Struct BoidsModel 

pub struct BoidsModel;

Boids flocking as an AgentModel.

Trait Implementations

impl AgentModel for BoidsModel

const CHUNK: usize = 64

Agents per chunk, smaller than the default since the kernel draws no random numbers and the population can be small. At 512, a thousand boids make two chunks and most of the pool sits idle.

fn index_cell_size(params: &BoidParams) -> f32

Returns a third of the visual range, so the walk covers about twice the disc it needs instead of about three times.

const NAME: &'static str = "Boids Flocking"

Name shown in the UI.

const ID: &'static str = "boids"

Stable id that identifies the model in a model set, on the command line and in a spec file.

const DESCRIPTION: &'static str = "A simulation of flocking behavior in a group of boids."

One-line description shown in the UI.

const PALETTE: &'static [[u8; 4]]

Agent colours. The field layer carries its own colours.

const STATS: &'static [StatDescriptor]

Stat series for the history chart. Declared once, so stats returns bare values.

const ACTIONS: &'static [ActionDescriptor] = ACTION_SPECS

One-off steps the user can trigger. Each gets a button in the Parameters panel.

const DEFAULT_AGENTS: u32 = 50_000

Default of num_agents.

const MAX_AGENTS: u32 = 1_000_000

Upper bound of num_agents.

const DEFAULT_EXTENT: Extent

Defaults of world_width and world_height.

type Lanes = BoidLanes

Agent storage, declared with agent_lanes!.

type Field = NoField

Grid layer under the population, or NoField for a model without a field.

type Index = SpatialHash

Neighbour index, SpatialHash when agents read each other and NoIndex otherwise.

type Params = BoidParams

Pre-extracted hot parameters, rebuilt once per tick.

type Tally = ()

Per chunk reduction, accumulated across ticks. () when there is nothing to count.

fn param_descriptors() -> Vec<ParamDescriptor>

Model parameters. num_agents, world_width and world_height are prepended by the engine at indices 0, 1 and 2.

fn from_params(params: &[ParamValue], extent: Extent) -> BoidParams

Extracts the hot parameters for one tick. params is this model’s own slice, so its indices are 0 based and cannot shift when the engine or a field layer changes.

fn init( lanes: &mut BoidLanes, extent: Extent, params: &[ParamValue], rng: &mut u64, )

Fills the lanes for a new run.

fn run_step_pass( lanes: &mut BoidLanes, ctx: &StepCtx<'_, Self>, seed: u64, tick: u64, )

Runs the step pass and returns its tally.

fn act( action: usize, lanes: &mut BoidLanes, _field: &mut NoField, _extent: Extent, params: &[ParamValue], rng: &mut u64, )

Runs Self::ACTIONS entry action over the current lanes and field.

fn stats(lanes: &BoidLanes, _field: &NoField, (): &()) -> Vec<StatValue>

Current statistics, in Self::STATS order.

fn run_deposit_pass( _lanes: &Self::Lanes, _deposits: &mut <Self::Field as FieldLayer>::DepositLanes, _ctx: &StepCtx<'_, Self>, )

Fills the field’s deposit lanes before the step pass, without moving any agent.

impl Debug for BoidsModel

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

Formats the value using the given formatter.