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Add cohesive_force function

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Robert Garrett
2024-07-15 10:01:43 -05:00
parent 18885d9b94
commit 930aa2e75d
1 changed files with 16 additions and 3 deletions
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19
src/birdoids_plugin.rs
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@@ -8,7 +8,7 @@ const BACKGROUND_COLOR: Color = Color::srgb(0.4, 0.4, 0.4);
const PLAYERBOID_COLOR: Color = Color::srgb(1.0, 0.0, 0.0); const PLAYERBOID_COLOR: Color = Color::srgb(1.0, 0.0, 0.0);
const TURN_FACTOR: f32 = 1.0; const TURN_FACTOR: f32 = 1.0;
const BOID_VIEW_RANGE: f32 = 50.0; const BOID_VIEW_RANGE: f32 = 50.0;
const COHESION_FACTOR: f32 = 1000.0; const COHESION_FACTOR: f32 = 1.0;
const SEPARATION_FACTOR: f32 = 100.0; const SEPARATION_FACTOR: f32 = 100.0;
const ALIGNMENT_FACTOR: f32 = 500.0; const ALIGNMENT_FACTOR: f32 = 500.0;
const SPACEBRAKES_COEFFICIENT: f32 = 0.01; const SPACEBRAKES_COEFFICIENT: f32 = 0.01;
@@ -197,8 +197,8 @@ fn cohesion(
for (transform, mut acceleration) in &mut boids { for (transform, mut acceleration) in &mut boids {
let neighbors = spatial_tree.within_distance(transform.translation.xy(), BOID_VIEW_RANGE); let neighbors = spatial_tree.within_distance(transform.translation.xy(), BOID_VIEW_RANGE);
if let Some(center_mass) = center_of_boids(neighbors.iter().map(|boid| boid.0)) { if let Some(center_mass) = center_of_boids(neighbors.iter().map(|boid| boid.0)) {
let towards = (center_mass.extend(0.0) - transform.translation).normalize(); let force = cohesive_force(center_mass, transform.translation.xy());
acceleration.0 += towards * COHESION_FACTOR; acceleration.0 += force.extend(0.0) * COHESION_FACTOR;
} }
} }
} }
@@ -296,3 +296,16 @@ fn average_of_vec2s(points: impl Iterator<Item = Vec2>) -> Option<Vec2> {
Some(avg) Some(avg)
} }
// f(x) = 4((x-0.5)^3 + 0.125)
fn cohesive_force(boid: Vec2, target: Vec2) -> Vec2 {
let deviation = target - boid;
/*
Scale deviation vector by the boid's view range. The curve is made to
operate on the range (0, 1), so that needs to be the viewing circle.
*/
let scaled = deviation / BOID_VIEW_RANGE;
let half_one = Vec2::ONE / 2.0;
let cube = (scaled - half_one).powf(3.0);
return (cube + 0.125) * 4.0;
}