Published
Edited
Mar 18, 2020
mutable balls = {
reset;
return newBalls()
}
newBalls = () => {
let balls = Array.from({length: populationSize}).map(newBall)
if (!balls[0]) return balls;
// infect the first ball
balls[0].state = 'infected'
// freeze the position of roughly nInPlace.
let nInPlace = Math.floor(percentRemainInPlace * balls.length)
for (let i = 1; i <= nInPlace; i++) {
if(!balls[i]) break // so it doesn't break at 100%
balls[i].dx = 0
balls[i].dy = 0
}
return balls;
}
newBall = () => {
const angle = Math.random() * Math.PI
return {
r: 10,
x: Math.random() * w,
y: Math.random() * h,
dx: Math.cos(angle) * speed,
dy: Math.sin(angle) * speed,
state: 'uninfected'
}
}
gameloop = {
i;
let temp = balls.map(moveBall);
//temp = balls.forEach(infectFrom);
mutable balls = temp
yield true;
}
infectFrom = function(ball, i, balls) {
balls.forEach((x) => infect(ball,x))
}
infect = (b1,b2) => {
if (collide(b1,b2) && b1.state == 'infected' && b2.state == 'uninfected') {
b2.state = 'infected'
}
}
moveBall = ball => {
let {r, x, y, dx, dy, state} = ball;
x += dx, y += dy;
//bounce off walls
if (x < r) dx = Math.abs(dx);
if (x + r > w) dx = -Math.abs(dx);
if (y < r) dy = Math.abs(dy);
if (y + r > h) dy = -Math.abs(dy);
const bz = balls
bz.forEach(infectFrom);
ball = {r, x, y, dx, dy, state}
return ball;
}
function collide(b1, b2) {
let dist = Math.sqrt(Math.pow(b1.x - b2.x,2) + Math.pow(b1.y - b2.y,2))
let hit = dist < b1.r + b2.r;
return hit;
}
colors = ({infected:'#f73bb9', uninfected: '#2679b5'})
// currently not using the scrubber value, just ticking when i is updated
viewof i = Scrubber(Array.from({length: 50}, (_, i) => i), {delay:10})
import {Scrubber} from '@mbostock/scrubber'
import {slider, button} from '@jashkenas/inputs'
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