90610c7638aa2b3a3ab2904fb9e5cdbecc643ddb3647212781c4ae3"
-dependencies = [
- "windows-implement",
- "windows-interface",
- "windows-link",
- "windows-result",
- "windows-strings",
-]
-
-[[package]]
-name = "windows-implement"
-version = "0.60.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a47fddd13af08290e67f4acabf4b459f647552718f683a7b415d290ac744a836"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "windows-interface"
-version = "0.59.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bd9211b69f8dcdfa817bfd14bf1c97c9188afa36f4750130fcdf3f400eca9fa8"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "windows-link"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76840935b766e1b0a05c0066835fb9ec80071d4c09a16f6bd5f7e655e3c14c38"
-
-[[package]]
-name = "windows-result"
-version = "0.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f42bd332cc6c8eac5af113fc0c1fd6a8fd2aa08a0119358686e5160d0586c6"
-dependencies = [
- "windows-link",
-]
-
-[[package]]
-name = "windows-strings"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56e6c93f3a0c3b36176cb1327a4958a0353d5d166c2a35cb268ace15e91d3b57"
-dependencies = [
- "windows-link",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
--- a/app-proto/Cargo.toml
+++ b/app-proto/Cargo.toml
@ -3,7 +3,6 @@ name = "dyna3"
 version = "0.1.0"
 authors = ["Aaron Fenyes", "Glen Whitney"]
 edition = "2021"
-rust-version = "1.86"

 [features]
 default = ["console_error_panic_hook"]
@ -15,10 +14,9 @@ js-sys = "0.3.70"
 lazy_static = "1.5.0"
 nalgebra = "0.33.0"
 readonly = "0.2.12"
-sycamore = "0.9.1"
-
-# We use Charming to help display engine diagnostics
-charming = { version = "0.5.1", features = ["wasm"] }
+rustc-hash = "2.0.0"
+slab = "0.4.9"
+sycamore = "0.9.0-beta.3"

 # The `console_error_panic_hook` crate provides better debugging of panics by
 # logging them with `console.error`. This is great for development, but requires
@ -49,33 +47,6 @@ features = [
 dyna3 = { path = ".", default-features = false, features = ["dev"] }
 wasm-bindgen-test = "0.3.34"

-# turn off spurious warnings about the custom config that Sycamore uses
-#
-#   https://sycamore.dev/book/troubleshooting#unexpected-cfg-condition-name--sycamore-force-ssr
-#
-[lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = ["cfg(sycamore_force_ssr)"] }
-
 [profile.release]
 opt-level = "s" # optimize for small code size
 debug = true # include debug symbols
-
-[[example]]
-name = "irisawa-hexlet"
-test = true
-harness = false
-
-[[example]]
-name = "kaleidocycle"
-test = true
-harness = false
-
-[[example]]
-name = "point-on-sphere"
-test = true
-harness = false
-
-[[example]]
-name = "three-spheres"
-test = true
-harness = false
--- a/app-proto/Trunk.toml
+++ b/app-proto/Trunk.toml
@ -1,2 +0,0 @@
-[build]
-public_url = "./"
--- a/app-proto/examples/common/print.rs
+++ b/app-proto/examples/common/print.rs
@ -1,36 +0,0 @@
-#![allow(dead_code)]
-
-use nalgebra::DMatrix;
-
-use dyna3::engine::{Q, DescentHistory, Realization};
-
-pub fn title(title: &str) {
-    println!("─── {title} ───");
-}
-
-pub fn realization_diagnostics(realization: &Realization) {
-    let Realization { result, history } = realization;
-    println!();
-    if let Err(ref message) = result {
-        println!("❌️ {message}");
-    } else {
-        println!("✅️ Target accuracy achieved!");
-    }
-    println!("Steps: {}", history.scaled_loss.len() - 1);
-    println!("Loss: {}", history.scaled_loss.last().unwrap());
-}
-
-pub fn gram_matrix(config: &DMatrix<f64>) {
-    println!("\nCompleted Gram matrix:{}", (config.tr_mul(&*Q) * config).to_string().trim_end());
-}
-
-pub fn config(config: &DMatrix<f64>) {
-    println!("\nConfiguration:{}", config.to_string().trim_end());
-}
-
-pub fn loss_history(history: &DescentHistory) {
-    println!("\nStep │ Loss\n─────┼────────────────────────────────");
-    for (step, scaled_loss) in history.scaled_loss.iter().enumerate() {
-        println!("{:<4} │ {}", step, scaled_loss);
-    }
-}
--- a/app-proto/examples/irisawa-hexlet.rs
+++ b/app-proto/examples/irisawa-hexlet.rs
@ -1,23 +1,25 @@
-#[path = "common/print.rs"]
-mod print;
-
-use dyna3::engine::{ConfigNeighborhood, examples::realize_irisawa_hexlet};
+use dyna3::engine::{Q, examples::realize_irisawa_hexlet};

 fn main() {
    const SCALED_TOL: f64 = 1.0e-12;
-    let realization = realize_irisawa_hexlet(SCALED_TOL);
-    print::title("Irisawa hexlet");
-    print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, .. }) = realization.result {
-        // print the diameters of the chain spheres
+    let (config, _, success, history) = realize_irisawa_hexlet(SCALED_TOL);
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    if success {
        println!("\nChain diameters:");
        println!("  {} sun (given)", 1.0 / config[(3, 3)]);
        for k in 4..9 {
            println!("  {} sun", 1.0 / config[(3, k)]);
        }
-        
-        // print the completed Gram matrix
-        print::gram_matrix(&config);
    }
-    print::loss_history(&realization.history);
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
+    }
 }
--- a/app-proto/examples/kaleidocycle.rs
+++ b/app-proto/examples/kaleidocycle.rs
@ -1,32 +1,30 @@
-#[path = "common/print.rs"]
-mod print;
-
 use nalgebra::{DMatrix, DVector};

-use dyna3::engine::{ConfigNeighborhood, examples::realize_kaleidocycle};
+use dyna3::engine::{Q, examples::realize_kaleidocycle};

 fn main() {
    const SCALED_TOL: f64 = 1.0e-12;
-    let realization = realize_kaleidocycle(SCALED_TOL);
-    print::title("Kaleidocycle");
-    print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, nbhd: tangent }) = realization.result {
-        // print the completed Gram matrix and the realized configuration
-        print::gram_matrix(&config);
-        print::config(&config);
-        
-        // find the kaleidocycle's twist motion by projecting onto the tangent
-        // space
-        const N_POINTS: usize = 12;
-        let up = DVector::from_column_slice(&[0.0, 0.0, 1.0, 0.0]);
-        let down = -&up;
-        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),
-            ]
-        ).sum();
-        let normalization = 5.0 / twist_motion[(2, 0)];
-        println!("\nTwist motion:{}", (normalization * twist_motion).to_string().trim_end());
+    let (config, tangent, success, history) = realize_kaleidocycle(SCALED_TOL);
+    print!("Completed Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    print!("Configuration:{}", config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}\n", history.scaled_loss.last().unwrap());
+    
+    // find the kaleidocycle's twist motion by projecting onto the tangent space
+    const N_POINTS: usize = 12;
+    let up = DVector::from_column_slice(&[0.0, 0.0, 1.0, 0.0]);
+    let down = -&up;
+    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)
+        ]
+    ).sum();
+    let normalization = 5.0 / twist_motion[(2, 0)];
+    print!("Twist motion:{}", normalization * twist_motion);
 }
--- a/app-proto/examples/point-on-sphere.rs
+++ b/app-proto/examples/point-on-sphere.rs
@ -1,13 +1,4 @@
-#[path = "common/print.rs"]
-mod print;
-
-use dyna3::engine::{
-    point,
-    realize_gram,
-    sphere,
-    ConfigNeighborhood,
-    ConstraintProblem,
-};
+use dyna3::engine::{Q, point, realize_gram, sphere, ConstraintProblem};

 fn main() {
    let mut problem = ConstraintProblem::from_guess(&[
@ -20,14 +11,21 @@ fn main() {
        }
    }
    problem.frozen.push(3, 0, problem.guess[(3, 0)]);
-    let realization = realize_gram(
+    println!();
+    let (config, _, success, history) = realize_gram(
        &problem, 1.0e-12, 0.5, 0.9, 1.1, 200, 110
    );
-    print::title("Point on a sphere");
-    print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, .. }) = realization.result {
-        print::gram_matrix(&config);
-        print::config(&config);
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    print!("Configuration:{}", config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
    }
-    print::loss_history(&realization.history);
 }
--- a/app-proto/examples/three-spheres.rs
+++ b/app-proto/examples/three-spheres.rs
@ -1,12 +1,4 @@
-#[path = "common/print.rs"]
-mod print;
-
-use dyna3::engine::{
-    realize_gram,
-    sphere,
-    ConfigNeighborhood,
-    ConstraintProblem,
-};
+use dyna3::engine::{Q, realize_gram, sphere, ConstraintProblem};

 fn main() {
    let mut problem = ConstraintProblem::from_guess({
@ -14,7 +6,7 @@ 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 {
@ -22,13 +14,20 @@ fn main() {
            problem.gram.push_sym(j, k, if j == k { 1.0 } else { -1.0 });
        }
    }
-    let realization = realize_gram(
+    println!();
+    let (config, _, success, history) = realize_gram(
        &problem, 1.0e-12, 0.5, 0.9, 1.1, 200, 110
    );
-    print::title("Three spheres");
-    print::realization_diagnostics(&realization);
-    if let Ok(ConfigNeighborhood { config, .. }) = realization.result {
-        print::gram_matrix(&config);
+    print!("\nCompleted Gram matrix:{}", config.tr_mul(&*Q) * &config);
+    if success {
+        println!("Target accuracy achieved!");
+    } else {
+        println!("Failed to reach target accuracy");
+    }
+    println!("Steps: {}", history.scaled_loss.len() - 1);
+    println!("Loss: {}", history.scaled_loss.last().unwrap());
+    println!("\nStep │ Loss\n─────┼────────────────────────────────");
+    for (step, scaled_loss) in history.scaled_loss.into_iter().enumerate() {
+        println!("{:<4} │ {}", step, scaled_loss);
    }
-    print::loss_history(&realization.history);
 }
--- a/app-proto/index.html
+++ b/app-proto/index.html
@ -6,12 +6,6 @@
    <link data-trunk rel="css" href="main.css"/>
    <link href="https://fonts.bunny.net/css?family=fira-sans:ital,wght@0,400;1,400&display=swap" rel="stylesheet">
    <link href="https://fonts.bunny.net/css?family=noto-emoji:wght@400&text=%f0%9f%94%97%e2%9a%a0&display=swap" rel="stylesheet">
-    
-    <!--
-      the Charming visualization crate, which we use to show engine diagnostics,
-      depends the ECharts JavaScript package
-    -->
-    <script src="https://cdn.jsdelivr.net/npm/echarts@5.5.1/dist/echarts.min.js"></script>
  </head>
  <body></body>
 </html>
--- a/app-proto/main.css
+++ b/app-proto/main.css
@ -18,17 +18,6 @@ body {
  font-family: 'Fira Sans', sans-serif;
 }

-.invalid {
-  color: var(--text-invalid);
-}
-
-.status {
-  width: 20px;
-  text-align: center;
-  font-family: 'Noto Emoji';
-  font-style: normal;
-}
-
 /* sidebar */

 #sidebar {
@ -53,7 +42,9 @@ body {
 }

 #add-remove > button {
+  width: 32px;
  height: 32px;
+  font-size: large;
 }

 /* KLUDGE */
@ -62,9 +53,7 @@ body {
  buttons need to be displayed in an emoji font
 */
 #add-remove > button.emoji {
-  width: 32px;
  font-family: 'Noto Emoji', sans-serif;
-  font-size: large;
 }

 /* outline */
@ -101,10 +90,6 @@ summary > div, .regulator {
  padding-right: 8px;
 }

-.element > input {
-  margin-left: 8px;
-}
-
 .element-switch {
  width: 18px;
  padding-left: 2px;
@ -149,7 +134,6 @@ details[open]:has(li) .element-switch::after {
 }

 .regulator-input {
-  margin-right: 4px;
  color: inherit;
  background-color: inherit;
  border: 1px solid var(--border);
@ -171,56 +155,22 @@ details[open]:has(li) .element-switch::after {
  border-color: var(--border-invalid);
 }

+.status {
+  width: 20px;
+  padding-left: 4px;
+  text-align: center;
+  font-family: 'Noto Emoji';
+  font-style: normal;
+}
+
 .regulator-input.invalid + .status::after, details:has(.invalid):not([open]) .status::after {
  content: '⚠';
  color: var(--text-invalid);
 }

-/* diagnostics */
-
-#diagnostics {
-  margin: 10px;
-}
-
-#diagnostics-bar {
-  display: flex;
-}
-
-#realization-status {
-  display: flex;
-  flex-grow: 1;
-}
-
-#realization-status .status {
-  margin-right: 4px;
-}
-
-#realization-status :not(.status) {
-  flex-grow: 1;
-}
-
-#realization-status .status::after {
-  content: '✓';
-}
-
-#realization-status.invalid .status::after {
-  content: '⚠';
-}
-
-.diagnostics-panel {
-  margin-top: 10px;
-  min-height: 180px;
-}
-
-.diagnostics-chart {
-  background-color: var(--display-background);
-  border: 1px solid var(--border);
-  border-radius: 8px;
-}
-
 /* display */

-#display {
+canvas {
  float: left;
  margin-left: 20px;
  margin-top: 20px;
@ -229,7 +179,7 @@ details[open]:has(li) .element-switch::after {
  border-radius: 16px;
 }

