rlottie-worker.js

importScripts('rlottie-wasm.js');

var RLottieWasm = (function () {
  // create a object;
  var obj = {};

  // object content.
  obj.Api = {};
  obj.lottieHandle = 0;

  // keep the api list
  function initApi() {
    obj.Api = {
      create: Module.cwrap('wasm_lottie_create', '', []),
      destroy: Module.cwrap('wasm_lottie_destroy', '', ['number']),
      resize: Module.cwrap('wasm_lottie_resize', '', ['number', 'number', 'number']),
      buffer: Module.cwrap('wasm_lottie_buffer_get', 'number', ['number']),
      bufferRelease: Module.cwrap('wasm_lottie_buffer_release', 'number', ['number']),
      frameCount: Module.cwrap('wasm_lottie_frame_count_get', 'number', ['number']),
      render: Module.cwrap('wasm_lottie_render', '', ['number', 'number']),
      loadFromData: Module.cwrap('wasm_lottie_load_from_data', 'number', ['number', 'number']),
    };
  }

  obj.init = function () {
    initApi();
    obj.lottieHandle = obj.Api.init();
    reply('ready');
    reply('info', obj.Api.frameCount(obj.lottieHandle));
  }

  obj.render = function (frameNo, width, height) {
    obj.Api.resize(obj.lottieHandle, width, height);
    obj.Api.render(obj.lottieHandle, frameNo);
    var bufferPointer = obj.Api.buffer(obj.lottieHandle);
    var result = new Uint8ClampedArray(Module.HEAP8.buffer, bufferPointer, width * height * 4);
    return result;
  }

  obj.reload = function (jsString) {
    var lengthBytes = lengthBytesUTF8(jsString) + 1;
    var stringOnWasmHeap = _malloc(lengthBytes);
    stringToUTF8(jsString, stringOnWasmHeap, lengthBytes + 1);
    var len = obj.Api.loadFromData(obj.lottieHandle, stringOnWasmHeap);

  }
  obj.frameCount = function () {
    return obj.Api.frameCount(obj.lottieHandle);
  }
  return obj;
}());


Module.onRuntimeInitialized = _ => {
  RLottieWasm.init();
};

var queryableFunctions = {
  // example #1: get the difference between two numbers:
  reload: function (jsString) {
    RLottieWasm.reload(jsString);
    reply('info', RLottieWasm.frameCount());
  },
  // example #2: wait three seconds
  render: function (frameNo, width, height) {
    var data = RLottieWasm.render(frameNo, width, height);
    var buffer = new Uint8ClampedArray(width * height * 4);
    buffer.set(data);
    reply('result', width, height, buffer, [buffer]);
  }
};

function defaultReply(message) {
  // your default PUBLIC function executed only when main page calls the queryableWorker.postMessage() method directly
  // do something
}

function reply() {
  if (arguments.length < 1) { throw new TypeError('reply - not enough arguments'); return; }
  postMessage({ 'queryMethodListener': arguments[0], 'queryMethodArguments': Array.prototype.slice.call(arguments, 1) });
}

onmessage = function (oEvent) {
  if (oEvent.data instanceof Object && oEvent.data.hasOwnProperty('queryMethod') && oEvent.data.hasOwnProperty('queryMethodArguments')) {
    queryableFunctions[oEvent.data.queryMethod].apply(self, oEvent.data.queryMethodArguments);
  } else {
    defaultReply(oEvent.data);
  }
};