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[WIP] feat: Implement get*NoiseValue functions #6

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[WIP] feat: Implement get*NoiseValue functions #6

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7ed2d65
implement get*NoiseValue functions
lukehesluke Jun 6, 2024
6c6dcf9
revert the more liberal options input in top-level functions AND use …
lukehesluke Jun 7, 2024
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182 changes: 132 additions & 50 deletions src/mod.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -36,20 +36,14 @@ export function makeCuboid(
scale,
}: Partial<Options> = {},
): number[][][] {
const options: Options = { amplitude, frequency, octaves, persistence, scale };
const field: number[][][] = new Array(width);
for (let x = 0; x < width; x++) {
field[x] = new Array(height);
for (let y = 0; y < height; y++) {
field[x][y] = new Array(depth);
for (let z = 0; z < depth; z++) {
let value = 0.0;
for (let octave = 0; octave < octaves; octave++) {
const freq = frequency * Math.pow(2, octave);
value += noise3(x * freq, y * freq, z * freq) *
(amplitude * Math.pow(persistence, octave));
}
field[x][y][z] = value / (2 - 1 / Math.pow(2, octaves - 1));
if (scale) field[x][y][z] = scale(field[x][y][z]);
field[x][y][z] = getCuboidNoiseValue(noise3, options, x, y, z);
}
}
}
Expand All @@ -68,22 +62,13 @@ export function makeCylinderSurface(
scale,
}: Partial<Options> = {},
): number[][] {
const radius = circumference / TWO_PI;
const options: Options = { amplitude, frequency, octaves, persistence, scale };
const radius = getCircleRadius(circumference);
const field: number[][] = new Array(circumference);
for (let x = 0; x < circumference; x++) {
field[x] = new Array(height);
for (let y = 0; y < height; y++) {
let value = 0.0;
for (let octave = 0; octave < octaves; octave++) {
const freq = frequency * Math.pow(2, octave);
const nx = x / circumference;
const rdx = nx * TWO_PI;
const [a, b] = [radius * Math.sin(rdx), radius * Math.cos(rdx)];
value += noise3(a * freq, b * freq, y * freq) *
(amplitude * Math.pow(persistence, octave));
}
field[x][y] = value / (2 - 1 / Math.pow(2, octaves - 1));
if (scale) field[x][y] = scale(field[x][y]);
field[x][y] = getCylinderSurfaceNoiseValue(noise3, options, circumference, radius, x, y);
}
}
return field;
Expand All @@ -100,15 +85,10 @@ export function makeLine(
scale,
}: Partial<Options> = {},
): number[] {
const options: Options = { amplitude, frequency, octaves, persistence, scale };
const field: number[] = new Array(length);
for (let x = 0; x < length; x++) {
let value = 0.0;
for (let octave = 0; octave < octaves; octave++) {
const freq = frequency * Math.pow(2, octaves);
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Minor note. I think this was a typo and should be octave. It's changed to that in the getLineNoiseValue function

value += noise1(x * freq) * (amplitude * Math.pow(persistence, octave));
}
field[x] = value / (2 - 1 / Math.pow(2, octaves - 1));
if (scale) field[x] = scale(field[x]);
field[x] = getLineNoiseValue(noise1, options, x);
}
return field;
}
Expand All @@ -125,18 +105,12 @@ export function makeRectangle(
scale,
}: Partial<Options> = {},
): number[][] {
const options: Options = { amplitude, frequency, octaves, persistence, scale };
const field: number[][] = new Array(width);
for (let x = 0; x < width; x++) {
field[x] = new Array(height);
for (let y = 0; y < height; y++) {
let value = 0.0;
for (let octave = 0; octave < octaves; octave++) {
const freq = frequency * Math.pow(2, octave);
value += noise2(x * freq, y * freq) *
(amplitude * Math.pow(persistence, octave));
}
field[x][y] = value / (2 - 1 / Math.pow(2, octaves - 1));
if (scale) field[x][y] = scale(field[x][y]);
field[x][y] = getRectangleNoiseValue(noise2, options, x, y);
}
}
return field;
Expand All @@ -153,26 +127,134 @@ export function makeSphereSurface(
scale,
}: Partial<Options> = {},
): number[][] {
const options: Options = { amplitude, frequency, octaves, persistence, scale };
const circumferenceSemi = circumference / 2;
const field: number[][] = new Array(circumference);
for (let x = 0; x < circumference; x++) {
const circumferenceSemi = circumference / 2;
field[x] = new Array(circumferenceSemi);
for (let y = 0; y < circumferenceSemi; y++) {
const [nx, ny] = [x / circumference, y / circumferenceSemi];
const [rdx, rdy] = [nx * TWO_PI, ny * Math.PI];
const sinY = Math.sin(rdy + Math.PI);
const a = TWO_PI * Math.sin(rdx) * sinY;
const b = TWO_PI * Math.cos(rdx) * sinY;
const d = TWO_PI * Math.cos(rdy);
let value = 0.0;
for (let octave = 0; octave < octaves; octave++) {
const freq = frequency * Math.pow(2, octave);
value += noise3(a * freq, b * freq, d * freq) *
(amplitude * Math.pow(persistence, octave));
}
field[x][y] = value / (2 - 1 / Math.pow(2, octaves - 1));
if (scale) field[x][y] = scale(field[x][y]);
field[x][y] = getSphereSurfaceNoiseValue(noise3, options, circumference, circumferenceSemi, x, y);
}
}
return field;
}