-#display:focus {
+canvas:focus {
  border-color: var(--border-focus-dark);
  outline: none;
 }
--- a/app-proto/run-examples
+++ b/app-proto/run-examples
@ -0,0 +1,12 @@
+#!/bin/sh
+
+# run all Cargo examples, as described here:
+#
+#   Karol Kuczmarski. "Add examples to your Rust libraries"
+#   http://xion.io/post/code/rust-examples.html
+#
+
+cargo run --example irisawa-hexlet
+cargo run --example three-spheres
+cargo run --example point-on-sphere
+cargo run --example kaleidocycle
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@ -0,0 +1,202 @@
+use sycamore::prelude::*;
+use web_sys::{console, wasm_bindgen::JsValue};
+
+use crate::{
+    engine,
+    AppState,
+    assembly::{Assembly, Element}
+};
+
+/* DEBUG */
+// load an example assembly for testing. this code will be removed once we've
+// built a more formal test assembly system
+fn load_gen_assemb(assembly: &Assembly) {
+    let _ = assembly.try_insert_element(
+        Element::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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+}
+
+/* DEBUG */
+// load an example assembly for testing. this code will be removed once we've
+// built a more formal test assembly system
+fn load_low_curv_assemb(assembly: &Assembly) {
+    let a = 0.75_f64.sqrt();
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            "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)
+        )
+    );
+    let _ = assembly.try_insert_element(
+        Element::new(
+            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)
+        )
+    );
+}
+
+#[component]
+pub fn AddRemove() -> View {
+    /* DEBUG */
+    let assembly_name = create_signal("general".to_string());
+    create_effect(move || {
+        // get name of chosen assembly
+        let name = assembly_name.get_clone();
+        console::log_1(
+            &JsValue::from(format!("Showing assembly \"{}\"", name.clone()))
+        );
+        
+        batch(|| {
+            let state = use_context::<AppState>();
+            let assembly = &state.assembly;
+            
+            // clear state
+            assembly.elements.update(|elts| elts.clear());
+            assembly.elements_by_id.update(|elts_by_id| elts_by_id.clear());
+            state.selection.update(|sel| sel.clear());
+            
+            // load assembly
+            match name.as_str() {
+                "general" => load_gen_assemb(assembly),
+                "low-curv" => load_low_curv_assemb(assembly),
+                _ => ()
+            };
+        });
+    });
+    
+    view! {
+        div(id="add-remove") {
+            button(
+                on:click=|_| {
+                    let state = use_context::<AppState>();
+                    state.assembly.insert_new_sphere();
+                }
+            ) { "+" }
+            button(
+                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=|_| {
+                    let state = use_context::<AppState>();
+                    let subjects: [_; 2] = state.selection.with(
+                        // the button is only enabled when two elements are
+                        // selected, so we know the cast to a two-element array
+                        // will succeed
+                        |sel| sel
+                            .clone()
+                            .into_iter()
+                            .collect::<Vec<_>>()
+                            .try_into()
+                            .unwrap()
+                    );
+                    state.assembly.insert_new_product_regulator(subjects);
+                    state.selection.update(|sel| sel.clear());
+                }
+            ) { "🔗" }
+            select(bind:value=assembly_name) { /* DEBUG */ // example assembly chooser
+                option(value="general") { "General" }
+                option(value="low-curv") { "Low-curvature" }
+                option(value="empty") { "Empty" }
+            }
+        }
+    }
+}
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
--- a/app-proto/src/components.rs
+++ b/app-proto/src/components.rs
@ -1,5 +0,0 @@
-pub mod add_remove;
-pub mod diagnostics;
-pub mod display;
-pub mod outline;
-pub mod test_assembly_chooser;
--- a/app-proto/src/components/add_remove.rs
+++ b/app-proto/src/components/add_remove.rs
@ -1,69 +0,0 @@
-use std::rc::Rc;
-use sycamore::prelude::*;
-
-use super::test_assembly_chooser::TestAssemblyChooser;
-use crate::{
-    AppState,
-    assembly::{InversiveDistanceRegulator, Point, Sphere},
-};
-
-#[component]
-pub fn AddRemove() -> View {
-    view! {
-        div(id = "add-remove") {
-            button(
-                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>();
-                    });
-                }
-            ) { "Add sphere" }
-            button(
-                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 = {
-                    let state = use_context::<AppState>();
-                    state.selection.with(|sel| sel.len() != 2)
-                },
-                on:click = |_| {
-                    let state = use_context::<AppState>();
-                    let subjects: [_; 2] = state.selection.with(
-                        // the button is only enabled when two elements are
-                        // selected, so we know the cast to a two-element array
-                        // will succeed
-                        |sel| sel
-                            .clone()
-                            .into_iter()
-                            .collect::<Vec<_>>()
-                            .try_into()
-                            .unwrap()
-                    );
-                    state.assembly.insert_regulator(
-                        Rc::new(InversiveDistanceRegulator::new(subjects))
-                    );
-                    state.selection.update(|sel| sel.clear());
-                }
-            ) { "🔗" }
-            TestAssemblyChooser {}
-        }
-    }
-}
--- a/app-proto/src/components/diagnostics.rs
+++ b/app-proto/src/components/diagnostics.rs
@ -1,256 +0,0 @@
-use charming::{
-    Chart,
-    WasmRenderer,
-    component::{Axis, DataZoom, Grid},
-    element::{AxisType, Symbol},
-    series::{Line, Scatter},
-};
-use sycamore::prelude::*;
-
-use crate::AppState;
-
-#[derive(Clone)]
-struct DiagnosticsState {
-    active_tab: Signal<String>,
-}
-
-impl DiagnosticsState {
-    fn new(initial_tab: String) -> Self {
-        Self { active_tab: create_signal(initial_tab) }
-    }
-}
-
-// a realization status indicator
-#[component]
-fn RealizationStatus() -> View {
-    let state = use_context::<AppState>();
-    let realization_status = state.assembly.realization_status;
-    view! {
-        div(
-            id = "realization-status",
-            class = realization_status.with(
-                |status| match status {
-                    Ok(_) => "",
-                    Err(_) => "invalid",
-                }
-            )
-        ) {
-            div(class = "status")
-            div {
-                (realization_status.with(
-                    |status| match status {
-                        Ok(_) => "Target accuracy achieved".to_string(),
-                        Err(message) => message.clone(),
-                    }
-                ))
-            }
-        }
-    }
-}
-
-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()) },
-    ]
-}
-
-// the loss history from the last realization
-#[component]
-fn LossHistory() -> View {
-    const CONTAINER_ID: &str = "loss-history";
-    let state = use_context::<AppState>();
-    let renderer = WasmRenderer::new_opt(None, Some(178));
-    
-    on_mount(move || {
-        create_effect(move || {
-            // get the loss history
-            let scaled_loss: Vec<_> = state.assembly.descent_history.with(
-                |history| history.scaled_loss
-                    .iter()
-                    .enumerate()
-                    .map(|(step, &loss)| (step, loss))
-                    .map(into_log10_time_point)
-                    .collect()
-            );
-            
-            // initialize the chart axes
-            let step_axis = Axis::new()
-                .type_(AxisType::Category)
-                .boundary_gap(false);
-            let scaled_loss_axis = Axis::new();
-            
-            // load the chart data. when there's no history, we load the data
-            // point (0, None) to clear the chart. it would feel more natural to
-            // load empty data vectors, but that turns out not to clear the
-            // chart: it instead leads to previous data being re-used
-            let scaled_loss_series = Line::new().data(
-                if scaled_loss.len() > 0 {
-                    scaled_loss
-                } else {
-                    vec![vec![Some(0.0), None::<f64>]]
-                }
-            );
-            let chart = Chart::new()
-                .animation(false)
-                .data_zoom(DataZoom::new().y_axis_index(0).right(40))
-                .x_axis(step_axis)
-                .y_axis(scaled_loss_axis)
-                .grid(Grid::new().top(20).right(80).bottom(30).left(60))
-                .series(scaled_loss_series);
-            renderer.render(CONTAINER_ID, &chart).unwrap();
-        });
-    });
-    
-    view! {
-        div(id = CONTAINER_ID, class = "diagnostics-chart")
-    }
-}
-
-// the spectrum of the Hessian during the last realization
-#[component]
-fn SpectrumHistory() -> View {
-    const CONTAINER_ID: &str = "spectrum-history";
-    let state = use_context::<AppState>();
-    let renderer = WasmRenderer::new(478, 178);
-    
-    on_mount(move || {
-        create_effect(move || {
-            // get the spectrum of the Hessian at each step, split into its
-            // positive, negative, and strictly-zero parts
-            let (
-                hess_eigvals_zero,
-                hess_eigvals_nonzero,
-            ): (Vec<_>, Vec<_>) = state.assembly.descent_history.with(
-                |history| history.hess_eigvals
-                    .iter()
-                    .enumerate()
-                    .map(
-                        |(step, eigvals)| eigvals.iter().map(
-                            move |&val| (step, val)
-                        )
-                    )
-                    .flatten()
-                    .partition(|&(_, val)| val == 0.0)
-            );
-            let zero_level = hess_eigvals_nonzero
-                .iter()
-                .map(|(_, val)| val.abs())
-                .reduce(f64::min)
-                .map(|val| 0.1 * val)
-                .unwrap_or(1.0);
-            let (
-                hess_eigvals_pos,
-                hess_eigvals_neg,
-            ): (Vec<_>, Vec<_>) = hess_eigvals_nonzero
-                .into_iter()
-                .partition(|&(_, val)| val > 0.0);
-            
-            // initialize the chart axes
-            let step_axis = Axis::new()
-                .type_(AxisType::Category)
-                .boundary_gap(false);
-            let eigval_axis = Axis::new();
-            
-            // load the chart data. when there's no history, we load the data
-            // point (0, None) to clear the chart. it would feel more natural to
-            // load empty data vectors, but that turns out not to clear the
-            // chart: it instead leads to previous data being re-used
-            let eigval_series_pos = Scatter::new()
-                .symbol_size(4.5)
-                .data(
-                    if hess_eigvals_pos.len() > 0 {
-                        hess_eigvals_pos
-                            .into_iter()
-                            .map(into_log10_time_point)
-                            .collect()
-                    } else {
-                        vec![vec![Some(0.0), None::<f64>]]
-                    }
-                );
-            let eigval_series_neg = Scatter::new()
-                .symbol(Symbol::Diamond)
-                .symbol_size(6.0)
-                .data(
-                    if hess_eigvals_neg.len() > 0 {
-                        hess_eigvals_neg
-                            .into_iter()
-                            .map(into_log10_time_point)
-                            .collect()
-                    } else {
-                        vec![vec![Some(0.0), None::<f64>]]
-                    }
-                );
-            let eigval_series_zero = Scatter::new()
-                .symbol(Symbol::Triangle)
-                .symbol_size(5.0)
-                .data(
-                    if hess_eigvals_zero.len() > 0 {
-                        hess_eigvals_zero
-                            .into_iter()
-                            .map(|(step, _)| (step, zero_level))
-                            .map(into_log10_time_point)
-                            .collect()
-                    } else {
-                        vec![vec![Some(0.0), None::<f64>]]
-                    }
-                );
-            let chart = Chart::new()
-                .animation(false)
-                .data_zoom(DataZoom::new().y_axis_index(0).right(40))
-                .x_axis(step_axis)
-                .y_axis(eigval_axis)
-                .grid(Grid::new().top(20).right(80).bottom(30).left(60))
-                .series(eigval_series_pos)
-                .series(eigval_series_neg)
-                .series(eigval_series_zero);
-            renderer.render(CONTAINER_ID, &chart).unwrap();
-        });
-    });
-    
-    view! {
-        div(id = CONTAINER_ID, class = "diagnostics-chart")
-    }
-}
-
-#[component(inline_props)]
-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(
-                |active_tab| {
-                    if active_tab == name {
-                        None
-                    } else {
-                        Some("")
-                    }
-                }
-            )
-        ) {
-            (children)
-        }
-    }
-}
-
-#[component]
-pub fn Diagnostics() -> View {
-    let diagnostics_state = DiagnosticsState::new("loss".to_string());
-    let active_tab = diagnostics_state.active_tab.clone();
-    provide_context(diagnostics_state);
-    
-    view! {
-        div(id = "diagnostics") {
-            div(id = "diagnostics-bar") {
-                RealizationStatus {}
-                select(bind:value = active_tab) {
-                    option(value = "loss") { "Loss" }
-                    option(value = "spectrum") { "Spectrum" }
-                }
-            }
-            DiagnosticsPanel(name = "loss") { LossHistory {} }
-            DiagnosticsPanel(name = "spectrum") { SpectrumHistory {} }
-        }
-    }
-}
--- a/app-proto/src/components/display.rs
+++ b/app-proto/src/components/display.rs
@ -1,921 +0,0 @@
-use core::array;
-use nalgebra::{DMatrix, DVector, Rotation3, Vector3};
-use std::rc::Rc;
-use sycamore::{prelude::*, motion::create_raf};
-use web_sys::{
-    console,
-    window,
-    KeyboardEvent,
-    MouseEvent,
-    WebGl2RenderingContext,
-    WebGlBuffer,
-    WebGlProgram,
-    WebGlShader,
-    WebGlUniformLocation,
-    wasm_bindgen::{JsCast, JsValue},
-};
-
-use crate::{
-    AppState,
-    assembly::{Element, ElementColor, ElementMotion, Point, Sphere},
-};
-
-// --- color ---
-
-const COLOR_SIZE: usize = 3;
-type ColorWithOpacity = [f32; COLOR_SIZE + 1];
-
-fn combine_channels(color: ElementColor, opacity: f32) -> ColorWithOpacity {
-    let mut color_with_opacity = [0.0; COLOR_SIZE + 1];
-    color_with_opacity[..COLOR_SIZE].copy_from_slice(&color);
-    color_with_opacity[COLOR_SIZE] = opacity;
-    color_with_opacity
-}
-
-// --- scene data ---
-
-struct SceneSpheres {
-    representations: Vec<DVector<f64>>,
-    colors_with_opacity: Vec<ColorWithOpacity>,
-    highlights: Vec<f32>,
-}
-
-impl SceneSpheres {
-    fn new() -> Self {
-        Self {
-            representations: Vec::new(),
-            colors_with_opacity: Vec::new(),
-            highlights: Vec::new(),
-        }
-    }
-    
-    fn len_i32(&self) -> i32 {
-        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,
-    ) {
-        self.representations.push(representation);
-        self.colors_with_opacity.push(combine_channels(color, opacity));
-        self.highlights.push(highlight);
-    }
-}
-
-struct ScenePoints {
-    representations: Vec<DVector<f64>>,
-    colors_with_opacity: Vec<ColorWithOpacity>,
-    highlights: Vec<f32>,
-    selections: Vec<f32>,
-}
-
-impl ScenePoints {
-    fn new() -> Self {
-        Self {
-            representations: Vec::new(),
-            colors_with_opacity: Vec::new(),
-            highlights: Vec::new(),
-            selections: Vec::new(),
-        }
-    }
-    
-    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);
-        self.selections.push(if selected { 1.0 } else { 0.0 });
-    }
-}
-
-pub struct Scene {
-    spheres: SceneSpheres,
-    points: ScenePoints,
-}
-
-impl Scene {
-    fn new() -> Self {
-        Self {
-            spheres: SceneSpheres::new(),
-            points: ScenePoints::new(),
-        }
-    }
-}
-
-pub trait DisplayItem {
-    fn show(&self, scene: &mut Scene, selected: bool);
-    
-    // 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>;
-}
-
-impl DisplayItem for Sphere {
-    fn show(&self, scene: &mut Scene, selected: bool) {
-        /* SCAFFOLDING */
-        const DEFAULT_OPACITY: f32 = 0.5;
-        const GHOST_OPACITY: f32 = 0.2;
-        const HIGHLIGHT: f32 = 0.2;
-        
-        let representation = self.representation.get_clone_untracked();
-        let color = if selected { self.color.map(|channel| 0.2 + 0.8*channel) } else { self.color };
-        let opacity = if self.ghost.get() { GHOST_OPACITY } else { DEFAULT_OPACITY };
-        let highlight = if selected { 1.0 } else { HIGHLIGHT };
-        scene.spheres.push(representation, color, opacity, highlight);
-    }
-    
-    // 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> {
-        // 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;
-        
-        let rep = self.representation.with_untracked(|rep| assembly_to_world * rep);
-        let a = -rep[3] * dir.norm_squared();
-        let b = rep.rows_range(..3).dot(&dir);
-        let c = -rep[4];
-        
-        let adjust = 4.0*a*c/(b*b);
-        if adjust < 1.0 {
-            // as long as `b` is non-zero, the linear approximation of
-            //
-            //   a*u^2 + b*u + c
-            //
-            // at `u = 0` will reach zero at a finite depth `u_lin`. the root of
-            // the quadratic adjacent to `u_lin` is stored in `lin_root`. if
-            // both roots have the same sign, `lin_root` will be the one closer
-            // to `u = 0`
-            let square_rect_ratio = 1.0 + (1.0 - adjust).sqrt();
-            let lin_root = -(2.0*c)/b / square_rect_ratio;
-            if a.abs() > DEG_THRESHOLD * b.abs() {
-                if lin_root > 0.0 {
-                    Some(lin_root)
-                } else {
-                    let other_root = -b/(2.*a) * square_rect_ratio;
-                    (other_root > 0.0).then_some(other_root)
-                }
-            } else {
-                (lin_root > 0.0).then_some(lin_root)
-            }
-        } else {
-            // the line through `dir` misses the sphere completely
-            None
-        }
-    }
-}
-
-impl DisplayItem for Point {
-    fn show(&self, scene: &mut Scene, selected: bool) {
-        /* SCAFFOLDING */
-        const GHOST_OPACITY: f32 = 0.4;
-        const HIGHLIGHT: f32 = 0.5;
-        
-        let representation = self.representation.get_clone_untracked();
-        let color = if selected { self.color.map(|channel| 0.2 + 0.8*channel) } else { self.color };
-        let opacity = if self.ghost.get() { GHOST_OPACITY } else { 1.0 };
-        let highlight = if selected { 1.0 } else { HIGHLIGHT };
-        scene.points.push(representation, color, opacity, highlight, selected);
-    }
-    
-    /* SCAFFOLDING */
-    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`
-            const POINT_RADIUS_PX: f64 = 4.0;
-            
-            // find the radius of the point in screen projection units
-            let point_radius_proj = POINT_RADIUS_PX * pixel_size;
-            
-            // find the squared distance between the screen projections of the
-            // ray and the point
-            let dir_proj = -dir.fixed_rows::<2>(0) / dir[2];
-            let rep_proj = -rep.fixed_rows::<2>(0) / rep[2];
-            let dist_sq = (dir_proj - rep_proj).norm_squared();
-            
-            // if the ray hits the point, return its depth
-            if dist_sq < point_radius_proj * point_radius_proj {
-                Some(rep[2] / dir[2])
-            } else {
-                None
-            }
-        } else {
-            None
-        }
-    }
-}
-
-// --- WebGL utilities ---
-
-fn compile_shader(
-    context: &WebGl2RenderingContext,
-    shader_type: u32,
-    source: &str,
-) -> WebGlShader {
-    let shader = context.create_shader(shader_type).unwrap();
-    context.shader_source(&shader, source);
-    context.compile_shader(&shader);
-    shader
-}
-
-fn set_up_program(
-    context: &WebGl2RenderingContext,
-    vertex_shader_source: &str,
-    fragment_shader_source: &str,
-) -> WebGlProgram {
-    // compile the shaders
-    let vertex_shader = compile_shader(
-        &context,
-        WebGl2RenderingContext::VERTEX_SHADER,
-        vertex_shader_source,
-    );
-    let fragment_shader = compile_shader(
-        &context,
-        WebGl2RenderingContext::FRAGMENT_SHADER,
-        fragment_shader_source,
-    );
-    
-    // create the program and attach the shaders
-    let program = context.create_program().unwrap();
-    context.attach_shader(&program, &vertex_shader);
-    context.attach_shader(&program, &fragment_shader);
-    context.link_program(&program);
-    
-    /* DEBUG */
-    // report whether linking succeeded
-    let link_status = context
-        .get_program_parameter(&program, WebGl2RenderingContext::LINK_STATUS)
-        .as_bool()
-        .unwrap();
-    let link_msg = if link_status {
-        "Linked successfully"
-    } else {
-        "Linking failed"
-    };
-    console::log_1(&JsValue::from(link_msg));
-    
-    program
-}
-
-fn get_uniform_array_locations<const N: usize>(
-    context: &WebGl2RenderingContext,
-    program: &WebGlProgram,
-    var_name: &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}]"),
-        };
-        context.get_uniform_location(&program, name.as_str())
-    })
-}
-
-// bind the given vertex buffer object to the given vertex attribute
-fn bind_to_attribute(
-    context: &WebGl2RenderingContext,
-    attr_index: u32,
-    attr_size: i32,
-    buffer: &Option<WebGlBuffer>,
-) {
-    context.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, buffer.as_ref());
-    context.vertex_attrib_pointer_with_i32(
-        attr_index,
-        attr_size,
-        WebGl2RenderingContext::FLOAT,
-        false, // don't normalize
-        0, // zero stride
-        0, // zero offset
-    );
-}
-
-// load the given data into a new vertex buffer object
-fn load_new_buffer(
-    context: &WebGl2RenderingContext,
-    data: &[f32],
-) -> Option<WebGlBuffer> {
-    // create a buffer and bind it to ARRAY_BUFFER
-    let buffer = context.create_buffer();
-    context.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, buffer.as_ref());
-    
-    // load the given data into the buffer. this block is unsafe because
-    // `Float32Array::view` creates a raw view into our module's
-    // `WebAssembly.Memory` buffer. allocating more memory will change the
-    // buffer, invalidating the view, so we have to make sure we don't allocate
-    // any memory until the view is dropped. we're okay here because the view is
-    // used as soon as it's created
-    unsafe {
-        context.buffer_data_with_array_buffer_view(
-            WebGl2RenderingContext::ARRAY_BUFFER,
-            &js_sys::Float32Array::view(&data),
-            WebGl2RenderingContext::STATIC_DRAW,
-        );
-    }
-    
-    buffer
-}
-
-fn bind_new_buffer_to_attribute(
-    context: &WebGl2RenderingContext,
-    attr_index: u32,
-    attr_size: i32,
-    data: &[f32],
-) {
-    let buffer = load_new_buffer(context, data);
-    bind_to_attribute(context, attr_index, attr_size, &buffer);
-}
-
-// the direction in camera space that a mouse event is pointing along
-fn event_dir(event: &MouseEvent) -> (Vector3<f64>, f64) {
-    let target: web_sys::Element = event.target().unwrap().unchecked_into();
