dyna3/app-proto/src/assembly.rs
2024-11-21 16:42:43 -08:00

233 lines
8.1 KiB
Rust

use nalgebra::{DMatrix, DVector};
use rustc_hash::FxHashMap;
use slab::Slab;
use std::{collections::BTreeSet, sync::atomic::{AtomicU64, Ordering}};
use sycamore::prelude::*;
use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
use crate::engine::{realize_gram, PartialMatrix};
// the types of the keys we use to access an assembly's elements and constraints
pub type ElementKey = usize;
pub type ConstraintKey = usize;
pub type ElementColor = [f32; 3];
/* KLUDGE */
// we should reconsider this design when we build a system for switching between
// assemblies. at that point, we might want to switch to hierarchical keys,
// where each each element has a key that identifies it within its assembly and
// each assembly has a key that identifies it within the sesssion
static NEXT_ELEMENT_SERIAL: AtomicU64 = AtomicU64::new(0);
#[derive(Clone, PartialEq)]
pub struct Element {
pub id: String,
pub label: String,
pub color: ElementColor,
pub representation: Signal<DVector<f64>>,
pub constraints: Signal<BTreeSet<ConstraintKey>>,
// a serial number, assigned by `Element::new`, that uniquely identifies
// each element (until `NEXT_ELEMENT_SERIAL` wraps around)
pub serial: u64,
// the configuration matrix column index that was assigned to this element
// last time the assembly was realized
column_index: usize
}
impl Element {
pub fn new(
id: String,
label: String,
color: ElementColor,
representation: DVector<f64>
) -> Element {
// take the next serial number, panicking if that was the last number we
// had left. the technique we use to panic on overflow is taken from
// _Rust Atomics and Locks_, by Mara Bos
//
// https://marabos.nl/atomics/atomics.html#example-handle-overflow
//
let serial = NEXT_ELEMENT_SERIAL.fetch_update(
Ordering::SeqCst, Ordering::SeqCst,
|serial| serial.checked_add(1)
).expect("Out of serial numbers for elements");
Element {
id: id,
label: label,
color: color,
representation: create_signal(representation),
constraints: create_signal(BTreeSet::default()),
serial: serial,
column_index: 0
}
}
}
#[derive(Clone)]
pub struct Constraint {
pub subjects: (ElementKey, ElementKey),
pub lorentz_prod: Signal<f64>,
pub lorentz_prod_text: Signal<String>,
pub lorentz_prod_valid: Signal<bool>,
pub active: Signal<bool>
}
// a complete, view-independent description of an assembly
#[derive(Clone)]
pub struct Assembly {
// elements and constraints
pub elements: Signal<Slab<Element>>,
pub constraints: Signal<Slab<Constraint>>,
// indexing
pub elements_by_id: Signal<FxHashMap<String, ElementKey>>
}
impl Assembly {
pub fn new() -> Assembly {
Assembly {
elements: create_signal(Slab::new()),
constraints: create_signal(Slab::new()),
elements_by_id: create_signal(FxHashMap::default())
}
}
// --- inserting elements and constraints ---
// insert an element into the assembly without checking whether we already
// have an element with the same identifier. any element that does have the
// same identifier will get kicked out of the `elements_by_id` index
fn insert_element_unchecked(&self, elt: Element) {
let id = elt.id.clone();
let key = self.elements.update(|elts| elts.insert(elt));
self.elements_by_id.update(|elts_by_id| elts_by_id.insert(id, key));
}
pub fn try_insert_element(&self, elt: Element) -> bool {
let can_insert = self.elements_by_id.with_untracked(
|elts_by_id| !elts_by_id.contains_key(&elt.id)
);
if can_insert {
self.insert_element_unchecked(elt);
}
can_insert
}
pub fn insert_new_element(&self) {
// find the next unused identifier in the default sequence
let mut id_num = 1;
let mut id = format!("sphere{}", id_num);
while self.elements_by_id.with_untracked(
|elts_by_id| elts_by_id.contains_key(&id)
) {
id_num += 1;
id = format!("sphere{}", id_num);
}
// create and insert a new element
self.insert_element_unchecked(
Element::new(
id,
format!("Sphere {}", id_num),
[0.75_f32, 0.75_f32, 0.75_f32],
DVector::<f64>::from_column_slice(&[0.0, 0.0, 0.0, 0.5, -0.5])
)
);
}
pub fn insert_constraint(&self, constraint: Constraint) {
let subjects = constraint.subjects;
let key = self.constraints.update(|csts| csts.insert(constraint));
let subject_constraints = self.elements.with(
|elts| (elts[subjects.0].constraints, elts[subjects.1].constraints)
);
subject_constraints.0.update(|csts| csts.insert(key));
subject_constraints.1.update(|csts| csts.insert(key));
}
// --- realization ---
pub fn realize(&self) {
// index the elements
self.elements.update_silent(|elts| {
for (index, (_, elt)) in elts.into_iter().enumerate() {
elt.column_index = index;
}
});
// set up the Gram matrix and the initial configuration matrix
let (gram, guess) = self.elements.with_untracked(|elts| {
// set up the off-diagonal part of the Gram matrix
let mut gram_to_be = PartialMatrix::new();
self.constraints.with_untracked(|csts| {
for (_, cst) in csts {
if cst.active.get_untracked() && cst.lorentz_prod_valid.get_untracked() {
let subjects = cst.subjects;
let row = elts[subjects.0].column_index;
let col = elts[subjects.1].column_index;
gram_to_be.push_sym(row, col, cst.lorentz_prod.get_untracked());
}
}
});
// set up the initial configuration matrix and the diagonal of the
// Gram matrix
let mut guess_to_be = DMatrix::<f64>::zeros(5, elts.len());
for (_, elt) in elts {
let index = elt.column_index;
gram_to_be.push_sym(index, index, 1.0);
guess_to_be.set_column(index, &elt.representation.get_clone_untracked());
}
(gram_to_be, guess_to_be)
});
/* DEBUG */
// log the Gram matrix
console::log_1(&JsValue::from("Gram matrix:"));
gram.log_to_console();
/* DEBUG */
// log the initial configuration matrix
console::log_1(&JsValue::from("Old configuration:"));
for j in 0..guess.nrows() {
let mut row_str = String::new();
for k in 0..guess.ncols() {
row_str.push_str(format!(" {:>8.3}", guess[(j, k)]).as_str());
}
console::log_1(&JsValue::from(row_str));
}
// look for a configuration with the given Gram matrix
let (config, success, history) = realize_gram(
&gram, guess, &[],
1.0e-12, 0.5, 0.9, 1.1, 200, 110
);
/* DEBUG */
// report the outcome of the search
console::log_1(&JsValue::from(
if success {
"Target accuracy achieved!"
} else {
"Failed to reach target accuracy"
}
));
console::log_2(&JsValue::from("Steps:"), &JsValue::from(history.scaled_loss.len() - 1));
console::log_2(&JsValue::from("Loss:"), &JsValue::from(*history.scaled_loss.last().unwrap()));
if success {
// read out the solution
for (_, elt) in self.elements.get_clone_untracked() {
elt.representation.update(
|rep| rep.set_column(0, &config.column(elt.column_index))
);
}
}
}
}