export function fractalNoiseOptions({
amplitude = defaultAmplitude,
frequency = defaultFrequency,
octaves = defaultOctaves,
persistence = defaultPersistence,
scale,
}: Partial<Options> = {}): Options {
return { amplitude, frequency, octaves, persistence, scale };
}

export function getCircleRadius(
circumference: number,
): number {
return circumference / TWO_PI;
}

export function getCuboidNoiseValue(
noise3: Noise3Fn,
options: Options,
x: number,
y: number,
z: number,
): number {
let value = 0.0;
for (let octave = 0; octave < options.octaves; octave++) {
const freq = options.frequency * Math.pow(2, octave);
value += noise3(x * freq, y * freq, z * freq) *
(options.amplitude * Math.pow(options.persistence, octave));
}
const result = normalizeFractalNoiseValue(options, value);
if (options.scale) return options.scale(result);
return result;
}

export function getCylinderSurfaceNoiseValue(
noise3: Noise3Fn,
options: Options,
circumference: number,
radius: number,
x: number,
y: number,
): number {
let value = 0.0;
for (let octave = 0; octave < options.octaves; octave++) {
const freq = options.frequency * Math.pow(2, octave);
const nx = x / circumference;
const rdx = nx * TWO_PI;
const [a, b] = [radius * Math.sin(rdx), radius * Math.cos(rdx)];
value += noise3(a * freq, b * freq, y * freq) *
(options.amplitude * Math.pow(options.persistence, octave));
}
const result = normalizeFractalNoiseValue(options, value);
if (options.scale) return options.scale(result);
return result;
}

export function getLineNoiseValue(
noise1: Noise1Fn,
options: Options,
x: number,
): number {
let value = 0.0;
for (let octave = 0; octave < options.octaves; octave++) {
const freq = options.frequency * Math.pow(2, octave);
value += noise1(x * freq) * (options.amplitude * Math.pow(options.persistence, octave));
}
const result = normalizeFractalNoiseValue(options, value);
if (options.scale) return options.scale(result);
return result;
}

export function getRectangleNoiseValue(
noise2: Noise2Fn,
options: Options,
x: number,
y: number,
): number {
let value = 0.0;
for (let octave = 0; octave < options.octaves; octave++) {
const freq = options.frequency * Math.pow(2, octave);
value += noise2(x * freq, y * freq) * (options.amplitude * Math.pow(options.persistence, octave));
}
const result = normalizeFractalNoiseValue(options, value);
if (options.scale) return options.scale(result);
return result;
}

export function getSphereSurfaceNoiseValue(
noise3: Noise3Fn,
options: Options,
circumference: number,
circumferenceSemi: number,
x: number,
y: number,
): number {
const [nx, ny] = [x / circumference, y / circumferenceSemi];
const [rdx, rdy] = [nx * TWO_PI, ny * Math.PI];
const sinY = Math.sin(rdy + Math.PI);
const a = TWO_PI * Math.sin(rdx) * sinY;
const b = TWO_PI * Math.cos(rdx) * sinY;
const d = TWO_PI * Math.cos(rdy);
let value = 0.0;
for (let octave = 0; octave < options.octaves; octave++) {
const freq = options.frequency * Math.pow(2, octave);
value += noise3(a * freq, b * freq, d * freq) *
(options.amplitude * Math.pow(options.persistence, octave));
}
const result = normalizeFractalNoiseValue(options, value);
if (options.scale) return options.scale(result);
return result;
}

/**
* Normalize the result so that it's within a similar range regardless of the
* number of octaves.
*/
function normalizeFractalNoiseValue(options: Options, value: number) {
return value / (2 - 1 / Math.pow(2, options.octaves - 1));
}