-    let rect = target.get_bounding_client_rect();
-    let width = rect.width();
-    let height = rect.height();
-    let shortdim = width.min(height);
-    
-    // this constant should be kept synchronized with `spheres.frag` and
-    // `point.vert`
-    const FOCAL_SLOPE: f64 = 0.3;
-    
-    (
-        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,
-        ),
-        FOCAL_SLOPE * 2.0 / shortdim,
-    )
-}
-
-// --- display component ---
-
-#[component]
-pub fn Display() -> View {
-    let state = use_context::<AppState>();
-    
-    // canvas
-    let display = create_node_ref();
-    
-    // viewpoint
-    let assembly_to_world = create_signal(DMatrix::<f64>::identity(5, 5));
-    
-    // navigation
-    let pitch_up = create_signal(0.0);
-    let pitch_down = create_signal(0.0);
-    let yaw_right = create_signal(0.0);
-    let yaw_left = create_signal(0.0);
-    let roll_ccw = create_signal(0.0);
-    let roll_cw = create_signal(0.0);
-    let zoom_in = create_signal(0.0);
-    let zoom_out = create_signal(0.0);
-    let turntable = create_signal(false); /* BENCHMARKING */
-    
-    // manipulation
-    let translate_neg_x = create_signal(0.0);
-    let translate_pos_x = create_signal(0.0);
-    let translate_neg_y = create_signal(0.0);
-    let translate_pos_y = create_signal(0.0);
-    let translate_neg_z = create_signal(0.0);
-    let translate_pos_z = create_signal(0.0);
-    let shrink_neg = create_signal(0.0);
-    let shrink_pos = create_signal(0.0);
-    
-    // change listener
-    let scene_changed = create_signal(true);
-    create_effect(move || {
-        state.assembly.elements.with(|elts| {
-            for elt in elts {
-                elt.representation().track();
-                elt.ghost().track();
-            }
-        });
-        state.selection.track();
-        scene_changed.set(true);
-    });
-    
-    /* INSTRUMENTS */
-    const SAMPLE_PERIOD: i32 = 60;
-    let mut last_sample_time = 0.0;
-    let mut frames_since_last_sample = 0;
-    let mean_frame_interval = create_signal(0.0);
-    
-    let assembly_for_raf = state.assembly.clone();
-    on_mount(move || {
-        // timing
-        let mut last_time = 0.0;
-        
-        // viewpoint
-        const ROT_SPEED: f64 = 0.4; // in radians per second
-        const ZOOM_SPEED: f64 = 0.15; // multiplicative rate per second
-        const TURNTABLE_SPEED: f64 = 0.1; /* BENCHMARKING */
-        let mut orientation = DMatrix::<f64>::identity(5, 5);
-        let mut rotation = DMatrix::<f64>::identity(5, 5);
-        let mut location_z: f64 = 5.0;
-        
-        // manipulation
-        const TRANSLATION_SPEED: f64 = 0.15; // in length units per second
-        const SHRINKING_SPEED: f64 = 0.15; // in length units per second
-        
-        // display parameters
-        const LAYER_THRESHOLD: i32 = 0; /* DEBUG */
-        const DEBUG_MODE: i32 = 0; /* DEBUG */
-        
-        /* INSTRUMENTS */
-        let performance = window().unwrap().performance().unwrap();
-        
-        // get the display canvas
-        let canvas = display.get().unchecked_into::<web_sys::HtmlCanvasElement>();
-        let ctx = canvas
-            .get_context("webgl2")
-            .unwrap()
-            .unwrap()
-            .dyn_into::<WebGl2RenderingContext>()
-            .unwrap();
-        
-        // disable depth testing
-        ctx.disable(WebGl2RenderingContext::DEPTH_TEST);
-        
-        // set blend mode
-        ctx.enable(WebGl2RenderingContext::BLEND);
-        ctx.blend_func(WebGl2RenderingContext::SRC_ALPHA, WebGl2RenderingContext::ONE_MINUS_SRC_ALPHA);
-        
-        // set up the sphere rendering program
-        let sphere_program = set_up_program(
-            &ctx,
-            include_str!("identity.vert"),
-            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"),
-        );
-        
-        /* DEBUG */
-        // print the maximum number of vectors that can be passed as
-        // uniforms to a fragment shader. the OpenGL ES 3.0 standard
-        // requires this maximum to be at least 224, as discussed in the
-        // documentation of the GL_MAX_FRAGMENT_UNIFORM_VECTORS parameter
-        // here:
-        //
-        //   https://registry.khronos.org/OpenGL-Refpages/es3.0/html/glGet.xhtml
-        //
-        // there are also other size limits. for example, on Aaron's
-        // machine, the the length of a float or genType array seems to be
-        // capped at 1024 elements
-        console::log_2(
-            &ctx.get_parameter(WebGl2RenderingContext::MAX_FRAGMENT_UNIFORM_VECTORS).unwrap(),
-            &JsValue::from("uniform vectors available"),
-        );
-        
-        // find the sphere program's vertex attribute
-        let viewport_position_attr = ctx.get_attrib_location(&sphere_program, "position") as u32;
-        
-        // find the sphere program's uniforms
-        const SPHERE_MAX: usize = 200;
-        let sphere_cnt_loc = ctx.get_uniform_location(&sphere_program, "sphere_cnt");
-        let sphere_sp_locs = get_uniform_array_locations::<SPHERE_MAX>(
-            &ctx, &sphere_program, "sphere_list", Some("sp")
-        );
-        let sphere_lt_locs = get_uniform_array_locations::<SPHERE_MAX>(
-            &ctx, &sphere_program, "sphere_list", Some("lt")
-        );
-        let sphere_color_locs = get_uniform_array_locations::<SPHERE_MAX>(
-            &ctx, &sphere_program, "color_list", None
-        );
-        let sphere_highlight_locs = get_uniform_array_locations::<SPHERE_MAX>(
-            &ctx, &sphere_program, "highlight_list", None
-        );
-        let resolution_loc = ctx.get_uniform_location(&sphere_program, "resolution");
-        let shortdim_loc = ctx.get_uniform_location(&sphere_program, "shortdim");
-        let layer_threshold_loc = ctx.get_uniform_location(&sphere_program, "layer_threshold");
-        let debug_mode_loc = ctx.get_uniform_location(&sphere_program, "debug_mode");
-        
-        // load the viewport vertex positions into a new vertex buffer object
-        const VERTEX_CNT: usize = 6;
-        let viewport_positions: [f32; 3*VERTEX_CNT] = [
-            // northwest triangle
-            -1.0, -1.0, 0.0,
-            -1.0,  1.0, 0.0,
-             1.0,  1.0, 0.0,
-            // southeast triangle
-            -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);
-        
-        // find the point program's vertex attributes
-        let point_position_attr = ctx.get_attrib_location(&point_program, "position") as u32;
-        let point_color_attr = ctx.get_attrib_location(&point_program, "color") as u32;
-        let point_highlight_attr = ctx.get_attrib_location(&point_program, "highlight") as u32;
-        let point_selection_attr = ctx.get_attrib_location(&point_program, "selected") as u32;
-        
-        // set up a repainting routine
-        let (_, start_animation_loop, _) = create_raf(move || {
-            // get the time step
-            let time = performance.now();
-            let time_step = 0.001*(time - last_time);
-            last_time = time;
-            
-            // get the navigation state
-            let pitch_up_val = pitch_up.get();
-            let pitch_down_val = pitch_down.get();
-            let yaw_right_val = yaw_right.get();
-            let yaw_left_val = yaw_left.get();
-            let roll_ccw_val = roll_ccw.get();
-            let roll_cw_val = roll_cw.get();
-            let zoom_in_val = zoom_in.get();
-            let zoom_out_val = zoom_out.get();
-            let turntable_val = turntable.get(); /* BENCHMARKING */
-            
-            // get the manipulation state
-            let translate_neg_x_val = translate_neg_x.get();
-            let translate_pos_x_val = translate_pos_x.get();
-            let translate_neg_y_val = translate_neg_y.get();
-            let translate_pos_y_val = translate_pos_y.get();
-            let translate_neg_z_val = translate_neg_z.get();
-            let translate_pos_z_val = translate_pos_z.get();
-            let shrink_neg_val = shrink_neg.get();
-            let shrink_pos_val = shrink_pos.get();
-            
-            // update the assembly's orientation
-            let ang_vel = {
-                let pitch = pitch_up_val - pitch_down_val;
-                let yaw = yaw_right_val - yaw_left_val;
-                let roll = roll_ccw_val - roll_cw_val;
-                if pitch != 0.0 || yaw != 0.0 || roll != 0.0 {
-                    ROT_SPEED * Vector3::new(-pitch, yaw, roll).normalize()
-                } else {
-                    Vector3::zeros()
-                }
-            } /* BENCHMARKING */ + if turntable_val {
-                Vector3::new(0.0, TURNTABLE_SPEED, 0.0)
-            } else {
-                Vector3::zeros()
-            };
-            let mut rotation_sp = rotation.fixed_view_mut::<3, 3>(0, 0);
-            rotation_sp.copy_from(
-                Rotation3::from_scaled_axis(time_step * ang_vel).matrix()
-            );
-            orientation = &rotation * &orientation;
-            
-            // update the assembly's location
-            let zoom = zoom_out_val - zoom_in_val;
-            location_z *= (time_step * ZOOM_SPEED * zoom).exp();
-            
-            // manipulate the assembly
-            if state.selection.with(|sel| sel.len() == 1) {
-                let sel = state.selection.with(
-                    |sel| sel.into_iter().next().unwrap().clone()
-                );
-                let translate_x = translate_pos_x_val - translate_neg_x_val;
-                let translate_y = translate_pos_y_val - translate_neg_y_val;
-                let translate_z = translate_pos_z_val - translate_neg_z_val;
-                let shrink = shrink_pos_val - shrink_neg_val;
-                let translating =
-                    translate_x != 0.0
-                    || translate_y != 0.0
-                    || translate_z != 0.0;
-                if translating || shrink != 0.0 {
-                    let elt_motion = {
-                        let u = if translating {
-                            TRANSLATION_SPEED * Vector3::new(
-                                translate_x, translate_y, translate_z
-                            ).normalize()
-                        } else {
-                            Vector3::zeros()
-                        };
-                        time_step * DVector::from_column_slice(
-                            &[u[0], u[1], u[2], SHRINKING_SPEED * shrink]
-                        )
-                    };
-                    assembly_for_raf.deform(
-                        vec![
-                            ElementMotion {
-                                element: sel,
-                                velocity: elt_motion.as_view(),
-                            }
-                        ]
-                    );
-                    scene_changed.set(true);
-                }
-            }
-            
-            if scene_changed.get() {
-                const SPACE_DIM: usize = 3;
-                const COLOR_SIZE: usize = 3;
-                
-                /* INSTRUMENTS */
-                // measure mean frame interval
-                frames_since_last_sample += 1;
-                if frames_since_last_sample >= SAMPLE_PERIOD {
-                    mean_frame_interval.set((time - last_sample_time) / (SAMPLE_PERIOD as f64));
-                    last_sample_time = time;
-                    frames_since_last_sample = 0;
-                }
-                
-                // --- get the assembly ---
-                
-                let mut scene = Scene::new();
-                
-                // find the map from assembly space to world space
-                let location = {
-                    let u = -location_z;
-                    DMatrix::from_column_slice(5, 5, &[
-                        1.0, 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,   u,
-                        0.0, 0.0, 2.0*u, 1.0, u*u,
-                        0.0, 0.0,   0.0, 0.0, 1.0,
-                    ])
-                };
-                let asm_to_world = &location * &orientation;
-                
-                // set up the scene
-                state.assembly.elements.with_untracked(
-                    |elts| for elt in elts {
-                        let selected = state.selection.with(|sel| sel.contains(elt));
-                        elt.show(&mut scene, selected);
-                    }
-                );
-                let sphere_cnt = scene.spheres.len_i32();
-                
-                // --- draw the spheres ---
-                
-                // use the sphere rendering program
-                ctx.use_program(Some(&sphere_program));
-                
-                // enable the sphere program's vertex attribute
-                ctx.enable_vertex_attrib_array(viewport_position_attr);
-                
-                // write the spheres in world coordinates
-                let sphere_reps_world: Vec<_> = scene.spheres.representations.into_iter().map(
-                    |rep| (&asm_to_world * rep).cast::<f32>()
-                ).collect();
-                
-                // set the resolution
-                let width = canvas.width() as f32;
-                let height = canvas.height() as f32;
-                ctx.uniform2f(resolution_loc.as_ref(), width, height);
-                ctx.uniform1f(shortdim_loc.as_ref(), width.min(height));
-                
-                // pass the scene data
-                ctx.uniform1i(sphere_cnt_loc.as_ref(), sphere_cnt);
-                for n in 0..sphere_reps_world.len() {
-                    let v = &sphere_reps_world[n];
-                    ctx.uniform3fv_with_f32_array(
-                        sphere_sp_locs[n].as_ref(),
-                        v.rows(0, 3).as_slice(),
-                    );
-                    ctx.uniform2fv_with_f32_array(
-                        sphere_lt_locs[n].as_ref(),
-                        v.rows(3, 2).as_slice(),
-                    );
-                    ctx.uniform4fv_with_f32_array(
-                        sphere_color_locs[n].as_ref(),
-                        &scene.spheres.colors_with_opacity[n],
-                    );
-                    ctx.uniform1f(
-                        sphere_highlight_locs[n].as_ref(),
-                        scene.spheres.highlights[n],
-                    );
-                }
-                
-                // pass the display parameters
-                ctx.uniform1i(layer_threshold_loc.as_ref(), LAYER_THRESHOLD);
-                ctx.uniform1i(debug_mode_loc.as_ref(), DEBUG_MODE);
-                
-                // bind the viewport vertex position buffer to the position
-                // attribute in the vertex shader
-                bind_to_attribute(&ctx, viewport_position_attr, SPACE_DIM as i32, &viewport_position_buffer);
-                
-                // draw the scene
-                ctx.draw_arrays(WebGl2RenderingContext::TRIANGLES, 0, VERTEX_CNT as i32);
-                
-                // disable the sphere program's vertex attribute
-                ctx.disable_vertex_attrib_array(viewport_position_attr);
-                
-                // --- draw the points ---
-                
-                if !scene.points.representations.is_empty() {
-                    // use the point rendering program
-                    ctx.use_program(Some(&point_program));
-                    
-                    // enable the point program's vertex attributes
-                    ctx.enable_vertex_attrib_array(point_position_attr);
-                    ctx.enable_vertex_attrib_array(point_color_attr);
-                    ctx.enable_vertex_attrib_array(point_highlight_attr);
-                    ctx.enable_vertex_attrib_array(point_selection_attr);
-                    
-                    // write the points in world coordinates
-                    let asm_to_world_sp = asm_to_world.rows(0, SPACE_DIM);
-                    let point_positions = DMatrix::from_columns(
-                        &scene.points.representations.into_iter().map(
-                            |rep| &asm_to_world_sp * rep
-                        ).collect::<Vec<_>>().as_slice()
-                    ).cast::<f32>();
-                    
-                    // load the point positions and colors into new buffers and
-                    // bind them to the corresponding attributes in the vertex
-                    // shader
-                    bind_new_buffer_to_attribute(&ctx, point_position_attr, SPACE_DIM as i32, point_positions.as_slice());
-                    bind_new_buffer_to_attribute(&ctx, point_color_attr, (COLOR_SIZE + 1) as i32, scene.points.colors_with_opacity.concat().as_slice());
-                    bind_new_buffer_to_attribute(&ctx, point_highlight_attr, 1 as i32, scene.points.highlights.as_slice());
-                    bind_new_buffer_to_attribute(&ctx, point_selection_attr, 1 as i32, scene.points.selections.as_slice());
-                    
-                    // draw the scene
-                    ctx.draw_arrays(WebGl2RenderingContext::POINTS, 0, point_positions.ncols() as i32);
-                    
-                    // disable the point program's vertex attributes
-                    ctx.disable_vertex_attrib_array(point_position_attr);
-                    ctx.disable_vertex_attrib_array(point_color_attr);
-                    ctx.disable_vertex_attrib_array(point_highlight_attr);
-                    ctx.disable_vertex_attrib_array(point_selection_attr);
-                }
-                
-                // --- update the display state ---
-                
-                // update the viewpoint
-                assembly_to_world.set(asm_to_world);
-                
-                // clear the scene change flag
-                scene_changed.set(
-                    pitch_up_val != 0.0
-                    || pitch_down_val != 0.0
-                    || yaw_left_val != 0.0
-                    || yaw_right_val != 0.0
-                    || roll_cw_val != 0.0
-                    || roll_ccw_val != 0.0
-                    || zoom_in_val != 0.0
-                    || zoom_out_val != 0.0
-                    || turntable_val /* BENCHMARKING */
-                );
-            } else {
-                frames_since_last_sample = 0;
-                mean_frame_interval.set(-1.0);
-            }
-        });
-        start_animation_loop();
-    });
-    
-    let set_nav_signal = move |event: &KeyboardEvent, value: f64| {
-        let mut navigating = true;
-        let shift = event.shift_key();
-        match event.key().as_str() {
-            "ArrowUp" if shift => zoom_in.set(value),
-            "ArrowDown" if shift => zoom_out.set(value),
-            "ArrowUp" => pitch_up.set(value),
-            "ArrowDown" => pitch_down.set(value),
-            "ArrowRight" if shift => roll_cw.set(value),
-            "ArrowLeft" if shift => roll_ccw.set(value),
-            "ArrowRight" => yaw_right.set(value),
-            "ArrowLeft" => yaw_left.set(value),
-            _ => navigating = false,
-        };
-        if navigating {
-            scene_changed.set(true);
-            event.prevent_default();
-        }
-    };
-    
-    let set_manip_signal = move |event: &KeyboardEvent, value: f64| {
-        let mut manipulating = true;
-        let shift = event.shift_key();
-        match event.key().as_str() {
-            "d" | "D" => translate_pos_x.set(value),
-            "a" | "A" => translate_neg_x.set(value),
-            "w" | "W" if shift => translate_neg_z.set(value),
-            "s" | "S" if shift => translate_pos_z.set(value),
-            "w" | "W" => translate_pos_y.set(value),
-            "s" | "S" => translate_neg_y.set(value),
-            "]" | "}" => shrink_neg.set(value),
-            "[" | "{" => shrink_pos.set(value),
-            _ => manipulating = false,
-        };
-        if manipulating {
-            event.prevent_default();
-        }
-    };
-    
-    view! {
-        /* TO DO */
-        // 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| {
-                if event.key() == "Shift" {
-                    // swap navigation inputs
-                    roll_cw.set(yaw_right.get());
-                    roll_ccw.set(yaw_left.get());
-                    zoom_in.set(pitch_up.get());
-                    zoom_out.set(pitch_down.get());
-                    yaw_right.set(0.0);
-                    yaw_left.set(0.0);
-                    pitch_up.set(0.0);
-                    pitch_down.set(0.0);
-                    
-                    // swap manipulation inputs
-                    translate_pos_z.set(translate_neg_y.get());
-                    translate_neg_z.set(translate_pos_y.get());
-                    translate_pos_y.set(0.0);
-                    translate_neg_y.set(0.0);
-                } else {
-                    if event.key() == "Enter" { /* BENCHMARKING */
-                        turntable.set_fn(|turn| !turn);
-                        scene_changed.set(true);
-                    }
-                    set_nav_signal(&event, 1.0);
-                    set_manip_signal(&event, 1.0);
-                }
-            },
-            on:keyup = move |event: KeyboardEvent| {
-                if event.key() == "Shift" {
-                    // swap navigation inputs
-                    yaw_right.set(roll_cw.get());
-                    yaw_left.set(roll_ccw.get());
-                    pitch_up.set(zoom_in.get());
-                    pitch_down.set(zoom_out.get());
-                    roll_cw.set(0.0);
-                    roll_ccw.set(0.0);
-                    zoom_in.set(0.0);
-                    zoom_out.set(0.0);
-                    
-                    // swap manipulation inputs
-                    translate_pos_y.set(translate_neg_z.get());
-                    translate_neg_y.set(translate_pos_z.get());
-                    translate_pos_z.set(0.0);
-                    translate_neg_z.set(0.0);
-                } else {
-                    set_nav_signal(&event, 0.0);
-                    set_manip_signal(&event, 0.0);
-                }
-            },
-            on:blur = move |_| {
-                pitch_up.set(0.0);
-                pitch_down.set(0.0);
-                yaw_right.set(0.0);
-                yaw_left.set(0.0);
-                roll_ccw.set(0.0);
-                roll_cw.set(0.0);
-            },
-            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()));
-                let mut clicked: Option<(Rc<dyn Element>, f64)> = None;
-                let tangible_elts = state.assembly.elements
-                    .get_clone_untracked()
-                    .into_iter()
-                    .filter(|elt| !elt.ghost().get());
-                for elt in tangible_elts {
-                    match assembly_to_world.with(|asm_to_world| elt.cast(dir, asm_to_world, pixel_size)) {
-                        Some(depth) => match clicked {
-                            Some((_, best_depth)) => {
-                                if depth < best_depth {
-                                    clicked = Some((elt, depth))
-                                }
-                            },
-                            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()),
-                };
-            },
-        )
-    }
-}
--- a/app-proto/src/components/point.frag
+++ b/app-proto/src/components/point.frag
@ -1,19 +0,0 @@
-#version 300 es
-
-precision highp float;
-
-in vec4 point_color;
-in float point_highlight;
-in float total_radius;
-
-out vec4 outColor;
-
-void main() {
-    float r = total_radius * length(2.*gl_PointCoord - vec2(1.));
-    
-    const float POINT_RADIUS = 4.;
-    float border = smoothstep(POINT_RADIUS - 1., POINT_RADIUS, r);
-    float disk = 1. - smoothstep(total_radius - 1., total_radius, r);
-    vec4 color = mix(point_color, vec4(1.), border * point_highlight);
-    outColor = vec4(vec3(1.), disk) * color;
-}
--- a/app-proto/src/components/point.vert
+++ b/app-proto/src/components/point.vert
@ -1,24 +0,0 @@
-#version 300 es
-
-in vec4 position;
-in vec4 color;
-in float highlight;
-in float selected;
-
-out vec4 point_color;
-out float point_highlight;
-out float total_radius;
-
-// camera
-const float focal_slope = 0.3;
-
-void main() {
-    total_radius = 5. + 0.5*selected;
-    
-    float depth = -focal_slope * position.z;
-    gl_Position = vec4(position.xy / depth, 0., 1.);
