Struct InteractionMatrix 

pub struct InteractionMatrix { /* private fields */ }

Interaction matrix storing force relationships between particle types.

Each cell [self_type][other_type] contains:

• strength: positive = attract, negative = repel, zero = ignore
• radius: interaction range

Implementations

impl InteractionMatrix

pub fn new(num_types: usize) -> Self

Create a new interaction matrix for num_types particle types.

All interactions start as ignore (strength=0, radius=0).

pub fn set<T: Into<u32>, U: Into<u32>>( &mut self, self_type: T, other_type: U, strength: f32, radius: f32, )

Set the interaction when self_type encounters other_type.

• strength > 0: attraction (pulls toward)
• strength < 0: repulsion (pushes away)
• strength = 0: ignore
• radius: how far the interaction reaches

Example

m.set(Predator, Prey, 2.0, 0.5);   // Predator attracted to Prey
m.set(Prey, Predator, -3.0, 0.4);  // Prey repelled by Predator

pub fn attract<T: Into<u32>, U: Into<u32>>( &mut self, self_type: T, other_type: U, strength: f32, radius: f32, )

Convenience: set attraction between types.

Equivalent to set(self_type, other_type, strength.abs(), radius).

pub fn repel<T: Into<u32>, U: Into<u32>>( &mut self, self_type: T, other_type: U, strength: f32, radius: f32, )

Convenience: set repulsion between types.

Equivalent to set(self_type, other_type, -strength.abs(), radius).

pub fn set_symmetric<T: Into<u32> + Copy, U: Into<u32> + Copy>( &mut self, type_a: T, type_b: U, strength: f32, radius: f32, )

Set symmetric interaction (both types affect each other the same way).

Useful for mutual attraction/repulsion.

pub fn num_types(&self) -> usize

Get number of types in this matrix.

pub fn max_radius(&self) -> f32

Get the maximum interaction radius.

pub fn data(&self) -> &[(f32, f32)]

Get raw interaction data for GPU upload.

pub fn to_wgsl_init(&self) -> String

Generate WGSL code for initializing interaction variables.

This goes before the neighbor loop.

pub fn to_wgsl_neighbor(&self) -> String

Generate WGSL code for the neighbor loop body.

This runs inside the neighbor loop with access to:

• other - the neighbor particle
• neighbor_dist - distance to neighbor
• neighbor_dir - direction toward self from neighbor

pub fn to_wgsl_post(&self) -> String

Generate WGSL code for applying accumulated interaction forces.

This goes after the neighbor loop.

Trait Implementations

impl Clone for InteractionMatrix

fn clone(&self) -> InteractionMatrix

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for InteractionMatrix

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

Formats the value using the given formatter.