Tiled Editor - Decoding Base 64 data does not seem to work

Question

I am using Tiled 1.2.x. The exported map is 40x40 tiles represented in Base 64 encoded data.

Here is the data (sorry for single line of data):

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            G                                                                                                                                                                                                                                                                                                       !   "   "   "   "   "   #                                                                                                                                       1   2   2   2   2   2   3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           1   2   3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            G                                                                                                                                                                                                                                                                                              !   "   "   "   "   "   "   "   "   "   #                                                                                                                     !   "   "   "   "   "   "   "   "   "   #                                                                                             1   3                   !   "   "   "   "   "   "   "   "   "   #                                                                                                             1   2   2   2   2   2   2   2   2   2   3                                         !   "   "   "   "   "   "   "   "   #                                                                                                                          1   2   2   2   2   2   2   2   2   3                                                                                                                                                 %   &   &   '                                                                                                                                                   5   6   6   7                                                                                                                                              5   6   6   7                                                                                                                                                  5   6   6   7                                                                                                                                                                                                                                                                                                 1   2   2   2   2   2   2   2   2   2   2   2   2   2   2   2   2   3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

The goal is to convert a Base 64 encoded string into a 2D Uint8Array, within Node.js. This array will store the unique IDs of each tile for my map.

Below is some code I have written to try to convert the encoded data into something more understandable.

let data = null;
let rawData = layer.data;

// ==================================
// == If applicable, decode Base64 ==
// ==================================
if(layer.encoding === 'base64') {
    console.log('Decoding data!');
    data = Buffer.from(rawData, 'base64');
}

// ============================================
// == If applicable, extract compressed data ==
// ============================================
if(layer.compression === 'gzip') {
    console.log('Extracting data!');
    zlib.gunzipSync(data);
}

// =============================================================
// == Use raw data if no Base64 encoding or GZIP compression. ==
// =============================================================
if(data === null) {
    data = rawData;
}

console.log(data.toString('ascii'));

However, the output continues to give me garbage data and I am unsure what is causing this issue. Or perhaps I don't understand the decoding process very well.

G!"""""#1222223123G!"""""""""#!"""""""""#13!"""""""""#12222222223!""""""""#1222222223%&&'566756675667122222222222222223

Does anyone have any suggestions as to why this is happening? Thanks!

Answer 1

After some researching I found a solution. I was correctly decoding and decompressing the data, but I was incorrectly reading the data.

According to the TMX Map Format docs, the decoded data is stored as unsigned 32-bit integers with little-endian ordering.

Node.js has a function for reading this exact data, Buffer.readUint32LE(offset). With a loop I can iterate over the buffer and read each integer using an increasing offset. For each iteration, I add the integer to a separate array.

My solution:

/**
 * @author         AdamInTheOculus
 * @purpose        Returns an array of Tiled layer data from a given layer.
 * @param  layer   Layer object. Contains metadata and map data.
 **/
function getTiles(layer) {

    let data = null;
    let rawData = layer.data;

    // ==================================
    // == If applicable, decode Base64 ==
    // ==================================
    if(layer.encoding === 'base64') {
        data = Buffer.from(rawData, 'base64');
    }

    // ============================================
    // == If applicable, extract compressed data ==
    // ============================================
    if(layer.compression === 'gzip') {
        data = zlib.gunzipSync(data);
    }

    // =============================================================
    // == Use raw data if no Base64 encoding or GZIP compression. ==
    // =============================================================
    if(data === null) {
        data = rawData;
        return new Uint8Array(data);
    }

    // ====================================
    // == Read buffer data every 4 bytes ==
    // ====================================

    // Each 32-bit integer is placed in an 8-bit integer array.
    // There will never be a tile ID greater than 255, so only 1 byte is required.
    let array = new Uint8Array(layer.width * layer.height);
    for(let i=0, index=0; i<data.length; i += 4, index++) {
        array[index] = data.readUInt32LE(i);
        index++;
    }

    return array;
}