-    gl_PointSize = 2.*total_radius;
-    
-    point_color = color;
-    point_highlight = highlight;
-}
--- a/app-proto/src/components/test_assembly_chooser.rs
+++ b/app-proto/src/components/test_assembly_chooser.rs
@ -1,941 +0,0 @@
-use itertools::izip;
-use std::{f64::consts::{FRAC_1_SQRT_2, PI}, rc::Rc};
-use nalgebra::Vector3;
-use sycamore::prelude::*;
-use web_sys::{console, wasm_bindgen::JsValue};
-
-use crate::{
-    AppState,
-    assembly::{
-        Assembly,
-        Element,
-        ElementColor,
-        InversiveDistanceRegulator,
-        Point,
-        Sphere,
-    },
-    engine,
-    engine::DescentHistory,
-    specified::SpecifiedValue,
-};
-
-// --- loaders ---
-
-/* DEBUG */
-// each of these functions loads an example assembly for testing. once we've
-// 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) {
-    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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-}
-
-fn load_low_curvature(assembly: &Assembly) {
-    // create the spheres
-    let a = 0.75_f64.sqrt();
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            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),
-        )
-    );
-    
-    // impose the desired tangencies and make the sides planar
-    let index_range = 1..=3;
-    let [central, assemb_plane] = ["central", "assemb_plane"].map(
-        |id| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[id].clone()
-        )
-    );
-    let sides = index_range.clone().map(
-        |k| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[&format!("side{k}")].clone()
-        )
-    );
-    let corners = index_range.map(
-        |k| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[&format!("corner{k}")].clone()
-        )
-    );
-    for plane in [assemb_plane.clone()].into_iter().chain(sides.clone()) {
-        // fix the curvature of each plane
-        let curvature = plane.regulators().with_untracked(
-            |regs| regs.first().unwrap().clone()
-        );
-        curvature.set_point().set(SpecifiedValue::try_from("0".to_string()).unwrap());
-    }
-    let all_perpendicular = [central.clone()].into_iter()
-        .chain(sides.clone())
-        .chain(corners.clone());
-    for sphere in all_perpendicular {
-        // make each side and packed sphere perpendicular to the assembly plane
-        let right_angle = InversiveDistanceRegulator::new([sphere, assemb_plane.clone()]);
-        right_angle.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-        assembly.insert_regulator(Rc::new(right_angle));
-    }
-    for sphere in sides.clone().chain(corners.clone()) {
-        // make each side and corner sphere tangent to the central sphere
-        let tangency = InversiveDistanceRegulator::new([sphere.clone(), central.clone()]);
-        tangency.set_point.set(SpecifiedValue::try_from("-1".to_string()).unwrap());
-        assembly.insert_regulator(Rc::new(tangency));
-    }
-    for (side_index, side) in sides.enumerate() {
-        // make each side tangent to the two adjacent corner spheres
-        for (corner_index, corner) in corners.clone().enumerate() {
-            if side_index != corner_index {
-                let tangency = InversiveDistanceRegulator::new([side.clone(), corner]);
-                tangency.set_point.set(SpecifiedValue::try_from("-1".to_string()).unwrap());
-                assembly.insert_regulator(Rc::new(tangency));
-            }
-        }
-    }
-}
-
-fn load_pointed(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),
-        )
-    );
-    let _ = assembly.try_insert_element(
-        Point::new(
-            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),
-        )
-    );
-    for index_x in 0..=1 {
-        for index_y in 0..=1 {
-            let x = index_x as f64 - 0.5;
-            let y = index_y as f64 - 0.5;
-            
-            let _ = assembly.try_insert_element(
-                Sphere::new(
-                    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),
-                )
-            );
-            
-            let _ = assembly.try_insert_element(
-                Point::new(
-                    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),
-                )
-            );
-        }
-    }
-}
-
-// to finish describing the tridiminished icosahedron, set the inversive
-// distance regulators as follows:
-//   A-A   -0.25
-//   A-B     "
-//   B-C     "
-//   C-C     "
-//   A-C   -0.25 * φ^2 = -0.6545084971874737
-fn load_tridiminished_icosahedron(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];
-    const COLOR_C: ElementColor = [0.25_f32, 0.50_f32, 1.00_f32];
-    let vertices = [
-        Point::new(
-            "a1".to_string(),
-            "A₁".to_string(),
-            COLOR_A,
-            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),
-        ),
-        Point::new(
-            "a3".to_string(),
-            "A₃".to_string(),
-            COLOR_A,
-            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),
-        ),
-        Point::new(
-            "b2".to_string(),
-            "B₂".to_string(),
-            COLOR_B,
-            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),
-        ),
-        Point::new(
-            "c1".to_string(),
-            "C₁".to_string(),
-            COLOR_C,
-            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),
-        ),
-        Point::new(
-            "c3".to_string(),
-            "C₃".to_string(),
-            COLOR_C,
-            engine::point(-1.0, -1.0, 0.0),
-        ),
-    ];
-    for vertex in vertices {
-        let _ = assembly.try_insert_element(vertex);
-    }
-    
-    // create the faces
-    const COLOR_FACE: ElementColor = [0.75_f32, 0.75_f32, 0.75_f32];
-    let frac_1_sqrt_6 = 1.0 / 6.0_f64.sqrt();
-    let frac_2_sqrt_6 = 2.0 * frac_1_sqrt_6;
-    let faces = [
-        Sphere::new(
-            "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),
-        ),
-        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),
-        ),
-        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),
-        ),
-    ];
-    for face in faces {
-        face.ghost().set(true);
-        let _ = assembly.try_insert_element(face);
-    }
-    
-    let index_range = 1..=3;
-    for j in index_range.clone() {
-        // make each face planar
-        let face = assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[&format!("face{j}")].clone()
-        );
-        let curvature_regulator = face.regulators().with_untracked(
-            |regs| regs.first().unwrap().clone()
-        );
-        curvature_regulator.set_point().set(
-            SpecifiedValue::try_from("0".to_string()).unwrap()
-        );
-        
-        // put each A vertex on the face it belongs to
-        let vertex_a = assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[&format!("a{j}")].clone()
-        );
-        let incidence_a = InversiveDistanceRegulator::new([face.clone(), vertex_a.clone()]);
-        incidence_a.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-        assembly.insert_regulator(Rc::new(incidence_a));
-        
-        // regulate the B-C vertex distances
-        let vertices_bc = ["b", "c"].map(
-            |series| assembly.elements_by_id.with_untracked(
-                |elts_by_id| elts_by_id[&format!("{series}{j}")].clone()
-            )
-        );
-        assembly.insert_regulator(
-            Rc::new(InversiveDistanceRegulator::new(vertices_bc))
-        );
-        
-        // get the pair of indices adjacent to `j`
-        let adjacent_indices = [j % 3 + 1, (j + 1) % 3 + 1];
-        
-        for k in adjacent_indices.clone() {
-            for series in ["b", "c"] {
-                // put each B and C vertex on the faces it belongs to
-                let vertex = assembly.elements_by_id.with_untracked(
-                    |elts_by_id| elts_by_id[&format!("{series}{k}")].clone()
-                );
-                let incidence = InversiveDistanceRegulator::new([face.clone(), vertex.clone()]);
-                incidence.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-                assembly.insert_regulator(Rc::new(incidence));
-                
-                // regulate the A-B and A-C vertex distances
-                assembly.insert_regulator(
-                    Rc::new(InversiveDistanceRegulator::new([vertex_a.clone(), vertex]))
-                );
-            }
-        }
-        
-        // regulate the A-A and C-C vertex distances
-        let adjacent_pairs = ["a", "c"].map(
-            |series| adjacent_indices.map(
-                |index| assembly.elements_by_id.with_untracked(
-                    |elts_by_id| elts_by_id[&format!("{series}{index}")].clone()
-                )
-            )
-        );
-        for pair in adjacent_pairs {
-            assembly.insert_regulator(
-                Rc::new(InversiveDistanceRegulator::new(pair))
-            );
-        }
-    }
-}
-
-// 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) {
-    // 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),
-        )
-    );
-    let substrate = assembly.elements_by_id.with_untracked(
-        |elts_by_id| elts_by_id["substrate"].clone()
-    );
-    
-    // fix the substrate's curvature
-    substrate.regulators().with_untracked(
-        |regs| regs.first().unwrap().clone()
-    ).set_point().set(
-        SpecifiedValue::try_from("0.5".to_string()).unwrap()
-    );
-    
-    // add the circles to be packed
-    const COLOR_A: ElementColor = [1.00_f32, 0.25_f32, 0.00_f32];
-    const COLOR_B: ElementColor = [1.00_f32, 0.00_f32, 0.25_f32];
-    const COLOR_C: ElementColor = [0.25_f32, 0.00_f32, 1.00_f32];
-    let phi = 0.5 + 1.25_f64.sqrt(); /* TO DO */ // replace with std::f64::consts::PHI when that gets stabilized
-    let phi_inv = 1.0 / phi;
-    let coord_scale = (phi + 2.0).sqrt();
-    let face_scales = [phi_inv, (13.0 / 12.0) / coord_scale];
-    let face_radii = [phi_inv, 5.0 / 12.0];
-    let mut faces = Vec::<Rc<dyn Element>>::new();
-    let subscripts = ["₀", "₁"];
-    for j in 0..2 {
-        for k in 0..2 {
-            let small_coord = face_scales[k] * (2.0*(j as f64) - 1.0);
-            let big_coord = face_scales[k] * (2.0*(k as f64) - 1.0) * phi;
-            
-            let id_num = format!("{j}{k}");
-            let label_sub = format!("{}{}", subscripts[j], subscripts[k]);
-            
-            // add the A face
-            let id_a = format!("a{id_num}");
-            let _ = assembly.try_insert_element(
-                Sphere::new(
-                    id_a.clone(),
-                    format!("A{label_sub}"),
-                    COLOR_A,
-                    engine::sphere(0.0, small_coord, big_coord, face_radii[k]),
-                )
-            );
-            faces.push(
-                assembly.elements_by_id.with_untracked(
-                    |elts_by_id| elts_by_id[&id_a].clone()
-                )
-            );
-            
-            // add the B face
-            let id_b = format!("b{id_num}");
-            let _ = assembly.try_insert_element(
-                Sphere::new(
-                    id_b.clone(),
-                    format!("B{label_sub}"),
-                    COLOR_B,
-                    engine::sphere(small_coord, big_coord, 0.0, face_radii[k]),
-                )
-            );
-            faces.push(
-                assembly.elements_by_id.with_untracked(
-                    |elts_by_id| elts_by_id[&id_b].clone()
-                )
-            );
-            
-            // add the C face
-            let id_c = format!("c{id_num}");
-            let _ = assembly.try_insert_element(
-                Sphere::new(
-                    id_c.clone(),
-                    format!("C{label_sub}"),
-                    COLOR_C,
-                    engine::sphere(big_coord, 0.0, small_coord, face_radii[k]),
-                )
-            );
-            faces.push(
-                assembly.elements_by_id.with_untracked(
-                    |elts_by_id| elts_by_id[&id_c].clone()
-                )
-            );
-        }
-    }
-    
-    // make each face sphere perpendicular to the substrate
-    for face in faces {
-        let right_angle = InversiveDistanceRegulator::new([face, substrate.clone()]);
-        right_angle.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-        assembly.insert_regulator(Rc::new(right_angle));
-    }
-    
-    // set up the tangencies that define the packing
-    for [long_edge_plane, short_edge_plane] in [["a", "b"], ["b", "c"], ["c", "a"]] {
-        for k in 0..2 {
-            let long_edge_ids = [
-                format!("{long_edge_plane}{k}0"),
-                format!("{long_edge_plane}{k}1")
-            ];
-            let short_edge_ids = [
-                format!("{short_edge_plane}0{k}"),
-                format!("{short_edge_plane}1{k}")
-            ];
-            let [long_edge, short_edge] = [long_edge_ids, short_edge_ids].map(
-                |edge_ids| edge_ids.map(
-                    |id| assembly.elements_by_id.with_untracked(
-                        |elts_by_id| elts_by_id[&id].clone()
-                    )
-                )
-            );
-            
-            // set up the short-edge tangency
-            let short_tangency = InversiveDistanceRegulator::new(short_edge.clone());
-            if k == 0 {
-                short_tangency.set_point.set(SpecifiedValue::try_from("-1".to_string()).unwrap());
-            }
-            assembly.insert_regulator(Rc::new(short_tangency));
-            
-            // set up the side tangencies
-            for i in 0..2 {
-                for j in 0..2 {
-                    let side_tangency = InversiveDistanceRegulator::new(
-                        [long_edge[i].clone(), short_edge[j].clone()]
-                    );
-                    if i == 0 && k == 0 {
-                        side_tangency.set_point.set(SpecifiedValue::try_from("-1".to_string()).unwrap());
-                    }
-                    assembly.insert_regulator(Rc::new(side_tangency));
-                }
-            }
-        }
-    }
-}
-
-// 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) {
-    // create the spheres
-    const R_OUTER: f64 = 10.0;
-    const R_INNER: f64 = 4.0;
-    let spheres = [
-        Sphere::new(
-            "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),
-        ),
-        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),
-        ),
-        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),
-        ),
-    ];
-    for sphere in spheres {
-        let _ = assembly.try_insert_element(sphere);
-    }
-    
-    // get references to the spheres
-    let [outer, a, b] = ["outer", "a", "b"].map(
-        |id| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[id].clone()
-        )
-    );
-    
-    // fix the diameters of the outer, sun, and moon spheres
-    for (sphere, radius) in [
-        (outer.clone(), R_OUTER),
-        (a.clone(), R_INNER),
-        (b.clone(), R_INNER),
-    ] {
-        let curvature_regulator = sphere.regulators().with_untracked(
-            |regs| regs.first().unwrap().clone()
-        );
-        let curvature = 0.5 / radius;
-        curvature_regulator.set_point().set(
-            SpecifiedValue::try_from(curvature.to_string()).unwrap()
-        );
-    }
-    
-    // set the inversive distances between the spheres. as described above, the
-    // initial configuration deliberately violates these constraints
-    for inner in [a, b] {
-        let tangency = InversiveDistanceRegulator::new([outer.clone(), inner]);
-        tangency.set_point.set(SpecifiedValue::try_from("1".to_string()).unwrap());
-        assembly.insert_regulator(Rc::new(tangency));
-    }
-}
-
-// 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) {
-    // 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),
-        ),
-    );
-    let _ = assembly.try_insert_element(
-        Sphere::new(
-            "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),
-        ),
-    );
-    
-    // get references to the elements
-    let point_and_sphere = ["point", "sphere"].map(
-        |id| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[id].clone()
-        )
-    );
-    
-    // put the point on the sphere
-    let incidence = InversiveDistanceRegulator::new(point_and_sphere);
-    incidence.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-    assembly.insert_regulator(Rc::new(incidence));
-}
-
-// setting the inversive distances between the vertices to -2 gives a regular
-// tetrahedron with side length 1, whose insphere and circumsphere have radii
-// 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) {
-    let index_range = 1..=4;
-    
-    // create the spheres
-    const GRAY: ElementColor = [0.75_f32, 0.75_f32, 0.75_f32];
-    let spheres = [
-        Sphere::new(
-            "sphere_faces".to_string(),
-            "Insphere".to_string(),
-            GRAY,
-            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),
-        ),
-    ];
-    for sphere in spheres {
-        let _ = assembly.try_insert_element(sphere);
-    }
-    
-    // create the vertices
-    let vertices = izip!(
-        index_range.clone(),
-        [
-            [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],
-        ].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),
-        ].into_iter()
-    ).map(
-        |(k, color, representation)| {
-            Point::new(
-                format!("v{k}"),
-                format!("Vertex {k}"),
-                color,
-                representation,
-            )
-        }
-    );
-    for vertex in vertices {
-        let _ = assembly.try_insert_element(vertex);
-    }
-    
-    // create the faces
-    let base_dir = Vector3::new(1.0, 0.75, 1.0).normalize();
-    let offset = base_dir.dot(&Vector3::new(-0.6, 0.8, 0.6));
-    let faces = izip!(
-        index_range.clone(),
-        [
-            [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],
-        ].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),
-        ].into_iter()
-    ).map(
-        |(k, color, representation)| {
-            Sphere::new(
-                format!("f{k}"),
-                format!("Face {k}"),
-                color,
-                representation,
-            )
-        }
-    );
-    for face in faces {
-        face.ghost().set(true);
-        let _ = assembly.try_insert_element(face);
-    }
-    
-    // impose the constraints
-    for j in index_range.clone() {
-        let [face_j, vertex_j] = [
-            format!("f{j}"),
-            format!("v{j}"),
-        ].map(
-            |id| assembly.elements_by_id.with_untracked(
-                |elts_by_id| elts_by_id[&id].clone()
-            )
-        );
-        
-        // make the faces planar
-        let curvature_regulator = face_j.regulators().with_untracked(
-            |regs| regs.first().unwrap().clone()
-        );
-        curvature_regulator.set_point().set(
-            SpecifiedValue::try_from("0".to_string()).unwrap()
-        );
-        
-        for k in index_range.clone().filter(|&index| index != j) {
-            let vertex_k = assembly.elements_by_id.with_untracked(
-                |elts_by_id| elts_by_id[&format!("v{k}")].clone()
-            );
-            
-            // fix the distances between the vertices
-            if j < k {
-                let distance_regulator = InversiveDistanceRegulator::new(
-                    [vertex_j.clone(), vertex_k.clone()]
-                );
-                assembly.insert_regulator(Rc::new(distance_regulator));
-            }
-            
-            // put the vertices on the faces
-            let incidence_regulator = InversiveDistanceRegulator::new([face_j.clone(), vertex_k.clone()]);
-            incidence_regulator.set_point.set(SpecifiedValue::try_from("0".to_string()).unwrap());
-            assembly.insert_regulator(Rc::new(incidence_regulator));
-        }
-    }
-}
-
-// to finish setting up the problem, fix the following curvatures:
-//   sun      1
-//   moon     5/3 = 1.666666666666666...
-//   chain1   2
-// a tiny `x` or `z` nudge of the outer sphere reliably prevents realization
-// failures before they happen, or resolves them after they happen. the result
-// depends sensitively on the translation direction, suggesting that realization
-// is failing because the engine is having trouble breaking a symmetry
-// /* TO DO */
-// the engine's performance on this problem is scale-dependent! with the current
-// initial conditions, realization fails for any order of imposing the remaining
-// curvature constraints. scaling everything up by a factor of ten, as done in
-// the original problem, makes realization succeed reliably. one potentially
-// relevant difference is that a lot of the numbers in the current initial
-// 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) {
-    let index_range = 1..=6;
-    let colors = [
-        [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, 1.00_f32, 0.00_f32],
-        [0.00_f32, 0.25_f32, 1.00_f32],
-        [0.25_f32, 0.00_f32, 1.00_f32],
-    ].into_iter();
-    
-    // create the spheres
-    let spheres = [
-        Sphere::new(
-            "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),
-        ),
-        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),
-        ),
-        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),
-        ),
-    ].into_iter().chain(
-        index_range.clone().zip(colors).map(
-            |(k, color)| {
-                let ang = (k as f64) * PI/3.0;
-                Sphere::new(
-                    format!("chain{k}"),
-                    format!("Chain {k}"),
-                    color,
-                    engine::sphere(1.0 * ang.sin(), 0.0, 1.0 * ang.cos(), 0.5),
-                )
-            }
-        )
-    );
-    for sphere in spheres {
-        let _ = assembly.try_insert_element(sphere);
-    }
-    
-    // put the outer sphere in ghost mode and fix its curvature
-    let outer = assembly.elements_by_id.with_untracked(
-        |elts_by_id| elts_by_id["outer"].clone()
-    );
-    outer.ghost().set(true);
-    let outer_curvature_regulator = outer.regulators().with_untracked(
-        |regs| regs.first().unwrap().clone()
-    );
-    outer_curvature_regulator.set_point().set(
-        SpecifiedValue::try_from((1.0 / 3.0).to_string()).unwrap()
-    );
-    
-    // impose the desired tangencies
-    let [outer, sun, moon] = ["outer", "sun", "moon"].map(
-        |id| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[id].clone()
-        )
-    );
-    let chain = index_range.map(
-        |k| assembly.elements_by_id.with_untracked(
-            |elts_by_id| elts_by_id[&format!("chain{k}")].clone()
-        )
-    );
-    for (chain_sphere, chain_sphere_next) in chain.clone().zip(chain.cycle().skip(1)) {
-        for (other_sphere, inversive_distance) in [
-            (outer.clone(), "1"),
-            (sun.clone(), "-1"),
-            (moon.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());
-            assembly.insert_regulator(Rc::new(tangency));
-        }
-    }
-    
-    let outer_sun_tangency = InversiveDistanceRegulator::new([outer.clone(), sun]);
-    outer_sun_tangency.set_point.set(SpecifiedValue::try_from("1".to_string()).unwrap());
-    assembly.insert_regulator(Rc::new(outer_sun_tangency));
-    
-    let outer_moon_tangency = InversiveDistanceRegulator::new([outer.clone(), moon]);
-    outer_moon_tangency.set_point.set(SpecifiedValue::try_from("1".to_string()).unwrap());
-    assembly.insert_regulator(Rc::new(outer_moon_tangency));
-}
-
-// --- chooser ---
-
-/* DEBUG */
-#[component]
-pub fn TestAssemblyChooser() -> View {
-    // create an effect that loads the selected test assembly
-    let assembly_name = create_signal("general".to_string());
-    create_effect(move || {
-        // get name of chosen assembly
-        let name = assembly_name.get_clone();
-        console::log_1(
-            &JsValue::from(format!("Showing assembly \"{}\"", name.clone()))
-        );
-        
-        batch(|| {
-            let state = use_context::<AppState>();
-            let assembly = &state.assembly;
-            
-            // clear state
-            assembly.regulators.update(|regs| regs.clear());
-            assembly.elements.update(|elts| elts.clear());
