AdventOfCode-js-2019/SpaceImageFormat/SpaceImageFormat.js

const { DeepClone } = require("../IntComp/common");
const SpaceImageFormatLayer = require("./SpaceImageFormatLayer");

module.exports = class SpaceImageFormat {
    /**
     * The Space Image Format
     *
     * @param {number} imageWidth The width of the image in pixels
     * @param {number} imageHeight The height of the image in pixels
     * @param {string} rawData The raw data for the complete SIF image
     */
    constructor(imageWidth, imageHeight, rawData) {
        this.width = imageWidth;
        this.height = imageHeight;
        /**
         * The layers of the image
         * @type {SpaceImageFormatLayer[]}
         */
        this.layers = this._parse(rawData);

        this.PIXEL_DEPTH = ["░", "▓"];
    }

    /**
     * Render an image to the console
     *
     * Given the simplicity of the image format's color space, we can easily
     * accomplish this using the "light shade" and "dark shade" ASCII characters.
     * @returns {void}
     */
    Render() {
        // Will be filled with a string containing the final image
        let renderedImage = "";
        // Get the first layer's rows
        let renderedLayerRows = DeepClone(this.layers[0].rows);
        // Iterate over subsequent layers
        for (let i = 1; i < this.layers.length; i++) {
            const layer = this.layers[i];

            for (let row = 0; row < renderedLayerRows.length; row++) {
                for (let column = 0; column < renderedLayerRows[row].length; column++) {
                    if (renderedLayerRows[row][column] == 2 && layer.rows[row][column] !== 2) { renderedLayerRows[row][column] = layer.rows[row][column]; }
                }
            }

            // Check if all transparent pixels have been filled in
            if (renderedLayerRows.flat(Infinity).indexOf(2) == -1) { break; }
        }

        // Convert each row from an array of 0's and 1's to a string
        renderedLayerRows = renderedLayerRows.map((row) => row.map((pixelValue) => this.PIXEL_DEPTH[pixelValue]).join(""));
        // Join all rows with new lines to complete the image
        renderedImage = renderedLayerRows.join("\n");

        console.log(renderedImage);
    }

    /**
     * Parse raw data in order to build the SIF layers
     *
     * @param {string} rawData The raw data of the image
     * @returns {SpaceImageFormatLayer[]} The layers of an SIF image
     */
    _parse(rawData) {
        const layers = [];

        const layerSize = this.width * this.height;
        const layerSplit = new RegExp(`(\\d{${layerSize}})`, "g");

        const tempLayers = rawData.split(layerSplit).filter((l) => !!l);

        tempLayers.forEach((layerData) => {
            layers.push(new SpaceImageFormatLayer(this.width, this.height, layerData));
        });

        return layers;
    }
};