Optimize biome noise visualizer

src/app/visualization/NormalNoise.ts

@@ -0,0 +1,44 @@
+import SimplexNoise from 'simplex-noise'
+
+export class NormalNoise {
+  private noiseLevels: SimplexNoise[]
+  private amplitudes: number[]
+  private valueFactor: number
+  private lowestFreqInputFactor: number
+  private lowestFreqValueFactor: number
+
+  constructor(seed: string, firstOctave: number, amplitudes: number[]) {
+    this.amplitudes = amplitudes
+    this.noiseLevels = amplitudes.map((a, i) => new SimplexNoise(seed + 'a' + i))
+
+    let min = +Infinity
+    let max = -Infinity
+    for (let a of amplitudes) {
+      if (a !== 0) {
+        min = Math.min(min, a)
+        max = Math.max(max, a)
+      }
+    }
+    const expectedDeviation = 0.1 * (1 + 1 / (max - min + 1))
+    this.valueFactor = (1/6) / expectedDeviation
+
+    this.lowestFreqInputFactor = Math.pow(2, firstOctave)
+    this.lowestFreqValueFactor = Math.pow(2, (amplitudes.length - 1)) / (Math.pow(2, amplitudes.length) - 1)
+  }
+
+  getValue(x: number, y: number) {
+    let value = 0
+    let inputF = this.lowestFreqInputFactor
+    let valueF = this.lowestFreqValueFactor
+    for (let i = 0; i < this.amplitudes.length; i += 1) {
+      value += this.amplitudes[i] * this.noiseLevels[i].noise2D(this.wrap(x * inputF), this.wrap(y * inputF) + i) * valueF
+      inputF *= 2
+      valueF /= 2
+    }
+    return 2 * value * this.valueFactor
+  }
+
+  private wrap(value: number) {
+    return value - Math.floor(value / 3.3554432E7 + 0.5) * 3.3554432E7
+  }
+}