imagerot
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A lightweight, cross-environment image library for applying unique effects via raw image buffers.
92 lines (91 loc) • 4.95 kB
JavaScript
;
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.fractalNoise = void 0;
const perlinNoise = (function () {
const p = new Array(512);
const permutation = [
151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225, 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23,
190, 6, 148, 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32, 57, 177, 33,
88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175, 74, 165, 71, 134, 139, 48, 27, 166,
77, 146, 158, 231, 83, 111, 229, 122, 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244,
102, 143, 54, 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169, 200, 196,
135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64, 52, 217, 226, 250, 124, 123,
5, 202, 38, 147, 118, 126, 255, 82, 85, 212, 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42,
223, 183, 170, 213, 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9,
129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104, 218, 246, 97, 228,
251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241, 81, 51, 145, 235, 249, 14, 239, 107,
49, 192, 214, 31, 181, 199, 106, 157, 184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254,
138, 236, 205, 93, 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180
];
for (let i = 0; i < 256; i++) {
p[256 + i] = p[i] = permutation[i];
}
function fade(t) {
return t * t * t * (t * (t * 6 - 15) + 10);
}
function lerp(t, a, b) {
return a + t * (b - a);
}
function grad(hash, x, y, z) {
const h = hash & 15;
const u = h < 8 ? x : y;
const v = h < 4 ? y : (h === 12 || h === 14 ? x : z);
return ((h & 1) === 0 ? u : -u) + ((h & 2) === 0 ? v : -v);
}
return function (x, y, z) {
const X = Math.floor(x) & 255;
const Y = Math.floor(y) & 255;
const Z = Math.floor(z) & 255;
x -= Math.floor(x);
y -= Math.floor(y);
z -= Math.floor(z);
const u = fade(x);
const v = fade(y);
const w = fade(z);
const A = p[X] + Y;
const AA = p[A] + Z;
const AB = p[A + 1] + Z;
const B = p[X + 1] + Y;
const BA = p[B] + Z;
const BB = p[B + 1] + Z;
return lerp(w, lerp(v, lerp(u, grad(p[AA], x, y, z), grad(p[BA], x - 1, y, z)), lerp(u, grad(p[AB], x, y - 1, z), grad(p[BB], x - 1, y - 1, z))), lerp(v, lerp(u, grad(p[AA + 1], x, y, z - 1), grad(p[BA + 1], x - 1, y, z - 1)), lerp(u, grad(p[AB + 1], x, y - 1, z - 1), grad(p[BB + 1], x - 1, y - 1, z - 1))));
};
})();
const fractalNoise = (_a, ...args_1) => __awaiter(void 0, [_a, ...args_1], void 0, function* ({ data, width, height }, options = {}) {
var _b, _c, _d, _e;
const octaves = (_b = options.octaves) !== null && _b !== void 0 ? _b : 4;
const persistence = (_c = options.persistence) !== null && _c !== void 0 ? _c : 0.5;
const scale = (_d = options.scale) !== null && _d !== void 0 ? _d : 4;
const intensity = (_e = options.intensity) !== null && _e !== void 0 ? _e : 0.5;
const maxValue = (1 - Math.pow(persistence, octaves)) / (1 - persistence); // Normalize factor for [-1,1] range
for (let y = 0; y < height; y++) {
for (let x = 0; x < width; x++) {
let noise = 0;
let amp = 1;
let freq = scale;
for (let o = 0; o < octaves; o++) {
noise += amp * perlinNoise(x / freq, y / freq, 0);
amp *= persistence;
freq *= 2;
}
noise /= maxValue; // Normalize to approx [-1,1]
const idx = (y * width + x) * 4;
const shift = noise * intensity * 128; // Scale to [-128,128] for overlay
data[idx] = Math.max(0, Math.min(255, data[idx] + shift)); // R
data[idx + 1] = Math.max(0, Math.min(255, data[idx + 1] + shift)); // G
data[idx + 2] = Math.max(0, Math.min(255, data[idx + 2] + shift)); // B
// Alpha unchanged
}
}
return data;
});
exports.fractalNoise = fractalNoise;