-            assembly.elements_by_id.update(|elts_by_id| elts_by_id.clear());
-            assembly.descent_history.set(DescentHistory::new());
-            state.selection.update(|sel| sel.clear());
-            
-            // 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),
-                _ => (),
-            };
-        });
-    });
-    
-    // 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" }
-        }
-    }
-}
--- a/app-proto/src/display.rs
+++ b/app-proto/src/display.rs
@ -0,0 +1,613 @@
+use core::array;
+use nalgebra::{DMatrix, DVector, Rotation3, Vector3};
+use sycamore::{prelude::*, motion::create_raf};
+use web_sys::{
+    console,
+    window,
+    Element,
+    KeyboardEvent,
+    MouseEvent,
+    WebGl2RenderingContext,
+    WebGlProgram,
+    WebGlShader,
+    WebGlUniformLocation,
+    wasm_bindgen::{JsCast, JsValue}
+};
+
+use crate::{AppState, assembly::{ElementKey, ElementMotion}};
+
+fn compile_shader(
+    context: &WebGl2RenderingContext,
+    shader_type: u32,
+    source: &str,
+) -> WebGlShader {
+    let shader = context.create_shader(shader_type).unwrap();
+    context.shader_source(&shader, source);
+    context.compile_shader(&shader);
+    shader
+}
+
+fn get_uniform_array_locations<const N: usize>(
+    context: &WebGl2RenderingContext,
+    program: &WebGlProgram,
+    var_name: &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}]")
+        };
+        context.get_uniform_location(&program, name.as_str())
+    })
+}
+
+// load the given data into the vertex input of the given name
+fn bind_vertex_attrib(
+    context: &WebGl2RenderingContext,
+    index: u32,
+    size: i32,
+    data: &[f32]
+) {
+    // create a data buffer and bind it to ARRAY_BUFFER
+    let buffer = context.create_buffer().unwrap();
+    context.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, Some(&buffer));
+    
+    // load the given data into the buffer. the function `Float32Array::view`
+    // creates a raw view into our module's `WebAssembly.Memory` buffer.
+    // allocating more memory will change the buffer, invalidating the view.
+    // that means we have to make sure we don't allocate any memory until the
+    // view is dropped
+    unsafe {
+        context.buffer_data_with_array_buffer_view(
+            WebGl2RenderingContext::ARRAY_BUFFER,
+            &js_sys::Float32Array::view(&data),
+            WebGl2RenderingContext::STATIC_DRAW,
+        );
+    }
+    
+    // allow the target attribute to be used
+    context.enable_vertex_attrib_array(index);
+    
+    // take whatever's bound to ARRAY_BUFFER---here, the data buffer created
+    // above---and bind it to the target attribute
+    //
+    //   https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/vertexAttribPointer
+    //
+    context.vertex_attrib_pointer_with_i32(
+        index,
+        size,
+        WebGl2RenderingContext::FLOAT,
+        false, // don't normalize
+        0, // zero stride
+        0, // zero offset
+    );
+}
+
+// the direction in camera space that a mouse event is pointing along
+fn event_dir(event: &MouseEvent) -> Vector3<f64> {
+    let target: Element = event.target().unwrap().unchecked_into();
+    let rect = target.get_bounding_client_rect();
+    let width = rect.width();
+    let height = rect.height();
+    let shortdim = width.min(height);
+    
+    // this constant should be kept synchronized with `inversive.frag`
+    const FOCAL_SLOPE: f64 = 0.3;
+    
+    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
+    )
+}
+
+#[component]
+pub fn Display() -> View {
+    let state = use_context::<AppState>();
+    
+    // canvas
+    let display = create_node_ref();
+    
+    // viewpoint
+    let assembly_to_world = create_signal(DMatrix::<f64>::identity(5, 5));
+    
+    // navigation
+    let pitch_up = create_signal(0.0);
+    let pitch_down = create_signal(0.0);
+    let yaw_right = create_signal(0.0);
+    let yaw_left = create_signal(0.0);
+    let roll_ccw = create_signal(0.0);
+    let roll_cw = create_signal(0.0);
+    let zoom_in = create_signal(0.0);
+    let zoom_out = create_signal(0.0);
+    let turntable = create_signal(false); /* BENCHMARKING */
+    
+    // manipulation
+    let translate_neg_x = create_signal(0.0);
+    let translate_pos_x = create_signal(0.0);
+    let translate_neg_y = create_signal(0.0);
+    let translate_pos_y = create_signal(0.0);
+    let translate_neg_z = create_signal(0.0);
+    let translate_pos_z = create_signal(0.0);
+    let shrink_neg = create_signal(0.0);
+    let shrink_pos = create_signal(0.0);
+    
+    // change listener
+    let scene_changed = create_signal(true);
+    create_effect(move || {
+        state.assembly.elements.with(|elts| {
+            for (_, elt) in elts {
+                elt.representation.track();
+            }
+        });
+        state.selection.track();
+        scene_changed.set(true);
+    });
+    
+    /* INSTRUMENTS */
+    const SAMPLE_PERIOD: i32 = 60;
+    let mut last_sample_time = 0.0;
+    let mut frames_since_last_sample = 0;
+    let mean_frame_interval = create_signal(0.0);
+    
+    let assembly_for_raf = state.assembly.clone();
+    on_mount(move || {
+        // timing
+        let mut last_time = 0.0;
+        
+        // viewpoint
+        const ROT_SPEED: f64 = 0.4; // in radians per second
+        const ZOOM_SPEED: f64 = 0.15; // multiplicative rate per second
+        const TURNTABLE_SPEED: f64 = 0.1; /* BENCHMARKING */
+        let mut orientation = DMatrix::<f64>::identity(5, 5);
+        let mut rotation = DMatrix::<f64>::identity(5, 5);
+        let mut location_z: f64 = 5.0;
+        
+        // manipulation
+        const TRANSLATION_SPEED: f64 = 0.15; // in length units per second
+        const SHRINKING_SPEED: f64 = 0.15; // in length units per second
+        
+        // display parameters
+        const OPACITY: f32 = 0.5; /* SCAFFOLDING */
+        const HIGHLIGHT: f32 = 0.2; /* SCAFFOLDING */
+        const LAYER_THRESHOLD: i32 = 0; /* DEBUG */
+        const DEBUG_MODE: i32 = 0; /* DEBUG */
+        
+        /* INSTRUMENTS */
+        let performance = window().unwrap().performance().unwrap();
+        
+        // get the display canvas
+        let canvas = display.get().unchecked_into::<web_sys::HtmlCanvasElement>();
+        let ctx = canvas
+            .get_context("webgl2")
+            .unwrap()
+            .unwrap()
+            .dyn_into::<WebGl2RenderingContext>()
+            .unwrap();
+        
+        // compile and attach the vertex and fragment shaders
+        let vertex_shader = compile_shader(
+            &ctx,
+            WebGl2RenderingContext::VERTEX_SHADER,
+            include_str!("identity.vert"),
+        );
+        let fragment_shader = compile_shader(
+            &ctx,
+            WebGl2RenderingContext::FRAGMENT_SHADER,
+            include_str!("inversive.frag"),
+        );
+        let program = ctx.create_program().unwrap();
+        ctx.attach_shader(&program, &vertex_shader);
+        ctx.attach_shader(&program, &fragment_shader);
+        ctx.link_program(&program);
+        let link_status = ctx
+            .get_program_parameter(&program, WebGl2RenderingContext::LINK_STATUS)
+            .as_bool()
+            .unwrap();
+        let link_msg = if link_status {
+            "Linked successfully"
+        } else {
+            "Linking failed"
+        };
+        console::log_1(&JsValue::from(link_msg));
+        ctx.use_program(Some(&program));
+        
+        /* DEBUG */
+        // print the maximum number of vectors that can be passed as
+        // uniforms to a fragment shader. the OpenGL ES 3.0 standard
+        // requires this maximum to be at least 224, as discussed in the
+        // documentation of the GL_MAX_FRAGMENT_UNIFORM_VECTORS parameter
+        // here:
+        //
+        //   https://registry.khronos.org/OpenGL-Refpages/es3.0/html/glGet.xhtml
+        //
+        // there are also other size limits. for example, on Aaron's
+        // machine, the the length of a float or genType array seems to be
+        // capped at 1024 elements
+        console::log_2(
+            &ctx.get_parameter(WebGl2RenderingContext::MAX_FRAGMENT_UNIFORM_VECTORS).unwrap(),
+            &JsValue::from("uniform vectors available")
+        );
+        
+        // find indices of vertex attributes and uniforms
+        const SPHERE_MAX: usize = 200;
+        let position_index = ctx.get_attrib_location(&program, "position") as u32;
+        let sphere_cnt_loc = ctx.get_uniform_location(&program, "sphere_cnt");
+        let sphere_sp_locs = get_uniform_array_locations::<SPHERE_MAX>(
+            &ctx, &program, "sphere_list", Some("sp")
+        );
+        let sphere_lt_locs = get_uniform_array_locations::<SPHERE_MAX>(
+            &ctx, &program, "sphere_list", Some("lt")
+        );
+        let color_locs = get_uniform_array_locations::<SPHERE_MAX>(
+            &ctx, &program, "color_list", None
+        );
+        let highlight_locs = get_uniform_array_locations::<SPHERE_MAX>(
+            &ctx, &program, "highlight_list", None
+        );
+        let resolution_loc = ctx.get_uniform_location(&program, "resolution");
+        let shortdim_loc = ctx.get_uniform_location(&program, "shortdim");
+        let opacity_loc = ctx.get_uniform_location(&program, "opacity");
+        let layer_threshold_loc = ctx.get_uniform_location(&program, "layer_threshold");
+        let debug_mode_loc = ctx.get_uniform_location(&program, "debug_mode");
+        
+        // create a vertex array and bind it to the graphics context
+        let vertex_array = ctx.create_vertex_array().unwrap();
+        ctx.bind_vertex_array(Some(&vertex_array));
+        
+        // set the vertex positions
+        const VERTEX_CNT: usize = 6;
+        let positions: [f32; 3*VERTEX_CNT] = [
+            // northwest triangle
+            -1.0, -1.0, 0.0,
+            -1.0,  1.0, 0.0,
+             1.0,  1.0, 0.0,
+            // southeast triangle
+            -1.0, -1.0, 0.0,
+             1.0,  1.0, 0.0,
+             1.0, -1.0, 0.0
+        ];
+        bind_vertex_attrib(&ctx, position_index, 3, &positions);
+        
+        // set up a repainting routine
+        let (_, start_animation_loop, _) = create_raf(move || {
+            // get the time step
+            let time = performance.now();
+            let time_step = 0.001*(time - last_time);
+            last_time = time;
+            
+            // get the navigation state
+            let pitch_up_val = pitch_up.get();
+            let pitch_down_val = pitch_down.get();
+            let yaw_right_val = yaw_right.get();
+            let yaw_left_val = yaw_left.get();
+            let roll_ccw_val = roll_ccw.get();
+            let roll_cw_val = roll_cw.get();
+            let zoom_in_val = zoom_in.get();
+            let zoom_out_val = zoom_out.get();
+            let turntable_val = turntable.get(); /* BENCHMARKING */
+            
+            // get the manipulation state
+            let translate_neg_x_val = translate_neg_x.get();
+            let translate_pos_x_val = translate_pos_x.get();
+            let translate_neg_y_val = translate_neg_y.get();
+            let translate_pos_y_val = translate_pos_y.get();
+            let translate_neg_z_val = translate_neg_z.get();
+            let translate_pos_z_val = translate_pos_z.get();
+            let shrink_neg_val = shrink_neg.get();
+            let shrink_pos_val = shrink_pos.get();
+            
+            // update the assembly's orientation
+            let ang_vel = {
+                let pitch = pitch_up_val - pitch_down_val;
+                let yaw = yaw_right_val - yaw_left_val;
+                let roll = roll_ccw_val - roll_cw_val;
+                if pitch != 0.0 || yaw != 0.0 || roll != 0.0 {
+                    ROT_SPEED * Vector3::new(-pitch, yaw, roll).normalize()
+                } else {
+                    Vector3::zeros()
+                }
+            } /* BENCHMARKING */ + if turntable_val {
+                Vector3::new(0.0, TURNTABLE_SPEED, 0.0)
+            } else {
+                Vector3::zeros()
+            };
+            let mut rotation_sp = rotation.fixed_view_mut::<3, 3>(0, 0);
+            rotation_sp.copy_from(
+                Rotation3::from_scaled_axis(time_step * ang_vel).matrix()
+            );
+            orientation = &rotation * &orientation;
+            
+            // update the assembly's location
+            let zoom = zoom_out_val - zoom_in_val;
+            location_z *= (time_step * ZOOM_SPEED * zoom).exp();
+            
+            // manipulate the assembly
+            if state.selection.with(|sel| sel.len() == 1) {
+                let sel = state.selection.with(
+                    |sel| *sel.into_iter().next().unwrap()
+                );
+                let translate_x = translate_pos_x_val - translate_neg_x_val;
+                let translate_y = translate_pos_y_val - translate_neg_y_val;
+                let translate_z = translate_pos_z_val - translate_neg_z_val;
+                let shrink = shrink_pos_val - shrink_neg_val;
+                let translating =
+                    translate_x != 0.0
+                    || translate_y != 0.0
+                    || translate_z != 0.0;
+                if translating || shrink != 0.0 {
+                    let elt_motion = {
+                        let u = if translating {
+                            TRANSLATION_SPEED * Vector3::new(
+                                translate_x, translate_y, translate_z
+                            ).normalize()
+                        } else {
+                            Vector3::zeros()
+                        };
+                        time_step * DVector::from_column_slice(
+                            &[u[0], u[1], u[2], SHRINKING_SPEED * shrink]
+                        )
+                    };
+                    assembly_for_raf.deform(
+                        vec![
+                            ElementMotion {
+                                key: sel,
+                                velocity: elt_motion.as_view()
+                            }
+                        ]
+                    );
+                    scene_changed.set(true);
+                }
+            }
+            
+            if scene_changed.get() {
+                /* INSTRUMENTS */
+                // measure mean frame interval
+                frames_since_last_sample += 1;
+                if frames_since_last_sample >= SAMPLE_PERIOD {
+                    mean_frame_interval.set((time - last_sample_time) / (SAMPLE_PERIOD as f64));
+                    last_sample_time = time;
+                    frames_since_last_sample = 0;
+                }
+                
+                // find the map from assembly space to world space
+                let location = {
+                    let u = -location_z;
+                    DMatrix::from_column_slice(5, 5, &[
+                        1.0, 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,   u,
+                        0.0, 0.0, 2.0*u, 1.0, u*u,
+                        0.0, 0.0,   0.0, 0.0, 1.0
+                    ])
+                };
+                let asm_to_world = &location * &orientation;
+                
+                // get the assembly
+                let (
+                    elt_cnt,
+                    reps_world,
+                    colors,
+                    highlights
+                ) = state.assembly.elements.with(|elts| {
+                    (
+                        // number of elements
+                        elts.len() as i32,
+                        
+                        // representation vectors in world coordinates
+                        elts.iter().map(
+                            |(_, elt)| elt.representation.with(|rep| &asm_to_world * rep)
+                        ).collect::<Vec<_>>(),
+                        
+                        // colors
+                        elts.iter().map(|(key, elt)| {
+                            if state.selection.with(|sel| sel.contains(&key)) {
+                                elt.color.map(|ch| 0.2 + 0.8*ch)
+                            } else {
+                                elt.color
+                            }
+                        }).collect::<Vec<_>>(),
+                        
+                        // highlight levels
+                        elts.iter().map(|(key, _)| {
+                            if state.selection.with(|sel| sel.contains(&key)) {
+                                1.0_f32
+                            } else {
+                                HIGHLIGHT
+                            }
+                        }).collect::<Vec<_>>()
+                    )
+                });
+                
+                // set the resolution
+                let width = canvas.width() as f32;
+                let height = canvas.height() as f32;
+                ctx.uniform2f(resolution_loc.as_ref(), width, height);
+                ctx.uniform1f(shortdim_loc.as_ref(), width.min(height));
+                
+                // pass the assembly
+                ctx.uniform1i(sphere_cnt_loc.as_ref(), elt_cnt);
+                for n in 0..reps_world.len() {
+                    let v = &reps_world[n];
+                    ctx.uniform3f(
+                        sphere_sp_locs[n].as_ref(),
+                        v[0] as f32, v[1] as f32, v[2] as f32
+                    );
+                    ctx.uniform2f(
+                        sphere_lt_locs[n].as_ref(),
+                        v[3] as f32, v[4] as f32
+                    );
+                    ctx.uniform3fv_with_f32_array(
+                        color_locs[n].as_ref(),
+                        &colors[n]
+                    );
+                    ctx.uniform1f(
+                        highlight_locs[n].as_ref(),
+                        highlights[n]
+                    );
+                }
+                
+                // pass the display parameters
+                ctx.uniform1f(opacity_loc.as_ref(), OPACITY);
+                ctx.uniform1i(layer_threshold_loc.as_ref(), LAYER_THRESHOLD);
+                ctx.uniform1i(debug_mode_loc.as_ref(), DEBUG_MODE);
+                
+                // draw the scene
+                ctx.draw_arrays(WebGl2RenderingContext::TRIANGLES, 0, VERTEX_CNT as i32);
+                
+                // update the viewpoint
+                assembly_to_world.set(asm_to_world);
+                
+                // clear the scene change flag
+                scene_changed.set(
+                    pitch_up_val != 0.0
+                    || pitch_down_val != 0.0
+                    || yaw_left_val != 0.0
+                    || yaw_right_val != 0.0
+                    || roll_cw_val != 0.0
+                    || roll_ccw_val != 0.0
+                    || zoom_in_val != 0.0
+                    || zoom_out_val != 0.0
+                    || turntable_val /* BENCHMARKING */
+                );
+            } else {
+                frames_since_last_sample = 0;
+                mean_frame_interval.set(-1.0);
+            }
+        });
+        start_animation_loop();
+    });
+    
+    let set_nav_signal = move |event: &KeyboardEvent, value: f64| {
+        let mut navigating = true;
+        let shift = event.shift_key();
+        match event.key().as_str() {
+            "ArrowUp" if shift => zoom_in.set(value),
+            "ArrowDown" if shift => zoom_out.set(value),
+            "ArrowUp" => pitch_up.set(value),
+            "ArrowDown" => pitch_down.set(value),
+            "ArrowRight" if shift => roll_cw.set(value),
+            "ArrowLeft" if shift => roll_ccw.set(value),
+            "ArrowRight" => yaw_right.set(value),
+            "ArrowLeft" => yaw_left.set(value),
+            _ => navigating = false
+        };
+        if navigating {
+            scene_changed.set(true);
+            event.prevent_default();
+        }
+    };
+    
+    let set_manip_signal = move |event: &KeyboardEvent, value: f64| {
+        let mut manipulating = true;
+        let shift = event.shift_key();
+        match event.key().as_str() {
+            "d" | "D" => translate_pos_x.set(value),
+            "a" | "A" => translate_neg_x.set(value),
+            "w" | "W" if shift => translate_neg_z.set(value),
+            "s" | "S" if shift => translate_pos_z.set(value),
+            "w" | "W" => translate_pos_y.set(value),
+            "s" | "S" => translate_neg_y.set(value),
+            "]" | "}" => shrink_neg.set(value),
+            "[" | "{" => shrink_pos.set(value),
+            _ => manipulating = false
+        };
+        if manipulating {
+            event.prevent_default();
+        }
+    };
+    
+    view! {
+        /* TO DO */
+        // switch back to integer-valued parameters when that becomes possible
+        // again
+        canvas(
+            ref=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());
+                    roll_ccw.set(yaw_left.get());
+                    zoom_in.set(pitch_up.get());
+                    zoom_out.set(pitch_down.get());
+                    yaw_right.set(0.0);
+                    yaw_left.set(0.0);
+                    pitch_up.set(0.0);
+                    pitch_down.set(0.0);
+                    
+                    // swap manipulation inputs
+                    translate_pos_z.set(translate_neg_y.get());
+                    translate_neg_z.set(translate_pos_y.get());
+                    translate_pos_y.set(0.0);
+                    translate_neg_y.set(0.0);
+                } else {
+                    if event.key() == "Enter" { /* BENCHMARKING */
+                        turntable.set_fn(|turn| !turn);
+                        scene_changed.set(true);
+                    }
+                    set_nav_signal(&event, 1.0);
+                    set_manip_signal(&event, 1.0);
+                }
+            },
+            on:keyup=move |event: KeyboardEvent| {
+                if event.key() == "Shift" {
+                    // swap navigation inputs
+                    yaw_right.set(roll_cw.get());
+                    yaw_left.set(roll_ccw.get());
+                    pitch_up.set(zoom_in.get());
+                    pitch_down.set(zoom_out.get());
+                    roll_cw.set(0.0);
+                    roll_ccw.set(0.0);
+                    zoom_in.set(0.0);
+                    zoom_out.set(0.0);
+                    
+                    // swap manipulation inputs
+                    translate_pos_y.set(translate_neg_z.get());
+                    translate_neg_y.set(translate_pos_z.get());
+                    translate_pos_z.set(0.0);
+                    translate_neg_z.set(0.0);
+                } else {
+                    set_nav_signal(&event, 0.0);
+                    set_manip_signal(&event, 0.0);
+                }
+            },
+            on:blur=move |_| {
+                pitch_up.set(0.0);
+                pitch_down.set(0.0);
+                yaw_right.set(0.0);
+                yaw_left.set(0.0);
+                roll_ccw.set(0.0);
+                roll_cw.set(0.0);
+            },
+            on:click=move |event: MouseEvent| {
+                // find the nearest element along the pointer direction
+                let dir = event_dir(&event);
+                console::log_1(&JsValue::from(dir.to_string()));
+                let mut clicked: Option<(ElementKey, f64)> = None;
+                for (key, elt) in state.assembly.elements.get_clone_untracked() {
+                    match assembly_to_world.with(|asm_to_world| elt.cast(dir, asm_to_world)) {
+                        Some(depth) => match clicked {
+                            Some((_, best_depth)) => {
+                                if depth < best_depth {
+                                    clicked = Some((key, depth))
+                                }
+                            },
+                            None => clicked = Some((key, depth))
+                        }
+                        None => ()
+                    };
+                }
+                
+                // if we clicked something, select it
+                match clicked {
+                    Some((key, _)) => state.select(key, event.shift_key()),
+                    None => state.selection.update(|sel| sel.clear())
+                };
+            }
+        )
+    }
+}
--- a/app-proto/src/engine.rs
+++ b/app-proto/src/engine.rs
@ -1,9 +1,10 @@
 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 ---

