Struct BHQuadtree 

pub struct BHQuadtree { /* private fields */ }

A Quadtree specially optimized for the Barnes-Hut algorithm

An interactive explanation of the algorithm can be found here

This quadtree is immutable and flat, not recursive. It is optimized to be rebuilt frequently and supports efficient accumulation of approximated force. Each step, convert your items into WeightedPoint and call the build method to clear and reconstruct the tree. Then for each item you need to accumulate force on, call the accumulate method, passing a custom force function.

This implementation is heavily inspired by DeadlockCode’s Barnes-Hut implementation

Implementations

impl BHQuadtree

pub fn new(node_capacity: usize, max_depth: usize, theta: f32) -> Self

Create a new empty BHQuadtree

Arguments

• node_capacity: The maximum number of items a node can hold before subdividing
• max_depth: The maximum depth of the tree at which nodes will ignore capacity
• theta: Theta parameter of Barnes-Hut algorithm

pub fn build(&mut self, items: Vec<WeightedPoint>)

Clear all internal data and reconstruct the tree from a sequence of weighted points

pub fn accumulate<F: Fn(WeightedPoint) -> Vec2>( &self, target: Vec2, force_fn: F, ) -> Vec2

Accumulate a force vector to act on a target position with an arbitrary force function, approximating weighted points based on the theta parameter.

Trait Implementations

impl Debug for BHQuadtree

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.