Oscillator Noise WIP

lib/index.js

@@ -10,4 +10,5 @@ export * from './components/index.js'
 export * from './data-structures/grid.js'
 export * from './data-structures/fractalized-line.js'
 export * from './noise/oscillator.js'
+export * from './noise/oscillator-noise.js'
 export * from './render.js'

lib/noise/oscillator-noise.js

@@ -0,0 +1,24 @@
+import { PI } from "../constants.js"
+import { createRng, random } from "../random.js"
+import { Oscillator } from "./oscillator.js"
+
+/**
+ * @callback OscillatorNoiseFn
+ * @param {number} x
+ * @param {number} [y=0]
+ * @returns {number} ideally in range [-1, 1]
+ */
+
+/**
+ * Creates a noise function based on oscillators
+ * @param {string} seed 
+ * @returns {OscillatorNoiseFn}
+ */
+export function createOscNoise(seed) {
+  const rng = createRng(seed)
+  // hmm... currently not working
+  const period = random(PI, 4 * PI, rng)
+  const phase = random(-PI, PI, rng)
+  const osc = new Oscillator({ amplitude: 1, period, phase, compress: false })
+  return (x, y = 0) => osc.output(x, y)
+}

lib/noise/oscillator-noise.test.js

@@ -0,0 +1,17 @@
+import { describe, it } from "node:test";
+import { createOscNoise } from './oscillator-noise.js'
+import { randomSeed } from "../random.js";
+import assert from "node:assert";
+
+describe("OscillatorNoise", () => {
+  it('returns consistent values for the same seed/x/y inputs', () => {
+    const seed = randomSeed()
+    const noiseFn1 = createOscNoise(seed)
+    const actual1 = noiseFn1(100, 100)
+
+    const noiseFn2 = createOscNoise(seed)
+    const actual2 = noiseFn2(100, 100)
+
+    assert.strictEqual(actual1, actual2, `Seed ${seed} gave 2 different values: ${actual1} and ${actual2}`)
+  })
+})