+#[cfg(feature = "dev")]
 pub fn point(x: f64, y: f64, z: f64) -> DVector<f64> {
    DVector::from_column_slice(&[x, y, z, 0.5, 0.5*(x*x + y*y + z*z)])
 }
@ -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)
    ])
 }

@ -30,42 +31,27 @@ 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)
    ])
 }

-// project a sphere's representation vector to the normalization variety by
-// contracting toward the last coordinate axis
-pub fn project_sphere_to_normalized(rep: &mut DVector<f64>) {
-    let q_sp = rep.fixed_rows::<3>(0).norm_squared();
-    let half_q_lt = -2.0 * rep[3] * rep[4];
-    let half_q_lt_sq = half_q_lt * half_q_lt;
-    let scaling = half_q_lt + (q_sp + half_q_lt_sq).sqrt();
-    rep.fixed_rows_mut::<4>(0).scale_mut(1.0 / scaling);
-}
-
-// normalize a point's representation vector by scaling
-pub fn project_point_to_normalized(rep: &mut DVector<f64>) {
-    rep.scale_mut(0.5 / rep[3]);
-}
-
 // --- partial matrices ---

 pub struct MatrixEntry {
    index: (usize, usize),
-    value: f64,
+    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) {
@ -75,6 +61,15 @@ impl PartialMatrix {
        }
    }
    
