let cols;

let rows;

let resolution = 5;

​

function make2DArray(cols, rows) {

  let arr = new Array(cols);

  for (let i = 0; i < arr.length; i++) {

    arr[i] = new Array(rows);

  }

  return arr;

}

​

function Cell(initState) {

  let pos = initState.pos;

​

  let currentState = {

    isAlive: initState.isAlive,

    lifetime: 1,

    isInfected:

      pos.x * resolution < width / 2 + 2 * resolution &&

      pos.x * resolution > width / 2 - 2 * resolution &&

      pos.y * resolution < height / 2 + 2 * resolution &&

      pos.y * resolution > height / 2 - 2 * resolution,

    // isImmune: random() < 0.5,

  };

  let nextState = {};

​

  const noiseVal = noise(pos.x, pos.y);

​

  let color = [noiseVal * 255, noiseVal * 10, noiseVal * 100];

​

  const getNeighbors = () => {

    const neighbors = [];

    for (let i = -1; i < 2; i++) {

      for (let j = -1; j < 2; j++) {

        let col = (pos.x + i + cols) % cols;

        let row = (pos.y + j + rows) % rows;

        if (!(i === 0 && j === 0)) {

          neighbors.push(grid[col][row].getState());

        }

      }

    }

    return neighbors;

  };

​

  const getNextState = () => {

    const { isAlive, lifetime, isInfected } = currentState;

    let neighbors = getNeighbors();

    let numLivingNeighbors = 0;

    let infectedCount = 0;

​

    neighbors.forEach(({ isAlive, isInfected }) => {

      if (isAlive) {

        numLivingNeighbors++;

        if (isInfected) {

          infectedCount++;

        }

      }

    });

​

    const nextInfected = infectedCount > 1 ? true : isInfected;

​

    let newIsAlive = isAlive;

    let newLifetime = lifetime;

    if (!isAlive && numLivingNeighbors == 3) {

      newIsAlive = true;

      newLifetime = 1;

    }

    if (isAlive && (numLivingNeighbors < 2 || numLivingNeighbors > 3)) {

      newIsAlive = false;

    }

​

    if (lifetime > 255) {

      newIsAlive = false;

    }

    return {

      ...currentState,

      isAlive: newIsAlive,

      lifetime: newLifetime,

      isInfected: nextInfected,

    };

  };

​

  return {

    getState: () => currentState,

    applyNextState: () => {

      currentState = nextState;

    },

    update: () => {

      currentState.lifetime += 0.5;

      nextState = getNextState();

    },

    show: () => {

      const { isAlive, lifetime, isInfected } = currentState;

​

      if (isAlive) {

        const w = noiseVal * resolution * 2;

        noStroke();

        rectMode(CENTER);

        if (isInfected) {

          fill(255, 255, 255, 255 / lifetime);

          ellipse(pos.x * resolution, pos.y * resolution, w, w);

        } else {

          fill(...color, 255 / lifetime);

          rect(pos.x * resolution, pos.y * resolution, w, w);

        }

      }

    },

  };

}

​

function setup() {

  createCanvas(800, 800);

  cols = width / resolution;

  rows = height / resolution;

  background(0);

​

  grid = make2DArray(cols, rows);

  for (let i = 0; i < cols; i++) {

    for (let j = 0; j < rows; j++) {

      grid[i][j] = new Cell({

        pos: createVector(i, j),

        isAlive: random() < 0.3,

      });

    }

  }

}

​

function draw() {

  background(0, 5);

​

  for (let i = 0; i < cols; i++) {

    for (let j = 0; j < rows; j++) {

      grid[i][j].update();

      grid[i][j].show();

    }

  }

​

  for (let i = 0; i < cols; i++) {

    for (let j = 0; j < rows; j++) {

      grid[i][j].applyNextState();

    }

  }

}

​