@onesy/utils/canvasFilterOldPhoto.js

Utils

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const clamp_1 = __importDefault(require("./clamp"));
const canvasFilterOldPhoto = (value, canvas) => {
    const context = canvas.getContext('2d');
    const imageData = context.getImageData(0, 0, canvas.width, canvas.height);
    const { data } = imageData;
    const percentage = (value_) => (Math.abs(value) / 100) * value_ * (value < 0 ? -1 : 1);
    for (let i = 0; i < data.length; i += 4) {
        data[i + 0] = (0, clamp_1.default)(((((data[i + 0] / 255) - 0.4) + (percentage(data[i + 0]) / 255)) + 0.4) * 255, 0, 255);
        data[i + 1] = (0, clamp_1.default)(((((data[i + 0] / 255) - 0.4) + (percentage(data[i + 0]) / 255)) + 0.4) * 255, 0, 255);
        data[i + 2] = (0, clamp_1.default)(((((data[i + 0] / 255) - 0.4) + (percentage(data[i + 0]) / 255)) + 0.4) * 255, 0, 255);
    }
    context.putImageData(imageData, 0, 0);
    return canvas;
};
exports.default = canvasFilterOldPhoto;