+    /* DEBUG */
+    pub fn log_to_console(&self) {
+        for &MatrixEntry { index: (row, col), value } in self {
+            console::log_1(&JsValue::from(
+                format!("  {} {} {}", row, col, value)
+            ));
+        }
+    }
+    
    fn freeze(&self, a: &DMatrix<f64>) -> DMatrix<f64> {
        let mut result = a.clone();
        for &MatrixEntry { index, value } in self {
@ -100,21 +95,12 @@ impl PartialMatrix {
    }
 }

-impl Display for PartialMatrix {
-    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
-        for &MatrixEntry { index: (row, col), value } in self {
-            writeln!(f, "  {row} {col} {value}")?;
-        }
-        Ok(())
-    }
-}
-
 impl IntoIterator for PartialMatrix {
    type Item = MatrixEntry;
    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 +121,22 @@ 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 +150,20 @@ 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 +173,7 @@ impl ConfigSubspace {
                |v| Into::<DMatrix<f64>>::into(
                    v.reshape_generic(Dyn(UNIFORM_DIM), Dyn(assembly_dim))
                )
-            ).collect(),
+            ).collect()
        }
    }
    
@ -218,18 +207,18 @@ 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 min_eigval: Vec<f64>,
    pub base_step: Vec<DMatrix<f64>>,
-    pub backoff_steps: Vec<i32>,
+    pub backoff_steps: Vec<i32>
 }

 impl DescentHistory {
-    pub fn new() -> Self {
-        Self {
+    fn new() -> DescentHistory {
+        DescentHistory {
            config: Vec::<DMatrix<f64>>::new(),
            scaled_loss: Vec::<f64>::new(),
            neg_grad: Vec::<DMatrix<f64>>::new(),
-            hess_eigvals: Vec::<DVector<f64>>::new(),
+            min_eigval: Vec::<f64>::new(),
            base_step: Vec::<DMatrix<f64>>::new(),
            backoff_steps: Vec::<i32>::new(),
        }
@ -245,21 +234,21 @@ 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 +262,25 @@ 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 +307,7 @@ 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 +316,7 @@ 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 +329,7 @@ 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 {
@ -351,17 +344,6 @@ fn seek_better_config(
    None
 }

-// a first-order neighborhood of a configuration
-pub struct ConfigNeighborhood {
-    pub config: DMatrix<f64>,
-    pub nbhd: ConfigSubspace,
-}
-
-pub struct Realization {
-    pub result: Result<ConfigNeighborhood, String>,
-    pub history: DescentHistory,
-}
-
 // seek a matrix `config` that matches the partial matrix `problem.frozen` and
 // has `config' * Q * config` matching the partial matrix `problem.gram`. start
 // at `problem.guess`, set the frozen entries to their desired values, and then
@ -373,30 +355,19 @@ pub fn realize_gram(
    backoff: f64,
    reg_scale: f64,
    max_descent_steps: i32,
-    max_backoff_steps: i32,
-) -> Realization {
+    max_backoff_steps: i32
+) -> (DMatrix<f64>, ConfigSubspace, bool, DescentHistory) {
    // 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 {
-                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
@ -437,12 +408,11 @@ pub fn realize_gram(
        hess = DMatrix::from_columns(hess_cols.as_slice());
        
        // regularize the Hessian
-        let hess_eigvals = hess.symmetric_eigenvalues();
-        let min_eigval = hess_eigvals.min();
+        let min_eigval = hess.symmetric_eigenvalues().min();
        if min_eigval <= 0.0 {
            hess -= reg_scale * min_eigval * DMatrix::identity(total_dim, total_dim);
        }
-        history.hess_eigvals.push(hess_eigvals);
+        history.min_eigval.push(min_eigval);
        
        // project the negative gradient and negative Hessian onto the
        // orthogonal complement of the frozen subspace
@ -461,40 +431,30 @@ pub fn realize_gram(
        if state.loss < tol { break; }
        
        // compute the Newton step
-        /* TO DO */
        /*
-          we should change our regularization to ensure that the Hessian is
-          is positive-definite, rather than just positive-semidefinite. ideally,
-          that would guarantee the success of the Cholesky decomposition---
-          although we'd still need the error-handling routine in case of
-          numerical hiccups
+          we need to either handle or eliminate the case where the minimum
+          eigenvalue of the Hessian is zero, so the regularized Hessian is
+          singular. right now, this causes the Cholesky decomposition to return
+          `None`, leading to a panic when we unrap
        */
-        let hess_cholesky = match hess.clone().cholesky() {
-            Some(cholesky) => cholesky,
-            None => return Realization {
-                result: Err("Cholesky decomposition failed".to_string()),
-                history,
-            },
-        };
-        let base_step_stacked = hess_cholesky.solve(&neg_grad_stacked);
+        let base_step_stacked = hess.clone().cholesky().unwrap().solve(&neg_grad_stacked);
        let base_step = base_step_stacked.reshape_generic(Dyn(element_dim), Dyn(assembly_dim));
        history.base_step.push(base_step.clone());
        
        // use backtracking line search to find a better configuration
-        if let Some((better_state, backoff_steps)) = seek_better_config(
+        match 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,
-            };
-        }
+            Some((better_state, backoff_steps)) => {
+                state = better_state;
+                history.backoff_steps.push(backoff_steps);
+            },
+            None => return (state.config, ConfigSubspace::zero(assembly_dim), false, history)
+        };
    }
-    let result = if state.loss < tol {
+    let success = state.loss < tol;
+    let tangent = if success {
        // express the uniform basis in the standard basis
        const UNIFORM_DIM: usize = 4;
        let total_dim_unif = UNIFORM_DIM * assembly_dim;
@ -507,13 +467,11 @@ 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 { config: state.config, nbhd: tangent })
+        ConfigSubspace::symmetric_kernel(hess, unif_to_std, assembly_dim)
    } else {
-        Err("Failed to reach target accuracy".to_string())
+        ConfigSubspace::zero(assembly_dim)
    };
-    Realization { result, history }
+    (state.config, tangent, success, history)
 }

 // --- tests ---
@ -532,12 +490,12 @@ pub mod examples {
    //   "Japan's 'Wasan' Mathematical Tradition", by Abe Haruki
    //   https://www.nippon.com/en/japan-topics/c12801/
    //
-    pub fn realize_irisawa_hexlet(scaled_tol: f64) -> Realization {
+    pub fn realize_irisawa_hexlet(scaled_tol: f64) -> (DMatrix<f64>, ConfigSubspace, bool, DescentHistory) {
        let mut problem = ConstraintProblem::from_guess(
            [
                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| {
@ -583,7 +541,7 @@ pub mod examples {
    
    // set up a kaleidocycle, made of points with fixed distances between them,
    // and find its tangent space
-    pub fn realize_kaleidocycle(scaled_tol: f64) -> Realization {
+    pub fn realize_kaleidocycle(scaled_tol: f64) -> (DMatrix<f64>, ConfigSubspace, bool, DescentHistory) {
        const N_HINGES: usize = 6;
        let mut problem = ConstraintProblem::from_guess(
            (0..N_HINGES).step_by(2).flat_map(
@ -596,7 +554,7 @@ 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 +597,15 @@ 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 +616,15 @@ 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 +642,7 @@ 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 +656,7 @@ 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 {
@ -707,10 +665,10 @@ mod tests {
        }
        problem.frozen.push(3, 0, problem.guess[(3, 0)]);
        problem.frozen.push(3, 1, 0.5);
-        let Realization { result, history } = realize_gram(
+        let (config, _, success, history) = realize_gram(
            &problem, 1.0e-12, 0.5, 0.9, 1.1, 200, 110
        );
-        let config = result.unwrap().config;
+        assert_eq!(success, true);
        for base_step in history.base_step.into_iter() {
            for &MatrixEntry { index, .. } in &problem.frozen {
                assert_eq!(base_step[index], 0.0);
@ -725,7 +683,7 @@ mod tests {
    fn irisawa_hexlet_test() {
        // solve Irisawa's problem
        const SCALED_TOL: f64 = 1.0e-12;
-        let config = realize_irisawa_hexlet(SCALED_TOL).result.unwrap().config;
+        let (config, _, _, _) = realize_irisawa_hexlet(SCALED_TOL);
        
        // check against Irisawa's solution
        let entry_tol = SCALED_TOL.sqrt();
@ -742,7 +700,7 @@ 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 {
@ -752,11 +710,11 @@ mod tests {
        for n in 0..ELEMENT_DIM {
            problem.frozen.push(n, 0, problem.guess[(n, 0)]);
        }
-        let Realization { result, history } = realize_gram(
+        let (config, tangent, success, history) = realize_gram(
            &problem, SCALED_TOL, 0.5, 0.9, 1.1, 200, 110
        );
-        let ConfigNeighborhood { config, nbhd: tangent } = result.unwrap();
        assert_eq!(config, problem.guess);
+        assert_eq!(success, true);
        assert_eq!(history.scaled_loss.len(), 1);
        
        // list some motions that should form a basis for the tangent space of
@ -772,8 +730,8 @@ 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 +741,8 @@ 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
@ -824,8 +782,8 @@ mod tests {
    fn tangent_test_kaleidocycle() {
        // set up a kaleidocycle and find its tangent space
        const SCALED_TOL: f64 = 1.0e-12;
-        let Realization { result, history } = realize_kaleidocycle(SCALED_TOL);
-        let ConfigNeighborhood { config, nbhd: tangent } = result.unwrap();
+        let (config, tangent, success, history) = realize_kaleidocycle(SCALED_TOL);
+        assert_eq!(success, true);
        assert_eq!(history.scaled_loss.len(), 1);
        
        // list some motions that should form a basis for the tangent space of
@ -860,10 +818,10 @@ 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 +854,7 @@ 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
        ])
    }
    
