Struct Simulation 

pub struct Simulation { /* private fields */ }

Public force simulation handle. Owns positions, velocities, edges, and a scratch quadtree that gets rebuilt every tick.

In 2D mode (config.dimensions == 2, the default) only the positions/velocities/forces vectors and the tree quadtree are used. In 3D mode the parallel positions_3d/velocities_3d/ forces_3d vectors are populated alongside an oct_tree octree, and positions mirrors the x/y pair of each 3D position so the positions() accessor stays zero-copy for the common 2D readers.

Implementations

impl Simulation

pub fn new(n_nodes: u32, config: SimulationConfig) -> Self

Build a simulation with n_nodes nodes. Initial positions are scattered uniformly inside a circle of radius sqrt(n) * 10 using a deterministic ChaCha8 RNG seeded from config.seed.

When config.dimensions == 3, the 3D positions_3d field is also populated with points scattered inside a ball of the same radius; the 2D positions field mirrors the x/y slice of each 3D point so consumers of the 2D accessor continue to see a sensible layout.

pub fn set_edges(&mut self, edges: &[(u32, u32, f32)])

Replace the edge set. Each edge is (src, dst, weight). Out-of-range or self-loop indices are silently dropped — callers who care should validate upstream.

pub fn node_count(&self) -> usize

Number of nodes in the simulation.

pub fn positions(&self) -> &[Vec2]

Borrow positions as a flat &[Vec2] for zero-copy consumption by downstream bindings.

pub fn positions_3d(&self) -> &[Vec3]

Borrow 3D positions as a flat &[Vec3]. Returns an empty slice when the simulation was constructed in 2D mode. Phase 224 Wave 2.

pub fn tick(&mut self, dt: f32)

Advance the simulation by one tick of size dt. Routes to the 3D octree pass when config.dimensions == 3, otherwise runs the 2D quadtree path.