通过sscanf使用指向指向浮点数[3]的指针的指针，获取异常

Question

编辑:好的，因为我之前太含糊了，这里有一个SSCCE：

typedef float vector[3]

int mainLoaderFunc() {

    char* memory = NULL;
    size_t size = loadFile(fileName, &memory); // load model file into memory, this works, tested and true

    // create vector arrays
    vector *vertexArray = NULL;         
    vector *normalArray = NULL;         
    vector *textureArray = NULL;        

    loadArrays(size, memory, &vertexArray, &normalArray, &textureArray);

    // do other stuff with arrays

}

void loadArrays(size_t size, char *memory, vector **vertexArray, vector **normalArray, vector **textureArray) {

    int numVerts = 0; 
    int numNormals = 0;  
    int numTextures = 0;  

    char* p = memory;           // pointer to start of memory
    char* e = memory + size;    // pointer to end of memory

    // count verts, normals, textures for memory allocation
    while (p != e) {
        if (memcmp(p, "vn", 2) == 0) {
            numNormals++;
        } else if (memcmp(p, "vt", 2) == 0) { 
            numTextures++;
        } else if (memcmp(p, "v",  1) == 0) {
            numVerts++;
        } 
        while (*p++ != (char) 0x0A);
    }

    // allocate memory for vector arrays
    *vertexArray        = new vector[numVerts];
    *normalArray        = new vector[numNormals];
    *textureArray       = new vector[numTextures];


    int vertexIndex = 0;
    int normalIndex = 0;
    int textureIndex = 0;  //*** IF BREAK POINT HERE: NO EXCEPTION

    // load data from memory into arrays
    while (p != e) {

        if (memcmp(p, "vn", 2) == 0) {
            sscanf(p, "vn %f %f %f", normalArray[normalIndex][0], normalArray[normalIndex][1], normalArray[normalIndex][2]);
            normalIndex++;
        } else if (memcmp(p, "vt", 2) == 0) {
            sscanf(p, "vt %f %f", textureArray[textureIndex][0], textureArray[textureIndex][1]);
            textureIndex++;
        } else if (memcmp(p, "v", 1) == 0) {
            sscanf(p, "v %f %f %f", vertexArray[vertexIndex][0], vertexArray[vertexIndex][1], vertexArray[vertexIndex][2]);
            vertexIndex++;
        } 
        while (*p++ != (char) 0x0A);
    }

}

一旦代码到达sscanf部分，我就得到了异常，我尝试将&和*放在数组的前面，但无论哪种方式，我都会得到异常。

Answer 1

sscanf在使用%f时需要一个float *。vertexArray是float ***，vertexArray[i]是float **，vertexArray[i][j]是float*。但是，这并不是您想要的，因为vertexArray是指向vertex数组的指针，所以您需要这样做：

&(*vertexArray)[i][j]

这将使您获得要传递给sscanf的正确float *。

Answer 2

我猜您必须将地址传递给sscanf

sscanf(myMemChunk, "%f %f %f", &myVector[i][0], &myVector[i][1], &myVector[i][2]);