砂丘/Dunes - OpenProcessing

mySketch
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let width = 150;
let height = 150;
let phase = 0;
let table = []
let result = []
let L0 = 5 // 風速
let b = 0.4 // 高さの調整
let q = 3 // 飛ぶ砂の量
let d = 0.2 // 転がる砂の量 高さのd*100%転がる
let generation = 0
​
function setup() {
  createCanvas(width, height);
  setTable()
}
​
function setTable() {
  table = []
  for (let y = 0; y < height; y++) {
    let array = []
    for (let x = 0; x < width; x++) {
      array[x] = random(0, 100)
    }
    table[y] = array
  }
}
​
function zeroTable() {
  let array1 = []
  for (let y = 0; y < height; y++) {
    let array2 = []
    for (let x = 0; x < width; x++) {
      array2[x] = 0
    }
    array1[y] = array2
  }
  return array1
}
​
function draw() {
  // 世代管理
  if (generation > 200) return
  generation++
  // if(generation % 20 == 0) {
  //   console.log(generation)
  // }
  background(220);
  warnerModel()
  plot()
}
​
function warnerModel(){
  result = zeroTable()
  
  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      if(random(10) < 3) continue
      hop(x, y)
      
      if(random(10) < 3) continue
      roll(x, y)
    }
  }
  
  addTable()
}
​
function hop(x, y) {
  const h = table[y][x]
  let L = L0 + b * h
  result[y][x] -= q
  let x2 = x + floor(L)
  if (x2 > width - 1) {
    x2 = x2 - width
  }
  result[y][x2] += q
}
​
function roll(x, y) {
  const h = table[y][x]
  // 転がる砂の量の単位
  const D = h * d * 1 / 8
  // 転がる向きはx>0のとこ
  addResult(x, y, -8 * D)
  addResult(x + 1, y, 2 * D)
  // addResult(x - 1, y, 2 * D)
  addResult(x, y + 1, 2 * D)
  addResult(x, y - 1, 2 * D)
​
  addResult(x + 1, y + 1, D)
  // addResult(x - 1, y + 1, D)
  // addResult(x - 1, y - 1, D)
  addResult(x - 1, y - 1, D)
}
​
function addResult(x, y, val) {
  if (x > width - 1) {
    x -= width
  }
  if (x < 0) {
    x += width
  }
​
  if (y > height - 1) {
    y -= height
  }
  if (y < 0) {
    y += height
  }
  result[y][x] += val
}
​
​
function addTable() {
  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      table[y][x] += result[y][x]
    }
  }
}
​
function plot() {
  for (let y = 0; y < height; y += 1) {
    for (let x = 0; x < width; x += 1) {
      let h = table[x][y]
      let r = map(h, 0, 100, 230, 90)
      let g = map(h, 0, 100, 200, 50)
      let b = map(h, 0, 100, 150, 0)
      stroke(color(r, g, b))
      point(x, y);
    }
  }
}