c - C中带有指针点的结构的深拷贝

我需要你的帮助！
我喜欢复制这样的结构：

typedef struct PackageObject_s {
  long  **vertex;          // vertices
  long    num_vertex;      // count of vertices
  long    objectType;      //
  REAL    r;               //
  long    bottom[3];       // bounding box bottom vector
  long    top[3];          // bounding box top vector
  long   *start;           //
  REAL    coverage;        //
} PackageObject __attribute__ ((aligned));

我就这样试试：

static inline void PackageObject_copy(PackageObject *dst, const PackageObject *src) {

  dst->num_vertex = src->num_vertex;
  dst->objectType = src->objectType;
  dst->r          = src->r;
  vec_assign3l(dst->bottom, src->bottom);
  vec_assign3l(dst->top,    src->top);

  // TODO copy **vertex ???

  dst->coverage   = src->coverage;
  dst->coverage   = src->coverage;
}

我该怎么解决？
提前谢谢你的帮助！！
更新-所有帮助的vertex-thx的deepcopy的“我的解决方案”：

dst->vertex = (long *)malloc(dst->num_vertex * 3 * sizeof(long));
for (long i=0; i < src->num_vertex; i++) {
  dst->vertex[i] = (long)malloc(3*sizeof(long));
  memcpy(dst->vertex[i],src->vertex[i],3 * sizeof(long));
}

最佳答案

我假设顶点不是在对象之间共享的。也就是说，它们属于所讨论的结构。
有两种主要情况需要考虑：

1. Copying into a new object
2. Copying into an existing object

复制到新对象很简单。

1a. Allocate space for <num_vertex> pointers.
1b. Allocate space for each vertex.
2a. Copy <num_vertex> pointers from source to destination.
2b. Copy <num_vertex> vertices from source to destination.

复制到现有对象与复制到一个新对象几乎相同，除非您必须先做以下操作。

0a. Loop through each element of <vertex> and free the vertex.
0b. Free the array of vertex pointers.
1. Follow the steps for copying into a new object.

希望这有帮助。