imagerot
Version:
A lightweight, cross-environment image library for applying unique effects via raw image buffers.
69 lines (68 loc) • 3.91 kB
JavaScript
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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.macroblock = void 0;
const macroblock = (_a, ...args_1) => __awaiter(void 0, [_a, ...args_1], void 0, function* ({ data, width, height }, options = {}) {
var _b, _c, _d, _e;
if (data.length === 0)
return data;
const lineThickness = (_b = options.lineThickness) !== null && _b !== void 0 ? _b : 2;
const interferenceIntensity = (_c = options.interferenceIntensity) !== null && _c !== void 0 ? _c : 0.3;
const noiseIntensity = (_d = options.noiseIntensity) !== null && _d !== void 0 ? _d : 0.1;
const colorBleed = (_e = options.colorBleed) !== null && _e !== void 0 ? _e : 0.2;
const tempData = new Uint8Array(data); // Copy for shifts and bleeding
// Apply scanlines: Darken every other set of rows
for (let y = 0; y < height; y++) {
const isScanline = (y % (lineThickness * 2)) < lineThickness; // Alternate bands
const darkenFactor = isScanline ? 0.85 : 1.0; // Slight darken for VHS lines
for (let x = 0; x < width; x++) {
const idx = (y * width + x) * 4;
// Darken for scanlines
data[idx] = Math.floor(tempData[idx] * darkenFactor);
data[idx + 1] = Math.floor(tempData[idx + 1] * darkenFactor);
data[idx + 2] = Math.floor(tempData[idx + 2] * darkenFactor);
// Add noise: Random perturbation
if (Math.random() < noiseIntensity) {
const noise = Math.floor(Math.random() * 50 - 25); // -25 to 25 shift
data[idx] = Math.max(0, Math.min(255, data[idx] + noise));
data[idx + 1] = Math.max(0, Math.min(255, data[idx + 1] + noise));
data[idx + 2] = Math.max(0, Math.min(255, data[idx + 2] + noise));
}
}
// Interference: Random row shifts for glitchy tracking
if (Math.random() < interferenceIntensity) {
const shift = Math.floor(Math.random() * 10 - 5); // -5 to 5 pixel horizontal shift
for (let x = 0; x < width; x++) {
const srcX = Math.max(0, Math.min(width - 1, x + shift));
const idx = (y * width + x) * 4;
const srcIdx = (y * width + srcX) * 4;
data[idx] = tempData[srcIdx];
data[idx + 1] = tempData[srcIdx + 1];
data[idx + 2] = tempData[srcIdx + 2];
}
}
}
// Add color bleed: Slight RGB channel shifts for VHS chromatic aberration
for (let y = 0; y < height; y++) {
for (let x = 0; x < width; x++) {
const idx = (y * width + x) * 4;
// Shift red slightly left, blue right (simple bleed)
const redShift = Math.floor(colorBleed * 5); // e.g., 1 pixel if colorBleed=0.2
const blueShift = -redShift;
const rSrcX = Math.max(0, Math.min(width - 1, x + redShift));
const bSrcX = Math.max(0, Math.min(width - 1, x + blueShift));
data[idx] = tempData[(y * width + rSrcX) * 4]; // Red from shifted
data[idx + 2] = tempData[(y * width + bSrcX) * 4 + 2]; // Blue from shifted
}
}
return data;
});
exports.macroblock = macroblock;