@ -908,16 +866,16 @@ 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);
        problem_orig.gram.push_sym(0, 1, 0.5);
-        let Realization { result: result_orig, history: history_orig } = realize_gram(
+        let (config_orig, tangent_orig, success_orig, history_orig) = realize_gram(
            &problem_orig, SCALED_TOL, 0.5, 0.9, 1.1, 200, 110
        );
-        let ConfigNeighborhood { config: config_orig, nbhd: tangent_orig } = result_orig.unwrap();
        assert_eq!(config_orig, problem_orig.guess);
+        assert_eq!(success_orig, true);
        assert_eq!(history_orig.scaled_loss.len(), 1);
        
        // find another pair of spheres that meet at 120°. we'll think of this
@ -926,19 +884,19 @@ 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(
+        let (config_tfm, tangent_tfm, success_tfm, history_tfm) = realize_gram(
            &problem_tfm, SCALED_TOL, 0.5, 0.9, 1.1, 200, 110
        );
-        let ConfigNeighborhood { config: config_tfm, nbhd: tangent_tfm } = result_tfm.unwrap();
        assert_eq!(config_tfm, problem_tfm.guess);
+        assert_eq!(success_tfm, true);
        assert_eq!(history_tfm.scaled_loss.len(), 1);
        
        // project a nudge to the tangent space of the solution variety at the
@ -960,7 +918,7 @@ 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;
--- a/app-proto/src/components/identity.vert
+++ b/app-proto/src/components/identity.vert
--- a/app-proto/src/components/spheres.frag
+++ b/app-proto/src/components/spheres.frag
@ -17,7 +17,7 @@ struct vecInv {
 const int SPHERE_MAX = 200;
 uniform int sphere_cnt;
 uniform vecInv sphere_list[SPHERE_MAX];
-uniform vec4 color_list[SPHERE_MAX];
+uniform vec3 color_list[SPHERE_MAX];
 uniform float highlight_list[SPHERE_MAX];

 // view
@ -25,6 +25,7 @@ uniform vec2 resolution;
 uniform float shortdim;

 // controls
+uniform float opacity;
 uniform int layer_threshold;
 uniform bool debug_mode;

@ -68,7 +69,7 @@ struct Fragment {
    vec4 color;
 };

-Fragment sphere_shading(vecInv v, vec3 pt, vec4 base_color) {
+Fragment sphere_shading(vecInv v, vec3 pt, vec3 base_color) {
    // the expression for normal needs to be checked. it's supposed to give the
    // negative gradient of the lorentz product between the impact point vector
    // and the sphere vector with respect to the coordinates of the impact
@ -78,7 +79,7 @@ Fragment sphere_shading(vecInv v, vec3 pt, vec4 base_color) {
    
    float incidence = dot(normal, light_dir);
    float illum = mix(0.4, 1.0, max(incidence, 0.0));
-    return Fragment(pt, normal, vec4(illum * base_color.rgb, base_color.a));
+    return Fragment(pt, normal, vec4(illum * base_color, opacity));
 }

 float intersection_dist(Fragment a, Fragment b) {
@ -191,11 +192,10 @@ void main() {
    vec3 color = vec3(0.);
    int layer = layer_cnt - 1;
    TaggedDepth hit = top_hits[layer];
-    vec4 sphere_color = color_list[hit.id];
    Fragment frag_next = sphere_shading(
        sphere_list[hit.id],
        hit.depth * dir,
-        vec4(hit.dimming * sphere_color.rgb, sphere_color.a)
+        hit.dimming * color_list[hit.id]
    );
    float highlight_next = highlight_list[hit.id];
    --layer;
@ -206,11 +206,10 @@ void main() {
        
        // shade the next fragment
        hit = top_hits[layer];
-        sphere_color = color_list[hit.id];
        frag_next = sphere_shading(
            sphere_list[hit.id],
            hit.depth * dir,
-            vec4(hit.dimming * sphere_color.rgb, sphere_color.a)
+            hit.dimming * color_list[hit.id]
        );
        highlight_next = highlight_list[hit.id];
        
--- a/app-proto/src/main.rs
+++ b/app-proto/src/main.rs
@ -1,49 +1,46 @@
+mod add_remove;
 mod assembly;
-mod components;
+mod display;
 mod engine;
+mod outline;
 mod specified;

-#[cfg(test)]
-mod tests;
-
-use std::{collections::BTreeSet, rc::Rc};
+use rustc_hash::FxHashSet;
 use sycamore::prelude::*;

-use assembly::{Assembly, Element};
-use components::{
-    add_remove::AddRemove,
-    diagnostics::Diagnostics,
-    display::Display,
-    outline::Outline,
-};
+use add_remove::AddRemove;
+use assembly::{Assembly, ElementKey};
+use display::Display;
+use outline::Outline;

 #[derive(Clone)]
 struct AppState {
    assembly: Assembly,
-    selection: Signal<BTreeSet<Rc<dyn Element>>>,
+    selection: Signal<FxHashSet<ElementKey>>
 }

 impl AppState {
-    fn new() -> Self {
-        Self {
+    fn new() -> AppState {
+        AppState {
            assembly: Assembly::new(),
-            selection: create_signal(BTreeSet::default()),
+            selection: create_signal(FxHashSet::default())
        }
    }
    
-    // in single-selection mode, select the given element. in multiple-selection
-    // mode, toggle whether the given element is selected
-    fn select(&self, element: &Rc<dyn Element>, multi: bool) {
+    // in single-selection mode, select the element with the given key. in
+    // multiple-selection mode, toggle whether the element with the given key
+    // is selected
+    fn select(&self, key: ElementKey, multi: bool) {
        if multi {
            self.selection.update(|sel| {
-                if !sel.remove(element) {
-                    sel.insert(element.clone());
+                if !sel.remove(&key) {
+                    sel.insert(key);
                }
            });
        } else {
            self.selection.update(|sel| {
                sel.clear();
-                sel.insert(element.clone());
+                sel.insert(key);
            });
        }
    }
@ -58,10 +55,9 @@ fn main() {
        provide_context(AppState::new());
        
        view! {
-            div(id = "sidebar") {
+            div(id="sidebar") {
                AddRemove {}
                Outline {}
-                Diagnostics {}
            }
            Display {}
        }
--- a/app-proto/src/components/outline.rs
+++ b/app-proto/src/components/outline.rs
@ -1,15 +1,21 @@
 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,
+    assembly,
    assembly::{
-        Element,
+        ElementKey,
        HalfCurvatureRegulator,
-        InversiveDistanceRegulator,
+        ProductRegulator,
        Regulator,
+        RegulatorKey
    },
    specified::SpecifiedValue
 };
@ -45,8 +51,8 @@ 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() {
@ -59,80 +65,90 @@ 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(),
-                        _ => (),
+                        _ => ()
                    }
                }
-            },
+            }
        )
    }
 }

 pub trait OutlineItem {
-    fn outline_item(self: Rc<Self>, element: &Rc<dyn Element>) -> View;
+    fn outline_item(self: Rc<Self>, element_key: ElementKey) -> View;
 }

-impl OutlineItem for InversiveDistanceRegulator {
-    fn outline_item(self: Rc<Self>, element: &Rc<dyn Element>) -> View {
-        let other_subject_label = if self.subjects[0] == element.clone() {
-            self.subjects[1].label()
+impl OutlineItem for ProductRegulator {
+    fn outline_item(self: Rc<Self>, element_key: ElementKey) -> View {
+        let state = use_context::<AppState>();
+        let other_subject = if self.subjects[0] == element_key {
+            self.subjects[1]
        } else {
-            self.subjects[0].label()
-        }.clone();
+            self.subjects[0]
+        };
+        let other_subject_label = state.assembly.elements.with(
+            |elts| elts[other_subject].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")
            }
        }
    }
 }

 impl OutlineItem for HalfCurvatureRegulator {
-    fn outline_item(self: Rc<Self>, _element: &Rc<dyn Element>) -> View {
+    fn outline_item(self: Rc<Self>, _element_key: ElementKey) -> View {
        view! {
-            li(class = "regulator") {
-                div(class = "regulator-label") // for spacing
-                div(class = "regulator-type") { "Half-curvature" }
-                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")
            }
        }
    }
 }

+// a list item that shows a regulator in an outline view of an element
+#[component(inline_props)]
+fn RegulatorOutlineItem(regulator_key: RegulatorKey, element_key: ElementKey) -> View {
+    let state = use_context::<AppState>();
+    let regulator = state.assembly.regulators.with(
+        |regs| regs[regulator_key].clone()
+    );
+    regulator.outline_item(element_key)
+}
+
 // a list item that shows an element in an outline view of an assembly
 #[component(inline_props)]
-fn ElementOutlineItem(element: Rc<dyn Element>) -> View {
+fn ElementOutlineItem(key: ElementKey, element: assembly::Element) -> View {
    let state = use_context::<AppState>();
-    let class = {
-        let element_for_class = element.clone();
-        state.selection.map(
-            move |sel| if sel.contains(&element_for_class) { "selected" } else { "" }
-        )
-    };
-    let label = element.label().clone();
-    let representation = element.representation().clone();
+    let class = state.selection.map(
+        move |sel| if sel.contains(&key) { "selected" } else { "" }
+    );
+    let label = element.label.clone();
    let rep_components = move || {
-        representation.with(
+        element.representation.with(
            |rep| rep.iter().map(
                |u| {
                    let u_str = format!("{:.3}", u).replace("-", "\u{2212}");
@ -141,26 +157,29 @@ fn ElementOutlineItem(element: Rc<dyn Element>) -> View {
            ).collect::<Vec<_>>()
        )
    };
-    let regulated = element.regulators().map(|regs| regs.len() > 0);
-    let regulator_list = element.regulators().map(
-        |regs| regs
+    let regulated = element.regulators.map(|regs| regs.len() > 0);
+    let regulator_list = element.regulators.map(
+        move |elt_reg_keys| elt_reg_keys
            .clone()
            .into_iter()
-            .sorted_by_key(|reg| reg.subjects().len())
-            .collect::<Vec<_>>()
+            .sorted_by_key(
+                |&reg_key| state.assembly.regulators.with(
+                    |regs| regs[reg_key].subjects().len()
+                )
+            )
+            .collect()
    );
    let details_node = create_node_ref();
    view! {
        li {
-            details(ref = details_node) {
+            details(ref=details_node) {
                summary(
-                    class = class.get(),
-                    on:keydown = {
-                        let element_for_handler = element.clone();
+                    class=class.get(),
+                    on:keydown={
                        move |event: KeyboardEvent| {
                            match event.key().as_str() {
                                "Enter" => {
-                                    state.select(&element_for_handler, event.shift_key());
+                                    state.select(key, event.shift_key());
                                    event.prevent_default();
                                },
                                "ArrowRight" if regulated.get() => {
@ -175,41 +194,51 @@ 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 = {
-                            let state_for_handler = state.clone();
-                            let element_for_handler = element.clone();
+                        class="element",
+                        on:click={
                            move |event: MouseEvent| {
-                                state_for_handler.select(&element_for_handler, event.shift_key());
+                                if event.shift_key() {
+                                    state.selection.update(|sel| {
+                                        if !sel.remove(&key) {
+                                            sel.insert(key);
+                                        }
+                                    });
+                                } else {
+                                    state.selection.update(|sel| {
+                                        sel.clear();
+                                        sel.insert(key);
+                                    });
+                                }
                                event.stop_propagation();
                                event.prevent_default();
                            }
                        }
                    ) {
-                        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()
-                        )
+                        div(class="element-label") { (label) }
+                        div(class="element-representation") { (rep_components) }
+                        div(class="status")
                    }
                }
-                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_key| view! {
+                            RegulatorOutlineItem(
+                                regulator_key=reg_key,
+                                element_key=key
+                            )
+                        },
+                        key=|reg_key| reg_key.clone()
                    )
                }
            }
@ -228,32 +257,28 @@ pub fn Outline() -> View {
    let state = use_context::<AppState>();
    
    // list the elements alphabetically by ID
-    /* TO DO */
-    // this code is designed to generalize easily to other sort keys. if we only
-    // ever wanted to sort by ID, we could do that more simply using the
-    // `elements_by_id` index
    let element_list = state.assembly.elements.map(
        |elts| elts
            .clone()
            .into_iter()
-            .sorted_by_key(|elt| elt.id().clone())
-            .collect::<Vec<_>>()
+            .sorted_by_key(|(_, elt)| elt.id.clone())
+            .collect()
    );
    
    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=|(key, elt)| view! {
+                    ElementOutlineItem(key=key, element=elt)
                },
-                key = |elt| elt.serial()
+                key=|(_, elt)| elt.serial
            )
        }
    }
--- a/app-proto/src/specified.rs
+++ b/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 {
@ -34,10 +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) }
            )
        }
    }
--- a/app-proto/src/tests.rs
+++ b/app-proto/src/tests.rs
@ -1,14 +0,0 @@
-use std::process::Command;
-
-// build and bundle the application, reporting success if there are no errors or
-// warnings. to see this test fail while others succeed, try moving `index.html`
-// or one of the assets that it links to
-#[test]
-fn trunk_build_test() {
-    let build_status = Command::new("trunk")
-        .arg("build")
-        .env("RUSTFLAGS", "-D warnings")
-        .status()
-        .expect("Call to Trunk failed");
-    assert!(build_status.success());
-}
--- a/deploy/.gitignore
+++ b/deploy/.gitignore
@ -1,5 +0,0 @@
-/dyna3.zip
-/dyna3/index.html
-/dyna3/dyna3-*.js
-/dyna3/dyna3-*.wasm
-/dyna3/main-*.css
--- a/tools/package-for-deployment.sh
+++ b/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/." "$DEST"
--- a/tools/run-examples.sh
+++ b/tools/run-examples.sh
@ -1,20 +0,0 @@
-# run all Cargo examples, as described here:
-#
-#   Karol Kuczmarski. "Add examples to your Rust libraries"
-#   http://xion.io/post/code/rust-examples.html
-#
-# you should invoke this script by calling `sh` or another interpreter, rather
-# than calling `souce`, to ensure that the script can find the manifest file for
-# the application prototype
-
-# find the manifest file for the application prototype
-MANIFEST="$(dirname -- $0)/../app-proto/Cargo.toml"
-
-# set up the command that runs each example
-RUN_EXAMPLE="cargo run --manifest-path $MANIFEST --example"
-
-# run the examples
-$RUN_EXAMPLE irisawa-hexlet; echo
-$RUN_EXAMPLE three-spheres; echo
-$RUN_EXAMPLE point-on-sphere; echo
-$RUN_EXAMPLE kaleidocycle
Author	SHA1	Message	Date
Aaron Fenyes	47cc559cd6	Add a half-curvature regulator In the process, add the `OutlineItem` trait so that each regulator can implement its own outline item view.	2025-04-01 22:23:08 -07:00
Aaron Fenyes	b117c00992	Specify the values of the frozen entries Before, a `ConstraintProblem` only specified the indices of the frozen entries. During realization, the frozen entries kept whatever values they had in the initial guess. This commit adds the values of the frozen entries to the `frozen` field of `ConstraintProblem`. The frozen entries of the guess are set to the desired values at the beginning of realization. This commit also improves the `PartialMatrix` structure, which is used to specify the indices and values of the frozen entries.	2025-03-27 13:57:46 -07:00
Aaron Fenyes	ca9de34427	Interpolate sphere ID and label, as intended Thanks, Clippy!	2025-03-27 02:56:46 -07:00
Aaron Fenyes	25f446499b	Introduce a regulator trait This will provide a common interface for Lorentz product regulators, curvature regulators, and hopefully all the other regulators too.	2025-03-27 00:29:27 -07:00
Aaron Fenyes	f1f87e97be	Store a product regulator's subjects in an array This lets us iterate over subjects. Based on commit 257ce33, with a few updates from 4a9e777.	2025-03-26 23:50:40 -07:00
Aaron Fenyes	677d770738	Let the elements and regulators write the problem When we realize an assembly, each element and regulator now writes its own data into the constraint problem.	2025-03-25 02:15:03 -07:00
Aaron Fenyes	c6e6e7be9f	Encapsulate the constraint problem data This will make it easier for elements and regulators to write themselves into the constraint problem.	2025-03-24 23:21:55 -04:00
Aaron Fenyes	d243f19e25	Start tracking `Cargo.lock`	2025-03-12 15:44:43 -07:00