Emscripten Uncaught RangeError: Source is too large, multipl

我试图为4x4矩阵乘法运行c++函数。2天后，它终于起作用了，但并不像预期的那样。

参数通常被反馈给函数，然后这一行:

dataHeap2.set( new Uint8Array(data2.buffer) );

产生错误"Uncaught RangeError: Source is too large"

乍一看，它看起来只是一个普通的Float32Array有16个元素，但在查看它的缓冲区大小后，它似乎是不同的

console.log(data2.buffer.bufferLength);

结果不是预期的64字节，而是像3342345这样的大数字。这就是问题所在吗?我通过手动复制值(如下所示)找到了一个解决方法，返回该值，然后问题就消失了。不幸的是，它使我的代码比直接在缓冲区上操作要慢得多。

// bad solution - which works
    for(var i = 0; i < 16; i++) {
        dataTarget[i] = result[i];
    }

希望今晚我能找到一个更好的解决方案，我想继续使用这个函数，因为它是使用ASM.JS + SIMD来动画多个字符的编译c++代码。在纯JavaScript中，它仍然太慢了。这是整个函数。我很确定data2正在使用Emscripten的HEAP，我想避免它。

matrix4multiply = function(data, data2) {
    // Import function from Emscripten generated file
    var mmul_vec4 = Module.cwrap(
      'mmul_vec4', 'number', ['number', 'number', 'number']
    );
    var dataTarget = new Float32Array(16);
    // Get data byte size, allocate memory on Emscripten heap, and get pointer
    var nDataBytes = dataTarget.length * dataTarget.BYTES_PER_ELEMENT;
    // First matrix copy data to Emscripten heap
    var dataPtr = Module._malloc(nDataBytes);
    var dataPtr2 = Module._malloc(nDataBytes);
    var dataPtr3 = Module._malloc(nDataBytes);
    var dataHeap = new Uint8Array(Module.HEAPU8.buffer, dataPtr, nDataBytes);
    dataHeap.set( new Uint8Array(data.buffer) );
    // second matrix allocate and copy to emscripten's heap
    var dataHeap2 = new Uint8Array(Module.HEAPU8.buffer, dataPtr2, nDataBytes);
    dataHeap2.set( new Uint8Array(data2.buffer) );
    // target heap
    var targetHeap = new Uint8Array(Module.HEAPU8.buffer, dataPtr3, nDataBytes);
    targetHeap.set( new Uint8Array(dataTarget.buffer) );
    // Call the function by passing a number pointing to the byte location of 
    // the array of pointers on the Emscripten heap.  Emscripten knows what to do!
    mmul_vec4(dataHeap.byteOffset, dataHeap2.byteOffset, targetHeap.byteOffset);
    // get result
    var result = new Float32Array(targetHeap.buffer, targetHeap.byteOffset, 16);
    // bad solution - which works
    //for(var i = 0; i < 16; i++) {
    //    dataTarget[i] = result[i];
    //}
    // Free memory
    Module._free(dataHeap.byteOffset);
    Module._free(dataHeap2.byteOffset);
    Module._free(targetHeap.byteOffset);
    return result;
}

编辑:简化版不用担心malloc等

    new Uint8Array(Module.HEAPU8.buffer, this.dataPtr, 64).set( new Uint8Array(data.buffer, data.byteOffset, 64) );
    // second matrix allocate and copy to emscripten's heap
    new Uint8Array(Module.HEAPU8.buffer, this.dataPtr + 72, 64).set( new Uint8Array(data2.buffer, data2.byteOffset, 64) );
    // multiply first two parameters and return in the last one 
    this.mmul_vec4(this.dataPtr, this.dataPtr + 72, this.dataPtr + 144);
    // like that it works, unfotunately copying is being made here
    return new Float32Array(Module.HEAPU8.buffer.slice(this.dataPtr + 144, this.dataPtr + 208));
    // with this version (if uncommented) there's just white screen(but it looks like the game is working.
    //return new Float32Array(Module.HEAPU8.buffer, this.dataPtr + 144, 16);